JP2004211109A - Composite material and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite material which has a reduced manufacturing cost as well as a dense microstructure. <P>SOLUTION: The composite material 5 has dispersion materials 7 dispersed in a matrix 6. This composite material has the dispersion materials 7 dispersed in the matrix 6, by using a reaction vessel 1 having a structure of forming a space, in which a mixed material 2 can be filled, by combining two or more vessel elements 1a and 1b each other; filling the mixed material 2 into a region 25 which is the space formed in the vessel element 1a; combining the vessel element 1b with the vessel element 1a in a condition that the mixed material 2 is fixed into a predetermined form; impregnating molten aluminum (Al) 4 into cavities 3 among the mixed materials 2 through one or more holes 10 formed on the upper part of the reaction vessel 1; and forming an aluminide intermetallic compound by a self-combustion reaction of a metallic powder with aluminum (Al) 4. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００５２】本発明においては、分散材の平均粒径に対する、金属粉末の平均粒径の比率（％）が、５〜８０％であることが好ましく、１０〜６０％であることが更に好ましい。金属粉末の平均粒径が分散材の平均粒径の５％未満である場合には、金属粉末自体の入手が困難及び粉塵爆発の危険性が伴なってくる点から取り扱いが不便となり、８０％超である場合には自己燃焼反応の活性度が充分に高められず、得られる複合材料が緻密化され難くなるために好ましくない。具体的には、分散材の平均粒径が５０μｍである場合には、金属粉末の平均粒径は２〜４０μｍであることが好ましく、５〜３０μｍであることが更に好ましい。
【００５３】次に、本発明の第二の側面について説明する。本発明の第二の側面は、反応容器の中に、アルミニウム（Ａｌ）と接触することにより自己燃焼反応を生起し得る金属粉末と分散材とを含む混合材料を充填するとともに、混合材料内部の空隙中にアルミニウム（Ａｌ）を溶融含浸させて、マトリックス中に分散材を分散させた複合材料を製造する方法であり、反応容器として、二以上の容器要素からなり、容器要素が合体することによって混合材料が充填される空間を形成するように構成された反応容器を用い、混合材料を一以上の容器要素の空間を形成する領域（空間形成領域）内に充填するとともに、一以上の容器要素を、空間形成領域内に充填された混合材料を所定の形状に固定した状態で合体させ、反応容器の上部に形成された一以上の孔を経由して混合材料内部の空隙中にアルミニウム（Ａｌ）を溶融含浸させ、金属粉末とアルミニウム（Ａｌ）との自己燃焼反応によってアルミナイド金属間化合物を生成させることにより、マトリックス中に分散材を分散させてなる複合材料を得ることを特徴とするものである。以下、その詳細について説明する。
【００５４】本発明の複合材料の製造方法では、図１に示すように、適当なサイズ及び形状の容器要素１ａの空間形成領域２５内に、分散材及び金属粉末を混合して得た混合材料２を充填し、その上面に溶融したアルミニウム（Ａｌ）を含浸させる孔１０を有する容器要素１ｂ（蓋部材）を載置して混合材料２を所定の形状に固定し、空隙３、即ち、隣接する混合材料２どうしにより形成される空隙３に、孔１０を経由してアルミニウム（Ａｌ）４を溶融含浸させる。本実施形態では、アルミニウム（Ａｌ）４を溶融含浸させることにより、混合材料２を構成する金属粉末（図示せず）と溶融状態のアルミニウム（Ａｌ）４を接触させて自己燃焼反応を生起させ、アルミニウム（Ａｌ）４をアルミナイド金属間化合物に置換させる。この結果、アルミナイド金属間化合物を含むマトリックス６に分散材７が分散してなる複合材料５を製造することができる。
【００５５】また、本実施形態では、アルミニウム（Ａｌ）と各種金属粉末との自己燃焼反応熱を利用してアルミナイド金属間化合物の生成を推進させるために、低温条件下において複合材料を製造することができる。更に、従来の製造方法である、ＨＰ法又はＨＩＰ法のような高圧を必要としないために、無加圧浸透によって複合材料を製造することができる。このことにより、製造装置の性能上困難であった比較的大きな、或いは複雑な形状を有する複合材料の製造が可能となる。
【００５６】更に、図１に示すように、本実施形態では一以上の孔１０を有する容器要素１ｂを混合粉体２の上面に載置し、孔１０を経由してアルミニウム（Ａｌ）４を含浸させる。このとき、容器要素１ａの空間形成領域２５内に充填された混合材料２は、容器要素１ｂにより所定形状となるように固定されているために、アルミニウム（Ａｌ）４が含浸されても、混合粉体２の所定の形状を維持することができる。更に、空隙３の細部にまでアルミニウム（Ａｌ）４を含浸させることができ、例えば図２に示すように、容器要素１ｂ（図１参照）を使用せずにアルミニウム（Ａｌ）４を含浸して得た複合材料５に比して開気孔率を低減することができ、高密度であるとともにより緻密な複合材料を製造することができる。また、アルミニウム（Ａｌ）を含浸した後にも変形等の不具合が発生し難く、得られる複合材料に所望とする形状を付与することができる。
【００５７】なお、混合材料２を所定形状となるように固定するためには、図１に示すように、例えばネジ部８を容器要素１ａに設ける等の手段を挙げることができ、このことにより、所望とする適度な圧力を混合材料２に対して付与するように微調整することができる。但し、混合材料を固定するための手段は、図１に示した態様に限定されるものでないことはいうまでもない。
【００５８】本発明において用いる金属粉末は、溶融状態のアルミニウム（Ａｌ）（アルミニウム（Ａｌ）溶湯）と接触することにより自己燃焼反応を生起し、アルミナイド金属間化合物を形成するものである。具体的にはチタン（Ｔｉ）、ニッケル（Ｎｉ）、及びニオブ（Ｎｂ）からなる群より選択される少なくとも一種の金属からなる粉末を用いることができる。これらの金属粉末は反応性が良好であるとともに、安定なアルミナイド金属間化合物を形成し、かつ、入手や取り扱いも容易であるために好ましい。これら金属粉末を用いた場合の反応の代表例を下記式（４）〜（６）に示す。下記式（４）〜（６）において示す通り、これらの反応は発熱反応（自己燃焼反応）であり、本発明においてはこの反応熱を利用する。
【００５９】
【数４】
３Ａｌ＋Ｔｉ→Ａｌ_３Ｔｉ ： ΔＨ_２９８＝−１４６ｋＪ／ｍｏｌ …（４）
ΔＨ：生成反応熱（Δ＜０にて発熱反応）
【００６０】
【数５】
３Ａｌ＋Ｎｉ→Ａｌ_３Ｎｉ ： ΔＨ_２９８＝−１５０ｋＪ／ｍｏｌ …（５）
ΔＨ：生成反応熱（Δ＜０にて発熱反応）
【００６１】
【数６】
３Ａｌ＋Ｎｂ→Ａｌ_３Ｎｂ ： ΔＨ_２９８＝−１６０ｋＪ／ｍｏｌ …（６）
ΔＨ：生成反応熱（Δ＜０にて発熱反応）
【００６２】また、特許第２６０９３７６号公報、及び、特開平９−２２７９６９号公報に示される他のｉｎ−ｓｉｔｕ複合材料の製造方法においては、分散材とマトリックスとを、ともにｉｎ−ｓｉｔｕ合成するのに対して、本発明ではｉｎ−ｓｉｔｕ合成するのはマトリックスのみである。従って、分散材の種類については自由に選択可能であり、所望の物理的特性を有する複合材料を製造することができる。更に、分散材の種類、及び体積比率を任意に選択・設定することにより、反応熱を制御することも可能となる。
【００６３】本発明においては、金属粉末がチタン（Ｔｉ）粉末である場合に、溶融含浸させるアルミニウム（Ａｌ）と、チタン（Ｔｉ）粉末の質量比（Ａｌ：Ｔｉ）が、１：０．１７〜１：０．５７であることが好ましい。このことにより、マトリックスに含まれるアルミニウム（Ａｌ）の、マトリックスの全体に対する割合を６０質量％以下、即ち、高破壊靭性であるとともに緻密な微構造を有する複合材料を得ることができる。
【００６４】また、金属粉末がニッケル（Ｎｉ）粉末である場合に、溶融含浸させるアルミニウム（Ａｌ）と、ニッケル（Ｎｉ）粉末の質量比（Ａｌ：Ｎｉ）が、１：０．２０〜１：０．７２であることが好ましい。このことにより、マトリックスに含まれるアルミニウム（Ａｌ）の、マトリックスの全体に対する割合を６０質量％以下、即ち、高破壊靭性であるとともに緻密な微構造を有する複合材料を得ることができる。
【００６５】更に、金属粉末がニオブ（Ｎｂ）粉末である場合に、溶融含浸させるアルミニウム（Ａｌ）と、ニッケル（Ｎｉ）粉末の質量比（Ａｌ：Ｎｉ）が、１：０．２７〜１：１．１３であることが好ましい。このことにより、マトリックスに含まれるアルミニウム（Ａｌ）の、マトリックスの全体に対する割合を６０質量％以下、即ち、高破壊靭性であるとともに緻密な微構造を有する複合材料を得ることができる。
【００６６】本発明においては、反応容器に複数の孔が形成されていることが好ましく、孔の数が１の場合に比して多量の混合材料を用いることが可能となる。即ち、アルミニウム（Ａｌ）溶湯の浸透性が良好となるために、大型であっても緻密な微構造を有する複合材料を製造することができる。
【００６７】本発明においては、特に大型部材を製造する場合に、孔が応力緩衝効果を有する環状部材により形成されてなることが好ましい。ここでいう「応力緩衝効果」とは、既に述べた通りである。即ち、孔付近に残留したアルミニウム（Ａｌ）が複合材料の収縮抵抗となり、孔と複合材料との組み合わせ部（接続部）において応力が集中し、得られる複合材料に破損等の不具合が発生する場合も想定されるが、孔が応力緩衝効果を備えた環状部材により形成されていることにより、前記不具合の発生が回避され得る。なお、このような応力緩衝効果を備えた環状部材を構成する材料の具体的な例としては、ポーラスカーボンや、断熱材として使用されるセラミックスファイバー等を挙げることができる。
【００６８】また、本発明においては、孔の内側の下部に混合材料を充填することが好ましい。孔の直下に相当する部分では、得られる複合材料の組織がアルミニウム（Ａｌ）過剰となり不均質となる場合がある。従って、孔の内側の下部に混合材料を充填した場合には、アルミニウム（Ａｌ）を溶融含浸後、孔の内側に相当する箇所のみを容易に除去することができ、全体的に均質な組織を有する複合材料を製造することができる。
【００６９】本発明においては、溶融含浸させるアルミニウム（Ａｌ）の最大浸透距離（Ｙ）に対する、孔の内径（Ｘ）の比の値（Ｘ／Ｙ）が、０．０６〜０．５であることが好ましく、０．０８〜０．４であることが更に好ましく、０．１〜０．３５であることが特に好ましい。Ｘ／Ｙを０．０６未満とした場合には、孔が小さ過ぎるためにアルミニウム（Ａｌ）の浸透性が向上し難くなるために好ましくない。一方、Ｘ／Ｙを０．５超とした場合も同様に、アルミニウム（Ａｌ）の浸透性向上効果が発揮され難くなるために好ましくない。
【００７０】次に、製造方法の一例を挙げて本発明の詳細を説明する。所定形状の分散材、所定の平均粒径を有する金属粉末、例えば、チタン（Ｔｉ）、ニッケル（Ｎｉ）、ニオブ（Ｎｂ）等、及び、反応容器内の混合材料の空隙に含浸させる金属としてアルミニウム（Ａｌ）を用意する。このとき、分散材の平均粒径に対する、金属粉末の平均粒径の比率（％）が、５〜８０％であることが好ましく、１０〜６０％であることが更に好ましい。金属粉末の平均粒径が分散材の平均粒径の５％に未満である場合には、金属粉末自体の入手が困難及び粉塵爆発の危険性が伴なってくる点から取り扱いが不便となり、８０％超である場合には、自己燃焼反応の活性度が充分に高められず、複合材料の緻密化をなし得ることができないためである。具体的には、平均粒径５０μｍの分散材に対しては平均粒径２〜４０μｍの金属粉末を用いることが好ましく、５〜３０μｍの金属粉末を用いることが更に好ましい。
【００７１】本発明においては、分散材が、繊維、粒子、及びウィスカーからなる群より選択される少なくとも一種の形状を有する無機材料であることが好ましい。これらの形状を有する無機材料を用いることにより、最終製品としての使用用途に沿った強度や特徴を有する複合材料を製造することができる。
【００７２】なお、本発明において「平均粒径１０〜１５０μｍの分散材」というときは、分散材の形状が粒子状の場合にあっては、「平均粒径１０〜１５０μｍの粒子」のことをいい、また粒子状ではなく、繊維、ウィスカー等の場合にあっては、「長さ／径、の比が１５０未満の場合で、径が０．１〜３０μｍの繊維、ウィスカー等」、又は「長さ／径、の比が１５０以上の場合で、径が０．５〜５００μｍの繊維及びウィスカー等」のことをいう。
【００７３】また、本発明においては、前述の無機材料が、Ａｌ_２Ｏ_３、ＡｌＮ、ＳｉＣ、及びＳｉ_３Ｎ_４からなる群より選択される少なくとも一種であることが好ましい。複合材料は、これを構成するマトリックスに含まれる金属間化合物と分散材との組み合わせにより種々の特性を示すものであり、用途に応じた特性を示す複合材料となる組み合わせを適宜選択すればよい。
【００７４】なお、得られる複合材料のマトリックスに含まれるアルミニウム（Ａｌ）とアルミナイド金属間化合物との質量比を調整するには、反応容器内に充填する混合材料の金属粉末：分散材の比（体積比）を変化させ、更に充填後の混合材料の厚みを測定することによって混合材料の空隙率を測定し、その空隙中にアルミニウム（Ａｌ）が完全に浸透するものとして、アルミニウム（Ａｌ）の必要量を算出する。これにより、金属粉末：分散材の体積比、及び混合材料の空隙率によって分散材の粒子体積率及びマトリックスの組成（質量比）を算出することができる。
【００７５】また、アルミニウム（Ａｌ）を含浸する前において目標とするマトリックスの組成は、含浸した後の実際のマトリックス組成とは完全には一致せず、若干変動する場合がある。次に、含浸した後の実際のマトリックス組成の算出方法について説明する。マトリックスに含まれるアルミニウム（Ａｌ）：アルミナイド金属間化合物の質量比は、特許文献４において記載された手法である、ＸＲＤ分析にて予め所定の質量比に調整したアルミニウム（Ａｌ）及びアルミナイド金属間化合物の混合粉体を用いて検量線を作成しておき、これを元にしてマトリックス組成を変化させた試料をＸＲＤ分析し、得られた測定結果のＸ線強度より算出することが可能である。
【００７６】分散材と金属粉末を混合して得た混合材料を、反応容器を構成する容器要素の空間形成領域内に充填するとともに、混合材料が所定の形状及び空隙率となるように適当な圧力にて成形を行う。なお、予め適当な圧力を付与することにより混合材料の成形を行っておき、これを反応容器中に充填してもよい。また、空隙率に関しては、成形する圧力を変化させることで任意に制御することができる。次いで、一以上の孔を有する容器要素を介して、前記成形体を容器要素どうしにて固定した状態で組み合わせることにより合体させ、その後に容器要素を介してアルミニウム（Ａｌ）を配置する。このとき既述の如く、混合材料を孔の内側の下部に充填してもよい。なお、配置するアルミニウム（Ａｌ）は純アルミニウム（Ａｌ）に限らず、約９０％以上の純度であれば差し支えなく使用することができ、また、各種アルミニウム（Ａｌ）合金を使用してもよい。続いて適度な減圧条件、例えば真空条件下で、アルミニウム（Ａｌ）が溶解する温度（約６６０℃）より数十℃高い温度、具体的には約７００℃まで加熱し、孔を経由して混合材料の空隙に溶融状態のアルミニウム（Ａｌ）を含浸させる。金属粉末と接触したアルミニウム（Ａｌ）は自己燃焼反応を生起するとともに毛細管浸透が誘起され、目的とする複合材料のマトリックスが瞬時に形成される。
【００７７】マトリックスの形成自体は非常に短時間で完了するため、加熱に要する時間は数分程度で充分である。更に、自己燃焼反応が終了した後に、得られた複合材料のマトリックスの均質化及び安定化を図るために、適宜等温保持や加熱保持を行ってもよい。このときの保持温度は、材料系によって若干左右されるが、自己燃焼反応が生じた温度と同一な温度から約４００〜５００℃程度高い温度で実施することが好ましく、また保持時間は約１時間から必要に応じて数時間実施すればよい。
【００７８】また、本発明においては、図１１に示すように、反応容器１が、少なくともその内壁が、カーボン材２２により構成されてなるものであることが好ましい。内壁がこのように構成された反応容器１を用いると、アルミニウム（Ａｌ）を溶融含浸して冷却した後、得られた複合材料を反応容器１から容易に取り出すことができる。即ち、複合材料の、反応容器１からの離型性が極めて良好となるために、反応容器１の耐久性も向上し、複合材料の製造コストを低減することができる。なお、図１１においては反応容器１の内壁のみをカーボン材２２により構成した状態を示しているが、反応容器１の全体がカーボン材により構成されていてもよく、少なくともアルミニウム（Ａｌ）や、製造される複合材料が接触する箇所がカーボン材により構成されていることが好ましい。また、更なる離型性の向上を図るため、溶融アルミニウム（Ａｌ）が接触する部位に、ＢＮスプレー等によるコーティングを行うこと、カーボンシート等を配置することも好ましい。なお、符号２４は、固定用ボルトを示す。
【００７９】本発明においては、図１３に示すように、反応容器１が、その側部に、反応容器１の上方から下方へと傾斜するスロープ状の湯道２３と、この湯道２３に連通した一以上の第２の孔２０を更に有するものであり、上部の孔１０と側部の第２の孔２０を各々独立に経由して、混合材料２の内部の空隙にアルミニウム（Ａｌ）４を溶融含浸させることが好ましい。即ち、第２の注湯口２０を適宜増加・形成した反応容器１を用意し、各々の孔１０、第２の孔２０からアルミニウム（Ａｌ）４を溶融含浸させることによって、肉厚（図１３の左右方向に長い場合）であっても、その全体に渡って緻密な微構造を有する複合材料を製造することができる。
【００８０】また、本発明においては、金属粉末がチタン（Ｔｉ）粉末、分散材がＡｌＮ、Ｓｉ、及びＳｉ_３Ｎ_４からなる群より選択される少なくとも一種のセラミックスからなる粒子（セラミックス粒子）である場合に、セラミックス粒子の体積に対する、チタン（Ｔｉ）粉末の体積の比の値（Ｔｉ／セラミックス（以下、単に「（Ｔｉ／セラミックス）値」と記す））と、容器内の容積に対する、空隙の割合（空隙率（％））とが、下記（１）〜（６）に示すいずれかの関係を満たすことが好ましい。
（１）０．１≦（Ｔｉ／セラミックス）＜０．１４、２５≦空隙率（％）≦６０
（２）０．１４≦（Ｔｉ／セラミックス）＜０．２７、２５≦空隙率（％）≦７０
（３）０．２７≦（Ｔｉ／セラミックス）＜０．５３、２５≦空隙率（％）≦７５
（４）０．５３≦（Ｔｉ／セラミックス）＜１、３０≦空隙率（％）≦７５
（５）１≦（Ｔｉ／セラミックス）＜１．４、４５≦空隙率（％）≦８０
（６）１．４≦（Ｔｉ／セラミックス）≦２、５０≦空隙率（％）≦８０
【００８１】即ち、混合材料の（Ｔｉ／セラミックス）値と、空隙率とを、上述したいずれかの関係となるように組み合わせることにより、この混合材料の間隙にアルミニウム（Ａｌ）を溶融含浸させるに際してその浸透性が極めて良好となり、ＨＰ法又はＨＩＰ法のように高加圧条件下でなくとも、より緻密で開気孔率が低減された複合材料を製造することができる。なお、アルミニウム（Ａｌ）の浸透性を更に向上させ、より緻密で開気孔率が低減された複合材料を製造する観点からは、（Ｔｉ／セラミックス）値と、空隙率（％）とが、下記（７）〜（１４）に示すいずれかの関係を満たすことが更に好ましい。
【００８２】
（７）０．１≦（Ｔｉ／セラミックス）＜０．１４、３０≦空隙率（％）≦４５
（８）０．１４≦（Ｔｉ／セラミックス）＜０．１８、２５≦空隙率（％）≦５５
（９）０．１８≦（Ｔｉ／セラミックス）＜０．２７、２５≦空隙率（％）≦６０
（１０）０．２７≦（Ｔｉ／セラミックス）＜０．４、３５≦空隙率（％）≦６５
（１１）０．４≦（Ｔｉ／セラミックス）＜０．５３、３５≦空隙率（％）≦７０
（１２）０．５３≦（Ｔｉ／セラミックス）＜０．７７、４０≦空隙率（％）≦７０
（１３）０．７７≦（Ｔｉ／セラミックス）＜１、４５≦空隙率（％）≦７５
（１４）１≦（Ｔｉ／セラミックス）＜２、５０≦空隙率（％）≦８０
【００８３】また、本発明においては、金属粉末がチタン（Ｔｉ）粉末、分散材がＡｌ_２Ｏ_３粒子である場合に、Ａｌ_２Ｏ_３粒子の体積に対する、チタン（Ｔｉ）粉末の体積の比の値（Ｔｉ／Ａｌ_２Ｏ_３（以下、単に「（Ｔｉ／Ａｌ_２Ｏ_３）値」と記す））と、金型容器内の容積に対する、空隙の割合（空隙率（％））とが、下記（１５）〜（２０）に示すいずれかの関係を満たすことが好ましい。
（１５）０．１≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．１４、２５≦空隙率（％）≦６０
（１６）０．１４≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．２７、２５≦空隙率（％）≦７０
（１７）０．２７≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．５３、２５≦空隙率（％）≦７５
（１８）０．５３≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１、３０≦空隙率（％）≦７５
（１９）１≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１．４、４５≦空隙率（％）≦８０
（２０）１．４≦（Ｔｉ／Ａｌ_２Ｏ_３）≦２、５０≦空隙率（％）≦８０
【００８４】即ち、混合材料の（Ｔｉ／Ａｌ_２Ｏ_３）値と、空隙率とを、上述したいずれかの関係となるように組み合わせることにより、この混合材料の間隙にアルミニウム（Ａｌ）を溶融含浸させるに際してその浸透性が極めて良好となり、ＨＰ法又はＨＩＰ法のように高加圧条件下でなくとも、より緻密で開気孔率が低減された複合材料を製造することができる。なお、アルミニウム（Ａｌ）の浸透性を更に向上させ、より緻密で開気孔率が低減された複合材料を製造する観点からは、（Ｔｉ／Ａｌ_２Ｏ_３）値と、空隙率（％）とが、下記（２１）〜（２９）に示すいずれかの関係を満たすことが更に好ましく、下記（３０）〜（３７）に示すいずれかの関係を満たすことが特に好ましい。
【００８５】
（２１）０．１≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．１４、３０≦空隙率（％）≦４５
（２２）０．１４≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．１８、３０≦空隙率（％）≦５５
（２３）０．１８≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．２７、３０≦空隙率（％）≦６０
（２４）０．２７≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．４、３５≦空隙率（％）≦６５
（２５）０．４≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．５３、３５≦空隙率（％）≦７０
（２６）０．５３≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．７７、４０≦空隙率（％）≦７０
（２７）０．７７≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１、４５≦空隙率（％）≦７５
（２８）１≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１．４、５０≦空隙率（％）≦７５
（２９）１．４≦（Ｔｉ／Ａｌ_２Ｏ_３）≦２、５５≦空隙率（％）≦８０
【００８６】
（３０）０．１４≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．１８、３５≦空隙率（％）≦４５
（３１）０．１８≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．２７、３５≦空隙率（％）≦５５
（３２）０．２７≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．４、４０≦空隙率（％）≦６０
（３３）０．４≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．５３、４０≦空隙率（％）≦６５
（３４）０．５３≦（Ｔｉ／Ａｌ_２Ｏ_３）＜０．７７、４５≦空隙率（％）≦６５
（３５）０．７７≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１、５０≦空隙率（％）≦７０
（３６）１≦（Ｔｉ／Ａｌ_２Ｏ_３）＜１．４、５５≦空隙率（％）≦７５
（３７）１．４≦（Ｔｉ／Ａｌ_２Ｏ_３）≦２、６０≦空隙率（％）≦７５
【００８７】上述してきた、本発明の複合材料の製造方法によれば、その特徴を生かして大型、或いは複雑形状であるとともに、緻密な微構造を有し、かつ、当該緻密化された微構造に起因した優れた材料特性を具備する複合材料を極めて簡便に製造することができる。また、最終製品の形状を考慮したニアネットシェイプ化を行うことができるために、その後の工程において機械加工処理が不必要である。更に、前処理工程であるアルミナイド金属間化合物の調製も不必要となるために、製造コストの削減を容易に達成することができる。
【００８８】
【実施例】以下、本発明の具体的な実施結果を説明する。
（各種物性値の測定方法、各種評価方法）
［開気孔率］：
測定対象から所定形状の試料を切り出し、アルキメデス法によって測定した。
【００８９】
［４点曲げ強度］：
測定対象から所定形状の試料を切り出し、ＪＩＳ Ｒ １６０１に従って、４点曲げ試験を実施することにより測定した。
【００９０】
［ヤング率］：
得られた複合材料から所定形状の試料を切り出し、ＪＩＳ Ｒ １６０１に従って、４点曲げ試験を実施することによりヤング率を測定した。
【００９１】
［破壊靭性値］：
得られた複合材料から切り込み（ノッチ）を導入した所定の形状の試料を作製して４点曲げ試験強度を測定し、シェブロンノッチ法に従い破壊靭性値の算出した。
【００９２】
［浸透率］：
下記式（７）に従って算出した。
【００９３】
【数７】
浸透率（％）＝１００×浸透距離／最大浸透距離 …（７）
（但し、「浸透距離」とは、実際にアルミニウム（Ａｌ）が浸透した距離（孔の内径を除く）であって、未浸透領域において観察される気孔の多い部分を除外した距離をいい、「最大浸透距離」とは、孔の端部から反応容器中に充填された混合材料の最端部までの距離をいう）
【００９４】
［空隙率］：
含浸前の空隙率については、調合量及び成形後における試料厚みを測定し、下記式（８）に従って算出した。また、含浸後の空隙率については、調合量及び含浸後における試料厚みを測定し、下記式（８）に従って算出した。
【００９５】
【数８】

（但し、Ｖ_ｐｏｒｅは空隙体積、Ｖ_Ｄは分散材の体積、Ｖ_{Ｍｅｔａｌ ｐｏｗｄｅｒ}は金属粉末の体積を示す）
【００９６】
［浸透性の評価］：
浸透率が１００％である場合を「◎」、浸透率が８５％以上である場合を「○」、浸透率が６０％以上である場合を「△」、浸透率が６０％未満の場合を「×」として評価した。
【００９７】
［緻密性の評価］：
開気孔率が０．１％以下である場合を「◎」、開気孔率が０．５％以下である場合を「○」、開気孔率が１．０％未満である場合を「△」、開気孔率が１．０％以上である場合を「×」として評価した。
【００９８】
（実施例１）
平均粒径が約４７μｍであるＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍであるチタン（Ｔｉ）粉末及び溶融含浸させるアルミニウム（Ａｌ）（市販の純Ａｌ（Ａ１０５０、純度＞９９．５％））を用意した。次に、チタン（Ｔｉ）粉末とＡｌ_２Ｏ_３粒子を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が０．５３となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、内径５０ｍｍφのカーボン製の容器に充填し、その形状に沿う形で圧縮成形を行い、空隙率約４９％の成形体とした。次に、内径１０ｍｍφの孔（注湯口）を有するカーボン製蓋部材を成形体の上面に載置し、このカーボン製蓋部材を、その外側に配置するカーボン製容器で固定し、その後、孔に溶融したアルミニウム（Ａｌ）が流れ込むようにアルミニウム（Ａｌ）（固体）を配置した。０．０１３Ｐａ以下の真空雰囲気下にて７００℃まで加熱して溶融したアルミニウム（Ａｌ）を無加圧含浸させ、約１時間保持後に徐冷して複合材料を製造した（実施例１）。得られた複合材料を切断・研磨した後、光学顕微鏡にて断面観察を行ったところ、アルミニウム（Ａｌ）が容器と蓋部材に囲まれた空間に沿った形状で端部まで良好に含浸されていた。開気孔率（％）及び４点曲げ強度の測定結果を表２に示す。
【００９９】
（比較例１）
蓋部材を用いずに、成形体の上面の全面よりアルミニウム（Ａｌ）を溶融含浸させること以外は実施例１と同様の操作により、複合材料を製造した（比較例１）。開気孔率（％）、密度、及び４点曲げ強度の測定結果を表２に示す。
【０１００】
（比較例２）
ホットプレス（ＨＰ）法を用いて、溶融アルミニウム（Ａｌ）の加圧含浸により複合材料の製造を行った。即ち、蓋部材を用いないこと、及びアルミニウム（Ａｌ）の加圧含浸に際して約３０ＭＰａの圧力を負荷すること以外は実施例１と同様の操作により、複合材料を製造した（比較例２）。開気孔率（％）、密度、及び４点曲げ強度の測定結果を表２に示す。
【０１０１】
【表２】

【０１０２】表２に示す結果から、成形体を蓋部材により固定したこと（実施例１）により、成形体内部の空隙に溶融アルミニウム（Ａｌ）が無加圧含浸され、自発的に緻密化が促進されることが判明した。更には、実施例１のように、反応熱を利用したアルミニウム（Ａｌ）の自発的な浸透現象が生起されることにより、比較例２に示されるＨＰ法による強制的な緻密化を行った場合と同等の開気孔率とすることができた。このため、実施例１の複合材料は、比較例１の複合材料に比して密度が高く、開気孔率を比較しても緻密性が向上していた。また、４点曲げ強度については、比較例１、２の複合材料が約２００ＭＰａであったのに対し、実施例１の複合材料は４００ＭＰａ以上と高強度であった。これは、複合材料内部の閉気孔が減少したこと、及び分散材とマトリックスとの界面強度が増加したことに起因するものと考えられる。従って、本発明によれば、構成元素間で生じる自発的な内部エネルギーを利用することでより緻密化された複合材料を製造することが可能であり、複合材料製造に際してのエネルギーコストの低減等に寄与すると考えられる。
【０１０３】
（実施例２〜２９、比較例３〜７）
表３に示す平均粒径のＡｌ_２Ｏ_３粒子、及びチタン（Ｔｉ）粉末と、溶融含浸させるアルミニウム（Ａｌ）（市販の純Ａｌ（Ａ１０５０、純度＞９９．５％））を用意した。次に、チタン（Ｔｉ）粉末とＡｌ_２Ｏ_３粒子を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が表３に示す値となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、内径５０ｍｍφのカーボン製の容器に充填し、その形状に沿う形で圧縮成形を行い、表３に示す空隙率の成形体とした。次に、内径１０ｍｍφの孔を有するカーボン製蓋部材を成形体の上面に載置し、このカーボン製蓋部材を、その外側に配置するカーボン製容器で固定し、その後、孔に溶融したアルミニウム（Ａｌ）が流れ込むようにアルミニウム（Ａｌ）（固体）を配置した。０．０１３Ｐａ以下の真空雰囲気下にて７００℃まで加熱して溶融したアルミニウム（Ａｌ）を無加圧含浸させ、約１時間保持後に徐冷して複合材料を製造した（実施例２〜２９、比較例３〜７）。浸透性及び緻密性の評価結果を表３に示す。
【０１０４】
【表３】

【０１０５】表３に示す結果から、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が大きくても、空隙率がある程度小さい場合には、アルミニウム（Ａｌ）の浸透性が低下することが判明した。また、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が小さい場合には、含浸駆動力となるチタン（Ｔｉ）粉末の量が少な過ぎるため、得られる複合材料の開気孔率が増大することが判明した。従って、緻密な微構造を有する複合材料を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値と空隙率との関係を規定することにより、好適に製造可能であることが判明した。
【０１０６】
（実施例３０〜３５）
Ａｌ_２Ｏ_３粒子の平均粒径が約４７μｍであること、チタン（Ｔｉ）粉末の平均粒径が約１０μｍであること、及び混合材料の（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値と空隙率を表４に示す値とすること以外は、実施例２〜２９と同様の操作により複合材料を製造した（実施例３０〜３５）。マトリックス組成の分析結果、並びに浸透率、、開気孔率、４点曲げ強度、ヤング率、及び破壊靭性値の測定結果を表４に示す。また、図５〜８に、実施例３０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００、×５００）、実施例３４の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００、×５００）を示す。なお、表４における「空隙率」のうち、「含浸前」とは、成形後の成形体厚みより計算される空隙率を意味し、「含浸後」とは、含浸後に得られた複合材料の厚みより計算される実空隙率を意味する。
【０１０７】
（比較例８、９）
分散材となる平均粒径４７μｍのＡｌ_２Ｏ_３粒子を一軸プレス機にて約８０ＭＰａの圧力で加圧成形して成形体を作製した。この成形体を大気中で７６０℃に予熱し、５００℃に予熱した金型内に設置した。その後、８５０℃で溶解した市販の純アルミニウム（Ａｌ）（Ａ１０５０）を金型内に入れ、５０ＭＰａの圧力にて加圧含浸させることにより複合材料を製造した（比較例８）。また、比較例９として、Ａｌ合金（Ａ５０５２（Ａｌ−２．５％Ｍｇ（質量％）））を用意した。得られた複合材料の物理的特性の測定結果を表４に示す。
【０１０８】
（比較例１０、１１）
分散材となる平均粒径４７μｍのＡｌ_２Ｏ_３粒子と、平均粒径４５μｍのチタン（Ｔｉ）粉末を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が１．０となるように配合した後、一軸プレス機にて約１００ＭＰａの圧力で加圧成形して、直径３４ｍｍφ×６ｍｍ、空隙率約３０％の成形体を作製した。この成形体を、０．０１３Ｐａ以下の真空雰囲気下にて、８５０℃まで加熱して溶融したアルミニウム（Ａｌ）合金（Ａ５０５２）中に浸漬させ、成形体中に溶融アルミニウム（Ａｌ）合金を無加圧含浸させることによって複合材料を製造した（比較例１０）。また、Ａｌ_２Ｏ_３粒子に代えて、平均粒径約５０μｍのＳｉＣ粒子を分散材とし、（Ｔｉ／ＳｉＣ）体積比の値が１．０となるように配合し、直径３４ｍｍφ×７．５ｍｍの空隙率約３０％の成形体を作製して用いたこと以外は、前記比較例１０の場合と同様の操作により、複合材料を作製した（比較例１１）。得られた複合材料の物理的特性の測定結果を表４に示す。なお、図９、１０に、比較例１０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００、×５００）を示す。
【０１０９】
【表４】

【０１１０】表４に示す結果から、所定の範囲内で（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を変化させた場合（実施例３０〜３５）に、浸透率１００％の複合材料を製造することができた。しかしながら、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を０．１０と低くした場合には、含浸駆動力となるＴｉ粉末量が減少することから開気孔率の増加が確認された。また、図５〜８に示すように、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を変化させることで、複合材料のＡｌ_２Ｏ_３粒子体積率、マトリックス組成（アルミナイド金属間化合物とＡｌ相）を制御可能であることが判明した。これに対し、比較例８の複合材料は、Ａｌ_２Ｏ_３粒子体積率を制御することでのみ、複合材料の特性を制御するものであった。このため、実施例の手法は、比較例８の手法と比較した場合、各相の量比を制御することにより、多様な材料特性制御が可能であった。
【０１１１】特に、アルミナイド金属間化合物は、アルミニウム（Ａｌ）に比して剛性が高い反面、破壊靭性値が低いものであるが、本発明では、表４に示すように、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を小さくすることにより、クラック進展時の破壊抵抗として作用し得るアルミニウム（Ａｌ）の含有量をマトリックス中に増加させ、破壊靭性値が大幅に向上した複合材料を製造することができた。また、ヤング率に関しても、Ａｌ_２Ｏ_３粒子に加えてマトリックス内にアルミナイド金属間化合物が含まれていることから、比較例８のマトリックスがアルミニウム（Ａｌ）のみからなる加圧含浸法により作製した金属基複合材料や、比較例９のアルミニウム（Ａｌ）合金と比較して高く、約２００ＧＰａ前後の値を示すものであった。
【０１１２】比較例１０、１１の複合材料は、分散材とチタン（Ｔｉ）粉末とからなる成形体を、溶融したアルミニウム（Ａｌ）合金に浸漬してなるものであり、図９に示すような無加圧含浸は可能ではあった。しかし、比較例１０の、（Ｔｉ／セラミックス）体積比の値が１．０である複合材料の微構造組織（図９）は、よりチタン（Ｔｉ）量を低減させている実施例３０、３４の（Ｔｉ／セラミックス）体積比の値が０．５３、０．１４である複合材料の微構造組織（図５、７）と比較してみても、Ａｌ_２Ｏ_３粒子体積率は低減し、かつ、マトリックス中に含有されるアルミニウム（Ａｌ）量が過剰となり、含浸後の粒子体積率とマトリックス組成は、当初目的とした値にはならなかった（表４）。これは、含浸時の発熱に起因して、成形体が押し広げられるように膨張することにより、過剰に溶融アルミニウム（Ａｌ）が供給され、空隙率が大きく変化したためであると考えられる。従って、比較例１０、１１の複合材料は無加圧含浸で製造されたものではあるが、粒子体積率及びマトリックス組成の制御に困難性を伴ったものである。これに対して、実施例３０〜３５の複合材料は、含浸時に成形体が固定されており、かつ、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値と空隙率とが好適な関係に規定されていたため、所望とする材料組成及び緻密な微構造を有する複合材料である。
【０１１３】
（実施例３６〜６２）
表５に示す分散材（セラミックス粒子）と、チタン（Ｔｉ）粉末を、（Ｔｉ／セラミックス）体積比の値が表５に示す値となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、内径５０ｍｍφのカーボン製の容器に充填し、その形状に沿う形で圧縮成形を行い、表５に示す空隙率の成形体とした。次に、内径１０ｍｍφの孔を有するカーボン製蓋部材を成形体の上面に載置し、このカーボン製蓋部材を、その外側に配置するカーボン製容器で固定し、その後、孔に溶融したアルミニウム（Ａｌ）（Ａ１０５０）又はアルミニウム（Ａｌ）合金（Ａ５０５２）が流れ込むようにアルミニウム（Ａｌ）又はアルミニウム（Ａｌ）合金（いずれも固体）を配置した。０．０１３Ｐａ以下又は１３Ｐａ以下の真空雰囲気下にて７００℃まで加熱して溶融したアルミニウム（Ａｌ）（Ａ１０５０）又はアルミニウム（Ａｌ）合金（Ａ５０５２）を無加圧含浸させ、約１時間保持後に徐冷して複合材料を製造した（実施例３６〜６２）。浸透性及び緻密性の評価結果を表５に示す。
【０１１４】
【表５】

【０１１５】表５に示す結果から明らかなように、分散材として、炭化物であるＳｉＣ、窒化物であるＡｌＮ及びＳｉ_３Ｎ_４を使用した場合も、複合材料を製造することが可能であった。また、含浸雰囲気を、粗引き状態となるＲＰ（ロータリーポンプ）で排気したレベルの低真空（１３Ｐａ以下）とした場合においても良好に含浸した。また、アルミニウム（Ａｌ）合金を使用した場合には、（Ｔｉ／セラミックス）体積比の値が低く、かつ、アルミニウム（Ａｌ）及びチタン（Ｔｉ）の酸化が懸念される低真空（１３Ｐａ以下）においても、緻密な微構造を有する複合材料を製造することができた。これは、アルミニウム（Ａｌ）合金に含まれるマグネシウム（Ｍｇ）が、アルミニウム（Ａｌ）表面に生じる酸化膜を還元する効果を示したためであると考えられる。
【０１１６】
（実施例６３〜６９）
平均粒径が約４７μｍのＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍのチタン（Ｔｉ）粉末、及び溶融含浸させるアルミニウム（Ａｌ）（Ａ１０５０）を使用し、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値、及び混合材料（成形体）の空隙率を表６に示す値として、実施例２〜２９と同様の操作により、複合材料を製造した（実施例６３〜６９）。なお、溶融含浸させるアルミニウム（Ａｌ）の最大浸透距離を１００ｍｍ、孔の内径を２０ｍｍとした。浸透率の測定結果を表６に示す。
【０１１７】
【表６】

【０１１８】表６に示す結果から明らかなように、特に（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が小さい場合には、浸透率が向上することが判明した。また、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が大きい場合には空隙率を増加させることが、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が小さい場合には空隙率を低下させることが、浸透率の向上させるために効果的であることが判明した。
【０１１９】
（実施例７０〜７３、比較例１２、１３）
平均粒径が約４７μｍのＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍのチタン（Ｔｉ）粉末、及び溶融含浸させるアルミニウム（Ａｌ）（Ａ１０５０）を使用し、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を０．２７、混合材料（成形体）の空隙率を４８％として、実施例２〜２９と同様の操作により、複合材料を製造した（実施例７０〜７３）。なお、溶融含浸させるアルミニウム（Ａｌ）の最大浸透距離は１００ｍｍに固定した。浸透性の評価結果を表７に示す。なお、表７における「浸透性評価」は、得られた複合材料を切断し、その断面を研磨した後、光学顕微鏡及びＳＥＭ観察を行い、混合材料中において浸透が一律に進行しているか否かを観察して評価した結果である。
【０１２０】
【表７】

【０１２１】表７に示す結果から明らかなように、Ｘ／Ｙを０．０８〜０．４とした場合には、未含浸部が発生することはなかったが、Ｘ／Ｙを０．０８未満とした場合には、未含浸部が発生した。また、Ｘ／Ｙを０．４超とした場合には、得られた複合材料の緻密性が低下することが判明した。
【０１２２】
（実施例７４）
平均粒径が約４７μｍのＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍのチタン（Ｔｉ）粉末、及び溶融含浸させるアルミニウム（Ａｌ）合金（Ａ５０５２）を用意した。次に、チタン（Ｔｉ）粉末とＡｌ_２Ｏ_３粒子を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が０．２７となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、内径１００ｍｍφのカーボン製の容器に充填し、その形状に沿う形で圧縮成形を行い、厚み３０ｍｍ、空隙率４８．１％の成形体とした。次に、７個の孔（２０ｍｍφ）を有する高密度カーボンからなる蓋部材を成形体の上面に載置し、これらの孔に溶融したアルミニウム（Ａｌ）合金が流れ込むようにアルミニウム（Ａｌ）合金を配置した。０．０１３Ｐａ以下の真空雰囲気下にて８００℃まで加熱して溶融したアルミニウム（Ａｌ）合金を無加圧含浸させ、約１時間保持後に徐冷して複合材料を製造した（実施例７４）。
【０１２３】得られた複合材料を切断し、その断面を研磨した後、光学顕微鏡及びＳＥＭ観察を行い確認を行ったところ、気孔が確認されず、また混合材料中における浸透性も非常に良好であった。このため、一つの孔だけでなく複数の孔を通じてアルミニウム（Ａｌ）の含浸を行った場合においても良好な複合材料が得られることが確認された。
【０１２４】
（実施例７５）
成形体に接触する孔の内側下部に混合材料を追加充填すること以外は、実施例１と同様の操作により複合材料を製造した（実施例７５）。この結果、孔の直下に相当する箇所にアルミニウム（Ａｌ）が過剰に含浸された不均一組織が形成されることなく、より組織的に均質である複合材料を製造することができた。
【０１２５】
（実施例７６〜７９）
平均粒径が約４７μｍのＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍのチタン（Ｔｉ）粉末、及び溶融含浸させるアルミニウム（Ａｌ）合金（Ａ５０５２）を用意した。次に、チタン（Ｔｉ）粉末とＡｌ_２Ｏ_３粒子を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が０．２７となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、図１１に示すような、その内部寸法が、長さ１００ｍｍ×幅１００ｍｍの、その内壁に高密度カーボンからなるカーボン材２２が設置された、ＳＵＳ３１６製の金型容器３０に混合材料を充填した。その後、前記形状に沿う形で圧縮成形を行い、厚み３０ｍｍ、空隙率４８．１％の成形体とした。次に、７個の孔（２０ｍｍφ）及び４個の孔（１０ｍｍφ）を有する高密度カーボンからなる蓋部材を成形体の上面に載置し、これらの孔に溶融したアルミニウム（Ａｌ）合金が流れ込むようにアルミニウム（Ａｌ）合金を配置した。０．０１３Ｐａ以下の真空雰囲気下にて８００℃まで加熱して溶融したアルミニウム（Ａｌ）合金を無加圧含浸させ、約１時間保持後に徐冷して複合材料を製造した（実施例７６）。また、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値を０．１８、０．４０、又は０．５３とすること以外は、実施例７６と同様の操作により複合材料を製造した（実施例７７〜７９）。この結果、製造された複合材料は、ＳＵＳ３１６製の金型容器３０を分解した後、カーボン材２２から容易に外れ、反応容器からの離型性に極めて優れていることが判明した。
【０１２６】
（実施例８０）
図１２に示すような、長さ１００ｍｍ×幅１００ｍｍ、底部の形状が凹凸形状である、その内壁に高密度カーボンからなるカーボン材２２が設置された金型容器３０を使用すること以外は、実施例７８と同様の操作により複合材料を製造した（実施例８０）。この結果、反応容器からの離型性に優れた、複雑形状を有する複合材料を製造することができた。
【０１２７】
（実施例８１）
平均粒径が約４７μｍのＡｌ_２Ｏ_３粒子、平均粒径が約１０μｍのチタン（Ｔｉ）粉末、及び溶融含浸させるアルミニウム（Ａｌ）合金（Ａ５０５２）を用意した。次に、チタン（Ｔｉ）粉末とＡｌ_２Ｏ_３粒子を、（Ｔｉ／Ａｌ_２Ｏ_３）体積比の値が０．２７となるように配合し、Ｖ型混合機により混合を行った。混合により得られた混合材料を、内径３００ｍｍφの、内壁に高密度カーボンを設置したＳＵＳ３１６製金型容器に充填し、その形状に沿う形で圧縮成形を行い、厚み３０ｍｍ、空隙率４８．１％の成形体とした。次に、６１個の孔（２０ｍｍφ）及び１２個の孔（１５ｍｍφ）を有する高密度カーボンからなる蓋部材を成形体の上面に載置して、外周部の容器にて圧粉体を固定させた構造とし、これらの孔に溶融したアルミニウム（Ａｌ）合金が流れ込むようにアルミニウム（Ａｌ）合金を配置した。１．３Ｐａ以下の真空雰囲気下、６００℃、１時間の均熱化処理を行い、その後８００℃にまで加熱して溶融したアルミニウム（Ａｌ）合金を無加圧含浸させ、約１時間保持後に徐冷して、大型の複合材料を製造した（実施例８１）。
【０１２８】得られた３００ｍｍφ×３０ｍｍの複合材料を任意に切断し、各切断面を観察したところ、概ね良好に複合材料化されており、切断されたいずれの部分においても顕著な気孔は確認されなかった。従って、本発明によれば、高圧を要する従来の製造プロセスでは困難であった大型の複合材料が、無加圧含浸で製造可能であることを確認することができた。
【０１２９】
（実施例８２）
図４に示すような、低応力で破壊し易い材料であるポーラスカーボンからなる環状部材１５によって形成された孔１０を有する、カーボンからなる蓋部材（容器要素１ｂ）を用いること以外は、実施例８１と同様の操作により、複合材料を製造した（実施例８２）。
【０１３０】この結果、アルミニウム（Ａｌ）溶融含浸後の徐冷時に、孔の内側に残留して収縮抵抗となったアルミニウム（Ａｌ）が、複合材料の熱収縮によって環状部材１５を破壊したため、得られた複合材料の孔の直下に相当する箇所にクラックが生じるような不具合が発生することがなかった。
【０１３１】
（実施例８３）
図１３に示すような、その内部寸法が、長さ１００ｍｍ×幅１００ｍｍ×深さ６０ｍｍであり、その上部に複数の孔１０と、その側部に反応容器１の上方から下方へと傾斜するスロープ状の湯道２３及び湯道２３に連通した複数個の第２の孔２０を有する反応容器１を使用すること以外は、実施例７６と同様の操作により複合材料を製造した（実施例８３）。この結果、肉厚でありながらも、その端部まで緻密な微構造を有する複合材料を製造することができた。
【０１３２】
（実施例８４）
図１４に示すような、屈曲した複雑な内部形状を有する反応容器１を使用すること以外は、実施例７６と同様の操作により複合材料を製造した（実施例８４）。この結果、複雑形状を有する複合材料５を製造することができた。
【０１３３】
【発明の効果】以上説明したように、本発明の複合材料は、所定の金属粉末と分散材とを含む混合材料を、所定の反応容器の中に充填し、これを固定した状態で所定の孔を経由して混合材料内部の空隙にアルミニウム（Ａｌ）を溶融含浸させ、マトリックス中に分散材を分散させてなるものであるため、簡便に緻密な微構造が形成されてなるものであるとともに、製造コストの低減がなされているものである。
【０１３４】また、本発明の複合材料の製造方法によれば、所定の金属粉末と分散材とを含む混合材料を、所定の反応容器の中に充填し、これを固定した状態で所定の孔を経由して混合材料内部の空隙にアルミニウム（Ａｌ）を溶融含浸させ、マトリックス中に分散材を分散させてなる複合材料を製造するため、製造工程が削減されているとともに、所望とする最終形状、特に大型・複雑形状とすることが可能であり、かつ、緻密な微構造を有する複合材料を簡便に製造することができる。
【図面の簡単な説明】
【図１】本発明の複合材料の製造方法の一例を説明する模式図である。
【図２】従来の複合材料の製造方法の一例を説明する模式図である。
【図３】本発明の複合材料の製造方法の別の例を説明する模式図である。
【図４】本発明の複合材料の製造方法の、更に別の例を説明する模式図である。
【図５】実施例３０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００）である。
【図６】実施例３０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×５００）である。
【図７】実施例３４の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００）である。
【図８】実施例３４の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×５００）である。
【図９】比較例１０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×１００）である。
【図１０】比較例１０の複合材料のミクロ組織を示す走査電子顕微鏡写真（倍率×５００）である。
【図１１】本発明の複合材料の製造方法の、更に別の例を説明する模式図である。
【図１２】本発明の複合材料の製造方法の、更に別の例を説明する模式図である。
【図１３】本発明の複合材料の製造方法の、更に別の例を説明する模式図である。
【図１４】本発明の複合材料の製造方法の、更に別の例を説明する模式図である。
【符号の説明】
１ａ，１ｂ…容器要素、１…反応容器、２…混合材料、３…空隙、４…アルミニウム（Ａｌ）、５…複合材料、６…マトリックス、７…分散材、８…ネジ部、１０…孔、１５…環状部材、２０…第２の孔、２１…外挿体、２２…カーボン材、２３…湯道、２４…固定用ボルト、２５…空間形成領域、３０…金型容器。[0001]
[0001] The present invention relates to a composite material and a method for producing the same.
[0002]
2. Description of the Related Art A composite material is a composition aggregate obtained by macroscopically mixing a plurality of materials, and makes it possible to express characteristics that cannot be realized by a single material by using the mechanical characteristics of each material in a complementary manner. It was done. Basically, it is a technique for combining materials, and there are various combinations depending on the matrix and the reinforcing material (dispersing material), the purpose of use, the cost, and the like.
[0003] Among them, a metal-based composite material or an intermetallic compound-based composite material is a metal such as Al, Ti, Ni, Nb, or TiAl, Ti. ₃ Al, Al ₃ Ti, NiAl, Ni ₃ Al, Ni ₂ Al ₃ , Al ₃ Ni, Nb ₃ Al, Nb ₂ Al, Al ₃ It is made into a composite material using an intermetallic compound such as Nb as a matrix and an inorganic material such as ceramics as a reinforcing material. Therefore, the metal-based composite material or the intermetallic compound-based composite material is being utilized in various fields including the field of space and aviation, taking advantage of its light weight and high strength.
[0004] In general, the intermetallic compound-based composite material has a drawback that the fracture toughness is lower than that of the metal-based composite material, but on the other hand, due to the mechanical and physical properties of the matrix, the heat resistance property is low. It has excellent wear resistance, low thermal expansion and high rigidity.
As a method for producing an intermetallic compound-based composite material, an intermetallic compound powder is produced in advance by mechanical alloying (MA) or the like, and together with fibers and / or particles serving as a reinforcing material, is subjected to high-temperature and high-pressure conditions. Hot pressing (HP) or hot isostatic pressing (HIP).
[0006] A problem with the conventional production method for producing an intermetallic compound-based composite material is that in order to produce a dense intermetallic compound-based composite material, it is necessary to mainly use powder metallurgy such as the HP method and the HIP method. It can be mentioned that the composite material needs to be densified by applying high temperature and high pressure by the method and sintering the intermetallic compound. For this reason, not only is there a need for a pretreatment step, but also the performance and scale of the manufacturing equipment are limited, and it is extremely difficult to manufacture large or complex-shaped composite materials, and the shape of the final product is taken into consideration. There is also a problem that the near-net shaping cannot be performed and a machining process is required in the subsequent steps.
[0007] Further, as a pretreatment step, synthesis of an intermetallic compound powder by MA or the like is necessary in advance, and there is a problem that the manufacturing process is multi-step and complicated. Therefore, as described above, in the production of the conventional intermetallic compound-based composite material, a multi-step process is required, and the production method is performed under high temperature and high pressure conditions, so that the production method is extremely expensive. is there.
Further, as a method for producing a metal matrix composite material, a sheet or foil metal and a fibrous or particulate ceramic are subjected to high pressure, such as a solid phase method such as an HP method or a HIP method. In general, the above-described powder metallurgy method using diffusion bonding and metal powder is known. Further, as the liquid phase method, a pressure impregnation method in which a composite material is forcibly made using mechanical energy such as applying a high pressure in consideration of a combination of a ceramic and a molten metal having poor wettability. For example, the solid-phase method and the liquid-phase method are both processes requiring high temperature and high pressure. In addition, each product made into a composite material has a simple shape such as a flat plate or a disc, and requires plastic working or machining to finish it to the final product. Therefore, the processing cost is high and the manufacturing method is extremely expensive.
A related technique for solving such a problem, particularly a method for producing a metal-based composite material which does not require a pressure, instead of a conventional high-pressure synthesis process, is disclosed for the purpose of reducing the cost of the composite material. ing. Specifically, as a method of impregnating a molten metal under no pressure, which is a liquid phase method, a molding method comprising a reinforcing material in the form of a fine piece and a fine piece of titanium (Ti) or the like having a getter effect of oxygen and nitrogen is used. A method for producing a metal-based composite material using a metal such as aluminum (Al) as a matrix by forming a body and immersing the body in a molten metal such as aluminum (Al) is disclosed (for example, Patent Document 1). reference).
However, according to the above-mentioned production method, it is necessary to apply pressure to the mixed powder during the production process to form a compact, and immerse the compact in a molten metal such as aluminum (Al) to hold it. It is necessary to impart strength to the molded body so that it can be handled. Therefore, it is necessary to increase the molding pressure when producing a molded body, and there are certain restrictions on the obtained product shape. Further, the obtained composite material is limited to a metal-based composite material having a matrix containing a metal containing as little as possible an intermetallic compound. Further, since the compact (sample) expands due to an exothermic reaction between titanium (Ti) and aluminum (Al), when the compact is immersed in the molten metal, the volume ratio of the reinforcing material is reduced, and the reinforcing material is reduced. There is a problem in that it is difficult to produce a composite material having a higher volume ratio, and it is difficult to produce a composite material with controlled material properties, such as higher strength.
As another technique, magnesium (Mg) is volatilized in a nitrogen gas, and the magnesium is evaporated by a gas phase reaction. ₃ N ₂ A method is known in which the wettability between ceramic and metal is improved by in-situ (in-situ) generation on the surface of ceramic particles, and non-pressure infiltration of molten aluminum (Al) into the ceramic porous body by capillary pressure is known. (For example, see Patent Documents 2 and 3). However, according to this technique, the vapor phase reaction causes ₃ N ₂ Is in-situ (in-situ) coating, so that the impregnation rate is very slow, and it takes time to adjust the atmosphere for non-pressure infiltration. Furthermore, since it is necessary to synthesize a ceramic porous body by previously calcining the ceramic particles at a high temperature, there is a problem that the cost of the composite material cannot be reduced.
As a related technique for solving the various problems described above, there is a method for producing an intermetallic compound-based composite material which causes a self-combustion reaction between a metal powder mixed with a predetermined reinforcing material and a molten aluminum (Al). It is disclosed (for example, see Patent Document 3). According to this manufacturing method, as shown in FIG. 2, self-combustion is performed by melting and impregnating aluminum (Al) 4 into gaps 3 of mixed material 2 composed of a dispersion material and metal powder filled in reaction vessel 1. In order to cause the reaction to occur in-situ (in situ), impregnation that completes the composite material 5 such as an intermetallic compound-based composite material having a high melting point under a low temperature and no pressure condition in a very short time A near net shape simulating the shape of the final product can be achieved by the process, and it can be said that this is a method for producing a composite material in which the amount of energy is significantly reduced and the production cost is reduced as compared with the conventional method.
[0013] However, in a material synthesis process similar to the above-described production method using a self-combustion reaction between elements (typically, a combustion synthesis reaction (SHS reaction)), an extremely large heat of reaction cannot be freely controlled. From the viewpoint, powder synthesis of ceramics and high melting point compounds (for example, AlN and Si in a nitrogen gas atmosphere using aluminum (Al) or silicon (Si) as a starting material) ₃ N ₄ While it is used in powder synthesis processes (direct nitridation method, etc.), in the case of bulk production, the resulting bulk is imparted with compactness due to the formation of pores accompanying the exothermic reaction. This is known to be very difficult, and it has been difficult to synthesize a highly dense composite material even in the above-mentioned production method. Therefore, it is an industry to create a composite material having a finer microstructure than the intermetallic compound-based composite material obtained by the above-described production method and having excellent material properties due to the fine structure, and a production method thereof. Requested from the world.
[0014]
[Patent Document 1]
Japanese Patent No. 3107563
[Patent Document 2]
JP-A-1-27359
[Patent Document 3]
JP-A-2-240227
[Patent Document 4]
JP 2002-47519 A
[0015]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. It is an object of the present invention to have a fine microstructure and reduce the manufacturing cost. A method for producing a composite material that has been made and a composite material that has a reduced number of manufacturing steps and can have a desired final shape, particularly a large and complex shape, and has a dense microstructure. To provide.
[0016]
According to the present invention, a mixed material containing a metal powder capable of causing a self-combustion reaction upon contact with aluminum (Al) and a dispersant is provided in a reaction vessel. A composite material that is filled and melt-impregnated with the aluminum (Al) in voids inside the mixed material to disperse a dispersing material in a matrix. A reaction vessel configured to form a space filled with the mixed material by combining the container elements, and using the mixed material to form an area (space) that forms the space of one or more of the container elements. And at least one container element is united with the mixed material filled in the space forming region fixed in a predetermined shape, and the reaction vessel The aluminum (Al) is melt-impregnated into voids inside the mixed material through one or more holes formed at the top of the aluminide, and a self-combustion reaction between the metal powder and the aluminum (Al) causes the aluminide By producing a compound, a composite material is provided, wherein the dispersant is dispersed in the matrix.
In the present invention, the ratio of aluminum (Al) contained in the matrix to the entire matrix is preferably 60% by mass or less, and the metal powder is composed of titanium (Ti), nickel (Ni), and nickel (Ni). It is preferable that the powder is made of at least one metal selected from the group consisting of niobium (Nb).
In the present invention, the hole is preferably formed by an annular member having a stress buffering effect, and the lower portion inside the hole is preferably filled with a mixed material.
In the present invention, the value (X / Y) of the ratio of the inner diameter (X) of the hole to the maximum penetration distance (Y) of the melt-impregnated aluminum (Al) is 0.06 to 0.5. It is preferable that the ratio (volume ratio) of the dispersant to the entire composite material be 10 to 70% by volume.
In the present invention, the dispersant is preferably an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers. ₂ O ₃ , AlN, SiC, and Si ₃ N ₄ It is preferably at least one selected from the group consisting of In the present invention, the ratio (%) of the average particle size of the metal powder to the average particle size of the dispersant is preferably 5 to 80%.
According to the present invention, a reaction vessel is filled with a mixed material containing a metal powder capable of causing a self-combustion reaction by being brought into contact with aluminum (Al) and a dispersing material. A method for producing a composite material in which a dispersing material is dispersed in a matrix by melt-impregnating the aluminum (Al) in an internal space, wherein the reaction container includes two or more container elements. Using a reaction vessel configured to form a space filled with the mixed material by combining the elements, the mixed material is placed in an area (space forming area) that forms the space of one or more of the container elements. And the one or more container elements are combined in a state where the mixed material filled in the space forming region is fixed in a predetermined shape, and the upper part of the reaction container The aluminum (Al) is melt-impregnated into voids inside the mixed material through one or more formed holes, and a self-combustion reaction between the metal powder and the aluminum (Al) generates an aluminide intermetallic compound. By doing so, there is provided a method for producing a composite material, wherein a composite material obtained by dispersing the dispersant in the matrix is obtained.
In the present invention, the metal powder is preferably a powder made of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni), and niobium (Nb).
In the present invention, when the metal powder is titanium (Ti) powder, the mass ratio (Al: Ti) of aluminum (Al) to be impregnated and titanium (Ti) powder is 1: 0.17. １ ： 1: 0.57, and when the metal powder is nickel (Ni) powder, the mass ratio (Al: Ni) of aluminum (Al) to be melt-impregnated and nickel (Ni) powder is , 1: 0.20 to 1: 0.72, and similarly, when the metal powder is niobium (Nb) powder, the mass of aluminum (Al) to be melt-impregnated and the niobium (Nb) powder Preferably, the ratio (Al: Nb) is 1: 0.27 to 1: 1.13.
In the present invention, the holes are preferably formed by an annular member having a stress buffering effect, and the mixed material is preferably filled in a lower portion inside the holes.
In the present invention, the value (X / Y) of the ratio of the inner diameter (X) of the hole to the maximum penetration distance (Y) of the aluminum (Al) to be melt-impregnated is 0.06 to 0.5. It is preferable that the dispersing material is an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers.
In the present invention, the inorganic material is Al ₂ O ₃ , AlN, SiC, and Si ₃ N ₄ Preferably, the ratio (%) of the average particle size of the metal powder to the average particle size of the dispersant is 5 to 80%. In the present invention, it is preferable that at least the inner wall of the reaction vessel is made of a carbon material.
In the present invention, the reaction vessel further has, on its side, a slope-shaped runner inclined from above to below the reaction vessel, and one or more second holes communicating with the runner. It is preferable that aluminum (Al) is melt-impregnated into the voids inside the mixed material via the holes and the second holes independently of each other.
In the present invention, the metal powder is titanium (Ti) powder, and the dispersants are AlN, Si, and Si. ₃ N ₄ In the case of particles (ceramic particles) made of at least one type of ceramic selected from the group consisting of: (a) the value of the ratio of the volume of titanium (Ti) powder to the volume of ceramic particles (Ti / ceramics); It is preferable that the ratio of voids (porosity (%)) to the volume of the space satisfies any of the following relationships (1) to (6).
(1) 0.1 ≦ (Ti / ceramics) <0.14, 25 ≦ porosity (%) ≦ 60
(2) 0.14 ≦ (Ti / ceramics) <0.27, 25 ≦ porosity (%) ≦ 70
(3) 0.27 ≦ (Ti / ceramics) <0.53, 25 ≦ porosity (%) ≦ 75
(4) 0.53 ≦ (Ti / ceramics) <1, 30 ≦ porosity (%) ≦ 75
(5) 1 ≦ (Ti / ceramics) <1.4, 45 ≦ porosity (%) ≦ 80
(6) 1.4 ≦ (Ti / ceramics) ≦ 2, 50 ≦ porosity (%) ≦ 80
In the present invention, the metal powder is titanium (Ti) powder and the dispersant is Al ₂ O ₃ In the case of particles, Al ₂ O ₃ The value of the ratio of the volume of the titanium (Ti) powder to the volume of the particles (Ti / Al ₂ O ₃ ) And the ratio of voids to the volume of the space in the reaction vessel (porosity (%)) preferably satisfy any of the following relationships (7) to (12).
(7) 0.1 ≦ (Ti / Al ₂ O ₃ ) <0.14, 25 ≦ porosity (%) ≦ 60
(8) 0.14 ≦ (Ti / Al ₂ O ₃ ) <0.27, 25 ≦ porosity (%) ≦ 70
(9) 0.27 ≦ (Ti / Al ₂ O ₃ ) <0.53, 25 ≦ porosity (%) ≦ 75
(10) 0.53 ≦ (Ti / Al ₂ O ₃ ) <1, 30 ≦ porosity (%) ≦ 75
(11) 1 ≦ (Ti / Al ₂ O ₃ ) <1.4, 45 ≦ porosity (%) ≦ 80
(12) 1.4 ≦ (Ti / Al ₂ O ₃ ) ≦ 2, 50 ≦ porosity (%) ≦ 80
[0030]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments, but the present invention is not limited to these embodiments.
A first aspect of the present invention is to fill a reaction vessel with a mixed material containing a metal powder and a dispersant capable of causing a self-combustion reaction by contacting aluminum (Al), and mixing the mixed material. A composite material in which a dispersion material is dispersed in a matrix by spontaneously melting and impregnating aluminum (Al) using reaction heat generated by a self-combustion reaction in a void inside the material as a driving force. A region (space) in which the mixed material forms a space for one or more container elements using a reaction vessel composed of the above container elements and configured to form a space filled with the mixed material by combining the container elements. Formation region), and one or more container elements are combined in a state where the mixed material filled in the space formation region is fixed in a predetermined shape, and formed at the top of the reaction vessel. The aluminum (Al) is melt-impregnated into the voids inside the mixed material through one or more of the holes thus produced, thereby causing a self-combustion reaction between the metal powder and the aluminum (Al), that is, in-situ (the Field) A dispersant is dispersed in a matrix by synthesizing an aluminide intermetallic compound by synthesis. Hereinafter, the details will be described.
FIG. 1 is a schematic view for explaining an example of the method for producing a composite material according to the present invention. In FIG. 1, a mixed material 2 obtained by mixing a dispersion material and a metal powder is filled in a space forming region 25 of a container element 1a having an appropriate size and shape, and a molten aluminum (Al) is formed on an upper surface thereof. A lid container element 1b (lid member) having a hole 10 (pouring spout) into which the mixed material 2 is impregnated is placed, and the mixed material 2 is fixed in a predetermined shape. A state in which aluminum (Al) 4 is melt-impregnated into the gap 3 through the hole 10 is shown. Reference numeral 1 denotes a reaction vessel, and reference numeral 21 denotes an extrapolation body.
In the present embodiment, the aluminum (Al) 4 is melt-impregnated, so that the metal powder (not shown) constituting the mixed material 2 and the molten aluminum (Al) 4 come into contact with each other to cause a self-combustion reaction. Is generated, and aluminum (Al) 4 is replaced by an aluminide intermetallic compound. As a result, the composite material 5 of the present embodiment in which the dispersant 7 is dispersed in the matrix 6 containing the aluminide intermetallic compound is obtained.
Further, in the composite material of the present embodiment, generation of an aluminide intermetallic compound is promoted by utilizing heat of self-combustion reaction between aluminum (Al) and various metal powders. That is, the molten aluminum (Al) penetrates into the mixed material using the exothermic reaction between the elements as a driving force for impregnation, and utilizes the internal energy thereof, so that it is manufactured under a low temperature condition. Therefore, high pressure is not required as in a conventional manufacturing method such as a pressure impregnation method, an HP method, or a HIP method, and it is manufactured by an infiltration process without pressure. Further, the composite material of the present embodiment can suitably cope with a relatively large or complicated shape, which has been difficult in terms of the performance of the manufacturing apparatus, and greatly reduces the processing time after the aluminum (Al) impregnation. It is possible to make the product near-net-shaped with a reduced number of products.
Further, as shown in FIG. 1, a container element 1b having one or more holes 10 is placed on the upper surface of the mixed material 2, and is impregnated with aluminum (Al) 4 via the holes 10. At this time, the mixed material 2 filled in the space forming region of the container element 1a is fixed to have a predetermined shape by the container element 1b, and even if the mixed material 2 is impregnated with aluminum (Al) 4, Is maintained. Further, aluminum (Al) 4 is easily impregnated into the details of the gap 3, and for example, as shown in FIG. 2, the aluminum (Al) 4 is impregnated without using the container element 1b (see FIG. 1). The open porosity is reduced as compared with the composite material 5 which has been made, and the composite material 5 has characteristics of being more dense. In addition, the composite material is less likely to cause a problem such as warpage after being impregnated with aluminum (Al) 4 and has a desired shape.
Further, complicated steps such as calcination and pressure molding for producing a preform having such a strength as not to collapse during the melt impregnation of aluminum (Al) are unnecessary, and the production is performed by a simple operation. It is a composite material.
In order to fix the mixed material 2 so as to have a predetermined shape, for example, as shown in FIG. 1, means such as providing a screw portion 8 in the container element 1a can be mentioned. Fine adjustment can be made so that a desired appropriate pressure is applied to the mixed material 2. However, it goes without saying that the means for fixing the mixed material is not limited to the embodiment shown in FIG.
In the present invention, the ratio of the aluminum (Al) contained in the matrix to the entire matrix is preferably 60% by mass or less, more preferably 2% to 50% by mass. That is, when aluminum (Al) remains in the matrix to be formed, the composite material of the present embodiment exhibits excellent fracture toughness, and the penetration path of aluminum (Al) is reduced by the mixed material. Aluminum (Al) is well-penetrated because it exists as a void. When the ratio of aluminum (Al) contained in the matrix to the entire matrix exceeds 60% by mass, the fracture toughness value of the composite material is increased, but the Young's modulus is reduced and the composite material is attractive as a highly rigid material. Is undesirably reduced, and phenomena such as a decrease in strength are likely to occur in the melting point region of aluminum (Al). Furthermore, when the ratio of aluminum (Al) is further increased, it is not preferable because the permeability decreases due to a decrease in the amount of the metal powder serving as the impregnating driving force.
The metal powder used in the present invention is one in which a self-combustion reaction is caused by contact with molten aluminum (Al) (aluminum (Al) molten metal) to form an aluminide intermetallic compound. Specifically, powders of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni), and niobium (Nb) are used, and these metal powders have good reactivity and This is preferable because an aluminide intermetallic compound is easily formed. The following formulas (1) to (3) show typical examples of reactions when these metal powders are used. As shown in the following formulas (1) to (3), these reactions are exothermic reactions (self-combustion reactions), and the composite material of the present invention can be obtained by utilizing this reaction heat.
[0040]
(Equation 1)
3Al + Ti → Al ₃ Ti: ΔH ₂₉₈ = -146 kJ / mol ... (1)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
[0041]
(Equation 2)
3Al + Ni → Al ₃ Ni: ΔH ₂₉₈ = -150 kJ / mol ... (2)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
[0042]
[Equation 3]
3Al + Nb → Al ₃ Nb: ΔH ₂₉₈ = -160 kJ / mol ... (3)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
FIG. 3 is a schematic view for explaining another example of the method for producing a composite material according to the present invention. In the present embodiment, it is preferable that a plurality of holes 10 are formed in the reaction container 1 (container element 1b), which is suitable when a larger amount of the mixed material is used, that is, when the composite material is larger. It is. That is, the supply of aluminum (Al) is efficiently performed through the plurality of holes, and the device has a dense microstructure even if it is large.
As shown in FIG. 4, it is preferable that the hole 10 is formed by an annular member 15 having a stress buffering effect when the composite material is larger. The term "stress buffering effect" as used herein refers to an effect of buffering stress caused by heat shrinkage, which is generated when the temperature is lowered after melt impregnation with aluminum (Al). That is, when aluminum (Al) remaining in the vicinity of the hole 10 becomes a shrinkage resistance, stress concentrates in a combination portion (connection portion) of the hole 10 and the composite material, and a problem such as breakage occurs in the obtained composite material. However, since the hole 10 is formed by the annular member 15 having a stress buffering effect, the occurrence of the above-described problem can be avoided. Note that specific examples of the material forming the annular member 15 having such a stress buffering effect include porous carbon and ceramic fibers used as a heat insulating material. In addition, it is also possible to alleviate the stress at the time of shrinkage by performing C removal or R attachment at the lowermost portion of the hole, that is, the portion where the hole is in contact with the composite material.
In the present invention, it is preferable that a mixed material is additionally filled in a lower portion inside the hole which comes into contact with the molded body. Since the portion corresponding to the portion immediately below the hole serves as a supply portion of the molten aluminum (Al) to be impregnated, the structure of the obtained composite material may be excessive (aluminum (Al)) and may be heterogeneous. Accordingly, in the composite material of the present invention in which the mixed material is filled in the lower portion inside the hole, only the portion corresponding to the inside of the hole can be easily removed after the melt impregnation of aluminum (Al), In this case, it is not necessary to process and remove the portion of the molded body placed immediately below the hole, that is, the portion that has become a composite material by impregnation, so that the yield during production and the production cost are reduced. In the present invention, the “lower portion inside the hole” refers to a position from １ ／ to ３ of the height of the hole.
In the present invention, the value (X / Y) of the ratio of the inner diameter (X) of the hole to the maximum penetration distance (Y) of the melt-impregnated aluminum (Al) is 0.06 to 0.5. Preferably, it is 0.08 to 0.4, more preferably 0.1 to 0.35. If X / Y is less than 0.06, the pores are too small, so that the supply of aluminum (Al) is not sufficient and the permeability is not easily improved, which is not preferable. On the other hand, when X / Y is more than 0.5, the effect of improving the permeability of aluminum (Al) is similarly difficult to be exhibited, which is not preferable.
The “maximum penetration distance” of aluminum (Al) in the present invention refers to the distance from the end of the hole 10 shown in FIG. 1 to the end of the mixed material 2 filled in the reaction vessel 1. Shall be referred to as the distance. In the present invention, the shape of the hole is not particularly limited, and may be any shape including a circle, an ellipse, a polygon, an irregular shape, and the like. The inner diameter of the hole is the inner diameter if the hole is circular, the average of the major and minor diameters if the hole is elliptical, and the maximum opening and minimum diameters if the hole is polygonal or irregular. It means the average value with the opening diameter.
In the present invention, the ratio (volume ratio) of the dispersant to the whole composite material is preferably from 10 to 70% by volume, and more preferably from 30 to 60% by volume. If the volume ratio of the dispersing material is less than 10% by volume, sufficient strength cannot be exhibited as a composite material, and if it exceeds 70% by volume, there is a problem in infiltration of molten aluminum (Al). This is not preferable because it is difficult to form an aluminide intermetallic compound and a heterogeneous structure is formed. In the present invention, the aluminum (Al) to be melt-impregnated is not limited to pure aluminum (Al), and needless to say, the effects described so far are exhibited even when various aluminum (Al) alloys are used. .
In the present invention, the dispersant is preferably an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers. Therefore, the composite material of the present invention has physical characteristics and the like in accordance with the intended use as a final product.
In the present invention, the inorganic material is Al ₂ O ₃ , AlN, SiC, and Si ₃ N ₄ It is preferably at least one selected from the group consisting of The composite material exhibits various characteristics depending on the combination of the intermetallic compound and the dispersant contained in the matrix constituting the composite material, and a combination that provides the composite material having the characteristics according to the application is appropriately selected. Table 1 shows an example of the types of dispersants made of various inorganic materials and the characteristics of the composite material when combined with an intermetallic compound.
[0051]
[Table 1]

In the present invention, the ratio (%) of the average particle size of the metal powder to the average particle size of the dispersant is preferably 5 to 80%, more preferably 10 to 60%. When the average particle size of the metal powder is less than 5% of the average particle size of the dispersing agent, handling becomes inconvenient because it is difficult to obtain the metal powder itself and there is a risk of dust explosion. If it is more than 1, the activity of the self-combustion reaction is not sufficiently increased, and the resulting composite material is difficult to be densified. Specifically, when the average particle size of the dispersion material is 50 μm, the average particle size of the metal powder is preferably 2 to 40 μm, and more preferably 5 to 30 μm.
Next, a second aspect of the present invention will be described. According to a second aspect of the present invention, a reaction vessel is filled with a mixed material containing a metal powder and a dispersing material capable of causing a self-combustion reaction by being brought into contact with aluminum (Al). This is a method for producing a composite material in which a void is melt-impregnated with aluminum (Al) to disperse a dispersing material in a matrix, and the reaction container is composed of two or more container elements. Using a reaction vessel configured to form a space to be filled with the mixed material, the mixed material is filled in a region (space forming region) forming a space of one or more container elements, and one or more container elements are filled. Are combined in a state in which the mixed material filled in the space forming region is fixed in a predetermined shape, and aluminum is introduced into the gap inside the mixed material through one or more holes formed in the upper part of the reaction vessel. A composite material obtained by dispersing a dispersing material in a matrix by melt-impregnating aluminum (Al) and generating an aluminide intermetallic compound by a self-combustion reaction between metal powder and aluminum (Al). Is what you do. Hereinafter, the details will be described.
In the method of manufacturing a composite material according to the present invention, as shown in FIG. 1, a mixed material obtained by mixing a dispersant and metal powder in a space forming region 25 of a container element 1a having an appropriate size and shape. 2 and a container element 1b (lid member) having a hole 10 for impregnating with molten aluminum (Al) is placed on the upper surface thereof to fix the mixed material 2 in a predetermined shape. Aluminum (Al) 4 is melt-impregnated into the gaps 3 formed between the mixed materials 2 via the holes 10. In the present embodiment, aluminum (Al) 4 is melt-impregnated, whereby a metal powder (not shown) constituting the mixed material 2 is brought into contact with molten aluminum (Al) 4 to cause a self-combustion reaction, Aluminum (Al) 4 is replaced with an aluminide intermetallic compound. As a result, it is possible to manufacture the composite material 5 in which the dispersant 7 is dispersed in the matrix 6 containing the aluminide intermetallic compound.
Further, in the present embodiment, in order to promote the formation of aluminide intermetallic compound by utilizing the heat of self-combustion reaction between aluminum (Al) and various metal powders, it is necessary to manufacture a composite material under low temperature conditions. Can be. Further, the composite material can be manufactured by pressureless infiltration because high pressure is not required as in the conventional manufacturing method such as the HP method or the HIP method. This makes it possible to manufacture a composite material having a relatively large or complicated shape, which has been difficult in terms of the performance of the manufacturing apparatus.
Further, as shown in FIG. 1, in this embodiment, a container element 1b having one or more holes 10 is placed on the upper surface of the mixed powder 2, and aluminum (Al) 4 is transferred through the holes 10. Impregnate. At this time, the mixed material 2 filled in the space forming region 25 of the container element 1a is fixed so as to have a predetermined shape by the container element 1b. The predetermined shape of the powder 2 can be maintained. Further, aluminum (Al) 4 can be impregnated into the details of the gap 3. For example, as shown in FIG. 2, the aluminum (Al) 4 is impregnated without using the container element 1 b (see FIG. 1). The open porosity can be reduced as compared with the obtained composite material 5, and a denser and more dense composite material can be manufactured. In addition, even after impregnation with aluminum (Al), defects such as deformation hardly occur, and a desired shape can be imparted to the obtained composite material.
In order to fix the mixed material 2 so as to have a predetermined shape, for example, as shown in FIG. 1, means such as providing a screw portion 8 on the container element 1a can be mentioned. Fine adjustment can be performed so that a desired appropriate pressure is applied to the mixed material 2. However, it goes without saying that the means for fixing the mixed material is not limited to the embodiment shown in FIG.
The metal powder used in the present invention generates a self-combustion reaction upon contact with molten aluminum (Al) (aluminum (Al) melt) to form an aluminide intermetallic compound. Specifically, a powder made of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni), and niobium (Nb) can be used. These metal powders are preferable because they have good reactivity, form a stable aluminide intermetallic compound, and are easy to obtain and handle. Representative examples of reactions using these metal powders are shown in the following formulas (4) to (6). As shown in the following formulas (4) to (6), these reactions are exothermic reactions (self-combustion reactions), and this reaction heat is used in the present invention.
[0059]
(Equation 4)
3Al + Ti → Al ₃ Ti: ΔH ₂₉₈ = -146 kJ / mol ... (4)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
[0060]
(Equation 5)
3Al + Ni → Al ₃ Ni: ΔH ₂₉₈ = -150 kJ / mol ... (5)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
[0061]
(Equation 6)
3Al + Nb → Al ₃ Nb: ΔH ₂₉₈ = -160 kJ / mol ... (6)
ΔH: heat of formation reaction (exothermic reaction when Δ <0)
In another method for producing an in-situ composite material disclosed in Japanese Patent No. 2609376 and Japanese Patent Application Laid-Open No. 9-227969, both a dispersant and a matrix are synthesized in-situ. In contrast, in the present invention, only the matrix is subjected to in-situ synthesis. Therefore, the type of the dispersant can be freely selected, and a composite material having desired physical characteristics can be manufactured. Furthermore, the heat of reaction can be controlled by arbitrarily selecting and setting the type of dispersion material and the volume ratio.
In the present invention, when the metal powder is titanium (Ti) powder, the mass ratio (Al: Ti) of the aluminum (Al) to be melt-impregnated and the titanium (Ti) powder is 1: 0.17. １ ： 1: 0.57 is preferred. This makes it possible to obtain a composite material having a proportion of aluminum (Al) contained in the matrix of 60% by mass or less based on the entire matrix, that is, a high fracture toughness and a dense microstructure.
When the metal powder is nickel (Ni) powder, the mass ratio (Al: Ni) of aluminum (Al) to be melt-impregnated and nickel (Ni) powder is 1: 0.20 to 1:20. It is preferably 0.72. This makes it possible to obtain a composite material having a proportion of aluminum (Al) contained in the matrix of 60% by mass or less based on the entire matrix, that is, a high fracture toughness and a dense microstructure.
Furthermore, when the metal powder is niobium (Nb) powder, the mass ratio (Al: Ni) of aluminum (Al) to be impregnated and nickel (Ni) powder is 1: 0.27 to 1: 0.2. It is preferably 1.13. This makes it possible to obtain a composite material having a proportion of aluminum (Al) contained in the matrix of 60% by mass or less based on the entire matrix, that is, a high fracture toughness and a dense microstructure.
In the present invention, it is preferable that a plurality of holes are formed in the reaction vessel, so that a larger amount of the mixed material can be used than in the case where the number of holes is one. That is, since the permeability of the molten aluminum (Al) is improved, it is possible to manufacture a composite material having a fine microstructure even if it is large.
In the present invention, particularly when a large member is manufactured, it is preferable that the hole is formed by an annular member having a stress buffering effect. The “stress buffering effect” here is as described above. In other words, when aluminum (Al) remaining near the hole becomes the contraction resistance of the composite material, stress is concentrated at a joint (connection portion) of the hole and the composite material, and a failure such as breakage occurs in the obtained composite material. However, since the hole is formed by an annular member having a stress buffering effect, the occurrence of the problem can be avoided. Note that specific examples of the material constituting the annular member having such a stress buffering effect include porous carbon and ceramic fibers used as a heat insulating material.
In the present invention, it is preferable to fill the lower portion inside the hole with the mixed material. In a portion corresponding to a portion immediately below the hole, the structure of the obtained composite material may be inhomogeneous due to excess aluminum (Al). Therefore, when the mixed material is filled in the lower portion inside the hole, only the portion corresponding to the inside of the hole can be easily removed after the melt impregnation with aluminum (Al), and a homogeneous structure as a whole can be obtained. A composite material having the same can be manufactured.
In the present invention, the ratio (X / Y) of the inner diameter (X) of the hole to the maximum penetration distance (Y) of the aluminum (Al) to be melt-impregnated is 0.06 to 0.5. It is more preferably 0.08 to 0.4, particularly preferably 0.1 to 0.35. When X / Y is less than 0.06, the pores are too small, and it is difficult to improve the permeability of aluminum (Al). On the other hand, when X / Y is more than 0.5, the effect of improving the permeability of aluminum (Al) is similarly difficult to be exhibited, which is not preferable.
Next, the present invention will be described in detail with reference to an example of a manufacturing method. Dispersion material having a predetermined shape, metal powder having a predetermined average particle size, for example, titanium (Ti), nickel (Ni), niobium (Nb), etc. (Al) is prepared. At this time, the ratio (%) of the average particle diameter of the metal powder to the average particle diameter of the dispersant is preferably 5 to 80%, more preferably 10 to 60%. If the average particle size of the metal powder is less than 5% of the average particle size of the dispersant, handling becomes inconvenient due to the difficulty in obtaining the metal powder itself and the risk of dust explosion. %, The activity of the self-combustion reaction is not sufficiently increased, and the composite material cannot be densified. Specifically, a metal powder having an average particle size of 2 to 40 μm is preferably used for a dispersant having an average particle size of 50 μm, and a metal powder having an average particle size of 5 to 30 μm is more preferably used.
In the present invention, the dispersant is preferably an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers. By using inorganic materials having these shapes, it is possible to manufacture a composite material having strength and characteristics suitable for the use as a final product.
In the present invention, the term “dispersion material having an average particle size of 10 to 150 μm” refers to “particles having an average particle size of 10 to 150 μm” when the shape of the dispersion material is particulate. In addition, in the case of fibers, whiskers, etc., not in the form of particles, "when the length / diameter ratio is less than 150, fibers having diameters of 0.1 to 30 μm, whiskers, etc." or " When the length / diameter ratio is 150 or more, fibers and whiskers having a diameter of 0.5 to 500 μm ”are referred to.
In the present invention, the inorganic material is Al ₂ O ₃ , AlN, SiC, and Si ₃ N ₄ It is preferably at least one selected from the group consisting of The composite material exhibits various characteristics depending on the combination of the intermetallic compound and the dispersant contained in the matrix constituting the composite material, and a combination that provides the composite material having the characteristics according to the application may be appropriately selected.
In order to adjust the mass ratio between aluminum (Al) and the aluminide intermetallic compound contained in the matrix of the obtained composite material, the ratio of metal powder: dispersion material of the mixed material to be charged into the reaction vessel ( Volume ratio), and further, by measuring the thickness of the mixed material after filling, the porosity of the mixed material is measured. Assuming that aluminum (Al) completely penetrates into the voids, Calculate the required amount. Thus, the particle volume ratio of the dispersant and the composition (mass ratio) of the matrix can be calculated from the volume ratio of the metal powder to the dispersant and the porosity of the mixed material.
Further, the composition of the target matrix before the impregnation with aluminum (Al) does not completely match the actual matrix composition after the impregnation, and may vary slightly. Next, a method of calculating the actual matrix composition after impregnation will be described. The mass ratio of aluminum (Al): aluminide intermetallic compound contained in the matrix was adjusted to a predetermined mass ratio in advance by XRD analysis, which is a method described in Patent Document 4, aluminum (Al) and aluminide intermetallic compound. It is possible to prepare a calibration curve using the mixed powder of the above, perform XRD analysis on a sample in which the matrix composition is changed based on the calibration curve, and calculate the X-ray intensity from the obtained measurement result.
The mixed material obtained by mixing the dispersing material and the metal powder is filled in the space forming region of the container element constituting the reaction vessel, and the mixed material has an appropriate shape and a predetermined porosity. Molding is performed under pressure. The mixed material may be molded by applying an appropriate pressure in advance, and may be filled in a reaction vessel. The porosity can be arbitrarily controlled by changing the molding pressure. Next, the molded bodies are combined by being fixed to each other through a container element having one or more holes, and then aluminum (Al) is arranged via the container element. At this time, as described above, the mixed material may be filled in the lower portion inside the hole. The aluminum (Al) to be disposed is not limited to pure aluminum (Al), and any aluminum (Al) having a purity of about 90% or more can be used without any problem. Various aluminum (Al) alloys may be used. Subsequently, the mixture is heated to a temperature several tens of degrees higher than the temperature at which aluminum (Al) dissolves (about 660 ° C.), specifically about 700 ° C., under a suitable reduced pressure condition, for example, a vacuum condition, and mixed via a hole. The voids in the material are impregnated with molten aluminum (Al). Aluminum (Al) in contact with the metal powder causes a self-combustion reaction and induces capillary permeation, thereby instantaneously forming a matrix of the target composite material.
Since the formation of the matrix itself is completed in a very short time, a heating time of about several minutes is sufficient. Further, after completion of the self-combustion reaction, isothermal holding or heating holding may be appropriately performed in order to homogenize and stabilize the matrix of the obtained composite material. The holding temperature at this time slightly depends on the material system, but it is preferable to carry out the heating at a temperature about 400 to 500 ° C. higher than the temperature at which the self-combustion reaction occurs, and the holding time is about 1 hour. It may be carried out for several hours as needed.
In the present invention, as shown in FIG. 11, it is preferable that the reaction vessel 1 has at least an inner wall made of a carbon material 22. When the reaction vessel 1 having the inner wall configured as described above is used, the obtained composite material can be easily taken out of the reaction vessel 1 after being melted and impregnated with aluminum (Al) and cooled. That is, since the releasability of the composite material from the reaction vessel 1 becomes extremely good, the durability of the reaction vessel 1 is also improved, and the production cost of the composite material can be reduced. Although FIG. 11 shows a state in which only the inner wall of the reaction vessel 1 is made of a carbon material 22, the entire reaction vessel 1 may be made of a carbon material, and at least aluminum (Al) It is preferable that a portion where the composite material to be contacted is made of a carbon material. Further, in order to further improve the releasability, it is also preferable to perform coating using a BN spray or the like, or to dispose a carbon sheet or the like in a portion where molten aluminum (Al) contacts. Reference numeral 24 indicates a fixing bolt.
In the present invention, as shown in FIG. 13, a reaction vessel 1 has a slope-shaped runner 23 which is inclined from the upper side to the lower side of the reaction vessel 1 on its side, and communicates with the runner 23. And one or more second holes 20 formed through the upper hole 10 and the second holes 20 on the side, respectively, and independently through the gaps inside the mixed material 2 with aluminum (Al) 4. Is preferably melt-impregnated. That is, the reaction vessel 1 in which the second pouring ports 20 are appropriately increased and formed is prepared, and aluminum (Al) 4 is melt-impregnated from each of the holes 10 and the second holes 20 to obtain a wall thickness (FIG. 13). Even if it is long in the left-right direction), a composite material having a dense microstructure can be manufactured over the entirety.
In the present invention, the metal powder is titanium (Ti) powder, and the dispersant is AlN, Si, and Si. ₃ N ₄ In the case of particles (ceramic particles) made of at least one kind of ceramics selected from the group consisting of, the value of the ratio of the volume of titanium (Ti) powder to the volume of ceramic particles (Ti / ceramics (hereinafter simply referred to as Ti / ceramics value)) and the ratio of voids (porosity (%)) to the volume in the container preferably satisfies any of the following relationships (1) to (6). .
(1) 0.1 ≦ (Ti / ceramics) <0.14, 25 ≦ porosity (%) ≦ 60
(2) 0.14 ≦ (Ti / ceramics) <0.27, 25 ≦ porosity (%) ≦ 70
(3) 0.27 ≦ (Ti / ceramics) <0.53, 25 ≦ porosity (%) ≦ 75
(4) 0.53 ≦ (Ti / ceramics) <1, 30 ≦ porosity (%) ≦ 75
(5) 1 ≦ (Ti / ceramics) <1.4, 45 ≦ porosity (%) ≦ 80
(6) 1.4 ≦ (Ti / ceramics) ≦ 2, 50 ≦ porosity (%) ≦ 80
That is, by combining the (Ti / ceramics) value of the mixed material and the porosity so as to satisfy one of the above-described relationships, the gaps of the mixed material are melt-impregnated with aluminum (Al). The permeability is extremely good, and a denser composite material having a reduced open porosity can be manufactured even under a high pressure condition unlike the HP method or the HIP method. From the viewpoint of further improving the permeability of aluminum (Al) and producing a denser composite material having a reduced open porosity, the (Ti / ceramic) value and the porosity (%) are as follows: More preferably, any one of the relationships shown in (7) to (14) is satisfied.
[0082]
(7) 0.1 ≦ (Ti / ceramics) <0.14, 30 ≦ porosity (%) ≦ 45
(8) 0.14 ≦ (Ti / ceramics) <0.18, 25 ≦ porosity (%) ≦ 55
(9) 0.18 ≦ (Ti / ceramics) <0.27, 25 ≦ porosity (%) ≦ 60
(10) 0.27 ≦ (Ti / ceramics) <0.4, 35 ≦ porosity (%) ≦ 65
(11) 0.4 ≦ (Ti / ceramics) <0.53, 35 ≦ porosity (%) ≦ 70
(12) 0.53 ≦ (Ti / ceramics) <0.77, 40 ≦ porosity (%) ≦ 70
(13) 0.77 ≦ (Ti / ceramics) <1, 45 ≦ porosity (%) ≦ 75
(14) 1 ≦ (Ti / ceramics) <2, 50 ≦ porosity (%) ≦ 80
In the present invention, the metal powder is titanium (Ti) powder, and the dispersant is Al. ₂ O ₃ In the case of particles, Al ₂ O ₃ The value of the ratio of the volume of the titanium (Ti) powder to the volume of the particles (Ti / Al ₂ O ₃ (Hereinafter, simply “(Ti / Al ₂ O ₃ ) Value) and the ratio of voids to the volume in the mold container (porosity (%)) preferably satisfy any of the following relationships (15) to (20).
(15) 0.1 ≦ (Ti / Al ₂ O ₃ ) <0.14, 25 ≦ porosity (%) ≦ 60
(16) 0.14 ≦ (Ti / Al ₂ O ₃ ) <0.27, 25 ≦ porosity (%) ≦ 70
(17) 0.27 ≦ (Ti / Al ₂ O ₃ ) <0.53, 25 ≦ porosity (%) ≦ 75
(18) 0.53 ≦ (Ti / Al ₂ O ₃ ) <1, 30 ≦ porosity (%) ≦ 75
(19) 1 ≦ (Ti / Al ₂ O ₃ ) <1.4, 45 ≦ porosity (%) ≦ 80
(20) 1.4 ≦ (Ti / Al ₂ O ₃ ) ≦ 2, 50 ≦ porosity (%) ≦ 80
That is, the mixed material (Ti / Al ₂ O ₃ ) And the porosity are combined so as to satisfy any one of the above-mentioned relations, so that when the gaps of the mixed material are melt-impregnated with aluminum (Al), the permeability becomes extremely good, and the HP method or HIP It is possible to produce a denser composite material having a reduced open porosity without using a high pressure condition as in the method. In addition, from the viewpoint of further improving the permeability of aluminum (Al) and producing a denser composite material having a reduced open porosity, (Ti / Al ₂ O ₃ ) Value and porosity (%) more preferably satisfy any of the following relationships (21) to (29), and preferably satisfy any of the following relationships (30) to (37): Is particularly preferred.
[0085]
(21) 0.1 ≦ (Ti / Al ₂ O ₃ ) <0.14, 30 ≦ porosity (%) ≦ 45
(22) 0.14 ≦ (Ti / Al ₂ O ₃ ) <0.18, 30 ≦ porosity (%) ≦ 55
(23) 0.18 ≦ (Ti / Al ₂ O ₃ ) <0.27, 30 ≦ porosity (%) ≦ 60
(24) 0.27 ≦ (Ti / Al ₂ O ₃ ) <0.4, 35 ≦ porosity (%) ≦ 65
(25) 0.4 ≦ (Ti / Al ₂ O ₃ ) <0.53, 35 ≦ porosity (%) ≦ 70
(26) 0.53 ≦ (Ti / Al ₂ O ₃ ) <0.77, 40 ≦ porosity (%) ≦ 70
(27) 0.77 ≦ (Ti / Al ₂ O ₃ ) <1, 45 ≦ porosity (%) ≦ 75
(28) 1 ≦ (Ti / Al ₂ O ₃ ) <1.4, 50 ≦ porosity (%) ≦ 75
(29) 1.4 ≦ (Ti / Al ₂ O ₃ ) ≦ 2, 55 ≦ porosity (%) ≦ 80
[0086]
(30) 0.14 ≦ (Ti / Al ₂ O ₃ ) <0.18, 35 ≦ porosity (%) ≦ 45
(31) 0.18 ≦ (Ti / Al ₂ O ₃ ) <0.27, 35 ≦ porosity (%) ≦ 55
(32) 0.27 ≦ (Ti / Al ₂ O ₃ ) <0.4, 40 ≦ porosity (%) ≦ 60
(33) 0.4 ≦ (Ti / Al ₂ O ₃ ) <0.53, 40 ≦ porosity (%) ≦ 65
(34) 0.53 ≦ (Ti / Al ₂ O ₃ ) <0.77, 45 ≦ porosity (%) ≦ 65
(35) 0.77 ≦ (Ti / Al ₂ O ₃ ) <1, 50 ≦ porosity (%) ≦ 70
(36) 1 ≦ (Ti / Al ₂ O ₃ ) <1.4, 55 ≦ porosity (%) ≦ 75
(37) 1.4 ≦ (Ti / Al ₂ O ₃ ) ≦ 2, 60 ≦ porosity (%) ≦ 75
According to the method for producing a composite material of the present invention described above, the composite material has a large or complex shape, a fine microstructure, and a fine microstructure. Thus, a composite material having excellent material properties due to the above can be produced very easily. In addition, since near-net shaping can be performed in consideration of the shape of the final product, machining processing is unnecessary in subsequent steps. Furthermore, since the preparation of the aluminide intermetallic compound, which is a pretreatment step, is not necessary, the reduction of the manufacturing cost can be easily achieved.
[0088]
DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific results of the present invention will be described below.
(Methods for measuring and evaluating various physical properties)
[Open porosity]:
A sample having a predetermined shape was cut out from the measurement target and measured by the Archimedes method.
[0089]
[4-point bending strength]:
A sample having a predetermined shape was cut out from the measurement target, and the measurement was performed by performing a four-point bending test according to JIS R1601.
[0090]
[Young's modulus]:
A sample having a predetermined shape was cut out from the obtained composite material, and a Young's modulus was measured by performing a four-point bending test according to JIS R1601.
[0091]
[Fracture toughness value]:
From the obtained composite material, a sample having a predetermined shape into which a notch was introduced was prepared, a four-point bending test strength was measured, and a fracture toughness value was calculated according to a chevron notch method.
[0092]
[Permeability]:
It was calculated according to the following equation (7).
[0093]
(Equation 7)
Permeability (%) = 100 x permeation distance / maximum permeation distance (7)
(However, the “penetration distance” is a distance (excluding the inner diameter of the hole) that aluminum (Al) has actually permeated, and refers to a distance excluding a portion with many pores observed in a non-penetrated region. "Maximum penetration distance" refers to the distance from the end of the hole to the end of the mixed material filled in the reaction vessel.)
[0094]
[Void ratio]:
The porosity before impregnation was calculated according to the following equation (8) by measuring the amount of mixture and the thickness of the sample after molding. The porosity after impregnation was calculated according to the following equation (8) by measuring the amount of mixture and the thickness of the sample after impregnation.
[0095]
(Equation 8)

(However, V _pore Is the void volume, V _D Is the volume of the dispersant, V _{Metal powder} Indicates the volume of the metal powder)
[0096]
[Evaluation of permeability]:
“◎” when the permeability is 100%, “○” when the permeability is 85% or more, “△” when the permeability is 60% or more, and “△” when the permeability is less than 60%. It was evaluated as "x".
[0097]
[Evaluation of Denseness]:
“◎” indicates that the open porosity is 0.1% or less, “」 ”indicates that the open porosity is 0.5% or less, and“ △ ”indicates that the open porosity is less than 1.0%. The case where the open porosity was 1.0% or more was evaluated as “x”.
[0098]
(Example 1)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle diameter of about 10 μm, and aluminum (Al) to be melt-impregnated (commercially pure Al (A1050, purity> 99.5%)) were prepared. Next, titanium (Ti) powder and Al ₂ O ₃ The particles are (Ti / Al ₂ O ₃ ) Blending was performed so that the value of the volume ratio was 0.53, and mixing was performed using a V-type mixer. The mixed material obtained by the mixing was filled in a carbon container having an inner diameter of 50 mmφ, and compression-molded in a shape conforming to the shape to obtain a molded body having a porosity of about 49%. Next, a carbon lid member having a hole (pouring spout) with an inner diameter of 10 mmφ is placed on the upper surface of the molded body, and the carbon lid member is fixed with a carbon container placed outside the molded body. Aluminum (Al) (solid) was arranged so that the molten aluminum (Al) flowed in. Aluminum (Al) melted by heating to 700 ° C. under a vacuum atmosphere of 0.013 Pa or less was impregnated with no pressure, and after holding for about 1 hour, was gradually cooled to produce a composite material (Example 1). After the obtained composite material was cut and polished, its cross section was observed with an optical microscope. As a result, it was found that aluminum (Al) was well impregnated to the end in a shape along the space surrounded by the container and the lid member. Was. Table 2 shows the measurement results of the open porosity (%) and the four-point bending strength.
[0099]
(Comparative Example 1)
A composite material was manufactured by the same operation as in Example 1 except that the entire upper surface of the molded body was melt-impregnated without using the lid member (Comparative Example 1). Table 2 shows the measurement results of the open porosity (%), the density, and the four-point bending strength.
[0100]
(Comparative Example 2)
Using a hot press (HP) method, a composite material was manufactured by pressure impregnation of molten aluminum (Al). That is, a composite material was produced by the same operation as in Example 1 except that no lid member was used and a pressure of about 30 MPa was applied during the pressure impregnation of aluminum (Al) (Comparative Example 2). Table 2 shows the measurement results of the open porosity (%), the density, and the four-point bending strength.
[0101]
[Table 2]

From the results shown in Table 2, by fixing the molded body with the lid member (Example 1), the gaps inside the molded body were impregnated with molten aluminum (Al) without pressure, and the densification was spontaneously performed. It was found to be promoted. Further, when the spontaneous infiltration phenomenon of aluminum (Al) utilizing the heat of reaction is caused as in Example 1, the forced densification by the HP method shown in Comparative Example 2 is performed. The open porosity was equivalent to that of. For this reason, the composite material of Example 1 had a higher density than the composite material of Comparative Example 1, and the denseness was improved even when comparing the open porosity. Regarding the four-point bending strength, the composite materials of Comparative Examples 1 and 2 were about 200 MPa, whereas the composite material of Example 1 was as high as 400 MPa or more. This is considered to be due to a decrease in closed pores inside the composite material and an increase in interfacial strength between the dispersant and the matrix. Therefore, according to the present invention, it is possible to produce a more densified composite material by utilizing the spontaneous internal energy generated between the constituent elements. It is thought to contribute.
[0103]
(Examples 2 to 29, Comparative Examples 3 to 7)
Al having an average particle size shown in Table 3 ₂ O ₃ Particles, titanium (Ti) powder, and aluminum (Al) to be melt-impregnated (commercially pure Al (A1050, purity> 99.5%)) were prepared. Next, titanium (Ti) powder and Al ₂ O ₃ The particles are (Ti / Al ₂ O ₃ ) The mixture was blended so that the value of the volume ratio became the value shown in Table 3, and the mixture was performed by a V-type mixer. The mixed material obtained by mixing was filled in a carbon container having an inner diameter of 50 mmφ, and compression-molded in a shape conforming to the shape to obtain a molded body having a porosity shown in Table 3. Next, a carbon lid member having a hole having an inner diameter of 10 mmφ is placed on the upper surface of the molded body, and the carbon lid member is fixed in a carbon container placed outside the carbon lid member. Aluminum (Al) (solid) was arranged so that Al) flowed in. Heating up to 700 ° C. in a vacuum atmosphere of 0.013 Pa or less and impregnating the molten aluminum (Al) without pressure, holding for about 1 hour, and then gradually cooling to produce a composite material (Examples 2 to 29, Comparative Examples 3 to 7). Table 3 shows the evaluation results of the permeability and the denseness.
[0104]
[Table 3]

From the results shown in Table 3, (Ti / Al ₂ O ₃ It was found that even if the value of the volume ratio was large, the permeability of aluminum (Al) was reduced when the porosity was small to some extent. In addition, (Ti / Al ₂ O ₃ It was found that when the value of the volume ratio was small, the amount of titanium (Ti) powder serving as the impregnating driving force was too small, and the open porosity of the obtained composite material increased. Therefore, a composite material having a dense microstructure is referred to as (Ti / Al ₂ O ₃ It has been found that by defining the relationship between the value of the volume ratio and the porosity, it is possible to manufacture it suitably.
[0106]
(Examples 30 to 35)
Al ₂ O ₃ The average particle diameter of the particles is about 47 μm, the average particle diameter of the titanium (Ti) powder is about 10 μm, and (Ti / Al ₂ O ₃ ) A composite material was produced by the same operation as in Examples 2 to 29 except that the value of the volume ratio and the porosity were set to the values shown in Table 4 (Examples 30 to 35). Table 4 shows the analysis results of the matrix composition and the measurement results of the permeability, open porosity, four-point bending strength, Young's modulus, and fracture toughness value. 5 to 8 show scanning electron micrographs (magnification × 100, × 500) showing the microstructure of the composite material of Example 30 and scanning electron micrographs (magnification ××) showing the microstructure of the composite material of Example 34. 100, × 500). In Table 4, among the "porosity", "before impregnation" means the porosity calculated from the thickness of the molded body after molding, and "after impregnation" refers to the composite material obtained after impregnation. It means the actual porosity calculated from the thickness.
[0107]
(Comparative Examples 8 and 9)
Al with an average particle size of 47 μm serving as a dispersion material ₂ O ₃ The particles were pressure-formed with a uniaxial press at a pressure of about 80 MPa to produce a formed body. The molded body was preheated to 760 ° C. in the atmosphere and placed in a mold preheated to 500 ° C. Thereafter, commercially available pure aluminum (Al) (A1050) melted at 850 ° C. was placed in a mold and impregnated under a pressure of 50 MPa to produce a composite material (Comparative Example 8). As Comparative Example 9, an Al alloy (A5052 (Al-2.5% Mg (mass%))) was prepared. Table 4 shows the measurement results of the physical properties of the obtained composite material.
[0108]
(Comparative Examples 10 and 11)
Al with an average particle size of 47 μm serving as a dispersion material ₂ O ₃ Particles and titanium (Ti) powder having an average particle diameter of 45 μm are mixed with (Ti / Al ₂ O ₃ ) After compounding so that the value of the volume ratio would be 1.0, it was press-formed at a pressure of about 100 MPa with a uniaxial press machine to produce a formed body having a diameter of 34 mmφ x 6 mm and a porosity of about 30%. The molded body was immersed in an aluminum (Al) alloy (A5052) melted by heating to 850 ° C. in a vacuum atmosphere of 0.013 Pa or less, and the molten aluminum (Al) alloy was not added to the molded body. A composite material was produced by pressure impregnation (Comparative Example 10). Also, Al ₂ O ₃ Instead of the particles, SiC particles having an average particle diameter of about 50 μm are used as a dispersant, and blended so that the value of the (Ti / SiC) volume ratio becomes 1.0, and a porosity of about 34% in diameter of 34 mmφ × 7.5 mm is used. A composite material was produced in the same manner as in Comparative Example 10 except that the molded article was produced and used (Comparative Example 11). Table 4 shows the measurement results of the physical properties of the obtained composite material. 9 and 10 show scanning electron micrographs (magnification × 100, × 500) showing the microstructure of the composite material of Comparative Example 10.
[0109]
[Table 4]

From the results shown in Table 4, within a predetermined range (Ti / Al ₂ O ₃ ) When the value of the volume ratio was changed (Examples 30 to 35), a composite material having a permeability of 100% could be produced. However, (Ti / Al ₂ O ₃ ) When the value of the volume ratio was reduced to 0.10, an increase in open porosity was confirmed because the amount of Ti powder as the impregnation driving force was reduced. 5 to 8, (Ti / Al ₂ O ₃ ) By changing the value of the volume ratio, the Al ₂ O ₃ It was found that the particle volume ratio and the matrix composition (aluminide intermetallic compound and Al phase) could be controlled. In contrast, the composite material of Comparative Example 8 was made of Al ₂ O ₃ Only by controlling the particle volume fraction was the property of the composite material controlled. For this reason, when compared with the method of Comparative Example 8, the method of the example could control various material properties by controlling the quantitative ratio of each phase.
In particular, the aluminide intermetallic compound has a higher stiffness than aluminum (Al), but a lower fracture toughness. In the present invention, as shown in Table 4, (Ti / Al ₂ O ₃ By decreasing the value of the volume ratio, it is possible to increase the content of aluminum (Al), which can act as a fracture resistance during crack propagation, in the matrix to produce a composite material having a significantly improved fracture toughness value. did it. Also, regarding Young's modulus, Al ₂ O ₃ Since the matrix contains an aluminide intermetallic compound in addition to the particles, the matrix of Comparative Example 8 was prepared by a pressure impregnation method comprising only aluminum (Al), and the matrix of Comparative Example 9 was made of aluminum. It was higher than that of the (Al) alloy and showed a value of about 200 GPa.
The composite materials of Comparative Examples 10 and 11 are obtained by immersing a molded body composed of a dispersant and titanium (Ti) powder in a molten aluminum (Al) alloy, as shown in FIG. Pressureless impregnation was possible. However, the microstructure (FIG. 9) of the composite material in which the value of the volume ratio of (Ti / ceramics) is 1.0 in Comparative Example 10 (FIG. 9) is Examples 30 and 34 in which the amount of titanium (Ti) is further reduced. In comparison with the microstructure of the composite material (FIG. 5 and FIG. 7) in which the (Ti / ceramics) volume ratio values of 0.53 and 0.14 are ₂ O ₃ The particle volume ratio was reduced, and the amount of aluminum (Al) contained in the matrix became excessive, so that the particle volume ratio and the matrix composition after impregnation did not reach the initially intended values (Table 4). It is considered that this is because, due to the heat generated during the impregnation, the molded body expanded so as to be expanded, whereby excessive molten aluminum (Al) was supplied, and the porosity changed significantly. Therefore, although the composite materials of Comparative Examples 10 and 11 were produced by pressureless impregnation, it was difficult to control the particle volume ratio and the matrix composition. On the other hand, in the composite materials of Examples 30 to 35, the compact was fixed at the time of impregnation, and (Ti / Al ₂ O ₃ ) Since the value of the volume ratio and the porosity are defined in a suitable relationship, the composite material has a desired material composition and a dense microstructure.
[0113]
(Examples 36 to 62)
The dispersing material (ceramic particles) shown in Table 5 and the titanium (Ti) powder were blended so that the value of the (Ti / ceramics) volume ratio became the value shown in Table 5, and mixed by a V-type mixer. . The mixed material obtained by mixing was filled into a carbon container having an inner diameter of 50 mmφ, and compression-molded in a shape conforming to the shape to obtain a molded body having a porosity shown in Table 5. Next, a carbon lid member having a hole having an inner diameter of 10 mmφ is placed on the upper surface of the molded body, and the carbon lid member is fixed by a carbon container placed outside the carbon lid member. Aluminum (Al) or an aluminum (Al) alloy (both solid) was arranged so that Al) (A1050) or an aluminum (Al) alloy (A5052) flowed in. Aluminum (Al) (A1050) or aluminum (Al) alloy (A5052) melted by heating to 700 ° C. under a vacuum atmosphere of 0.013 Pa or less or 13 Pa or less is impregnated with no pressure, and gradually held after holding for about 1 hour. Upon cooling, a composite material was produced (Examples 36 to 62). Table 5 shows the evaluation results of the permeability and the denseness.
[0114]
[Table 5]

As is clear from the results shown in Table 5, as the dispersing materials, SiC as a carbide, AlN and Si as a nitride were used as dispersants. ₃ N ₄ In the case where was used, a composite material could be produced. In addition, even when the impregnation atmosphere was set to a low vacuum (13 Pa or less) at a level evacuated by a RP (rotary pump) that is in a roughing state, the impregnation was satisfactory. In addition, when an aluminum (Al) alloy is used, in a low vacuum (13 Pa or less) where the value of the volume ratio of (Ti / ceramics) is low and oxidation of aluminum (Al) and titanium (Ti) is concerned. Also, a composite material having a dense microstructure was able to be manufactured. This is probably because magnesium (Mg) contained in the aluminum (Al) alloy had an effect of reducing an oxide film formed on the aluminum (Al) surface.
[0116]
(Examples 63 to 69)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle size of about 10 μm, and aluminum (Al) (A1050) to be melt-impregnated. ₂ O ₃ ) Composite materials were produced by the same operation as in Examples 2 to 29 with the values of the volume ratio and the porosity of the mixed material (molded product) shown in Table 6 (Examples 63 to 69). The maximum penetration distance of the aluminum (Al) to be melt-impregnated was 100 mm, and the inner diameter of the hole was 20 mm. Table 6 shows the measurement results of the permeability.
[0117]
[Table 6]

As is clear from the results shown in Table 6, in particular, (Ti / Al ₂ O ₃ It was found that when the value of the volume ratio was small, the permeability increased. In addition, (Ti / Al ₂ O ₃ ) If the value of the volume ratio is large, increasing the porosity can be achieved by (Ti / Al ₂ O ₃ It has been found that lowering the porosity when the value of the volume ratio is small is effective for improving the permeability.
[0119]
(Examples 70 to 73, Comparative Examples 12 and 13)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle size of about 10 μm, and aluminum (Al) (A1050) to be melt-impregnated. ₂ O ₃ ) A composite material was manufactured by the same operation as in Examples 2 to 29, except that the value of the volume ratio was 0.27 and the porosity of the mixed material (molded product) was 48% (Examples 70 to 73). The maximum penetration distance of the aluminum (Al) to be melt-impregnated was fixed at 100 mm. Table 7 shows the evaluation results of the permeability. The “permeability evaluation” in Table 7 refers to whether the obtained composite material was cut, its cross section was polished, and then subjected to optical microscope and SEM observation to determine whether or not the permeation had progressed uniformly in the mixed material. Are the results of evaluation by observing.
[0120]
[Table 7]

As is apparent from the results shown in Table 7, when X / Y was set to 0.08 to 0.4, no unimpregnated portion was generated, but X / Y was set to 0.08 to 0.08. When it was less than the above, an unimpregnated portion occurred. Further, it was found that when X / Y was more than 0.4, the denseness of the obtained composite material was reduced.
[0122]
(Example 74)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle diameter of about 10 μm, and an aluminum (Al) alloy (A5052) to be melt-impregnated were prepared. Next, titanium (Ti) powder and Al ₂ O ₃ The particles are (Ti / Al ₂ O ₃ ) Mixing was performed so that the value of the volume ratio was 0.27, and mixing was performed using a V-type mixer. The mixed material obtained by the mixing was filled in a carbon container having an inner diameter of 100 mmφ, and compression-molded in a shape conforming to the shape to obtain a molded body having a thickness of 30 mm and a porosity of 48.1%. Next, a lid member made of high-density carbon having seven holes (20 mmφ) is placed on the upper surface of the molded body, and an aluminum (Al) alloy is applied so that the molten aluminum (Al) alloy flows into these holes. Placed. An aluminum (Al) alloy melted by heating to 800 ° C. in a vacuum atmosphere of 0.013 Pa or less was impregnated without pressure, and after holding for about 1 hour, gradually cooled to produce a composite material (Example 74).
After the obtained composite material was cut and its cross section was polished, it was confirmed by an optical microscope and SEM observation. As a result, no pores were confirmed and the permeability in the mixed material was very good. there were. Therefore, it was confirmed that a good composite material could be obtained even when the impregnation with aluminum (Al) was performed not only through one hole but also through a plurality of holes.
[0124]
(Example 75)
A composite material was produced in the same manner as in Example 1, except that the mixed material was additionally filled in the lower portion inside the hole that contacts the molded body (Example 75). As a result, it was possible to produce a composite material that was more structurally homogeneous without forming a non-uniform structure in which aluminum (Al) was excessively impregnated at a portion corresponding to immediately below the hole.
[0125]
(Examples 76 to 79)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle diameter of about 10 μm, and an aluminum (Al) alloy (A5052) to be melt-impregnated were prepared. Next, titanium (Ti) powder and Al ₂ O ₃ The particles are (Ti / Al ₂ O ₃ ) Mixing was performed so that the value of the volume ratio was 0.27, and mixing was performed using a V-type mixer. As shown in FIG. 11, the mixed material obtained by mixing was a SUS316 mold having an inner dimension of 100 mm in length × 100 mm in width and a carbon material 22 made of high-density carbon installed on the inner wall thereof. The container 30 was filled with the mixed material. Thereafter, compression molding was performed in a shape conforming to the above-mentioned shape to obtain a molded body having a thickness of 30 mm and a porosity of 48.1%. Next, a lid member made of high-density carbon having seven holes (20 mmφ) and four holes (10 mmφ) is placed on the upper surface of the molded body, and a molten aluminum (Al) alloy flows into these holes. (Al) alloy is arranged as described above. An aluminum (Al) alloy melted by heating to 800 ° C. in a vacuum atmosphere of 0.013 Pa or less was impregnated without pressure, and after holding for about 1 hour, gradually cooled to produce a composite material (Example 76). In addition, (Ti / Al ₂ O ₃ ) A composite material was produced in the same manner as in Example 76 except that the value of the volume ratio was set to 0.18, 0.40, or 0.53 (Examples 77 to 79). As a result, it was found that the manufactured composite material was easily detached from the carbon material 22 after disassembling the mold container 30 made of SUS316, and was extremely excellent in releasability from the reaction container.
[0126]
(Example 80)
Except for using a mold container 30 having a length of 100 mm x a width of 100 mm, a bottom having an uneven shape, and a carbon material 22 made of high-density carbon on its inner wall as shown in FIG. A composite material was produced in the same manner as in Example 78 (Example 80). As a result, it was possible to produce a composite material having a complicated shape, which was excellent in releasability from the reaction vessel.
[0127]
(Example 81)
Al with an average particle size of about 47 μm ₂ O ₃ Particles, titanium (Ti) powder having an average particle diameter of about 10 μm, and an aluminum (Al) alloy (A5052) to be melt-impregnated were prepared. Next, titanium (Ti) powder and Al ₂ O ₃ The particles are (Ti / Al ₂ O ₃ ) Mixing was performed so that the value of the volume ratio was 0.27, and mixing was performed using a V-type mixer. The mixed material obtained by mixing is filled into a SUS316 mold container having an inner diameter of 300 mmφ and high-density carbon provided on the inner wall, and compression-molded in a shape conforming to the shape, and a thickness of 30 mm and a porosity of 48.1%. Molded article. Next, a lid member made of high-density carbon having 61 holes (20 mmφ) and 12 holes (15 mmφ) is placed on the upper surface of the molded body, and the green compact is fixed in a container at the outer peripheral portion. The aluminum (Al) alloy was arranged such that the molten aluminum (Al) alloy flowed into these holes. In a vacuum atmosphere of 1.3 Pa or less, heat treatment is performed at 600 ° C. for 1 hour, and then heated to 800 ° C. to impregnate the molten aluminum (Al) alloy without pressure. Upon cooling, a large composite material was produced (Example 81).
The obtained composite material of 300 mmφ × 30 mm was arbitrarily cut, and each cut surface was observed. As a result, it was found that the composite material was almost in good condition, and remarkable pores were confirmed in any of the cut portions. Did not. Therefore, according to the present invention, it was confirmed that a large-sized composite material, which was difficult in the conventional manufacturing process requiring high pressure, can be manufactured without pressure impregnation.
[0129]
(Example 82)
Example 2 except that a lid member (container element 1b) made of carbon having a hole 10 formed by an annular member 15 made of porous carbon, which is a material easily broken by low stress, as shown in FIG. A composite material was manufactured by the same operation as in Example 81 (Example 82).
As a result, at the time of slow cooling after the aluminum (Al) melt impregnation, the aluminum (Al) remaining inside the holes and having shrinkage resistance destroyed the annular member 15 due to the heat shrinkage of the composite material. There was no such a problem that a crack was generated at a portion corresponding to immediately below the hole of the obtained composite material.
[0131]
(Example 83)
As shown in FIG. 13, the internal dimensions are 100 mm long × 100 mm wide × 60 mm deep, a plurality of holes 10 on the upper part, and a slope inclined from the upper side to the lower side of the reaction vessel 1 on the side. A composite material was produced by the same operation as in Example 76 except that the reaction vessel 1 having the shape of the runner 23 and the plurality of second holes 20 communicating with the runner 23 was used (Example 83). . As a result, it was possible to produce a composite material having a fine microstructure up to its end, despite its thickness.
[0132]
(Example 84)
A composite material was manufactured by the same operation as in Example 76 except that the reaction vessel 1 having a bent and complicated internal shape as shown in FIG. 14 was used (Example 84). As a result, a composite material 5 having a complicated shape could be manufactured.
[0133]
As described above, in the composite material of the present invention, a mixed material containing a predetermined metal powder and a dispersing material is filled in a predetermined reaction vessel, and the mixed material is fixed to a predetermined reaction vessel. Aluminum (Al) is melt-impregnated into the voids inside the mixed material via the pores and the dispersing material is dispersed in the matrix, so that a dense microstructure is easily formed. In addition, the manufacturing cost is reduced.
Further, according to the method for producing a composite material of the present invention, a mixed material containing a predetermined metal powder and a dispersing material is filled in a predetermined reaction vessel, and fixed in a predetermined hole. In order to produce a composite material in which the gap inside the mixed material is melt-impregnated with aluminum (Al) via a vial and a dispersant is dispersed in a matrix, the number of production steps is reduced and the desired final shape is obtained. In particular, it is possible to easily produce a composite material having a large and complicated shape and a dense microstructure.
[Brief description of the drawings]
FIG. 1 is a schematic view illustrating an example of a method for producing a composite material according to the present invention.
FIG. 2 is a schematic diagram illustrating an example of a conventional method for producing a composite material.
FIG. 3 is a schematic view illustrating another example of the method for producing a composite material according to the present invention.
FIG. 4 is a schematic view illustrating still another example of the method for producing a composite material according to the present invention.
FIG. 5 is a scanning electron micrograph (× 100) showing the microstructure of the composite material of Example 30.
FIG. 6 is a scanning electron micrograph (× 500 magnification) showing the microstructure of the composite material of Example 30.
FIG. 7 is a scanning electron micrograph (× 100) showing the microstructure of the composite material of Example 34.
FIG. 8 is a scanning electron micrograph (× 500) showing the microstructure of the composite material of Example 34.
FIG. 9 is a scanning electron micrograph (× 100) showing the microstructure of the composite material of Comparative Example 10.
10 is a scanning electron micrograph (magnification: 500) showing the microstructure of the composite material of Comparative Example 10. FIG.
FIG. 11 is a schematic view illustrating still another example of the method for producing a composite material according to the present invention.
FIG. 12 is a schematic view illustrating still another example of the method for producing a composite material according to the present invention.
FIG. 13 is a schematic view illustrating still another example of the method for producing a composite material according to the present invention.
FIG. 14 is a schematic view illustrating still another example of the method for producing a composite material according to the present invention.
[Explanation of symbols]
1a, 1b: container element, 1: reaction vessel, 2 ... mixed material, 3 ... void, 4 ... aluminum (Al), 5 ... composite material, 6 ... matrix, 7 ... dispersing material, 8 ... screw part, 10 ... hole , 15 ... annular member, 20 ... second hole, 21 ... outer insert, 22 ... carbon material, 23 ... runner, 24 ... fixing bolt, 25 ... space forming area, 30 ... mold container.

Claims (25)

A reaction vessel is filled with a mixed material containing a metal powder capable of causing a self-combustion reaction by being brought into contact with aluminum (Al) and a dispersant, and the aluminum (Al) is filled in a void inside the mixed material. Is a composite material formed by dispersing a dispersant in a matrix by melt impregnation of
As the reaction vessel, using a reaction vessel composed of two or more container elements, and configured to form a space filled with the mixed material by combining the container elements, the mixed material is one or more of the Filling the space (space forming region) forming the space of the container element,
One or more of the container elements are united in a state where the mixed material filled in the space forming region is fixed in a predetermined shape, and the container material is passed through one or more holes formed in an upper portion of the reaction container. The aluminum (Al) is melt-impregnated into voids inside the mixed material, and the aluminide intermetallic compound is generated by a self-combustion reaction between the metal powder and the aluminum (Al). A composite material characterized by being dispersed. The composite material according to claim 1, wherein a ratio of the aluminum (Al) contained in the matrix to the whole of the matrix is 60% by mass or less. The composite material according to claim 1, wherein the metal powder is a powder made of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni), and niobium (Nb). The composite material according to any one of claims 1 to 3, wherein the hole is formed by an annular member having a stress buffering effect. The composite material according to any one of claims 1 to 4, wherein a lower portion inside the hole is filled with the mixed material. The value (X / Y) of the ratio of the inside diameter (X) of the hole to the maximum penetration distance (Y) of the melt-impregnated aluminum (Al) is 0.06 to 0.5. The composite material according to any one of the above. The composite material according to any one of claims 1 to 6, wherein a ratio (volume ratio) of the dispersant to the entire composite material is 10 to 70% by volume. The composite material according to any one of claims 1 to 7, wherein the dispersant is an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers. Wherein the inorganic _material, Al ₂ O 3, AlN, composite material according to claim 8 is at least one selected from the group consisting of SiC, and _Si 3 _{N 4.} The composite material according to any one of claims 1 to 9, wherein a ratio (%) of an average particle size of the metal powder to an average particle size of the dispersant is 5 to 80%. A reaction vessel is filled with a mixed material containing a metal powder capable of causing a self-combustion reaction by being brought into contact with aluminum (Al) and a dispersant, and the aluminum (Al) is filled in a void inside the mixed material. Is a method for producing a composite material in which a dispersant is dispersed in a matrix by melt-impregnating
As the reaction vessel, using a reaction vessel composed of two or more container elements, and configured to form a space filled with the mixed material by combining the container elements, the mixed material is one or more of the Filling the space (space forming region) forming the space of the container element,
One or more of the container elements are united in a state where the mixed material filled in the space forming region is fixed in a predetermined shape, and the container material is passed through one or more holes formed in an upper portion of the reaction container. The aluminum (Al) is melt-impregnated into voids inside the mixed material, and the aluminide intermetallic compound is generated by a self-combustion reaction between the metal powder and the aluminum (Al). A method for producing a composite material, wherein a composite material obtained by dispersing the composite material is obtained. The method according to claim 11, wherein the metal powder is a powder made of at least one metal selected from the group consisting of titanium (Ti), nickel (Ni), and niobium (Nb). When the metal powder is titanium (Ti) powder,
The production of the composite material according to claim 11 or 12, wherein a mass ratio (Al: Ti) of the aluminum (Al) and the titanium (Ti) powder to be melt-impregnated is 1: 0.17 to 1: 0.57. Method. When the metal powder is nickel (Ni) powder,
The composite material according to claim 11 or 12, wherein a mass ratio (Al: Ni) of the aluminum (Al) to be melt-impregnated and the nickel (Ni) powder is 1: 0.20 to 1: 0.72. Production method. When the metal powder is niobium (Nb) powder,
The composite material according to claim 11 or 12, wherein a mass ratio (Al: Nb) of the aluminum (Al) to be melt-impregnated and the niobium (Nb) powder is 1: 0.27 to 1: 1.13. Production method. The method for producing a composite material according to any one of claims 11 to 15, wherein the hole is formed by an annular member having a stress buffering effect. The method for producing a composite material according to any one of claims 11 to 16, wherein the mixed material is filled in a lower portion inside the hole. The value (X / Y) of the ratio of the inside diameter (X) of the hole to the maximum penetration distance (Y) of the aluminum (Al) to be melt-impregnated is 0.06 to 0.5. A method for producing the composite material according to any one of the preceding claims. The method for producing a composite material according to any one of claims 11 to 18, wherein the dispersant is an inorganic material having at least one shape selected from the group consisting of fibers, particles, and whiskers. Wherein the inorganic _{material, Al 2 O 3, AlN,} SiC, and a manufacturing method of a composite material according to claim 19 _Si 3 _N is at _least one ₄ is selected from the group consisting of. The method for producing a composite material according to any one of claims 11 to 20, wherein a ratio (%) of an average particle size of the metal powder to an average particle size of the dispersant is 5 to 80%. 22. The method for producing a composite material according to claim 11, wherein the reaction vessel has at least an inner wall made of a carbon material. The reaction vessel further includes, on its side, a slope-shaped runner inclined downward from above the reaction vessel, and one or more second holes communicating with the runner. The method for producing a composite material according to any one of claims 11 to 22, wherein the aluminum (Al) is melt-impregnated into voids inside the mixed material via each of the second holes independently. When the metal powder is titanium (Ti) powder, and the dispersant is particles (ceramic particles) of at least one ceramic selected from the group consisting of AlN, Si, and Si ₃ N ₄ ,
The value of the ratio of the volume of the titanium (Ti) powder to the volume of the ceramic particles (Ti / ceramics), and the ratio of the voids (porosity (%)) to the volume of the space of the reaction vessel are: The method for producing a composite material according to any one of claims 11 to 23, which satisfies one of the following relationships (1) to (6).
(1) 0.1 ≦ (Ti / ceramics) <0.14, 25 ≦ porosity (%) ≦ 60
(2) 0.14 ≦ (Ti / ceramics) <0.27, 25 ≦ porosity (%) ≦ 70
(3) 0.27 ≦ (Ti / ceramics) <0.53, 25 ≦ porosity (%) ≦ 75
(4) 0.53 ≦ (Ti / ceramics) <1, 30 ≦ porosity (%) ≦ 75
(5) 1 ≦ (Ti / ceramics) <1.4, 45 ≦ porosity (%) ≦ 80
(6) 1.4 ≦ (Ti / ceramics) ≦ 2, 50 ≦ porosity (%) ≦ 80 When the metal powder is titanium (Ti) powder and the dispersant is Al ₂ O ₃ particles,
The value of the ratio of the volume of the titanium (Ti) powder to the volume of the Al ₂ O ₃ particles (Ti / Al ₂ O ₃ ), and the ratio (porosity (porosity) of the voids to the volume of the space of the reaction vessel %)) Satisfies one of the following relationships (7) to (12): The method for producing a composite material according to any one of claims 11 to 23.
(7) 0.1 ≦ (Ti / Al ₂ O ₃ ) <0.14, 25 ≦ porosity (%) ≦ 60
(8) 0.14 ≦ (Ti / Al ₂ O ₃ ) <0.27, 25 ≦ porosity (%) ≦ 70
(9) 0.27 ≦ (Ti / Al ₂ O ₃ ) <0.53, 25 ≦ porosity (%) ≦ 75
(10) 0.53 ≦ (Ti / Al ₂ O ₃ ) <1, 30 ≦ porosity (%) ≦ 75
(11) 1 ≦ (Ti / Al ₂ O ₃ ) <1.4, 45 ≦ porosity (%) ≦ 80
(12) 1.4 ≦ (Ti / Al ₂ O ₃ ) ≦ _2, 50 ≦ porosity (%) ≦ 80

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