JPH035371A - Production of si3n4 sintered compact - Google Patents
Production of si3n4 sintered compactInfo
- Publication number
- JPH035371A JPH035371A JP1137363A JP13736389A JPH035371A JP H035371 A JPH035371 A JP H035371A JP 1137363 A JP1137363 A JP 1137363A JP 13736389 A JP13736389 A JP 13736389A JP H035371 A JPH035371 A JP H035371A
- Authority
- JP
- Japan
- Prior art keywords
- powder
- si3n4
- strength
- weight
- powder mixture
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 239000000843 powder Substances 0.000 claims abstract description 19
- 229910052596 spinel Inorganic materials 0.000 claims abstract description 8
- 239000011029 spinel Substances 0.000 claims abstract description 8
- 239000012299 nitrogen atmosphere Substances 0.000 claims abstract 2
- 239000011812 mixed powder Substances 0.000 claims description 5
- RUDFQVOCFDJEEF-UHFFFAOYSA-N yttrium(III) oxide Inorganic materials [O-2].[O-2].[O-2].[Y+3].[Y+3] RUDFQVOCFDJEEF-UHFFFAOYSA-N 0.000 abstract description 23
- 229910052581 Si3N4 Inorganic materials 0.000 abstract description 21
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 abstract description 10
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 abstract description 10
- 239000000203 mixture Substances 0.000 abstract description 10
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum oxide Inorganic materials [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 abstract description 7
- KTUFCUMIWABKDW-UHFFFAOYSA-N oxo(oxolanthaniooxy)lanthanum Chemical compound O=[La]O[La]=O KTUFCUMIWABKDW-UHFFFAOYSA-N 0.000 abstract description 7
- 238000005245 sintering Methods 0.000 abstract description 7
- FIXNOXLJNSSSLJ-UHFFFAOYSA-N ytterbium(III) oxide Inorganic materials O=[Yb]O[Yb]=O FIXNOXLJNSSSLJ-UHFFFAOYSA-N 0.000 abstract description 7
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 abstract 2
- 229910052593 corundum Inorganic materials 0.000 abstract 2
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 2
- 235000019402 calcium peroxide Nutrition 0.000 abstract 1
- 239000002994 raw material Substances 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 239000011521 glass Substances 0.000 description 12
- 239000012071 phase Substances 0.000 description 12
- 230000000694 effects Effects 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 5
- 238000010304 firing Methods 0.000 description 5
- 238000002425 crystallisation Methods 0.000 description 4
- 230000008025 crystallization Effects 0.000 description 4
- 230000006866 deterioration Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 229910052747 lanthanoid Inorganic materials 0.000 description 3
- 150000002602 lanthanoids Chemical class 0.000 description 3
- 239000007791 liquid phase Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 239000012752 auxiliary agent Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910005091 Si3N Inorganic materials 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000005238 degreasing Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 229910000311 lanthanide oxide Inorganic materials 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000013001 point bending Methods 0.000 description 1
- 238000003303 reheating Methods 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000004017 vitrification Methods 0.000 description 1
- 230000004580 weight loss Effects 0.000 description 1
Landscapes
- Ceramic Products (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、高温高強度を要求される構造材料に用いられ
るＳｉ３Ｎ４焼結体の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a Si3N4 sintered body used as a structural material requiring high temperature and high strength.
〔従来の技術ｌ
Ｓｉ３Ｎ４焼結体は高温強度、耐食性、耐熱衝撃性に優
れ、−５ｉＣに比較して、大きな破壊靭性をもつなど、
材料特性のバランスにすぐれた耐熱材料であり、ターボ
チャージャーのロータ、ガスタービン部材などの耐熱構
造材料として注目されている。[Conventional technology l Si3N4 sintered bodies have excellent high-temperature strength, corrosion resistance, and thermal shock resistance, and have greater fracture toughness than -5iC.
It is a heat-resistant material with excellent balance of material properties, and is attracting attention as a heat-resistant structural material for turbocharger rotors, gas turbine components, etc.
Ｓｉ３Ｎ４は共有結合性が大きいために自己拡散係数が
小さ（、難焼結材料であるため、通常、Ｙ２Ｏ３ 、Ａ
１２２Ｏａ 、Ｍ ｇ Ｏ等（７）酸化物ヲ添加し、
それらが形成する液相を利用した液相焼結法が採用され
ている。Si3N4 has a small self-diffusion coefficient due to its large covalent bonding properties (because it is a difficult-to-sinter material, it is usually
Adding (7) oxides such as 122Oa and MgO,
A liquid phase sintering method that utilizes the liquid phase they form has been adopted.
ところがこのようにして製造された焼結体は液相から生
成するガラス相が８００〜１０００℃を超えると軟化す
るため、焼結体の高温強度の劣化が認められる。However, in the sintered body produced in this manner, the glass phase generated from the liquid phase softens when the temperature exceeds 800 to 1000°C, so that the high temperature strength of the sintered body deteriorates.
この問題を解決するために、
（１）ガラス相の組成を制御してガラス相の耐熱性を上
げること、
（２）ガラス相を結晶化し耐熱性を上げること、が提案
されている。In order to solve this problem, it has been proposed to (1) increase the heat resistance of the glass phase by controlling the composition of the glass phase, and (2) increase the heat resistance by crystallizing the glass phase.
Ｓｉ３Ｎ４の助剤系として、スピネル（Ｍ ｇ Ｏ・Ａ
ｌ２２Ｏ３ ）−Ｙ２ ｏａ系は中でも高温強度にすぐ
れる系であり、特開昭６２−５９５７２号においては必
要に応じて上記組成物に０．０１〜１．０重量％のＬａ
２Ｏ３ 、ＣｅＯ２といったランタニド元素の酸化物を
添加し、１６００℃〜１７５０℃で焼成後、ガラス相を
結晶化させるために１１００〜１３５０℃で再焼成を行
い、高温強度を改善させることが提案されている。As an auxiliary agent system for Si3N4, spinel (M g O・A
The 12O3 )-Y2 oa system is a system with excellent high-temperature strength, and in JP-A-62-59572, 0.01 to 1.0% by weight of La is added to the above composition as necessary.
It has been proposed to improve high-temperature strength by adding lanthanide element oxides such as 2O3 and CeO2, firing at 1600-1750°C, and then re-firing at 1100-1350°C to crystallize the glass phase. There is.
上記熱処理によるガラス相の結晶化により高温強度はか
なり改善されるが、熱処理工程を別途設ける必要があり
、生産性が悪くかつコスト高になる。Although the high-temperature strength is considerably improved by the crystallization of the glass phase by the above-mentioned heat treatment, it is necessary to provide a separate heat treatment step, resulting in poor productivity and high cost.
本発明者らはＳｉ３Ｎ４焼結体の焼結助剤の効果、特に
スピネル−Ｙ２ ｏａ系にランタニド系酸化物を添加す
る効果について詳細に検討した結果、焼結助剤の組成を
厳密に制御することにより特開昭６２−５９５７２に示
されたような粒界相の結晶化機構でなく、高融点ガラス
化によってＳｉ３Ｎ４焼結体の高温強度特性を発現しう
ることを見出した。The present inventors have conducted detailed studies on the effects of sintering aids for Si3N4 sintered bodies, particularly the effects of adding lanthanide oxides to spinel-Y2 OA systems, and have determined that the composition of the sintering aids can be strictly controlled. As a result, it has been found that the high-temperature strength characteristics of the Si3N4 sintered body can be expressed not by the crystallization mechanism of the grain boundary phase as shown in JP-A-62-59572, but by high melting point vitrification.
すなわち、本発明はＭｇＡｌ２２Ｏ４−Ｙ２ Ｏａ系の
改良特許として位置付けられる。That is, the present invention is positioned as an improved patent for the MgAl22O4-Y2Oa system.
特開昭６２−５９５７２においては、
０粒界の結晶化を再熱処理することにより達成すること
、
■場合によっては、焼結助剤としてスピネル−Ｙ２Ｏ３
に加えて結晶化を阻害しない範囲（０，０１〜１．０％
）のＬａ２Ｏ３ 、ＣｅＯ２を添加すること、
を特徴としているが、本発明では粒界ガラスの耐熱性を
従来のスピネル−Ｙ２Ｏ３系より高（することを意図し
、これを実現するために従来のスピネル−Ｙ２Ｏ３の配
合割合の中でＹ２Ｏ３の添加量のうち８０％以下をＬａ
２Ｏａ 、ＣｅＯ２、Ｙｂ２ ｏａといったランタニド
元素で置換した助剤系を採用したものである。In JP-A No. 62-59572, crystallization of zero grain boundaries is achieved by reheating; ■ In some cases, spinel-Y2O3 is used as a sintering aid.
In addition to the range that does not inhibit crystallization (0.01 to 1.0%
However, in the present invention, the grain boundary glass is intended to have higher heat resistance than the conventional spinel-Y2O3 system, and in order to achieve this, the conventional spinel-Y2O3 system is -In the blending ratio of Y2O3, 80% or less of the added amount of Y2O3
It employs an auxiliary agent system substituted with lanthanide elements such as 2Oa, CeO2, and Yb2oa.
本発明は、再熱処理といった手段を講することなく、室
温から１３００℃まで機械的強度の劣化の少ないＳｉ３
Ｎ４質焼結体を提供することを目的とするものである。The present invention provides Si3 with minimal deterioration in mechanical strength from room temperature to 1300°C without taking any measures such as reheat treatment.
The purpose is to provide an N4 quality sintered body.
本発明は、スピネル（ＭｇＡｊ２２Ｏ４ ）またはＭｇ
ＯとＡｅ２Ｏａをモル比で１：１に配合した混合粉末１
．５〜６重量％と、Ｙ２ ｏａ ２〜５重量％と、Ｌａ
２Ｏ３ 、ＣｅＯ２およびＹｂ２ ｏａから選ばれた１
種以上およびＹ２Ｏ３の合計３．５〜６．３重量％を含
み、かつ
≦０．８
であって残部がＳｉ３Ｎ４粉末からなる混合粉末を成形
し、得られた成形体を窒素雰囲気下で１６５０〜１９５
０℃の温度範囲で焼成することを特徴とするＳｉ３Ｎ４
焼結体の製造方法であり、かくしてＳｉ３Ｎ４焼結体の
粒界ガラス相の耐熱性を、スピネル−Ｙ２Ｏ３系におけ
るそれより向上せしめ、特開昭６２−５９５７２のよう
な焼成コストの高くなる再熱処理を必要とせずに、室温
から１３００℃まで機械的性質の劣化の少ないＳｉ３Ｎ
４焼結体を供給するものである。The present invention uses spinel (MgAj22O4) or Mg
Mixed powder 1 containing O and Ae2Oa in a molar ratio of 1:1
．． 5-6% by weight, Y2 oa 2-5% by weight, and La
1 selected from 2O3, CeO2 and Yb2 oa
A mixed powder containing a total of 3.5 to 6.3 wt. 195
Si3N4 characterized by being fired in a temperature range of 0°C
This is a method for producing a sintered body, thus improving the heat resistance of the grain boundary glass phase of the Si3N4 sintered body compared to that in the spinel-Y2O3 system, and eliminating the need for reheat treatment, which increases the firing cost, as in JP-A-62-59572. Si3N with minimal deterioration of mechanical properties from room temperature to 1300℃ without the need for
4 sintered bodies.
〔作用１ 本発明においては、その焼結助剤の配合が特徴となる。[Effect 1 The present invention is characterized by the combination of the sintering aid.
スピネルまたはＭｇＯとＡｌ２２Ｏ３をモル比１：１で
配合した混合粉末の何れかまたはけ両者を１．５重量％
〜６重量％配合する。１．５重量％未満では緻密な焼結
体が得られず強度の低下を招き、６重量％を越えて配合
してもその効果は変わらず、かえって粒界ガラス相の量
を増やすことになり高温強度の低下を招（ので、上記の
ように制限する。1.5% by weight of either spinel or a mixed powder containing MgO and Al22O3 at a molar ratio of 1:1, or both.
~6% by weight is blended. If it is less than 1.5% by weight, it will not be possible to obtain a dense sintered body, leading to a decrease in strength, and if it is more than 6% by weight, the effect will not change, but the amount of grain boundary glass phase will increase. This leads to a decrease in high-temperature strength (therefore, it is limited as described above).
Ｙ２Ｏ３ 、Ｌａ２Ｏ３ 、ＣｅＯ２、Ｙｂ２Ｏ３の総
記合量を３．５〜６．３重量％とする。これらの総記合
量が３．５重量％未満では、緻密な焼結体が得られない
ため強度の低下を招き、６重量％を越える配合では、粒
界ガラス相の量が多すぎるため、高温強度の低下を招く
。The total amount of Y2O3, La2O3, CeO2, and Yb2O3 is 3.5 to 6.3% by weight. If the total amount of these is less than 3.5% by weight, a dense sintered body cannot be obtained, leading to a decrease in strength, and if it exceeds 6% by weight, the amount of grain boundary glass phase is too large, so it cannot be used at high temperatures. This results in a decrease in strength.
またＹ２Ｏ３ ／ （Ｙ２Ｏ３ ＋Ｌａ２Ｏ３ ＋Ｃｅ
Ｏ２＋Ｙｂ２Ｏ３ ）≦０．８（重量比）の範囲に限定
するのは、このモル比が０．３未満ではＹ２Ｏ３の配合
が少なすぎるためＳｉ３Ｎ４特有の柱状組織が形成しに
くくなり、破壊靭性値の低下を招く。また逆にこのモル
比が０．８を越えると粒界ガラス相の耐熱性の向上が少
ないためか高温強度の低下を招く。Also, Y2O3 / (Y2O3 +La2O3 +Ce
O2 + Yb2O3 ) ≦ 0.8 (weight ratio) is limited to the range of 0.8 (weight ratio) because if this molar ratio is less than 0.3, the proportion of Y2O3 is too small, making it difficult to form the columnar structure peculiar to Si3N4, and decreasing the fracture toughness value. invite. On the other hand, if this molar ratio exceeds 0.8, the heat resistance of the grain boundary glass phase will be little improved, leading to a decrease in high-temperature strength.
Ｙ２Ｏａ ／ （Ｙ２Ｏ３ ＋Ｌａ２Ｏ３ ＋ＣｅＯ２
＋Ｙｂ２Ｏａ ）：重量比で整理したのは、Ｙ２Ｏ３の
配合が必須であり、かつＹ２Ｏ３に対してランタニド元
素をどの程度置換えるかを示すパラメータが本発明にお
いて必要であるためである。Y2Oa / (Y2O3 +La2O3 +CeO2
+Yb2Oa): The reason why the weight ratio was arranged is that the blending of Y2O3 is essential, and the present invention requires a parameter indicating how much lanthanide element is substituted for Y2O3.
Ｙ２Ｏ３が２％未満ではＳｉ３Ｎ４特有の針状晶組織が
形成しにくくなり、破壊靭性値の低下を招く。またＹ２
Ｏ３が５％を越えると粒界のガラス相の量が必要以上に
多くなり、高温強度の低下を招（。If Y2O3 is less than 2%, it becomes difficult to form the acicular crystal structure peculiar to Si3N4, resulting in a decrease in fracture toughness. Also Y2
If O3 exceeds 5%, the amount of glass phase at the grain boundaries will be larger than necessary, leading to a decrease in high-temperature strength (.
本発明において焼成温度を１６５０−１９５０℃に限定
したのは１６５０’未満ではＳｉ３Ｎ４の緻密化が進ま
ず、強度の低下を招き、１９５０℃を越えると、焼成中
の重量損失が大きく、異常粒成長が見られるようになり
強度の低下を招くからである。In the present invention, the firing temperature is limited to 1650-1950°C.If the temperature is less than 1650°C, the densification of Si3N4 will not proceed, resulting in a decrease in strength.If it exceeds 1950°C, the weight loss during firing will be large and abnormal grain growth will occur. This is because the cracks become visible, leading to a decrease in strength.
本発明に用いるＳｉ３Ｎ４粉末は平均粒径が４μｍ以下
、好ましくは１μｍ以下とする。このようなＳｉ３Ｎ４
は金属不純物が１％以下で好適である。The Si3N4 powder used in the present invention has an average particle size of 4 μm or less, preferably 1 μm or less. Si3N4 like this
The metal impurity content is preferably 1% or less.
ＭｇＯ１Ａ １２２Ｏ３ 、Ｍ ｇ２ Ａ １２２Ｏｓ
、Ｙ２Ｏ３ 、Ｌａ２Ｏ３、ＣｅＯ２、Ｙｂ２Ｏ３は
純度９７％以上、平均粒径が２μｍ以下のものが好まし
い。MgO1A 122O3, Mg2A 122Os
, Y2O3, La2O3, CeO2, and Yb2O3 preferably have a purity of 97% or more and an average particle size of 2 μm or less.
〔実施例］
平均粒径０，７μｍ、酸素含有量２．０重量％、金属不
純物量０．０５重量％の高純度Ｓｉ３Ｎ４粉末と、平均
粒径１．Ｏｇｍ、純度９９．９重量％のＭｇＡ９２Ｏ４
粉末、Ｙ２Ｏ３扮末、Ｙｂ２Ｏ３粉末、Ｌ ａ ２Ｏ３
粉末、ＣｅＯ２粉末を第１表。[Example] High purity Si3N4 powder with an average particle size of 0.7 μm, an oxygen content of 2.0% by weight, and a metal impurity amount of 0.05% by weight, and an average particle size of 1.0% by weight. Ogm, MgA92O4 with purity 99.9% by weight
Powder, Y2O3 powder, Yb2O3 powder, L a 2O3
Table 1 shows powder and CeO2 powder.
第２表に示す９合で総量がＩｋｇになるように秤量し、
バイ２フ２Ｏｇ、エタノールｔ ０００ｇをＳｉ３Ｎ４
ボールと共にプラスチック製ポットに入れ、回転ミルに
て２４時時間式混合した。Weigh the 9 cups shown in Table 2 so that the total amount is I kg,
Bi2F2Og, ethanol t000g to Si3N4
The mixture was placed in a plastic pot together with a ball, and mixed 24 hours a day in a rotary mill.
混合後スラリーをスプレードライヤーにて乾燥造粒し、
成形用粉末とした。After mixing, the slurry is dried and granulated using a spray dryer.
It was made into powder for molding.
この粉末を０．５ｔ／ｃｒｎ’の圧力で一軸成形後。This powder was uniaxially molded at a pressure of 0.5t/crn'.
１．５ｔ／ｃｒｎ”の圧力でコールド・アイソスタチッ
クプレス処理を行い、５０ｍｍＸ５０ｍｍｘ２Ｏｍｍの
大きさの成形体を得た。A cold isostatic press treatment was performed at a pressure of 1.5 t/crn'' to obtain a molded product with a size of 50 mm x 50 mm x 2 O mm.
この成形体をＮ２気流中で５００℃にて脱脂を行った後
、その成形体を黒鉛容器内にて第１表。After degreasing this molded body at 500°C in a N2 stream, the molded body was placed in a graphite container as shown in Table 1.
第２表に示す条件でＮ２：９．５ｋｇ／ｃｍ”の圧力の
もとて焼成し、窒化珪素質焼結体を得た。It was fired under the conditions shown in Table 2 under a pressure of N2: 9.5 kg/cm'' to obtain a silicon nitride sintered body.
これら焼結体の相対密度および室温、１２Ｏ０℃、１３
００℃での４点曲げ強度を測定した。結果は第１表２第
２表に併記した。Relative density of these sintered bodies and room temperature, 12O0℃, 13
Four-point bending strength at 00°C was measured. The results are also listed in Table 1 and Table 2.
実施例１〜２２に見られるように、１３００℃まで強度
の劣化の少ないＳ ｉ ３ Ｎ ４質焼結体が得られる
。この時の破壊靭性値を５ＥＰＢ法（Ｓｉｎｇｌｅ Ｅ
ｄｇｅ Ｐｒｅｃｒａｃｋｅｄ Ｂｅａｍ法）で測定し
たところ、すべて６ Ｍ Ｎ ／ ｍ ”２以上であっ
た。As seen in Examples 1 to 22, Si3N4 sintered bodies with little deterioration in strength up to 1300°C can be obtained. The fracture toughness value at this time was determined using the 5EPB method (Single E
When measured by dge Precracked Beam method), all of them were 6 M N/m''2 or more.
また、実施例２３〜２５ではスピネルの代りにＭｇＯと
／１２Ｏ３をモル比で１＝１で混合したものを用いたも
のを示し、これらも全く同様の効果が得られることがわ
かる。Moreover, in Examples 23 to 25, a mixture of MgO and /12O3 in a molar ratio of 1=1 was used instead of spinel, and it can be seen that exactly the same effect can be obtained with these.
比較例１．２においては、スピネル−Ｙ２Ｏ３単独添加
の場合は、室温〜１２Ｏ０°Ｃまでは本発明と同等の強
度を有するが、１３００℃においては３０ｋｇ／ｍｍ″
程度まで強度が低下することを示した。In Comparative Example 1.2, when spinel-Y2O3 is added alone, it has the same strength as the present invention from room temperature to 1200°C, but at 1300°C, it has a strength of 30 kg/mm''
It was shown that the strength decreased to a certain degree.
比較例３〜５ではＹ２Ｏ３ ＋Ｌａ２Ｏａ ＋ＣｅＯ２
＋Ｙｂ２Ｏ３が６．３０重量％を越えると、１３５０℃
での強度が極めて低いことがわかる。In Comparative Examples 3 to 5, Y2O3 +La2Oa +CeO2
+Yb2O3 exceeds 6.30% by weight, 1350℃
It can be seen that the strength is extremely low.
比較例６ではスピネルの配合が６％をこえるため１３０
０℃での強度が小さい。In Comparative Example 6, the spinel content exceeded 6%, so 130
The strength at 0°C is low.
比較例７〜８によればＹ ２Ｏ ａ ／ （Ｙ ２Ｏ３
＋Ｙｂ２Ｏａ）が０．８を越えたとき、および０．３
未満では１３００℃での強度が小さいことがわかる。According to Comparative Examples 7 and 8, Y 2O a / (Y 2O3
+Yb2Oa) exceeds 0.8, and 0.3
It can be seen that the strength at 1300° C. is low when the temperature is less than 1300° C.
比較例の９、ｌＯではＹ２Ｏ３の配合量が２％より少な
いので、１３００℃での強度も小さく。In Comparative Example 9, 1O, the amount of Y2O3 blended is less than 2%, so the strength at 1300°C is also low.
破壊靭性値も４ＭＮ／ｍ３′２と低かった。The fracture toughness value was also as low as 4 MN/m3'2.
本発明により再熱処理を用いることなく、１３００℃ま
で機械的性質の劣化の少ないＳｉ３Ｎ４質焼結体の製造
が可能となった。According to the present invention, it has become possible to produce a Si3N4 sintered body with little deterioration in mechanical properties up to 1300° C. without using reheat treatment.
第１図は本発明による５−ｉ３Ｎ４の高温強度の改善を
示すグラフである。FIG. 1 is a graph showing the improvement in high temperature strength of 5-i3N4 according to the present invention.
Claims (1)
ｌ＿２Ｏ＿３をモル比で１：１に配合した混合粉末１．
５〜６重量％と、Ｙ＿２Ｏ＿３２〜５重量％と、Ｌａ＿
２Ｏ＿３、ＣｅＯ＿２およびＹｂ＿２Ｏ＿３から選ばれ
た１種以上およびＹ＿２Ｏ＿３の合計３．５〜６．３０
重量％を含み、かつ（Ｙ＿２Ｏ＿３）／（Ｙ＿２Ｏ＿３
＋Ｌａ＿２Ｏ＿３＋ＣｅＯ＿２＋Ｙｂ＿２Ｏ＿３）≦０
．８であって残部がＳｉ＿３Ｎ＿４粉末からなる混合粉
末を成形し、得られた成形体を窒素雰囲気下で １６５０〜１９５０℃の温度範囲で焼成することを特徴
とするＳｉ＿３Ｎ＿４焼結体の製造方法。[Claims] 1 Spinel (MgAl_2O_4) or MgO and A
Mixed powder containing l_2O_3 at a molar ratio of 1:1 1.
5-6% by weight, Y_2O_32-5% by weight, and La_
2O_3, one or more selected from CeO_2 and Yb_2O_3, and a total of 3.5 to 6.30 Y_2O_3
% by weight, and (Y_2O_3)/(Y_2O_3
+La_2O_3+CeO_2+Yb_2O_3)≦0
．． A method for producing a Si_3N_4 sintered body, characterized in that a mixed powder of No. 8 and the remainder is Si_3N_4 powder is molded, and the obtained molded body is fired in a temperature range of 1650 to 1950°C in a nitrogen atmosphere.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1137363A JPH035371A (en) | 1989-06-01 | 1989-06-01 | Production of si3n4 sintered compact |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1137363A JPH035371A (en) | 1989-06-01 | 1989-06-01 | Production of si3n4 sintered compact |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH035371A true JPH035371A (en) | 1991-01-11 |
Family
ID=15196924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1137363A Pending JPH035371A (en) | 1989-06-01 | 1989-06-01 | Production of si3n4 sintered compact |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH035371A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6388139A (en) * | 1986-10-02 | 1988-04-19 | Asahi Chem Ind Co Ltd | Production of cycloolefin |
| US5457251A (en) * | 1992-01-24 | 1995-10-10 | Asahi Kasei Kogyo Kabushiki Kaisha | Method for partially hydrogenating a monocyclic aromatic hydrocarbon |
| US7056850B2 (en) * | 2001-07-24 | 2006-06-06 | Kabushiki Kaisha Toshiba | Wear-resistant silicon nitride member and method of manufacture thereof |
| JP2007308368A (en) * | 2007-07-13 | 2007-11-29 | Toshiba Corp | Method for producing silicon nitride wear resistant member |
-
1989
- 1989-06-01 JP JP1137363A patent/JPH035371A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6388139A (en) * | 1986-10-02 | 1988-04-19 | Asahi Chem Ind Co Ltd | Production of cycloolefin |
| US5457251A (en) * | 1992-01-24 | 1995-10-10 | Asahi Kasei Kogyo Kabushiki Kaisha | Method for partially hydrogenating a monocyclic aromatic hydrocarbon |
| US7056850B2 (en) * | 2001-07-24 | 2006-06-06 | Kabushiki Kaisha Toshiba | Wear-resistant silicon nitride member and method of manufacture thereof |
| JP2007308368A (en) * | 2007-07-13 | 2007-11-29 | Toshiba Corp | Method for producing silicon nitride wear resistant member |
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