JP2004108466A

JP2004108466A - Copper-based bearing material

Info

Publication number: JP2004108466A
Application number: JP2002270992A
Authority: JP
Inventors: Koji Saito; 斉藤　康志; Eisaku Inoue; 井上　栄作; Hiroaki Yoshida; 吉田　広明; Yoshitake Suzuki; 鈴木　良剛
Original assignee: Daido Steel Co Ltd; Daido Metal Co Ltd
Current assignee: Daido Steel Co Ltd; Daido Metal Co Ltd
Priority date: 2002-09-18
Filing date: 2002-09-18
Publication date: 2004-04-08
Anticipated expiration: 2022-09-18
Also published as: JP3839765B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-based bearing material with a titanium or titanium alloy back plate by a continuous sintering method and a continuous roll pressure-welding method suitable for mass production and manufacturable at a low cost. <P>SOLUTION: The back plate 3 is formed of Ti or Ti alloy, and an intermediate layer 4 formed of Fe or Fe-Cr alloy is provided between a copper-based bearing layer 2 and the back plate 3. The direct contact of Ti or Ti alloy with metal liable to form an intermetallic compound or with gas is thereby prevented to suppress the formation of the intermetallic compound or a compound with gas. Furthermore, since Fe and Cr used for the intermediate layer 4 are not liable to form an intermetallic compound with Ti at a heat treatment temperature after sintering and pressure welding of a Cu alloy, the copper-based bearing material 1 using Ti or Ti alloy for the back plate 3 can be manufactured without lowering the strength of the copper-based bearing material 1 by the continuous sintering method or the continuous roll pressure-welding method manufacturable at a low cost while allowing sintering and heat treatment. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、裏金の一側面に銅又は銅合金からなる銅系軸受層を固着してなる銅系軸受材料に関するものである。
【０００２】
【従来の技術】
従来、内燃機関のコネクティングロッド用銅系軸受材料は、例えば、特開平６−１５９３６７号公報に示されるように、低炭素鋼上に銅合金粉末を焼結したものが知られている。そして内燃機関の中でも特に軽量化及び高出力が要求される用途の内燃機関のコネクティングロッドには軽量で強度が高いチタン合金製のものが使用されている。コネクティングロッドに用いる軸受は、軸受の外形をコネクティングロッド内径より若干大きくし、締め代を持たせてコネクティングロッドに組み付け、軸受半径方向に一定以上の応力を発生させることによりハウジングに固定し、軸との供回りやハウジングから抜け出ることを防いでいる。
【０００３】
【特許文献１】
特開平６−１５９３６７号公報（段落００１４）
通常、軸受の締め代は、内燃機関の常用運転時の軸受部温度で適正な半径方向応力が発生するように設計されるが、チタン合金コネクティングロッドと従来の鋼裏金軸受の組み合わせであるとチタン合金と鋼の熱膨張率が異なるため軸受部温度が変化すると半径方向応力も変化する。自動車用等、大部分の内燃機関は長時間連続的に運転する場合よりも、運転、停止が繰り返されるような運転条件の場合のほうが多い。この場合、運転開始から常用運転温度に達する間は適正な軸受半径方向応力以下で運転されるため、軸受の軸との供回りやコネクティングロッドからの抜け出しが起こりやすいという問題がある。さらに、軸受半径方向応力によりコネクティングロッド内径が拡大するが、この拡大量も軸受部温度により変化するのでコネクティングロッド組み込み時の軸受内径が変化することになる。また、軸受設計上、最も重要な要素の一つとして軸受内径と軸とのクリアランスがあり、このクリアランスも内燃機関の常用運転時の軸受部温度にて適正な値となるように設計されるが、内燃機関の運転開始から常用運転温度に達するまでの間は適正クリアランス以下となるため、軸と軸受内面が接触し焼きつきが起こりやすいという問題もある。これらの問題を解決するには、コネクティングロッドと同等な熱膨張を有するチタン又はチタン合金裏金軸受が必要とされていた。
【０００４】
【発明が解決しようとする課題】
しかし、金属の中でも活性な金属であるチタン及びチタン合金は一般的な内燃機関用銅系軸受材料である銅鉛合金、鉛青銅、青銅の主成分、添加成分、不純物である銅、鉛、スズ、ニッケル、銀、リン等と容易に金属間化合物となり、又、焼結や熱処理に必要な還元性ガスや不活性ガスの成分である水素、窒素、一酸化炭素、二酸化炭素とも容易に化合物となるか大量に固溶し脆化するため、最も大量生産に適し、安価に製造できる連続焼結法や連続ロール圧接法によるチタン又はチタン合金裏金付銅系軸受材料がなかった。
【０００５】
一方、チタン及びチタン合金裏金付銅系軸受材料は、ＨＩＰ等真空雰囲気にて軸受層である銅合金成分と裏金層のチタン及びチタン合金との化合物の生成速度を遅らせ、低温で長時間焼結することにより製造できる可能性はあるが、生産性が非常に悪く、高価となるため実用化は困難である。他にも、チタン又はチタン合金上に銅合金粉末を溶射する方法が挙げられるが、素地と溶射粉末の接着がほぼ機械的な接着であるため化合物はできにくいものの、溶射法の中では最も素地と溶射金属層の接着力が高く、溶射層中の空孔が少なくできるとされる高速ガス溶射法を用いても従来の鋼上に銅合金を焼結したものより接着力は弱いという欠点がある。さらに、高速ガス溶射法では銅合金層中の空孔も多くなるという欠点もある。また、従来の焼結及び圧接法による銅合金層中には酸化物はほとんど含まれていないが、溶射法による銅合金層中には酸化物を多く含むため銅合金層中の強度も弱くなるという欠点もある。本発明は、上記した事情に鑑みなされたもので、その目的とするところは、大量生産に適し、安価に製造できる連続焼結法及び連続ロール圧接法によるチタン又はチタン合金裏金付銅系軸受材料を提供することにある。
【０００６】
【課題を解決するための手段】
上記した目的を達成するために、請求項１に係る発明においては、裏金の一側面に銅（Ｃｕ）又は銅（Ｃｕ）合金からなる銅系軸受層を固着してなる銅系軸受材料において、前記裏金は、チタン（Ｔｉ）又はチタン（Ｔｉ）合金で構成されると共に、前記銅系軸受層との間に鉄（Ｆｅ）又は鉄（Ｆｅ）−クロム（Ｃｒ）合金からなる中間層を設けたことを特徴とする。このように構成することにより、銅系軸受層と裏金との間にＦｅ又はＦｅ−Ｃｒ合金からなる中間層を設けたため、金属間化合物となりやすい金属又はガスとＴｉ又はＴｉ合金とが直接接することを防ぎ、金属間化合物又はガスとの化合物の生成を抑えることができる。更に、中間層に用いたＦｅ及びＣｒはＣｕ合金の焼結や圧接後の熱処理温度ではＴｉとの金属間化合物を生成しにくいため、焼結及び熱処理が可能となり、安価に製造できる連続焼結法又は連続ロール圧接法により銅系軸受材料の強度を落とすことなくＴｉ又はＴｉ合金を裏金に用いた銅系軸受材料の製造が可能となる。
【０００７】
また、請求項２に係る発明においては、前記裏金の他側面に前記中間層と同一成分の背面層を固着したことを特徴とする。このように構成することにより、銅系軸受層が積層されない裏金の他側面が中間層と同一成分の背面層によって覆われるため、Ｔｉ又はＴｉ合金と焼結やロール圧接後の熱処理に必要な還元性ガス、不活性ガス成分であるＮ_２、Ｈ_２、ＣＯ、ＣＯ_２等と反応して化合物を生成したり、大量に固溶して脆化したりすることがなくなり、還元性ガス、不活性ガス中で加熱することができ、Ｔｉ又はＴｉ合金を裏金に用いた銅系軸受材料が大量生産に向き安価に製造できる連続焼結法又は連続ロール圧接法を利用して製造することが可能となる。
【０００８】
また、請求項３に係る発明においては、前記中間層は、Ｆｅ又はＦｅ−Ｃｒ合金に含有される炭素（Ｃ）、硫黄（Ｓ）及びリン（Ｐ）の合計が０．５質量％以下であることを特徴とする。このように構成することにより、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる中間層との接着力を低下させることがない。即ち、Ｃ、Ｓ及びＰの合計が０．５質量％を超えると、Ｔｉ又はＴｉ合金とＦｅ又はＦｅ−Ｃｒ合金界面でのＴｉとＣ，Ｓ，Ｐとの化合物が多く生成され、接着力が低くなりすぎてしまう。
【０００９】
また、請求項４に係る発明においては、前記背面層は、Ｆｅ又はＦｅ−Ｃｒ合金に含有される炭素（Ｃ）、硫黄（Ｓ）及びリン（Ｐ）の合計が０．５質量％以下であることを特徴とする。このように構成することにより、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる背面層との接着力を低下させることがない。即ち、Ｃ、Ｓ及びＰの合計が０．５質量％を超えると、Ｔｉ又はＴｉ合金とＦｅ又はＦｅ−Ｃｒ合金界面でのＴｉとＣ，Ｓ，Ｐとの化合物が多く生成され、接着力が低くなりすぎてしまう。
【００１０】
また、請求項５に係る発明においては、前記中間層及び背面層は、それぞれ１μｍ以上の厚みを有し、且つ前記裏金の厚さの２０％以下であることを特徴とする。このように構成することにより、中間層及び背面層に破断部ができにくくしてＴｉ又はＴｉ合金や銅系軸受層と還元性ガス又は不活性ガスとが直接接触することを防ぐことができる一方、中間層及び背面層におけるＴｉ又はＴｉ合金からなる裏金に対する厚さを薄くしたため、Ｔｉ又はＴｉ合金からなる裏金の熱膨張率をＴｉ合金製コンロッドの熱膨張率とほぼ同等の熱膨張率に維持することができる。
【００１１】
【発明の実施の形態】
以下、本発明の実施の形態について図面及び表を参照して説明する。図１は、本実施形態に係る銅系軸受材料１の断面の模式図である。
【００１２】
銅系軸受材料１は、図１に示すように銅又は銅合金からなる銅系軸受層２と、銅系軸受層２を固着するＴｉ又はＴｉ合金からなる裏金３と、からなる。裏金３と銅系軸受層２との間には、中間層４が設けられている。更に裏金３の中間層４が設けられない他側面に背面層５が設けられている。
【００１３】
次に本実施形態に用いた銅系焼結軸受材料１の作製方法及び銅系軸受層２と裏金３の接着力測定について表１、図２を参照して説明する。表１は本実施形態に用いた銅系軸受材料１の組成及び接着力試験結果である。図２は接着力測定用試験片７の模式図である。
【００１４】
【表１】

【００１５】
実施例のＮｏ．１〜３の試料は、予め表１の組成のＴｉ又はＴｉ合金からなる裏金３に中間層４、背面層５として表１の組成のＦｅまたはＦｅ−Ｃｒ合金を厚さがそれぞれ２０μｍとなり総厚が１．３５ｍｍとなるように圧接したものを用いた。この裏金３上に銅系軸受層２としてアトマイズ法により製造した組成がＣｕ−１０質量％Ｓｎの青銅粉（−６０メッシュ）を０．８ｍｍの厚さで散布し、還元性雰囲気を有する焼結炉にて温度８５０℃で２０分焼結後、ロールで冷間圧延を施し、再び同一条件で焼結及び圧延を施すことにより中間層４、背面層５の厚さがそれぞれ約１５μｍ、総厚が１．５ｍｍとなるように銅系軸受材料１を作製した。
【００１６】
実施例のＮｏ．４の試料は予め裏金３のＴｉに中間層４、背面層５としてＦｅを厚さが４０μｍとなり総厚が２．０ｍｍとなる様にロール圧接したものを用い、銅系軸受層２として組成がＣｕ−１０質量％Ｓｎで厚さが０．７ｍｍの青銅板をロール圧接後、還元性雰囲気を有する焼結炉にて温度７００℃で３０分の熱処理を施し、その後、ロールで５％の冷間圧延を施して、中間層４、背面層５の厚さがそれぞれ約１５μｍ、総厚が１．５ｍｍとなるように銅系軸受材料１を作製した。
【００１７】
比較例のＮｏ．１は、裏金３に従来の一般的な銅系軸受材料でありＳ１０Ｃ相当の組成の鋼を用い、比較例のＮｏ．２は裏金３としてＴｉを用いた。比較例のＮｏ．１及び２は、中間層４、背面層５を設けていない以外は実施例のＮｏ．１〜３と同じ焼結方法で銅系軸受材料１を作製した。
【００１８】
比較例のＮｏ．３は、比較例のＮｏ．２の試料に中間層４、背面層５を設けた以外は同じ方法で作製したものであるが、中間層４、背面層５として本発明範囲外であるＣ，Ｓ，Ｐを総量で０．６質量％含むＦｅ−Ｃｒ合金層を用いた銅系軸受材料１を作製した。
【００１９】
上記の方法により作製された銅系軸受材料１を、図２に示す試験片７に加工した。試験片７には、円形の開口８が２つ設けられ、その円形開口８を引張試験機にて引っ張ることにより銅系軸受層２と裏金３との接着力を測定した。試験結果を表１に示す。
【００２０】
表１から明らかなように、本実施形態におけるＴｉ又はＴｉ合金からなる裏金３、Ｆｅ又はＦｅ−Ｃｒ合金からなる中間層４及び背面層５、銅系軸受層２からなる銅系軸受材料１は従来の一般的な低炭素鋼裏金付銅系軸受材料である比較例１に対し、銅系軸受層２と裏金３との接着力は同等以上であることがわかる。
【００２１】
比較例のＮｏ．２は、銅系軸受層２とＴｉからなる裏金３が直接接触した状態で焼結されたものであるが、銅系軸受層２と裏金３との界面部に金属間化合物が多量に生成し、接着力測定試験片加工時に剥離してしまい接着力測定を行うことができなかった。
【００２２】
比較例のＮｏ．３は、中間層４、背面層５として用いたＦｅ−Ｃｒ合金が本発明範囲外であるＣ，Ｓ，Ｐを総量で０．６質量％含むもので、焼結時の加熱により裏金３のＴｉと中間層４及び背面層５のＦｅ−Ｃｒ合金層界面でＣ，Ｓ，ＰとＴｉの化合物が多く生成している。そのため、接着力測定では、Ｃ，Ｓ，ＰとＴｉの化合物から剥離がおき、従来の一般的な低炭素鋼裏金付銅系軸受材料である比較例のＮｏ．１に対して銅系軸受層２と裏金３との接着力は低くなった。
【００２３】
以上、実施形態に係る銅系軸受材料１の構造及び作用について説明してきたが、本実施形態によれば、裏金３の一側面にＣｕ又はＣｕ合金からなる銅系軸受層２を固着してなる銅系軸受材料１において、前記裏金３は、Ｔｉ又はＴｉ合金で構成されると共に、前記銅系軸受層２との間にＦｅ又はＦｅ−Ｃｒ合金からなる中間層４を設けたことにより、金属間化合物となりやすい金属又はガスとＴｉ又はＴｉ合金とが直接接することを防ぎ、金属間化合物又はガスとの化合物の生成を抑えることができる。更に、中間層４に用いたＦｅ及びＣｒはＣｕ合金の焼結や圧接後の熱処理温度ではＴｉとの金属間化合物を生成しにくい性質があるため、焼結及び熱処理が可能となり、安価に製造できる連続焼結法又は連続ロール圧接法により銅系軸受材料１の強度を落とすことなくＴｉ又はＴｉ合金を裏金３に用いた銅系軸受材料１の製造が可能となる。
【００２４】
また、前記裏金３の他側面に前記中間層４と同一成分の背面層５を固着したことにより、銅系軸受層２が積層されない裏金３の他側面が中間層４と同一成分の背面層５によって覆われるため、Ｔｉ又はＴｉ合金と焼結やロール圧接後の熱処理に必要な還元性ガス、不活性ガス成分であるＮ_２、Ｈ_２、ＣＯ、ＣＯ_２等と反応して化合物を生成したり、大量に固溶して脆化したりすることがなくなり、還元性ガス、不活性ガス中で加熱することができ、Ｔｉ又はＴｉ合金を裏金３に用いた銅系軸受材料１が大量生産に向き安価に製造できる連続焼結法又は連続ロール圧接法を利用して製造することが可能となる。
【００２５】
また、前記中間層４は、Ｆｅ又はＦｅ−Ｃｒ合金に含有されるＣ、Ｓ及びＰの合計が０．５質量％以下であることにより、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる中間層４との接着力を低下させることがない。
【００２６】
また、前記背面層５は、Ｆｅ又はＦｅ−Ｃｒ合金に含有されるＣ、Ｓ及びＰの合計が０．５質量％以下であることにより、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる背面層５との接着力を低下させることがない。
【００２７】
また、前記中間層４及び背面層５は、それぞれ１μｍ以上の厚みを有し、且つ前記裏金３の厚さの２０％以下であることにより、中間層４及び背面層５に破断部ができにくくしてＴｉ又はＴｉ合金や銅系軸受層２と還元性ガス又は不活性ガスとが直接接触することを防ぐことができる一方、中間層４及び背面層５におけるＴｉ又はＴｉ合金からなる裏金３に対する厚さを薄くしたため、Ｔｉ又はＴｉ合金からなる裏金３の熱膨張率をＴｉ合金製コンロッドの熱膨張率とほぼ同等の熱膨張率に維持することができる。
【００２８】
なお、本発明に用いる裏金３のＴｉ合金は、以下に示す１種又は複数種の元素をＴｉに含む組成であっても良い。
【００２９】
元素　　　　　　　　　　　添加量
バナジウム（Ｖ）　　　：２５質量％以下
モリブデン（Ｍｏ）　　：１６質量％以下
アルミニウム（Ａｌ）　：８質量％以下
スズ（Ｓｎ）　　　　　：５質量％以下
ジルコニウム（Ｚｒ）　：７質量％以下
鉄（Ｆｅ）　　　　　　：５質量％以下
クロム（Ｃｒ）　　　　：１２質量％以下
ケイ素（Ｓｉ）　　　　：０．５質量％以下
鉛（Ｐｄ）　　　　　　：０．２５質量％以下
また、本実施形態における銅系焼結軸受材料１は、銅系軸受層２と裏金３とからなるバイメタルタイプであるが、これに限定されるものではなく、例えば銅系軸受層２の上部表面にオーバレイ層を設けたものであってもよい。
【００３０】
【発明の効果】
以上説明したところから明らかなように、請求項１の発明においては銅系軸受層と裏金との間にＦｅ又はＦｅ−Ｃｒ合金からなる中間層を設けたため、金属間化合物となりやすい金属又はガスとＴｉ又はＴｉ合金とが直接接することを防ぎ、金属間化合物又はガスとの化合物の生成を抑えることができる。更に、中間層に用いたＦｅ及びＣｒはＣｕ合金の焼結や圧接後の熱処理温度ではＴｉとの金属間化合物を生成しにくいため、焼結及び熱処理が可能となり、安価に製造できる連続焼結法又は連続ロール圧接法により銅系軸受材料の強度を落とすことなくＴｉ又はＴｉ合金を裏金に用いた銅系軸受材料の製造が可能となる。
【００３１】
また、請求項２の発明においては、銅系軸受層が積層されない裏金の他側面が中間層と同一成分の背面層によって覆われるため、Ｔｉ又はＴｉ合金と焼結やロール圧接後の熱処理に必要な還元性ガス、不活性ガス成分であるＮ_２、Ｈ_２、ＣＯ、ＣＯ_２等と反応して化合物を生成したり、大量に固溶して脆化したりすることがなくなり、還元性ガス、不活性ガス中で加熱することができ、Ｔｉ又はＴｉ合金を裏金に用いた銅系軸受材料が大量生産に向き安価に製造できる連続焼結法又は連続ロール圧接法を利用して製造することが可能となる。
【００３２】
また、請求項３の発明においては、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる中間層との接着力を低下させることがない。
【００３３】
また、請求項４の発明においては、金属間化合物となりやすい成分を少量しか含まないため、金属間化合物が生成してもその量が少なく、Ｔｉ又はＴｉ合金からなる裏金とＦｅ又はＦｅ−Ｃｒ合金からなる背面層との接着力を低下させることがない。
【００３４】
また、請求項５の発明においては、中間層及び背面層に破断部ができにくくしてＴｉ又はＴｉ合金や銅系軸受層と還元性ガス又は不活性ガスとが直接接触することを防ぐことができる一方、中間層及び背面層におけるＴｉ又はＴｉ合金からなる裏金に対する厚さを薄くしたため、Ｔｉ又はＴｉ合金からなる裏金の熱膨張率をＴｉ合金製コンロッドの熱膨張率とほぼ同等の熱膨張率に維持することができる。
【図面の簡単な説明】
【図１】本実施形態に係る銅系軸受材料１の断面の模式図である。
【図２】接着力測定用試験片の模式図である。
【符号の説明】
１　銅系軸受材料
２　銅系軸受層
３　裏金
４　中間層
５　背面層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a copper-based bearing material in which a copper-based bearing layer made of copper or a copper alloy is fixed to one side surface of a back metal.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a copper-based bearing material for a connecting rod of an internal combustion engine, for example, as disclosed in Japanese Patent Application Laid-Open No. H6-15967, a material obtained by sintering a copper alloy powder on low carbon steel is known. Among the internal combustion engines, a lightweight and high-strength titanium alloy is used as a connecting rod for an internal combustion engine that is particularly required to be lightweight and have high output. The bearing used for the connecting rod has the outer shape of the bearing slightly larger than the inner diameter of the connecting rod, has an interference, is assembled to the connecting rod, and is fixed to the housing by generating a certain stress or more in the radial direction of the bearing. To prevent it from rotating around and getting out of the housing.
[0003]
[Patent Document 1]
JP-A-6-15967 (paragraph 0014)
Normally, the interference of the bearing is designed so that an appropriate radial stress is generated at the temperature of the bearing part during the normal operation of the internal combustion engine.However, if the combination of the titanium alloy connecting rod and the conventional steel back metal bearing is used, the interference of the titanium is determined. Since the thermal expansion coefficients of the alloy and steel are different, when the temperature of the bearing changes, the radial stress also changes. Most internal combustion engines, such as those for automobiles, are more likely to be operated and stopped repeatedly under operating conditions than when operated continuously for a long time. In this case, since the bearing is operated with an appropriate bearing radial stress or less from the start of the operation until the normal operating temperature is reached, there is a problem that the bearing rotates with the shaft or comes off from the connecting rod easily. Further, the inner diameter of the connecting rod is increased by the stress in the bearing radial direction, and the amount of the expansion also changes depending on the temperature of the bearing portion, so that the inner diameter of the bearing when the connecting rod is incorporated changes. Also, one of the most important factors in bearing design is the clearance between the bearing inner diameter and the shaft, and this clearance is also designed to be an appropriate value at the temperature of the bearing during normal operation of the internal combustion engine. However, since the clearance is not more than the appropriate clearance from the start of the operation of the internal combustion engine to the normal operating temperature, there is a problem that the shaft and the inner surface of the bearing come into contact with each other and seizure easily occurs. To solve these problems, a titanium or titanium alloy back metal bearing having a thermal expansion equivalent to that of a connecting rod has been required.
[0004]
[Problems to be solved by the invention]
However, among the metals, titanium and titanium alloys, which are active metals, are commonly used as copper-based bearing materials for internal combustion engines, such as copper-lead alloy, lead bronze, and the main components, additional components, and impurities such as copper, lead, and tin. Easily becomes an intermetallic compound with nickel, silver, phosphorus, etc., and easily forms compounds such as hydrogen, nitrogen, carbon monoxide and carbon dioxide which are components of reducing gas and inert gas necessary for sintering and heat treatment. Because of its solid solution and embrittlement, the copper-based bearing material with titanium or titanium alloy back metal by the continuous sintering method or the continuous roll pressing method, which is most suitable for mass production and can be manufactured at low cost, has not been available.
[0005]
On the other hand, the copper-based bearing material with titanium and titanium alloy backing metal slows down the generation rate of the compound between the copper alloy component of the bearing layer and the titanium and titanium alloy of the backing metal layer in a vacuum atmosphere such as HIP, and is sintered at low temperature for a long time. Although there is a possibility that it can be manufactured by performing the method, it is difficult to put it to practical use because the productivity is very low and the cost is high. Another method is to spray copper alloy powder on titanium or titanium alloy.However, although the bonding between the base and the sprayed powder is almost mechanical, it is difficult to produce a compound. The disadvantage is that even with the high-speed gas spraying method, which is said to have a high adhesive strength between the sprayed metal layer and the pores in the sprayed layer and can reduce the porosity in the sprayed layer, the adhesive strength is lower than that of a conventional copper alloy sintered on steel. is there. Further, the high-speed gas spraying method has a disadvantage that the number of holes in the copper alloy layer increases. In addition, the copper alloy layer formed by the conventional sintering and pressure welding method contains almost no oxide, but the copper alloy layer formed by the thermal spraying method contains a large amount of oxide, so that the strength in the copper alloy layer also decreases. There is also a disadvantage. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a copper-based bearing material having a titanium or titanium alloy backing metal by a continuous sintering method and a continuous roll pressing method, which is suitable for mass production and can be manufactured at low cost. Is to provide.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the invention according to claim 1, a copper-based bearing material in which a copper-based bearing layer made of copper (Cu) or a copper (Cu) alloy is fixed to one side surface of a back metal, The back metal is made of titanium (Ti) or a titanium (Ti) alloy, and an intermediate layer made of iron (Fe) or an iron (Fe) -chromium (Cr) alloy is provided between the back metal and the copper-based bearing layer. It is characterized by having. With such a configuration, since the intermediate layer made of Fe or Fe-Cr alloy is provided between the copper-based bearing layer and the back metal, the metal or gas that easily becomes an intermetallic compound and Ti or Ti alloy directly contact with each other. And the formation of a compound with an intermetallic compound or a gas can be suppressed. Furthermore, since the Fe and Cr used for the intermediate layer are unlikely to form an intermetallic compound with Ti at the heat treatment temperature after sintering or pressing of the Cu alloy, sintering and heat treatment become possible, and continuous sintering that can be manufactured at low cost It is possible to manufacture a copper-based bearing material using Ti or a Ti alloy for the backing metal without reducing the strength of the copper-based bearing material by the method or the continuous roll pressing method.
[0007]
The invention according to claim 2 is characterized in that a back layer having the same composition as the intermediate layer is fixed to the other side surface of the back metal. With this configuration, the other side surface of the backing metal on which the copper-based bearing layer is not laminated is covered with the backing layer having the same composition as the intermediate layer, so that the reduction required for heat treatment after sintering or roll pressing with Ti or Ti alloy is performed. It does not react with reactive gases or inert gas components such as N ₂ , H ₂ , CO, CO ₂ to form compounds, or to dissolve in large quantities to form embrittlement. It can be heated in a gas, and can be manufactured using a continuous sintering method or a continuous roll pressing method that can produce copper-based bearing materials using Ti or Ti alloy for backing metal for mass production at low cost. Become.
[0008]
In the invention according to claim 3, the intermediate layer has a total of carbon (C), sulfur (S), and phosphorus (P) contained in Fe or Fe—Cr alloy of 0.5% by mass or less. There is a feature. With such a configuration, since only a small amount of a component that easily becomes an intermetallic compound is contained, even if an intermetallic compound is generated, the amount is small, and the back metal made of Ti or Ti alloy and Fe or Fe-Cr alloy are used. There is no decrease in adhesion to the intermediate layer. That is, when the total of C, S, and P exceeds 0.5% by mass, a large amount of a compound of Ti and C, S, P at the interface of Ti or Ti alloy and Fe or Fe—Cr alloy is generated, and the adhesive force Is too low.
[0009]
Further, in the invention according to claim 4, the back layer has a total content of carbon (C), sulfur (S) and phosphorus (P) contained in Fe or Fe—Cr alloy of 0.5% by mass or less. There is a feature. With such a configuration, since only a small amount of a component that easily becomes an intermetallic compound is contained, even if an intermetallic compound is generated, the amount is small, and the back metal made of Ti or Ti alloy and Fe or Fe-Cr alloy are used. There is no decrease in adhesion to the back layer. That is, when the total of C, S, and P exceeds 0.5% by mass, a large amount of a compound of Ti and C, S, P at the interface of Ti or Ti alloy and Fe or Fe—Cr alloy is generated, and the adhesive force Is too low.
[0010]
In the invention according to claim 5, the intermediate layer and the back layer each have a thickness of 1 μm or more and 20% or less of the thickness of the back metal. With this configuration, it is difficult to form a broken portion in the intermediate layer and the back layer, and it is possible to prevent direct contact between the reducing gas or the inert gas and the Ti or Ti alloy or the copper-based bearing layer. Since the thickness of the intermediate layer and the back layer with respect to the back metal made of Ti or Ti alloy is reduced, the coefficient of thermal expansion of the back metal made of Ti or Ti alloy is maintained at a thermal expansion coefficient substantially equal to that of the connecting rod made of Ti alloy. can do.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings and tables. FIG. 1 is a schematic diagram of a cross section of the copper-based bearing material 1 according to the present embodiment.
[0012]
As shown in FIG. 1, the copper-based bearing material 1 includes a copper-based bearing layer 2 made of copper or a copper alloy, and a back metal 3 made of Ti or a Ti alloy that fixes the copper-based bearing layer 2. An intermediate layer 4 is provided between the back metal 3 and the copper-based bearing layer 2. Further, a back layer 5 is provided on the other side of the back metal 3 where the intermediate layer 4 is not provided.
[0013]
Next, a method of manufacturing the copper-based sintered bearing material 1 used in the present embodiment and a measurement of an adhesive force between the copper-based bearing layer 2 and the back metal 3 will be described with reference to Table 1 and FIG. Table 1 shows the composition of the copper-based bearing material 1 used in the present embodiment and the results of the adhesion test. FIG. 2 is a schematic view of the test piece 7 for measuring adhesive strength.
[0014]
[Table 1]

[0015]
No. of the embodiment. Samples 1 to 3 had a thickness of 20 μm each of Fe or Fe—Cr alloy having the composition shown in Table 1 as a middle layer 4 and a back layer 5 previously formed on a back metal 3 made of Ti or a Ti alloy having the composition shown in Table 1. Was pressed so as to be 1.35 mm. A bronze powder (-60 mesh) having a composition of Cu-10 mass% Sn manufactured by an atomizing method as a copper-based bearing layer 2 is sprayed on the back metal 3 at a thickness of 0.8 mm, and sintered with a reducing atmosphere. After sintering at a temperature of 850 ° C. for 20 minutes in a furnace, cold rolling with a roll, and sintering and rolling again under the same conditions, the thickness of the intermediate layer 4 and the back layer 5 are each about 15 μm, and the total thickness. Was made to be 1.5 mm.
[0016]
No. of the embodiment. The sample No. 4 was prepared by pressing rolls of Ti on the back metal 3 in advance so that the intermediate layer 4 and the back layer 5 were Fe-pressed to a thickness of 40 μm and a total thickness of 2.0 mm. A bronze plate having a thickness of 0.7 mm with Cu-10 mass% Sn is roll-welded, and then subjected to a heat treatment at a temperature of 700 ° C. for 30 minutes in a sintering furnace having a reducing atmosphere. Cold rolling was performed to produce a copper-based bearing material 1 such that the thickness of each of the intermediate layer 4 and the back layer 5 was about 15 μm, and the total thickness was 1.5 mm.
[0017]
No. of the comparative example. No. 1 is a conventional general copper-based bearing material for the back metal 3 and uses steel having a composition equivalent to S10C. 2 used Ti as the back metal 3. No. of the comparative example. Nos. 1 and 2 of the Examples except that the intermediate layer 4 and the back layer 5 were not provided. A copper-based bearing material 1 was produced by the same sintering method as in Examples 1 to 3.
[0018]
No. of the comparative example. No. 3 is No. of the comparative example. Sample 2 was prepared by the same method except that the intermediate layer 4 and the back layer 5 were provided. However, C, S, and P, which are out of the range of the present invention, were used as the intermediate layer 4 and the back layer 5 in a total amount of 0.1. A copper-based bearing material 1 using an Fe-Cr alloy layer containing 6% by mass was produced.
[0019]
The copper-based bearing material 1 produced by the above method was processed into a test piece 7 shown in FIG. The test piece 7 was provided with two circular openings 8 and the adhesive force between the copper-based bearing layer 2 and the back metal 3 was measured by pulling the circular openings 8 with a tensile tester. Table 1 shows the test results.
[0020]
As is clear from Table 1, the backing metal 3 made of Ti or Ti alloy, the intermediate layer 4 and the back surface layer 5 made of Fe or Fe—Cr alloy, and the copper-based bearing material 1 made of the copper-based bearing layer 2 in the present embodiment are: It can be seen that the adhesive strength between the copper-based bearing layer 2 and the back metal 3 is equal to or greater than Comparative Example 1 which is a conventional general low-carbon steel backed copper-based bearing material.
[0021]
No. of the comparative example. No. 2 is sintered in a state where the copper-based bearing layer 2 and the back metal 3 made of Ti are in direct contact with each other, but a large amount of intermetallic compound is generated at the interface between the copper-based bearing layer 2 and the back metal 3. In addition, the test piece was peeled off during the processing of the adhesive force measurement specimen, so that the adhesive force measurement could not be performed.
[0022]
No. of the comparative example. Reference numeral 3 denotes a material in which the Fe—Cr alloy used as the intermediate layer 4 and the back layer 5 contains C, S, and P in a total amount of 0.6% by mass, which is outside the scope of the present invention. Many compounds of C, S, P and Ti are generated at the interface between Ti and the Fe—Cr alloy layer between the intermediate layer 4 and the back layer 5. For this reason, in the measurement of the adhesive strength, peeling occurred from the compound of C, S, P, and Ti, and No. 1 of Comparative Example, which is a conventional general low-carbon steel-backed copper bearing material. The adhesive strength between the copper bearing layer 2 and the back metal 3 was lower than that of No. 1.
[0023]
Although the structure and operation of the copper-based bearing material 1 according to the embodiment have been described above, according to the embodiment, the copper-based bearing layer 2 made of Cu or a Cu alloy is fixed to one side surface of the back metal 3. In the copper-based bearing material 1, the back metal 3 is made of Ti or a Ti alloy, and the intermediate layer 4 made of Fe or an Fe—Cr alloy is provided between the backing metal 3 and the copper-based bearing layer 2. It is possible to prevent a metal or gas that easily becomes an intermetallic compound from directly contacting Ti or a Ti alloy, and to suppress the generation of a compound with an intermetallic compound or gas. Further, since Fe and Cr used for the intermediate layer 4 have a property that it is difficult to generate an intermetallic compound with Ti at a heat treatment temperature after sintering and pressing of the Cu alloy, sintering and heat treatment can be performed, and the production is inexpensive. The copper-based bearing material 1 using Ti or a Ti alloy for the back metal 3 can be manufactured without reducing the strength of the copper-based bearing material 1 by a continuous sintering method or a continuous roll pressing method.
[0024]
Further, since the back layer 5 having the same component as the intermediate layer 4 is fixed to the other side surface of the back metal 3, the other side surface of the back metal 3 on which the copper-based bearing layer 2 is not laminated is the same as the back layer 5 having the same component as the intermediate layer 4. Since it is covered with Ti or a Ti alloy, it reacts with N ₂ , H ₂ , CO, CO _2, etc., which are the reducing gas and inert gas components necessary for heat treatment after sintering or roll pressing, to form compounds. , And can be heated in a reducing gas or an inert gas, and the copper-based bearing material 1 using Ti or a Ti alloy for the back metal 3 can be mass-produced. It can be manufactured using a continuous sintering method or a continuous roll pressing method that can be manufactured at low cost.
[0025]
Further, since the intermediate layer 4 contains only 0.5% by mass or less of the total of C, S, and P contained in Fe or the Fe—Cr alloy, it contains only a small amount of a component that easily becomes an intermetallic compound. Even if an intermetallic compound is generated, the amount thereof is small, and the adhesion between the back metal made of Ti or Ti alloy and the intermediate layer 4 made of Fe or Fe—Cr alloy does not decrease.
[0026]
In addition, the back layer 5 contains only a small amount of a component that easily becomes an intermetallic compound because the total of C, S, and P contained in Fe or the Fe—Cr alloy is 0.5% by mass or less. Even if an intermetallic compound is generated, the amount thereof is small, and the adhesion between the back metal made of Ti or Ti alloy and the back layer 5 made of Fe or Fe—Cr alloy does not decrease.
[0027]
Further, the intermediate layer 4 and the back layer 5 each have a thickness of 1 μm or more, and are not more than 20% of the thickness of the back metal 3, so that the intermediate layer 4 and the back layer 5 are not easily broken. To prevent direct contact between the reducing gas or the inert gas and the Ti or Ti alloy or the copper-based bearing layer 2, while preventing the back metal 3 made of Ti or the Ti alloy in the intermediate layer 4 and the back layer 5. Since the thickness is reduced, the coefficient of thermal expansion of the back metal 3 made of Ti or Ti alloy can be maintained at a coefficient of thermal expansion substantially equal to the coefficient of thermal expansion of the connecting rod made of Ti alloy.
[0028]
The Ti alloy of the back metal 3 used in the present invention may have a composition containing one or more of the following elements in Ti.
[0029]
Element Vanadium (V): 25% by mass or less Molybdenum (Mo): 16% by mass or less Aluminum (Al): 8% by mass or less Tin (Sn): 5% by mass or less Zirconium (Zr): 7% by mass or less Iron ( Fe): 5% by mass or less Chromium (Cr): 12% by mass or less Silicon (Si): 0.5% by mass or less Lead (Pd): 0.25% by mass or less Reference numeral 1 denotes a bimetal type including a copper-based bearing layer 2 and a back metal 3, but is not limited thereto. For example, an overlay layer may be provided on the upper surface of the copper-based bearing layer 2. .
[0030]
【The invention's effect】
As is apparent from the above description, in the invention of claim 1, since the intermediate layer made of Fe or Fe-Cr alloy is provided between the copper-based bearing layer and the backing metal, the metal or the gas that easily becomes an intermetallic compound is formed. It can prevent direct contact with Ti or a Ti alloy, and can suppress generation of a compound with an intermetallic compound or a gas. Furthermore, since the Fe and Cr used for the intermediate layer are unlikely to form an intermetallic compound with Ti at the heat treatment temperature after sintering or pressing of the Cu alloy, sintering and heat treatment become possible, and continuous sintering that can be manufactured at low cost It is possible to manufacture a copper-based bearing material using Ti or a Ti alloy for the backing metal without reducing the strength of the copper-based bearing material by the method or the continuous roll pressing method.
[0031]
According to the second aspect of the present invention, the other side surface of the back metal on which the copper-based bearing layer is not laminated is covered with the back layer having the same composition as the intermediate layer, so that it is necessary for sintering with Ti or Ti alloy or heat treatment after roll pressing. Reacts with various reducing gas and inert gas components such as N ₂ , H ₂ , CO, and CO ₂ to form a compound or to be dissolved in a large amount to be embrittled. It can be heated in an inert gas, and can be manufactured using a continuous sintering method or a continuous roll pressing method that can produce copper-based bearing materials using Ti or Ti alloy as backing metal for mass production at low cost. It becomes possible.
[0032]
Further, in the invention of claim 3, since only a small amount of a component that easily becomes an intermetallic compound is contained, even if an intermetallic compound is generated, the amount is small, and a back metal made of Ti or Ti alloy and Fe or Fe-Cr alloy are formed. Does not decrease the adhesive strength with the intermediate layer composed of
[0033]
Further, in the invention of claim 4, since only a small amount of a component that easily becomes an intermetallic compound is contained, even if an intermetallic compound is formed, the amount is small, and a back metal made of Ti or Ti alloy and Fe or Fe-Cr alloy are formed. The adhesive strength with the back layer made of is not reduced.
[0034]
Further, in the invention of claim 5, it is difficult to form a broken portion in the intermediate layer and the back layer to prevent direct contact between the reducing gas or the inert gas and the Ti or Ti alloy or the copper-based bearing layer. On the other hand, since the thickness of the intermediate layer and the back layer with respect to the back metal made of Ti or Ti alloy is reduced, the coefficient of thermal expansion of the back metal made of Ti or Ti alloy is almost equal to the coefficient of thermal expansion of the connecting rod made of Ti alloy. Can be maintained.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a cross section of a copper-based bearing material 1 according to the present embodiment.
FIG. 2 is a schematic view of a test piece for measuring adhesive strength.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Copper-based bearing material 2 Copper-based bearing layer 3 Back metal 4 Intermediate layer 5 Back layer

Claims

In a copper-based bearing material obtained by fixing a copper-based bearing layer made of copper or a copper alloy to one side of a back metal,
The copper-based bearing material, wherein the back metal is made of titanium or a titanium alloy, and an intermediate layer made of iron or an iron-chromium alloy is provided between the back metal and the copper-based bearing layer.

The copper-based bearing material according to claim 1, wherein a back layer having the same composition as the intermediate layer is fixed to the other side surface of the back metal.

3. The copper-based bearing material according to claim 1, wherein the intermediate layer has a total of carbon, sulfur, and phosphorus contained in iron or an iron-chromium alloy of 0.5 mass% or less. 4.

3. The copper-based bearing material according to claim 1, wherein the back layer has a total of carbon, sulfur, and phosphorus contained in iron or an iron-chromium alloy of 0.5% by mass or less. 4.

4. The copper bearing according to claim 1, wherein the intermediate layer and the back layer each have a thickness of 1 μm or more and 20% or less of a thickness of the back metal. 5. material.