JPH08252702A - Whisker-reinforced silicon nitride-based ceramic cutting tool with excellent fracture resistance - Google Patents
Whisker-reinforced silicon nitride-based ceramic cutting tool with excellent fracture resistanceInfo
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- JPH08252702A JPH08252702A JP7056201A JP5620195A JPH08252702A JP H08252702 A JPH08252702 A JP H08252702A JP 7056201 A JP7056201 A JP 7056201A JP 5620195 A JP5620195 A JP 5620195A JP H08252702 A JPH08252702 A JP H08252702A
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- whisker
- whiskers
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Abstract
(57)【要約】
【目的】 耐欠損性に優れたホイスカ−強化窒化ケイ素
基セラミックス製切削工具を提供する。
【構成】 本発明の耐欠損性に優れたホイスカ−強化窒
化ケイ素基セラミック製切削工具は、ＲｅをＹを含む希
土類元素のうちの１種以上とすると、Ｒｅの酸化物を５
〜２０モル％固溶した酸化ジルコニウム：０．５〜１０
ｗｔ％、ガラスに含まれる金属元素に対する割合でＲ
ｅ：５０〜７０モル％、Ｚｒ：１〜５モル％を含むＲｅ
−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガラスとＲｅシリケ−ト
からなる結合相：０．０５〜２０ｗｔ％、Ａｌ2Ｏ3、Ａ
ｌ2Ｏ3−Ｂ2Ｏ3系またはＳｉＣウィスカ−：１０〜３０
％、Ａｌ2Ｏ3、Ａｌ2Ｏ3−Ｂ2Ｏ3系またはＳｉＣ粒子：
０．５〜１０ｗｔ％、β−Ｓｉ3Ｎ4：残部からなること
を特徴とする。(57) [Summary] [Purpose] To provide a cutting tool made of whisker-reinforced silicon nitride-based ceramics having excellent fracture resistance. The cutting tool made of whisker-reinforced silicon nitride-based ceramic excellent in fracture resistance according to the present invention has a Re oxide of 5 or less when Re is one or more of rare earth elements including Y.
~ 20 mol% zirconium oxide in solid solution: 0.5 to 10
wt%, R as a ratio to the metal element contained in glass
e: Re containing 50 to 70 mol% and Zr: 1 to 5 mol%
-Zr-Al-Si-O- N based glass and Re silicate - consisting preparative binding phase: 0.05~20wt%, Al 2 O 3 , A
l 2 O 3 -B 2 O 3 system or SiC whisker -: 10 to 30
%, Al 2 O 3 , Al 2 O 3 -B 2 O 3 system or SiC particles:
0.5 to 10 wt%, β-Si 3 N 4 : The balance.
Description
【０００１】[0001]
【産業上の利用分野】この発明は、耐欠損性に優れたホ
イスカ−強化窒化ケイ素基セラミックス製切削工具に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a whisker-reinforced silicon nitride-based ceramic cutting tool having excellent fracture resistance.
【０００２】[0002]
【従来の技術】一般に窒化ケイ素基セラミックスは、高
温における強度、硬さ、化学的安定性などに優れている
ところから、エンジニアリングセラミックスの１つとし
て知られている。例えば、特開昭６２−２０２８６４号
では、Ｙ2Ｏ3を固溶した部分安定化、または安定化ジル
コニアとガラス成分とβ−Ｓｉ3Ｎ4からなる窒化ケイ素
基セラミックスが提案されており、さらに特開昭６４−
５１３７９号では、３〜２５ｖｏｌ％の立方晶ＺｒＯ2
とＹシリケートとβ−Ｓｉ3Ｎ4からなる窒化ケイ素基セ
ラミックスが提案されており、いずれも高温特性に優れ
ているとされている。2. Description of the Related Art Generally, silicon nitride based ceramics are known as one of engineering ceramics because they are excellent in strength, hardness and chemical stability at high temperatures. For example, Japanese Patent Application Laid-Open No. 62-202864 proposes a silicon nitride-based ceramics comprising Y 2 O 3 as a solid solution, partially stabilized or stabilized zirconia, a glass component and β-Si 3 N 4. JP-A-64-
No. 51379, 3-25 vol% cubic ZrO 2
And silicon nitride-based ceramics composed of Y silicate and β-Si 3 N 4 have been proposed, and all of them are said to have excellent high temperature characteristics.
【０００３】[0003]
【発明が解決しようとする課題】上記、従来の窒化ケイ
素基セラミックスは、高温構造部材として優れていて
も、この窒化ケイ素基セラミックスを、切削工具として
用いた場合には、特に耐欠損性が不足し、切削工具とし
て問題であった。Although the above-mentioned conventional silicon nitride-based ceramics are excellent as high-temperature structural members, when the silicon nitride-based ceramics are used as a cutting tool, the chipping resistance is particularly insufficient. However, it was a problem as a cutting tool.
【０００４】[0004]
【課題を解決するための手段】そこで、本発明者等は、
従来よりも優れた耐欠損性を有する窒化ケイ素基セラミ
ックス製切削工具を得るべく研究を行った結果、Ｒｅを
Ｙを含む希土類元素のうちの１種以上とすると、（ａ）
Ｒｅの酸化物を５〜２０モル％固溶した酸化ジルコニウ
ム：０．５〜１０ｗｔ％、（ｂ）ガラスに含まれる金属
元素に対する割合でＲｅ：５０〜７０モル％Ｚｒ：１〜
５モル％を含むＲｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガラ
スとＲｅシリケートからなる結合相：０．０５〜２０ｗ
ｔ％、（ｃ）Ａｌ2Ｏ3ホイスカー、Ａｌ2Ｏ3−Ｂ2Ｏ3系
ホイスカー、またはＳｉＣホイスカー：１０〜３５ｗｔ
％、（ｄ）Ａｌ2Ｏ3粒子、Ａｌ2Ｏ3−Ｂ2Ｏ3系粒子、ま
たはＳｉＣ粒子：０．５〜１０ｗｔ％、（ｅ）β−Ｓｉ
3Ｎ4および不可避不純物：残部の組成からなり、上記ホ
イスカーは、平均直径が、０．１〜１０μｍ、平均長さ
が、１〜２００μｍであり、該ホイスカーの２０〜９０
％が、すくい面と平行方向に配向したセラミックスは、
従来の窒化ケイ素基セラミックスよりも耐欠損性に優れ
ており、切削工具に適用した場合でも、優れた切削性能
が得られるという知見を得たのである。Therefore, the present inventors have
As a result of research to obtain a silicon nitride-based ceramic cutting tool having better fracture resistance than before, when Re is one or more of rare earth elements including Y, (a)
Zirconium oxide in which 5 to 20 mol% of Re oxide is solid-solved: 0.5 to 10 wt%, (b) Re: 50 to 70 mol% Zr: 1 to metal element contained in glass
Binder phase composed of Re-Zr-Al-Si-O-N-based glass containing 5 mol% and Re silicate: 0.05 to 20 w
t%, (c) Al 2 O 3 whiskers, Al 2 O 3 -B 2 O 3 system whiskers, or SiC whiskers: 10 to 35 wt.
%, (D) Al 2 O 3 particles, Al 2 O 3 —B 2 O 3 system particles, or SiC particles: 0.5 to 10 wt%, (e) β-Si
3 N 4 and unavoidable impurities: The balance consists of the composition, and the above whiskers have an average diameter of 0.1 to 10 μm and an average length of 1 to 200 μm.
% Ceramics oriented parallel to the rake face,
They have found that they have better fracture resistance than conventional silicon nitride-based ceramics, and that even when applied to a cutting tool, excellent cutting performance can be obtained.
【０００５】本発明は、かかる知見に基づいてなされた
ものであって、ＲｅをＹを含む希土類元素のうちの１種
以上とすると、Ｒｅの酸化物を５〜２０モル％固溶した
酸化ジルコニウム：０．５〜１０ｗｔ％、ガラスに含ま
れる金属元素に対する割合でＲｅ：５０〜７０モル％Ｚ
ｒ：１〜５モル％を含むＲｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−
Ｎ系ガラスとＲｅシリケートガラスからなる結合相：
０．０５〜２０ｗｔ％、Ａｌ2Ｏ3ホイスカー、Ａｌ2Ｏ3
−Ｂ2Ｏ3系ホイスカー、またはＳｉＣホイスカー：１０
〜３０ｗｔ％Ａｌ2Ｏ3粒子、Ａｌ2Ｏ3−Ｂ2Ｏ3系粒子、
またはＳｉＣ粒子：０．５〜１０ｗｔ％、β−Ｓｉ3Ｎ4
および不可避不純物：残部からなる組成を有し、上記ホ
イスカーは、平均直径が、０．１〜１０μｍ、平均長さ
が、１〜２００μｍであり、該ホイスカーの２０〜９０
％が、すくい面と平行方向に配向した焼結体からなる耐
欠損性に優れた繊維強化窒化ケイ素基セラミックス製切
削工具に特徴を有するものである。The present invention has been made on the basis of such findings, and when Re is one or more kinds of rare earth elements including Y, zirconium oxide containing 5 to 20 mol% of Re oxide as a solid solution. : 0.5 to 10 wt%, Re: 50 to 70 mol% Z in proportion to the metal element contained in the glass
r: Re-Zr-Al-Si-O- containing 1 to 5 mol%
Binder phase composed of N-based glass and Re silicate glass:
0.05-20 wt%, Al 2 O 3 whiskers, Al 2 O 3
-B 2 O 3 based whiskers or SiC whiskers,: 10
~ 30 wt% Al 2 O 3 particles, Al 2 O 3 -B 2 O 3 system particles,
Or SiC particles: 0.5-10 wt%, β-Si 3 N 4
And unavoidable impurities: the composition comprising the balance, the above whiskers have an average diameter of 0.1 to 10 μm and an average length of 1 to 200 μm.
% Is characterized by a fiber-reinforced silicon nitride-based ceramics cutting tool which is made of a sintered body oriented in a direction parallel to the rake face and has excellent fracture resistance.
【０００６】上記、窒化ケイ素基セラミックスの成分組
成並びに構成を、上記の如く数値限定した理由を説明す
る。The reason why the composition and composition of the silicon nitride based ceramics are numerically limited as described above will be explained.
【０００７】（１）Ｒｅの酸化物を固溶した酸化ジルコ
ニウム 酸化ジルコニウムは、窒化ケイ素基焼結体の耐欠損性を
向上させる作用効果があるが、そのためには、Ｒｅの酸
化物を５〜２０モル％（好ましくは１２〜１８モル％）
を固溶した安定化または部分安定化酸化ジルコニウムで
あることが必要で、その含有量が０．５ｗｔ％未満で
は、上記作用効果が得られず、また一方、その含有量１
０ｗｔ％を越えると、焼結体の硬さが低下し、焼結体の
耐摩耗性が低下するので好ましくない。したがってその
含有量を０．５〜１０ｗｔ％に、好ましくは０．８〜８
ｗｔ％に定めた。上記Ｒｅの酸化物は、主としてＲｅ2
Ｏ3であり、さらに酸化ジルコニウムには、窒素が微量
固溶可能であるから、窒素雰囲気中での焼結により窒素
が固溶することがあるが、窒素が固溶しても何らさしつ
かえない。(1) Zirconium oxide in which Re oxide is solid-soluted Zirconium oxide has the effect of improving the fracture resistance of the silicon nitride-based sintered body. 20 mol% (preferably 12-18 mol%)
It is necessary that the zirconium oxide is a solid solution of stabilized or partially stabilized zirconium oxide, and if the content is less than 0.5 wt%, the above-mentioned effects cannot be obtained.
If it exceeds 0 wt%, the hardness of the sintered body is lowered and the wear resistance of the sintered body is lowered, which is not preferable. Therefore, its content should be 0.5-10 wt%, preferably 0.8-8.
It was set to wt%. The oxide of Re is mainly Re 2
Since it is O 3 and a small amount of nitrogen can be solid-dissolved in zirconium oxide, nitrogen may be solid-dissolved by sintering in a nitrogen atmosphere, but it does not matter even if nitrogen is solid-dissolved.
【０００８】（２）Ｒｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系
ガラスとＲｅシリケート結晶からなる結合相、 この結合相は、窒化ケイ素基焼結体の耐欠損性を向上さ
せる作用を有するが、その量が、０．０５ｗｔ％未満で
はβ−Ｓｉ3Ｎ4粒子の結合には不十分であり、一方、２
０ｗｔ％を越えると、窒化ケイ素基焼結体の硬さが小さ
くなって耐摩耗性が低下し、この窒化ケイ素基焼結体か
らなる切削工具の耐摩耗性が低下して実用上好ましくな
い。したがって、Ｒｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガ
ラスとＲｅシリケートからなる結合相は、０．０５〜２
０ｗｔ％、さらに好ましい範囲は、０．０７〜１２ｗｔ
％と定めた。(2) Binder phase composed of Re-Zr-Al-Si-O-N type glass and Re silicate crystal, which has the function of improving the fracture resistance of the silicon nitride-based sintered body. If the amount is less than 0.05 wt%, it is insufficient for binding β-Si 3 N 4 particles, while 2
If it exceeds 0 wt%, the hardness of the silicon nitride-based sintered body decreases and the wear resistance decreases, and the wear resistance of the cutting tool made of this silicon nitride-based sintered body decreases, which is not preferable in practice. Therefore, the binder phase composed of Re-Zr-Al-Si-O-N-based glass and Re silicate has a content of 0.05 to 2
0 wt%, more preferably 0.07 to 12 wt
Defined as%.
【０００９】（３）Ａｌ2Ｏ3 この結合相を構成するＲｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ
系ガラスに含まれるＲｅは含まれる金属元素に対する割
合で５０モル％未満であると結合相の耐欠損性が不足
し、７０モル％を越えると焼結時にガラス相の生成が困
難となるので好ましくない。したがって、Ｒｅ−Ｚｒ−
Ａｌ−Ｓｉ−Ｏ−Ｎ系ガラスに含まれるＲｅは、金属元
素の割合で５０〜７０モル％に定めた。またＲｅ−Ｚｒ
−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガラスに含まれるＺｒもＲｅと
ほぼ同じ理由により１〜５モル％に定めた。(3) Al 2 O 3 Re-Zr-Al-Si-O-N constituting this bonding phase
When the Re contained in the system glass is less than 50 mol% with respect to the contained metal elements, the fracture resistance of the binder phase is insufficient, and when it exceeds 70 mol%, it is difficult to form the glass phase during sintering, which is preferable. Absent. Therefore, Re-Zr-
Re contained in the Al-Si-O-N based glass was defined as 50 to 70 mol% in terms of the metal element. Also, Re-Zr
Zr contained in the —Al—Si—O—N-based glass was also set to 1 to 5 mol% for the same reason as Re.
【００１０】（４）Ａｌ2Ｏ3ホイスカー、Ａｌ2Ｏ3−Ｂ
2Ｏ3系ホイスカー、またはＳｉＣホイスカー これらホイスカー成分には、焼結体中に均一に分散して
焼結体の耐熱衝撃性を著しく向上させる作用があるが、
その含有量が１０ｗｔ％未満の場合には、上記所望の作
用効果が得られず、一方その含有量が３０ｗｔ％を越え
ると、曲げ強度および破壊強度が低下することから、そ
の含有量を１０〜３０ｗｔ％、望ましくは１５〜２５ｗ
ｔ％に定めた。(4) Al 2 O 3 whiskers, Al 2 O 3 -B
2 O 3 system whiskers or SiC whiskers These whisker components have the action of uniformly dispersing in the sintered body and significantly improving the thermal shock resistance of the sintered body,
When the content is less than 10 wt%, the above-mentioned desired effects cannot be obtained, while when the content exceeds 30 wt%, the bending strength and the fracture strength are lowered, so that the content is 10 to 10%. 30wt%, desirably 15-25w
It was set to t%.
【００１１】（５）Ａｌ2Ｏ3粒子、Ａｌ2Ｏ3−Ｂ2Ｏ3系
粒子、またはＳｉＣ粒子 これら成分には、焼結体中に分散して、焼結体の耐熱性
を向上させる作用を有するが、その含有量が、０．５ｗ
ｔ％未満では、上記所望の作用効果が得られず、一方、
その含有量が１０ｗｔ％を越えると、耐熱衝撃性が低下
することから、その含有量を０．５〜１０ｗｔ％、望ま
しくは０．８〜８ｗｔ％に定めた。(5) Al 2 O 3 particles, Al 2 O 3 -B 2 O 3 system particles, or SiC particles These components are dispersed in the sintered body to improve the heat resistance of the sintered body. It has an action, but its content is 0.5w
If it is less than t%, the above-mentioned desired effects cannot be obtained, while
If the content exceeds 10 wt%, the thermal shock resistance decreases, so the content was set to 0.5 to 10 wt%, preferably 0.8 to 8 wt%.
【００１２】（６）各ホイスカーの平均直径 各ホイスカーの平均直径が０．１μｍ未満では焼結体の
靱性が低下し、一方その平均直径が１０μｍを越える
と、ホイスカー自体が粗大粒子と同様の働きをする様に
なり、曲げ強度を低下せしめるので、その平均直径を
０．１〜１０μｍ、望ましくは０．５〜５μｍに定め
た。(6) Average diameter of each whisker When the average diameter of each whisker is less than 0.1 μm, the toughness of the sintered body is lowered, and when the average diameter exceeds 10 μm, the whisker itself acts like coarse particles. As a result, the average bending diameter is set to 0.1 to 10 μm, preferably 0.5 to 5 μm.
【００１３】（７）各ホイスカーの平均長さ 各ホイスカーの平均長さが１μｍ未満では、焼結体の靱
性が低下し、一方、その平均長さが２００μｍを越える
と、曲げ強度が低下するので、その平均長さを、１〜２
００μｍ、望ましくは１０〜５０μｍに定めた。(7) Average Length of Each Whisker If the average length of each whisker is less than 1 μm, the toughness of the sintered body is reduced, while if the average length exceeds 200 μm, the bending strength is reduced. , Its average length is 1-2
The thickness is set to 00 μm, preferably 10 to 50 μm.
【００１４】（８）ホイスカーの配向比（％） ホイスカーは、焼結体中に配向性良く分散して、曲げ強
度を向上させる作用があるが、その配向比が、２０％未
満では、上記所望の作用効果が得られず、一方その値が
９０％を越えると別方向での曲げ強度が低下するので、
その値を２０〜９０％に定めた。(8) Orientation ratio (%) of whiskers Whiskers disperse in the sintered body with good orientation and have the effect of improving bending strength. However, if the orientation ratio is less than 20%, the above-mentioned desired However, if the value exceeds 90%, the bending strength in the other direction will decrease.
The value was set to 20 to 90%.
【００１５】この発明の耐欠損性に優れた窒化ケイ素基
焼結体からなる切削工具を製造する時に、Ａｌ2Ｏ3粉末
を０．５〜４ｗｔ％未満添加すると、１６００℃以上
で、Ａｌ2Ｏ3粉末、Ｒｅ2Ｏ3粉末、およびＳｉ3Ｎ4粉末
とＺｒＯ2粉末の一部が反応してＲｅ−Ｚｒ−Ａｌ−Ｓ
ｉ−Ｏ−Ｎ系の液相が生成する。焼結後冷却する過程で
上記Ｒｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系液相からＲｅ−
Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガラスとＲｅシリケート
（Ｒｅ2Ｓｉ2Ｏ7、Ｒｅ2ＳｉＯ5など）からなる結合相が
生成し、生成したＲｅ−Ｚｒ−Ａｌ−Ｓｉ−Ｏ−Ｎ系ガ
ラスのＲｅおよびＺｒ量が増加するにつれて、結合相の
ヤング率および熱膨張係数が大きくなり、焼結後に針状
のβ−Ｓｉ3Ｎ4粒子に圧縮応力を生じさせ、β−Ｓｉ3
Ｎ4粒子が容易に破断せずに強化粒子として働き、耐欠
損性が大きく向上するものと考えられる。When a cutting tool made of a silicon nitride-based sintered body having excellent fracture resistance according to the present invention is manufactured, if Al 2 O 3 powder is added in an amount of less than 0.5 to 4 wt%, Al 2 O 3 powder, Re 2 O 3 powder, and Si 3 N 4 powder partially react with ZrO 2 powder to cause Re-Zr-Al-S.
A liquid phase of i-O-N system is generated. In the process of cooling after sintering, the Re-Zr-Al-Si-O-N liquid phase is removed from the Re-
Zr-Al-SiO-N based glass and Re silicate (Re 2 Si 2 O 7, Re 2 , etc. SiO 5) binder phase is produced consisting of the generated Re-Zr-Al-SiO- N based As the Re and Zr contents of the glass increase, the Young's modulus and the coefficient of thermal expansion of the binder phase increase, causing compressive stress in the acicular β-Si 3 N 4 particles after sintering, and β-Si 3
It is considered that the N 4 particles act as reinforcing particles without easily breaking and the fracture resistance is greatly improved.
【００１６】Ａｌ2Ｏ3粉末を添加しない場合には、液相
の生成が困難となり、ガラス相が形成されにくく、４ｗ
ｔ％以上添加する場合には、焼結中に生成する液相の粘
性が高くなってガラス中にＺｒを含有することが困難と
なるばかりでなく、ガラス相に含まれるＲｅ量が相対的
に少なくなり、耐欠損性向上が不十分となる。したがっ
て、添加するＡｌ2Ｏ3粉末の量はＲｅ2Ｏ3量と密接な関
係があり、Ｒｅ2Ｏ3／Ａｌ2Ｏ3比はモルで１〜３の範囲
内にあることが好ましい。When the Al 2 O 3 powder is not added, it is difficult to form a liquid phase and it is difficult to form a glass phase.
When it is added in an amount of t% or more, the viscosity of the liquid phase generated during sintering becomes high, which makes it difficult to contain Zr in the glass, and the amount of Re contained in the glass phase is relatively large. It becomes less, and improvement in fracture resistance becomes insufficient. Therefore, the amount of Al 2 O 3 powder to be added is closely related to the amount of Re 2 O 3, and the Re 2 O 3 / Al 2 O 3 ratio is preferably in the range of 1 to 3 in terms of mol.
【００１７】この発明の耐欠損性に優れた窒化ケイ素基
焼結体からなる切削工具を製造する時にＺｒＯ2粉末を
添加するが、ＺｒＯ2はＲｅ2Ｏ3の１部と反応し、Ｒｅ2
Ｏ3を固溶する。大部分のＺｒＯ2はβ−Ｓｉ3Ｎ4粒子の
粒界に存在し、粒界のすべりを抑制することにより高温
特性を向上させる。しかし、切削工具として用いた場合
には、ＺｒＯ2量が増加するにつれて硬さが低下し、耐
摩耗性が低下する。したがって、ＺｒＯ2粉末の添加量
の上限は、１０ｗｔ％に定めた。一方、ＺｒＯ2を少な
くすると、硬度の低下が抑えられるばかりでなく、Ｚｒ
Ｏ2に固溶するＲｅ2Ｏ3の量が多くなり、同時に結合相
中に含まれるＲｅ量も多くなってヤング率および熱膨張
係数が大きくなり、焼結後に針状β−Ｓｉ3Ｎ4粒子に働
く圧縮応力が大きくなることから、β−Ｓｉ3Ｎ4粒子が
容易に破断せずに強化粒子として働き、耐欠損性が大き
く向上するが、ＺｒＯ2量が余り少なくなりすぎると結
合相中に含まれるＺｒ量がすくなくなり、耐欠損性が低
下するので好ましくない。したがってＺｒＯ2粉末添加
量の下限は、０．７ｗｔ％とした。上記ＺｒＯ2粉末に
はＲｅ2Ｏ3が固溶した安定化または部分安定化したＺｒ
Ｏ2粉末を用いても良い。ZrO 2 powder is added when manufacturing a cutting tool made of a silicon nitride-based sintered body having excellent fracture resistance according to the present invention. ZrO 2 reacts with 1 part of Re 2 O 3 to produce Re 2
Solid solution of O 3 . Most of ZrO 2 exists in the grain boundaries of β-Si 3 N 4 grains, and suppresses the slip of the grain boundaries to improve the high temperature characteristics. However, when used as a cutting tool, the hardness decreases and the wear resistance decreases as the amount of ZrO 2 increases. Therefore, the upper limit of the amount of ZrO 2 powder added is set to 10 wt%. On the other hand, decreasing ZrO 2 not only suppresses the decrease in hardness, but also reduces ZrO 2.
The amount of Re 2 O 3 solid-dissolved in O 2 increases, and at the same time, the amount of Re contained in the binder phase also increases and the Young's modulus and thermal expansion coefficient increase, and needle-like β-Si 3 N 4 after sintering increases. Since the compressive stress acting on the particles increases, the β-Si 3 N 4 particles act as reinforcing particles without being easily broken, and the fracture resistance is greatly improved. However, if the amount of ZrO 2 is too small, the binder phase It is not preferable because the amount of Zr contained therein becomes low and the fracture resistance is lowered. Therefore, the lower limit of the added amount of ZrO 2 powder is set to 0.7 wt%. In the above ZrO 2 powder, Re 2 O 3 is solid-dissolved in stabilized or partially stabilized Zr.
O 2 powder may be used.
【００１８】Ｒｅは、Ｙを含む希土類元素であるが、通
常ＲｅはＹであり、その他Ｌａ,Ｎｄ,Ｅｒ,Ｙｂなどの
希土類元素が用いられる。Re is a rare earth element containing Y, but usually Re is Y, and other rare earth elements such as La, Nd, Er and Yb are used.
【００１９】なお、Ａｌ2Ｏ3、Ａｌ2Ｏ3−Ｂ2Ｏ3系、ま
たはＳｉＣホイスカーは、通常単独で含有されるが、２
種または２種以上が同時に含有されても、本発明の特性
に何等の悪い影響を与えるものではない。またＡｌ2Ｏ3
−Ｂ2Ｏ3系ホイスカーでは、通常Ａｌ2Ｏ3５〜２５モル
％Ｂ2Ｏ3の組成のものが利用される。The Al 2 O 3 , Al 2 O 3 -B 2 O 3 system or SiC whiskers are usually contained alone, but 2
Even if one kind or two or more kinds are contained at the same time, it does not adversely affect the characteristics of the present invention. Also Al 2 O 3
The -B 2 O 3 based whiskers, is utilized as the composition of normal Al 2 O 3 5 to 25 mole% B 2 O 3.
【００２０】上述せる如く、この発明の切削工具は、ホ
イスカー成分以外の結合相を含む素地の優れた耐欠損性
に加えて、適度な寸法を有するホイスカー成分が、すく
い面と平行方向に相当量が配向していることにより、特
に耐熱衝撃性が向上し、高負荷（高速、高送り、高切り
込み）下における切削条件下においても、充分な耐欠損
性を示すものである。As mentioned above, in addition to the excellent fracture resistance of the base material containing the binder phase other than the whisker component, the cutting tool of the present invention has the whisker component having an appropriate size in a considerable amount in the direction parallel to the rake face. The orientation of the particles improves the thermal shock resistance, and exhibits sufficient fracture resistance even under cutting conditions under high load (high speed, high feed, high cutting depth).
【００２１】[0021]
【実施例】平均粒径０．６μｍのＳｉ3Ｎ4（α相含有
率：９０ｖｏｌ％）粉末、平均粒径０．４μｍのＺｒＯ
2粉末、平均粒径０．４μｍのＡｌ2Ｏ3粉末、平均粒径
１．３μｍのＹ2Ｏ3粉末等を表１および表２に示すよう
な割合に混合し、２４ｈｒボ−ルミルを行い、水中に分
散させた。さらに、表３および表４に示す仕様のホイス
カ−を、表３および表４に示す本発明焼結体Ａ〜Ｋおよ
び比較焼結体Ｌ〜Ｕの配合組成を持つように配合し、５
ｈｒボ−ルミルを行い均一に分散させた。この様にして
作製したスラリ−を、石膏型に鋳込み、十分に吸水させ
た後脱型して、１０Ｘ２０Ｘ１１０の成形体を得た。こ
の成形体を乾燥、脱脂したのち、１気圧のＮ2雰囲気
中、温度１７５０〜１８５０℃で、２〜１０時間保持の
条件で燒結し、さらにＮ2雰囲気中、温度：１７８０
℃、圧力：１０００ｋｇｆ／ｃｍ2の条件でＨＩＰ燒結
し、本発明焼結体Ａ〜Ｋおよび比較焼結体Ｌ〜Ｕを作製
した。EXAMPLE Si 3 N 4 (α phase content: 90 vol%) powder having an average particle size of 0.6 μm, ZrO having an average particle size of 0.4 μm
2 powder was mixed Al 2 O 3 powder having an average particle size of 0.4 .mu.m, a Y 2 O 3 powder having an average particle size of 1.3μm to the ratio shown in Table 1 and Table 2, 24 hr or ball - performed mill , Dispersed in water. Further, whiskers having the specifications shown in Tables 3 and 4 were blended so as to have the blended compositions of the sintered bodies A to K of the present invention and the comparative sintered bodies L to U shown in Tables 3 and 4.
An hr ball mill was performed to disperse the particles uniformly. The slurry thus produced was cast into a gypsum mold, allowed to absorb water sufficiently, and then demolded to obtain a 10 × 20 × 110 compact. Drying the molded body, after degreasing, in N 2 atmosphere at 1 atm, at a temperature from 1,750 to 1,850 ° C., and sintered under conditions of 2 to 10 hour hold, further N 2 atmosphere, temperature: 1780
HIP sintering was performed under the conditions of ° C and pressure: 1000 kgf / cm 2 to produce the present sintered bodies A to K and comparative sintered bodies L to U.
【００２２】[0022]
【表１】 [Table 1]
【００２３】[0023]
【表２】 [Table 2]
【００２４】[0024]
【表３】 [Table 3]
【００２５】[0025]
【表４】 [Table 4]
【００２６】上記燒結体の組成は、Ｘ線回折によりＺｒ
Ｏ2、Ｒｅシリケ−ト、Ａｌ2Ｏ3、Ｂ 2Ｏ3、ＳｉＣを同
定、定量し、さらにＴＥＭによりＺｒＯ2中に含まれる
Ｒｅ量、ガラスに含まれるＲｅ量を定量分析し、同時に
ＺｒＯ2量と結合相との総量を測定して成分組成を確か
めた。さらに燒結体の組織から、Ａｌ2Ｏ3ホイスカ−、
Ａｌ2Ｏ3−Ｂ2Ｏ3系ホイスカ−、またはＳｉＣホイスカ
−の含有量、平均直径、平均長さ、および切削切刃のす
くい面と平行に配向しているホイスカ−の配向率(％)を
測定し、これらの結果を表５、表６、表７および表８に
示した。（比較燒結体は、本発明の条件から外れた組
成、または組織を有するもので、＊印をもつて、表６お
よび表８に示した。）The composition of the above sintered body was determined by X-ray diffraction to be Zr.
O2, Re silicate, Al2O3, B 2O3, SiC same
ZrO by TEM2Contained in
Quantitative analysis of Re amount and Re amount contained in glass, and at the same time
ZrO2Quantity and total amount of binder phase to measure the composition of ingredients
I have Furthermore, from the structure of the sintered body, Al2O3Whisker,
Al2O3-B2O3System whisker or SiC whisker
-Content, average diameter, average length, and cutting edge
The orientation ratio (%) of the whiskers oriented parallel to the rake face
The results are shown in Table 5, Table 6, Table 7 and Table 8.
Indicated. (Comparative sintered body is a group which is out of the condition of the present invention.
Table 6
And Table 8 below. )
【００２７】[0027]
【表５】 [Table 5]
【００２８】[0028]
【表６】 [Table 6]
【００２９】[0029]
【表７】 [Table 7]
【００３０】[0030]
【表８】 [Table 8]
【００３１】次いで、上記それぞれの燒結体を、研削加
工し、ＩＳＯ規格ＳＮＧＮ１２０４０８相当の形状を有
する切刃とし、これをそれぞれシャンクにロ−付し、本
発明切削工具１〜１１、および比較切削工具１〜１０を
作製した。Next, each of the above sintered bodies is ground to form cutting edges having a shape equivalent to ISO standard SNGN120408, which are respectively attached to shanks, and cutting tools 1 to 11 of the present invention and comparative cutting tools. 1-10 were produced.
【００３２】引き続き、上記本発明切削工具１〜１１、
および比較切削工具１〜１０を用い、 被削材：ＦＣ２５（４本溝付丸棒） 切削速度：３００ｍ／ｍｉｎ． 送り：０．４５ｍｍ／ｒｅｖ． 切り込み：１ｍｍ． の条件の湿式切削試験を行い、欠損までの時間を測定
し、その結果を表９に示した。Subsequently, the above cutting tools 1 to 11 of the present invention,
And comparative cutting tools 1-10, Work material: FC25 (round bar with four grooves) Cutting speed: 300 m / min. Feed: 0.45 mm / rev. Notch: 1 mm. The wet cutting test under the conditions of No. 2 was performed, the time until the defect was measured, and the results are shown in Table 9.
【００３３】[0033]
【表９】 [Table 9]
【００３４】さらに、市販の窒化ケイ素基燒結体製切削
工具（以下、従来切削工具と言う）を用い、上記本発
明、および比較切削工具と同じ条件の湿式切削試験を行
い、欠損までの時間を測定し、その結果を同じく表９に
示した。Further, using a commercially available silicon nitride-based sintered body cutting tool (hereinafter referred to as a conventional cutting tool), a wet cutting test was conducted under the same conditions as those of the present invention and the comparative cutting tool, and the time to chipping was determined. The measurement was performed, and the results are also shown in Table 9.
【００３５】[0035]
【発明の効果】表９から明らかな様に、本発明の切削工
具１〜１１は、従来切削工具に比較して、格段の優れた
切削寿命を有している。また、本発明の条件から外れた
組成、または組織を有する比較切削工具１〜１０は、本
発明の切削工具に比べて、可成り短い切削寿命を示す。
上記の如く、本発明の切削工具を構成するホイスカ−強
化窒化ケイ素基セラミツクス燒結体は、優れた耐欠損性
を有し、さらに、耐熱衝撃性にも優れているため、これ
を切削工具の切刃として使用した場合、格段に工具寿命
が長く、産業上優れた効果を奏するものである。As is apparent from Table 9, the cutting tools 1 to 11 of the present invention have a significantly longer cutting life than the conventional cutting tools. Further, the comparative cutting tools 1 to 10 having a composition or a structure deviating from the conditions of the present invention show a considerably shorter cutting life than the cutting tool of the present invention.
As described above, the whisker-reinforced silicon nitride based ceramics sintered body constituting the cutting tool of the present invention has excellent fracture resistance and further excellent thermal shock resistance. When it is used as a blade, it has a remarkably long tool life and has an excellent industrial effect.
Claims (1)
以上とすると、Ｒｅの酸化物を５〜２０モル％固溶した
酸化ジルコニウム：０．５〜１０wt％、 ガラスに含まれる金属元素に対する割合でＲｅ：５０〜
７０モル％、Ｚｒ：１〜５％モルを含むＲｅ−Ｚｒ−Ａ
ｌ−Ｓｉ−Ｏ−Ｎ系ガラスとＲｅシリケートからなる結
合相：０．０５〜２０ｗｔ％、 Ａｌ2Ｏ3ホイスカー、Ａｌ2Ｏ3−Ｂ2Ｏ3系ホイスカーま
たはＳｉＣホイスカー：１０〜３０ｗｔ％、 Ａｌ2Ｏ3粒子、Ａｌ2Ｏ3−Ｂ2Ｏ3系粒子またはＳｉＣ粒
子：０．５〜１０ｗｔ％、 β−Ｓｉ3Ｎ4および不可避不純物：残部からなる組成を
有し、上記ホイスカーは、平均直径が、０．１〜１０μ
ｍ、平均長さが、１〜２００μｍであり、該ホイスカー
の２０〜９０％が、すくい面と平行方向に配向した焼結
体からなることを特徴とする耐欠損性に優れたホイスカ
−強化窒化ケイ素基セラミックス製切削工具。1. Zirconium oxide in which 5 to 20 mol% of Re oxide is solid-soluted: 0.5 to 10 wt%, where Re is one or more of rare earth elements including Y: a metal element contained in glass. Re: 50-
Re-Zr-A containing 70 mol% and Zr: 1 to 5% mol
binding phase consisting of l-Si-O-N based glass and Re silicate: 0.05~20wt%, Al 2 O 3 whiskers, Al 2 O 3 -B 2 O 3 based whiskers or SiC whiskers: 10 to 30 wt%, Al 2 O 3 particles, Al 2 O 3 -B 2 O 3 system particles or SiC particles: 0.5 to 10 wt%, β-Si 3 N 4 and inevitable impurities: the composition consisting of the balance, the above whiskers, Average diameter is 0.1-10μ
m, the average length is 1 to 200 μm, and 20 to 90% of the whiskers is composed of a sintered body oriented in a direction parallel to the rake face. Whisker-reinforced nitriding excellent in fracture resistance. Cutting tool made of silicon-based ceramics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7056201A JPH08252702A (en) | 1995-03-15 | 1995-03-15 | Whisker-reinforced silicon nitride-based ceramic cutting tool with excellent fracture resistance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7056201A JPH08252702A (en) | 1995-03-15 | 1995-03-15 | Whisker-reinforced silicon nitride-based ceramic cutting tool with excellent fracture resistance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08252702A true JPH08252702A (en) | 1996-10-01 |
Family
ID=13020510
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7056201A Withdrawn JPH08252702A (en) | 1995-03-15 | 1995-03-15 | Whisker-reinforced silicon nitride-based ceramic cutting tool with excellent fracture resistance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08252702A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104311144A (en) * | 2014-09-19 | 2015-01-28 | 大连理工大学 | Layered alumina-epoxy resin composite material containing whisker perpendicular to bed interface and in directional alignment and preparation method thereof |
-
1995
- 1995-03-15 JP JP7056201A patent/JPH08252702A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104311144A (en) * | 2014-09-19 | 2015-01-28 | 大连理工大学 | Layered alumina-epoxy resin composite material containing whisker perpendicular to bed interface and in directional alignment and preparation method thereof |
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