JP2537132B2 - High toughness ceramic sintered body excellent in heat resistance stability and method for producing the same - Google Patents
High toughness ceramic sintered body excellent in heat resistance stability and method for producing the sameInfo
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- JP2537132B2 JP2537132B2 JP5227826A JP22782693A JP2537132B2 JP 2537132 B2 JP2537132 B2 JP 2537132B2 JP 5227826 A JP5227826 A JP 5227826A JP 22782693 A JP22782693 A JP 22782693A JP 2537132 B2 JP2537132 B2 JP 2537132B2
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、きわめて高強度でしか
も同時に熱安定性に著しく優れる高靱性セラミック焼結
体及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high toughness ceramic sintered body having extremely high strength and at the same time excellent thermal stability, and a method for producing the same.
【０００２】[0002]
【従来の技術】ジルコニア焼結体は高温領域の立方晶か
ら正方晶を経て単斜晶に相転移をするが、その際体積変
化を伴い、特に正方晶から単斜晶への相転移の体積変化
が大きく、そのため焼結体がこの体積変化により破壊し
てしまうという欠点がある。この欠点を取り除くため
に、ＺｒＯ2にＣａＯ、ＭｇＯ、Ｙ2Ｏ3などを固溶させ
て転移を起こさせないようにし、常温でも立方晶からな
る部分安定化ジルコニアあるいは立方晶と単斜晶より成
る部分安定化ジルコニアが数多く発表されている。ま
た、準安定相である正方晶を常温で焼結体内に存在させ
た部分安定化ジルコニアが高強度を示すことが発表され
ている。これは一つには機械的な外部応力が加わった際
に、準安定な正方晶から室温安定相である単斜晶への相
転移が誘起され、応力が吸収されることによる。2. Description of the Related Art A zirconia sintered body undergoes a phase transition from a cubic crystal to a tetragonal crystal in a high temperature region to a monoclinic crystal. At that time, a volume change occurs, and particularly, the volume of the phase transition from the tetragonal crystal to the monoclinic crystal is increased. The change is large, so that there is a drawback that the sintered body is destroyed by this volume change. In order to eliminate this defect, CaO, MgO, Y 2 O 3 etc. are solid-dissolved in ZrO 2 so as not to cause a transition, and partially stabilized zirconia consisting of cubic crystals or cubic and monoclinic crystals at room temperature. Many partially stabilized zirconia have been announced. In addition, it has been announced that partially stabilized zirconia obtained by allowing a tetragonal crystal, which is a metastable phase, to exist in a sintered body at room temperature exhibits high strength. This is partly because, when a mechanical external stress is applied, a phase transition from a metastable tetragonal crystal to a monoclinic crystal that is a room temperature stable phase is induced and the stress is absorbed.
【０００３】この様に常温において主として準安定な正
方晶からなる焼結体を得るための安定化剤としては、従
来より主としてＹ2Ｏ3が用いられ特に高靱性、高強度を
発現している。しかし、このように主として正方晶から
なる部分安定化ジルコニアは、高温相を低温域までもた
らした結果生ずる準安定相であるため、その構造や性質
が経時変化をし、特に２００℃ないし４００℃という比
較的低温における加熱により単斜晶へ相転移を起こし、
強度の経時劣化が極めて大きい。また、この強度劣化は
水分等の存在下では著しく促進され、この様な特性の経
時劣化が問題となっている。As described above, Y 2 O 3 has been mainly used as a stabilizer for obtaining a sintered body composed of a tetragonal crystal that is mainly metastable at room temperature, and particularly high toughness and high strength are exhibited. . However, since the partially stabilized zirconia mainly composed of tetragonal crystals is a metastable phase generated as a result of bringing a high temperature phase to a low temperature region, its structure and properties change with time, and particularly 200 ° C. to 400 ° C. When heated at a relatively low temperature, it causes a phase transition to monoclinic,
The deterioration of strength with time is extremely large. Further, this strength deterioration is remarkably promoted in the presence of water or the like, and such deterioration of characteristics over time poses a problem.
【０００４】また、高靱性ジルコニア焼結体として、Ｙ
2Ｏ3、ＭｇＯ、ＣａＯを安定化剤として含むジルコニア
にＡｌ2Ｏ3を０．５〜６０重量％まで含む焼結体（特開
昭５８−３２０６６）及びＹ2Ｏ3、ＭｇＯ、ＣａＯを安
定化剤として含むジルコニアにＡｌ2Ｏ3あるいは各種の
ホウ化物、炭化物、窒化物及びＡｌ2Ｏ3を含む焼結体
（特開昭５８−１２０５７１）が開示されている。Further, as a high toughness zirconia sintered body, Y
Zirconia containing 2 O 3 , MgO and CaO as stabilizers, a sintered body containing Al 2 O 3 in an amount of 0.5 to 60 wt% (Japanese Patent Laid-Open No. 58-32066) and Y 2 O 3 , MgO and CaO. There is disclosed a sintered body containing Al 2 O 3 or various borides, carbides, nitrides and Al 2 O 3 in zirconia as a stabilizer (JP-A-58-120571).
【０００５】しかし、これらの開示されたジルコニア焼
結体のうちＭｇＯ、ＣａＯを安定化剤とするものは、Ｙ
2Ｏ3を安定化剤とするものに比べ機械的強度が低い上、
１０００℃付近の長時間の保持により、脱安定化すなわ
ち正方晶から単斜晶への変態を生じ、その結果機械的強
度の低下を生ずるため、構造材としての用途は限られた
ものとなっている。さらに、Ｙ2Ｏ3によって安定化され
た高靱性ジルコニア焼結体は、上記したように２００℃
〜４００℃の低温において容易に相転移を生じ、時間と
共に焼結体表面より内部へ向かって転移が進行し強度、
靱性の劣化は著しく、強靱化のメカニズムが作用しなく
なることはもとより、相転移にともなう体積膨張によ
り、マイクロクラックが発生してついには破壊してしま
うという重大な欠陥を有し、構造材としての信頼性に乏
しいものである。However, among these disclosed zirconia sintered bodies, those having MgO or CaO as a stabilizer are Y
In addition to having lower mechanical strength than those using 2 O 3 as a stabilizer,
Holding for a long time at around 1000 ° C causes destabilization, that is, transformation from tetragonal to monoclinic, resulting in a decrease in mechanical strength, so that its use as a structural material is limited. There is. Furthermore, the high toughness zirconia sintered body stabilized by Y 2 O 3 has a temperature of 200 ° C. as described above.
A phase transition easily occurs at a low temperature of up to 400 ° C, and the transition progresses from the surface of the sintered body to the inside with time,
Degradation of toughness is remarkable, and in addition to the mechanism of toughness not working, there is a serious defect that microcracks are generated and eventually fracture due to volume expansion accompanying the phase transition, and as a structural material, It is unreliable.
【０００６】またＹ2Ｏ3を安定化剤とするＺｒＯ2にア
ルミナを含有させ、ＨＩＰ処理を行うことにより、更に
曲げ強度の高い高強度ジルコニアセラミックスの製造法
が開示されている（特開昭６０−８６０７３）。Also disclosed is a method for producing high strength zirconia ceramics having higher bending strength by incorporating alumina into ZrO 2 having Y 2 O 3 as a stabilizer and subjecting it to HIP treatment (Japanese Patent Application Laid-Open No. Sho-6). 60-86073).
【０００７】同公報では、ジルコニアセラミックスの強
度は改善されているものの、Ｙ2Ｏ3を安定化剤とするジ
ルコニアを主成分としている為、２００℃〜４００℃に
おいて相変わらず依然として経時劣化を生じるという問
題がある。According to the publication, although the strength of zirconia ceramics is improved, since zirconia containing Y 2 O 3 as a stabilizer is the main component, deterioration with time still occurs at 200 ° C. to 400 ° C. There is.
【０００８】一方、Ｙ2Ｏ3とＣｅＯ2を安定化剤とする
ジルコニア磁器及びその製造法（特開昭６０−１４１６
７３）や、ＣｅＯ2を安定化剤とするジルコニア及びこ
れにアルミナを含有するジルコニア質焼結体が開示され
ている（特開昭６０−１０８３６７）。On the other hand, zirconia porcelain using Y 2 O 3 and CeO 2 as stabilizers and a method for producing the same (Japanese Patent Laid-Open No. 60-1416).
73) and zirconia containing CeO 2 as a stabilizer and a zirconia-based sintered body containing alumina therein (JP-A-60-108367).
【０００９】これら公報に開示されたＣｅＯ2を含有す
るジルコニアセラミックスは、Ｙ2Ｏ3を安定化剤とする
ジルコニアセラミックスと比較して熱安定性は改善され
ているものの、強度が低く、十分でないという欠点があ
り、構造材としての用途は限定されたものとなってい
る。The zirconia ceramics containing CeO 2 disclosed in these publications have improved thermal stability as compared with zirconia ceramics containing Y 2 O 3 as a stabilizer, but have low strength and are not sufficient. However, its use as a structural material is limited.
【００１０】[0010]
【発明が解決しようとする課題】このように、Ｙ2Ｏ3を
安定化剤として含むＹ2Ｏ3−ＺｒＯ2系ジルコニアセラ
ミックス及びこれにアルミナを含有するＹ2Ｏ3−ＺｒＯ
2−Ａｌ2Ｏ3系ジルコニアセラミックスは、２００℃〜
４００℃の低温において経時劣化を生じるという欠点を
有している。一方、Ｙ2Ｏ3とＣｅＯ2を安定化剤として
含むＹ2Ｏ3−ＣｅＯ2−ＺｒＯ2系ジルコニアセラミック
スあるいはＣｅＯ2を安定化剤として含むＣｅＯ2−Ｚｒ
Ｏ2系、ＣｅＯ2−ＺｒＯ2−Ａｌ2Ｏ3系ジルコニアセラ
ミックスは強度が低いという欠点を有している。[Problems that the Invention is to Solve Thus, Y 2 O 3 and Y 2 O 3 containing Y 2 O 3 -ZrO 2 zirconia ceramics and this alumina comprises as a stabilizer -ZrO
2- Al 2 O 3 system zirconia ceramics is 200 ℃ ~
It has a drawback that it deteriorates with time at a low temperature of 400 ° C. On the other hand, CeO 2 -Zr containing Y 2 O 3 and Y 2 O 3 -CeO 2 -ZrO 2 zirconia ceramics or CeO 2 containing CeO 2 as a stabilizer as a stabilizer
O 2 system, CeO 2 -ZrO 2 -Al 2 O 3 zirconia ceramics has the disadvantage of low strength.
【００１１】本発明の目的は、強度と熱安定性の両者を
同時に飛躍的に改善した高靱性ジルコニアセラミックス
及びその製造方法を提供しようとするものである。It is an object of the present invention to provide a high toughness zirconia ceramic which is dramatically improved in both strength and thermal stability, and a method for producing the same.
【００１２】[0012]
【課題を解決するための手段】第１の発明（請求項１）
の耐熱安定性に優れた高靱性セラミック焼結体は、 (a) Ｙ2Ｏ3とＣｅＯ2を安定化剤として含む主として正
方晶より成る部分安定化ジルコニアに対し (b) 第２成分として、Ａｌ2Ｏ3、又はＡｌ2Ｏ3とＭｇＯ
・Ａｌ2Ｏ3（スピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ム
ライト）から選ばれた１種又は２種とを１〜７０内部重
量％含み、 (c) 熱間プレス法あるいは熱間静水圧プレス法で焼結さ
れた焼結体であって、 (d) 焼結体中に含まれる正方晶ジルコニアの結晶粒子の
平均粒子径が２μｍ以下であり、 (e) かつ３点曲げ強度が１４９ｋｇ／ｍｍ2以上で、 (f) 焼結体のかさ密度が理論密度の９９％以上であり、 (g) ３００℃大気中に３０００時間保持試験後の焼結体
に含まれるジルコニアの単斜晶量が３％以下でありかつ
３点曲げ強度が１４７ｋｇ／ｍｍ2以上であること、 (h) 前記部分安定化ジルコニアは、これに含まれるＹ2
Ｏ3、ＣｅＯ2が添付図面に示すように正三角形に交わる
三軸にそれぞれＺｒＯ2、ＹＯ1.5、ＣｅＯ2のｍｏｌ％
を表示した三角座標において、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｂ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｃ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５．０ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 １３．０ｍｏｌ％） で示された特定４組成点を結ぶ点で囲まれた範囲内の組
成にあること、を特徴とする。[Means for Solving the Problems] First invention (Claim 1)
The high toughness ceramic sintered body excellent in heat resistance of (a) is (a) for partially stabilized zirconia mainly composed of tetragonal crystals containing Y 2 O 3 and CeO 2 as stabilizers, and (b) as a second component, Al 2 O 3 , or Al 2 O 3 and MgO
· Al 2 O 3 (spinel), 3Al 2 O 3 · 2SiO 2 and a one or more of the compounds selected from (mullite) 1-70 Internal wt%, (c) hot pressing method or a hot isostatic (D) The average particle size of the tetragonal zirconia crystal particles contained in the sintered body is 2 μm or less, and (e) the three-point bending strength is 149 kg. / F 2 or more, (f) the bulk density of the sintered body is 99% or more of the theoretical density, and (g) the monoclinic crystal of zirconia contained in the sintered body after 3000 hours of holding test in the air at 300 ° C. The amount is 3% or less, and the three-point bending strength is 147 kg / mm 2 or more, (h) the partially stabilized zirconia contains Y 2
O 3 and CeO 2 are mol% of ZrO 2 , YO 1.5 , and CeO 2 , respectively, on the three axes intersecting the equilateral triangle as shown in the attached drawing.
In the triangular coordinate displaying, point A (ZrO 2 87.5 mol%, YO 1.5 12mo
1%, CeO 2 0.5 mol%) Point B (ZrO 2 95.5 mol%, YO 1.5 4 mol
%, CeO 2 0.5 mol%) Point C (ZrO 2 95.5 mol%, YO 1.5 2 mol
%, CeO 2 2.5 mol%) Point D (ZrO 2 85.0 mol%, YO 1.5 2 mol
%, CeO 2 13.0 mol%), and the composition is within the range surrounded by the points connecting the four specific composition points.
【００１３】第２の発明（請求項２）は、第１の発明に
対し、第２成分としてＭｇＯ・Ａｌ2Ｏ3（スピネル）及
び３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）の１種又は２種
を用いること、３００℃大気中の保持試験前後の曲げ強
度を夫々１３７ｋｇ／ｍｍ2以上、１３５ｋｇ／ｍｍ2以
上とした以外、第１の発明と同様である。[0013] The second invention (Claim 2), relative to the first invention, one of MgO · Al 2 O 3 (spinel) and 3Al 2 O 3 · 2SiO 2 (mullite) as a second component or 2 The same as the first invention except that the seeds are used and the bending strength before and after the holding test in the atmosphere at 300 ° C. is set to 137 kg / mm 2 or more and 135 kg / mm 2 or more, respectively.
【００１４】第３の発明（請求項３）の耐熱安定性に優
れた高靱性セラミック焼結体の製造方法は、 (a) Ｙ2Ｏ3とＣｅＯ2を安定化剤として含む第１成分と
してのＺｒＯ2粉末材料であって、該ＺｒＯ2粉末材料
は、ＺｒＯ2のゾルおよび／または水溶性の塩をＹ
2Ｏ3、ＣｅＯ2を生ずる水溶性の塩と共に溶液の 状態で
均一に混合した後、沈澱の形で分離して得られ、Ｙ
2Ｏ3、ＣｅＯ2が正三角形に交わる三軸にそれぞれＺｒ
Ｏ2、ＹＯ1.5、ＣｅＯ2のｍｏｌ％を表示した三角座標
において、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｂ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｃ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５．０ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 １３．０ｍｏｌ％） で示された特定４組成点を結ぶ点で囲まれた範囲内の組
成にあるＺｒＯ2粉末材料に対し、 (b) 第２成分として、Ａｌ2Ｏ3、ＭｇＯ・Ａｌ2Ｏ3（ス
ピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）から選
ばれた１種又は２種以上との粉末を合計で１〜７０内部
重量％の範囲で含む混合粉末を (c) 温度１１００℃以上１６００℃以下で熱間プレス法
あるいは熱間静水圧プレス法で、 (d) 含まれる正方晶ジルコニアの結晶粒子の平均粒子径
が２μｍ以下であり、焼結体のかさ密度が理論密度の９
９％以上であり、かつ３００℃大気中に３０００時間保
持試験後の焼結体に含まれるジルコニアの単斜晶量が３
％以下となるように焼結することを特徴とする。The method for producing a high toughness ceramic sintered body excellent in heat resistance stability according to the third aspect of the invention (claim 3) is (a) as a first component containing Y 2 O 3 and CeO 2 as stabilizers. ZrO 2 powder material, wherein the ZrO 2 powder material comprises a ZrO 2 sol and / or a water-soluble salt.
2 O 3 and CeO 2 are uniformly mixed with a water-soluble salt in the form of a solution and then separated in the form of a precipitate to obtain Y.
2 O 3 and CeO 2 each have Zr on the three axes intersecting the equilateral triangle.
On the triangular coordinate showing the mol% of O 2 , YO 1.5 , and CeO 2 , the point A (ZrO 2 87.5 mol%, YO 1.5 12mo
1%, CeO 2 0.5 mol%) Point B (ZrO 2 95.5 mol%, YO 1.5 4 mol
%, CeO 2 0.5 mol%) Point C (ZrO 2 95.5 mol%, YO 1.5 2 mol
%, CeO 2 2.5 mol%) Point D (ZrO 2 85.0 mol%, YO 1.5 2 mol
%, CeO 2 13.0 mol%) for the ZrO 2 powder material having a composition within the range surrounded by the points connecting the four specific composition points, (b) as the second component, Al 2 O 3 , A mixed powder containing a powder of one or more selected from MgO.Al 2 O 3 (spinel) and 3Al 2 O 3 .2SiO 2 (mullite) in a total amount of 1 to 70 internal weight% ( c) Hot pressing method or hot isostatic pressing method at a temperature of 1100 ° C. or more and 1600 ° C. or less, (d) the average particle size of tetragonal zirconia crystal particles contained is 2 μm or less, and the bulk density of the sintered body is Is the theoretical density of 9
9% or more, and the amount of zirconia monoclinic crystal contained in the sintered body after the holding test at 300 ° C. in the atmosphere for 3000 hours is 3
It is characterized in that it is sintered so as to be less than or equal to%.
【００１５】[0015]
【作用】本発明の耐熱安定性に優れた高靱性セラミック
焼結体は、後述する実施例の焼結体の強度、破壊靱性
値、熱劣化試験結果を参照すれば明らかなように、極め
て高強度でしかも同時に熱安定性に著しく優れる。The high toughness ceramic sintered body of the present invention, which is excellent in heat stability, has an extremely high strength as can be seen by referring to the strength, fracture toughness value and heat deterioration test result of the sintered body of Examples described later. It is strong and at the same time has excellent thermal stability.
【００１６】従って、Ｙ2Ｏ3−ＺｒＯ2系の部分安定化
ジルコニア焼結体が不安定とされる２００〜４００℃の
温度領域における長時間の熱劣化試験後もジルコニア結
晶相の変化及び強度劣化も殆ど無い。すなわち、３００
℃大気中に３０００時間保持試験後の焼結体に含まれる
ジルコニアの単斜晶量が３％以下でありかつ３点曲げ強
度が１４７ｋｇ／ｍｍ2以上（請求項１）ないし１３５
ｋｇ／ｍｍ2以上（請求項２）であり、最高約２００ｋ
ｇ／ｍｍ2にも達する。Therefore, even after a long-term thermal deterioration test in the temperature range of 200 to 400 ° C. where the Y 2 O 3 —ZrO 2 system partially stabilized zirconia sintered body is unstable, the change and strength of the zirconia crystal phase are obtained. Almost no deterioration. That is, 300
The monoclinic crystal content of zirconia contained in the sintered body after the 3000 hour holding test in the atmosphere is 3% or less and the three-point bending strength is 147 kg / mm 2 or more (Claim 1) to 135.
It is more than kg / mm 2 (claim 2), and the maximum is about 200k.
It even reaches g / mm 2 .
【００１７】これは第１にＹ2Ｏ3とＣｅＯ2の両者の同
時添加によって安定化された正方晶ジルコニアの結晶構
造が従来のＹ2Ｏ3のみによって安定化された正方晶ジル
コニアよりもジルコニアの高温安定相である立方晶の結
晶構造により近くなるので、正方晶ジルコニア自体の安
定性が高まったためであると考えられる。This is because the crystal structure of tetragonal zirconia stabilized by simultaneous addition of both Y 2 O 3 and CeO 2 is higher than that of conventional tetragonal zirconia stabilized by Y 2 O 3 alone. It is thought that this is because the stability of the tetragonal zirconia itself is increased because it is closer to the crystal structure of cubic crystal which is a high temperature stable phase.
【００１８】第２に、主成分であるジルコニアよりも高
弾性なＡｌ2Ｏ3等の第２成分の添加によって、ＺｒＯ2
粒界あるいは周囲に高弾性物質が存在する微細組織とな
った。Secondly, by adding a second component such as Al 2 O 3 having a higher elasticity than that of zirconia as the main component, ZrO 2 is added.
It became a fine structure in which highly elastic substances existed at or around the grain boundaries.
【００１９】すなわち、ＺｒＯ2粒子が、周囲の高弾性
物質に押さえ込まれた形となり、体積膨張を伴う正方晶
→単斜晶相転移にもとづく熱劣化反応が生じにくくなっ
たと考えられる。In other words, it is considered that the ZrO 2 particles were pressed into the surrounding high elasticity material, and the thermal deterioration reaction based on the tetragonal → monoclinic phase transition accompanied by volume expansion did not easily occur.
【００２０】第３に、熱間プレス法あるいは熱間静水圧
プレス法等の加圧焼結により、焼結体は一段と緻密化さ
れた為、体積膨張を伴う正方晶→単斜晶相転移（熱劣化
反応）が生じにくくなったものと考えられる。Thirdly, the sintered body is further densified by pressure sintering such as hot pressing or hot isostatic pressing, so that the tetragonal to monoclinic phase transition accompanied by volume expansion ( It is considered that the heat deterioration reaction) is less likely to occur.
【００２１】焼結体の強度についてみると、本発明の焼
結体では３点曲げ強度が１４９ｋｇ／ｍｍ2以上ないし
１３７ｋｇ／ｍｍ2以上であり、Ｙ2Ｏ3を安定化剤とし
て含むＹ2Ｏ3−ＺｒＯ2系、及びこれにアルミナ等の第
２成分を含有するＹ2Ｏ3−ＺｒＯ2−Ａｌ2Ｏ3系、Ｙ2Ｏ
3とＣｅＯ2を安定化剤として含むＹ2Ｏ3−ＣｅＯ2−Ｚ
ｒＯ2系及びこれにアルミナ等の第２成分を含有するＹ2
Ｏ3−ＣｅＯ2−ＺｒＯ2−Ａｌ2Ｏ3系、ＣｅＯ2を安定化
剤として含むＣｅＯ2−ＺｒＯ2系、及びこれにアルミナ
等の分散成分を含有するＣｅＯ2−ＺｒＯ2−Ａｌ2Ｏ3系
の常圧焼結体と比較して一段と高強度であることはもと
より、Ｙ2Ｏ3−ＺｒＯ2系、Ｙ2Ｏ3−ＣｅＯ2−ＺｒＯ2
系、ＣｅＯ2−ＺｒＯ2系のＡｌ2Ｏ3等の第２成分を含有
しない加圧焼結体と比較してもより一層高強度である。With respect to the strength of the sintered body, the three-point bending strength of the sintered body of the present invention is 149 kg / mm 2 or more or 137 kg / mm 2 or more, and Y 2 O 3 containing Y 2 O 3 as a stabilizer is used. O 3 —ZrO 2 system, Y 2 O 3 —ZrO 2 —Al 2 O 3 system containing a second component such as alumina, Y 2 O
Y 2 O 3 containing 3 and CeO 2 as a stabilizer -CeO 2 -Z
rO 2 system and Y 2 containing a second component such as alumina
O 3 -CeO 2 -ZrO 2 -Al 2 O 3 system, CeO 2 -ZrO 2 system containing CeO 2 as a stabilizer, and CeO 2 -ZrO 2 -Al 2 O containing a dispersion component such as alumina to 3 system as compared to the normal pressure sintering of well it is further high strength, Y 2 O 3 -ZrO 2 system, Y 2 O 3 -CeO 2 -ZrO 2
The strength is even higher than that of a pressure-sintered body that does not contain a second component such as a CeO 2 -ZrO 2 -based Al 2 O 3 system.
【００２２】これは第１に熱間プレス法あるいは熱間静
水圧プレス法等の加圧焼結により、焼結体中に含まれる
気孔等の欠陥が除去されるとともに一層緻密化した。緻
密体では体積膨張をともなうような、ＺｒＯ2粒の正方
晶→単斜晶相転移が生じにくいと考えられる。First, defects such as pores contained in the sintered body were removed and further densified by pressure sintering such as hot pressing or hot isostatic pressing. It is considered that a dense body is unlikely to undergo a tetragonal → monoclinic phase transition of ZrO 2 grains accompanied by volume expansion.
【００２３】すなわち、焼結体が破壊される際に応力集
中部分で生じる正方晶から単斜晶への相転移現象におい
て、この相転移を生じさせるのに必要な破壊エネルギー
が増大する為と考えられる。That is, it is considered that, in the phenomenon of the phase transition from tetragonal to monoclinic which occurs in the stress concentration portion when the sintered body is destroyed, the fracture energy required to cause this phase transition increases. To be
【００２４】第２に、主成分であるＺｒＯ2よりも高弾
性なＡｌ2Ｏ3等の第２成分の添加と加圧焼結の相乗効果
により、正方晶ＺｒＯ2粒界及びその周囲に高弾性物質
が存在する緻密な微細組織となった。これにより破壊時
に正方晶ジルコニア粒子が単斜晶ジルコニアへ相転移す
るのをさまたげられるとともに焼結体全体の弾性率も上
昇し、破壊エネルギーが増大した為と考えられる。Secondly, due to the synergistic effect of the addition of the second component such as Al 2 O 3 having a higher elasticity than ZrO 2 which is the main component, and the pressure sintering, the tetragonal ZrO 2 grain boundary and its surroundings are highly enhanced. It became a fine microstructure with the presence of elastic material. It is considered that this prevents the tetragonal zirconia particles from undergoing phase transition to monoclinic zirconia at the time of fracture and also increases the elastic modulus of the entire sintered body, thereby increasing fracture energy.
【００２５】また別の作用として、第２成分の存在によ
り硬度も改善され、耐摩耗性も優れたものとなった。As another function, the presence of the second component improves the hardness and the abrasion resistance.
【００２６】第３の作用として、第２成分の存在により
焼結性が改善され、より高密度・微細結晶粒径の焼結体
が得られ、耐熱安定性のより一層の増大に寄与する。As a third action, the presence of the second component improves the sinterability, obtains a sintered body having a higher density and a fine crystal grain size, and contributes to a further increase in heat stability.
【００２７】本発明ではジルコニアの安定化剤としてＹ
2Ｏ3及びＣｅＯ2を必須とする。Ｙ2Ｏ3、ＣｅＯ2、Ｚｒ
Ｏ2の３成分の配合量は、図１に示すような三角座標に
おいて、点Ａ、Ｂ、Ｃ、Ｄを結ぶ線で囲まれた範囲内で
選ぶ。この範囲内であると正方晶の安定性が特に高く耐
熱性に優れるが、この範囲を外れると大幅に耐熱性が低
下する傾向を示し、また機械的特性も劣ったものとなる
傾向がある。すなわち、点Ａ（ＹＯ1.5 １２ｍｏｌ
％）よりもＹＯ1.5を多く含むと靱性が低下し、点Ｂ
（ＹＯ1.5 ４ｍｏｌ％）よりもＹＯ1.5が少ない場合に
は、耐熱安定性が失われる。点Ｃ（ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％）よりもＹＯ1.5及びＣｅ
Ｏ2が少ない場合には、耐熱安定性が乏しくなる。ま
た、点Ｄ（ＣｅＯ2１３．０ｍｏｌ％）よりもＣｅＯ2が
多い場合には充分な機械的強度が得られない。In the present invention, Y is used as a stabilizer for zirconia.
2 O 3 and CeO 2 are essential. Y 2 O 3 , CeO 2 , Zr
The blending amounts of the three components of O 2 are selected within the range surrounded by the line connecting points A, B, C and D on the triangular coordinates as shown in FIG. Within this range, the stability of the tetragonal crystal is particularly high and the heat resistance is excellent, but outside this range, the heat resistance tends to be significantly reduced and the mechanical properties tend to be inferior. That is, point A (YO 1.5 12 mol
Containing more YO 1.5 than%) the toughness is lowered, the point B
When YO 1.5 is less than (YO 1.5 4 mol%), heat stability is lost. Point C (YO 1.5 2 mol
%, CeO 2 2.5 mol%) and YO 1.5 and Ce
If the O 2 content is low, the heat stability becomes poor. Further, when CeO 2 is more than the point D (CeO 2 13.0 mol%), sufficient mechanical strength cannot be obtained.
【００２８】図１に関し、表４に示す参考例を上記３成
分の組成に関し参照されたい。With reference to FIG. 1, see the reference example shown in Table 4 for the composition of the above three components.
【００２９】本発明をより効果あるものとするために
は、上記３成分の配合量を図面に示すような三角座標に
おいて、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｈ（ＺｒＯ2 ９４．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 １．５ｍｏｌ％） 点Ｇ（ＺｒＯ2 ９４．５ｍｏｌ％、ＹＯ1.5 ２．５ｍ
ｏｌ％、ＣｅＯ2 ３．０ｍｏｌ％） 点Ｆ（ＺｒＯ2 ８９ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ％、
ＣｅＯ2 ９ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ％、
ＣｅＯ2 １３ｍｏｌ％） を結ぶ実線で囲まれた範囲内に選択するとよい。なお、
Ｙ2Ｏ3の一部をＮｄ2Ｏ3、Ｙｂ2Ｏ3、Ｌａ2Ｏ3、Ｅｒ2
Ｏ3等の希土類金属酸化物で置換することも可能であ
る。In order to make the present invention more effective, the compounding amounts of the above three components are represented by the points A (ZrO 2 87.5 mol%, YO 1.5 12 mo) in the triangular coordinates as shown in the drawing.
1%, CeO 2 0.5 mol%) Point H (ZrO 2 94.5 mol%, YO 1.5 4 mol
%, CeO 2 1.5 mol%) Point G (ZrO 2 94.5 mol%, YO 1.5 2.5 m
ol%, CeO 2 3.0 mol%) F (ZrO 2 89 mol%, YO 1.5 2 mol%,
CeO 2 9 mol%) Point D (ZrO 2 85 mol%, YO 1.5 2 mol%,
CeO 2 ( 13 mol%) is preferably selected within the range surrounded by a solid line. In addition,
Part of Y 2 O 3 is Nd 2 O 3 , Yb 2 O 3 , La 2 O 3 , Er 2
Substitution with a rare earth metal oxide such as O 3 is also possible.
【００３０】本発明では、Ａｌ2Ｏ3、ＭｇＯ・Ａｌ2Ｏ3
（スピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）か
ら選ばれた１種又は２種以上を第２成分として１〜７０
内部重量％含む必要がある。第２成分の添加量を限定し
た理由は、１内部重量％以下では添加の効果が少なく、
７０内部重量％以上では靱性あるＺｒＯ2の含有量を低
めるからである。In the present invention, Al 2 O 3 , MgO.Al 2 O 3
1 to 70 or more selected from (spinel) and 3Al 2 O 3 .2SiO 2 (mullite) as the second component.
Must contain internal weight percent. The reason why the addition amount of the second component is limited is that the effect of addition is small when the content is 1% by weight or less
This is because the content of tough ZrO 2 is lowered when the content is 70% by weight or more.
【００３１】本発明をより効果あるものとするためには
第２成分の添加量を５〜５０内部重量％の範囲に選択す
るとよい。In order to make the present invention more effective, it is advisable to select the addition amount of the second component in the range of 5 to 50% by weight.
【００３２】なお、この範囲内では第２成分は主として
分散成分として作用すると考えられるが、これより第２
成分が多くなると第２成分が連続相を成す場合がある。Within this range, the second component is considered to act mainly as a dispersive component.
When the amount of the component increases, the second component may form a continuous phase.
【００３３】本発明の製造方法は、通常次のように実施
される。Ｙ2Ｏ3及びＣｅＯ2を安定化剤として含むＺｒ
Ｏ2粉末材料（但し、Ｙ2Ｏ3は１モル％以上）に対し、
第２成分としてＡｌ2Ｏ3、ＭｇＯ・Ａｌ2Ｏ3（スピネ
ル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）から選ばれ
た１種又は２種以上の粉末を合計で１〜７０内部重量％
の範囲で加えた粉末を粉末混合した混合粉末または予備
成形体を温度１１００℃〜１６００℃の範囲でホットプ
レス（ＨＰ）、またはホットアイソスタティックプレス
（ＨＩＰ）にて加圧焼結する。The manufacturing method of the present invention is usually carried out as follows. Zr containing Y 2 O 3 and CeO 2 as stabilizers
O 2 powder material (however, Y 2 O 3 is 1 mol% or more),
As a second component, 1 to 70 internal weight% of one or two or more kinds of powder selected from Al 2 O 3 , MgO · Al 2 O 3 (spinel) and 3Al 2 O 3 · 2SiO 2 (mullite) are added in total.
The mixed powder obtained by powder-mixing the powders added in the above range or a preformed body is pressure-sintered by a hot press (HP) or a hot isostatic press (HIP) in a temperature range of 1100 ° C to 1600 ° C.
【００３４】ＺｒＯ2粉末としては、比表面積１０ｍ2／
ｇ以上、好ましくは１５ｍ2／ｇ以上、より好ましくは
２０ｍ2／ｇ以上のものを用いる。The ZrO 2 powder has a specific surface area of 10 m 2 /
g or more, preferably 15 m 2 / g or more, more preferably 20 m 2 / g or more.
【００３５】加圧焼結の際上記温度としたのは、温度が
１１００℃未満では十分に高密度な焼結体が得られず、
１６００℃を超えると焼結体中のジルコニア結晶粒子が
粒成長し、２μｍ以上となり好ましくないためである。In the pressure sintering, the above temperature is set because the temperature is less than 1100 ° C., a sufficiently high density sintered body cannot be obtained.
This is because if the temperature exceeds 1600 ° C., the zirconia crystal particles in the sintered body grow and the particle size becomes 2 μm or more, which is not preferable.
【００３６】ＨＰ法の場合は５０〜３００ｋｇ／ｃｍ2
の圧力下でＨＩＰ法の場合は常圧焼結、ガス加圧焼結、
ホットプレス等で予め相対密度９５％以上の非通気性焼
結体を得たのち、熱間静水圧プレス内にて１０００ｋｇ
／ｃｍ2以上のガス圧力、１１００℃以上１６００℃以
下の温度条件にて０．５ｈｒ以上の焼結を行うことが好
適である。あるいはカプセル中に混合粉末を充填し、そ
のまま熱間静水圧プレス処理する方法もまた好適であ
る。In the case of HP method, 50 to 300 kg / cm 2
In the case of the HIP method under normal pressure, normal pressure sintering, gas pressure sintering,
After obtaining a non-breathable sintered body with a relative density of 95% or more in advance by hot pressing etc., 1000 kg in a hot isostatic press
It is preferable to perform sintering for 0.5 hr or more under a gas pressure of 1 / cm 2 or more and a temperature condition of 1100 ° C. or more and 1600 ° C. or less. Alternatively, a method in which the mixed powder is filled in a capsule and hot isostatic pressing is performed as it is is also suitable.
【００３７】本発明の部分安定化ジルコニアはＺｒＯ2
のゾルおよび／または水溶性の塩を安定化剤の水溶性の
塩と共に溶液の状態で均一に混合した後沈澱の形で分離
して得られた原料を用いた場合、ＺｒＯ2に安定化剤が
均一に分散し、極めて微粒子からなる易焼結性の粉体を
原料とすることができる。この結果、微粒で均一な組成
を有し、マイクロポアの殆どない焼結体が得られ、強度
及び靱性についても所期の値が得られる。The partially stabilized zirconia of the present invention is ZrO 2
When the raw material obtained by uniformly mixing the sol and / or the water-soluble salt of the above with the water-soluble salt of the stabilizer in the form of a solution and then separating in the form of a precipitate is used, ZrO 2 It is possible to use as a raw material a powder that is uniformly dispersed and that is made of extremely fine particles and that is easily sintered. As a result, a sintered body having fine particles and a uniform composition and almost no micropores can be obtained, and desired values can be obtained for strength and toughness.
【００３８】なお、本発明の高靱性セラミック焼結体
は、耐熱安定性を高めるため焼結体の相対密度が本実施
例にあるように９９％以上であり、より好ましくは９
９．５％以上がよい。また、相対密度が高いほど焼結体
に含まれる正方晶ジルコニアの安定性が高まり、耐熱安
定性に優れ、強度及び靱性に優れると共にその熱劣化を
生じない。In the high toughness ceramic sintered body of the present invention, the relative density of the sintered body is 99% or more, and more preferably 9%, as in the present embodiment, in order to enhance the heat resistance stability.
9.5% or more is preferable. In addition, the higher the relative density, the higher the stability of the tetragonal zirconia contained in the sintered body, the excellent heat resistance stability, the excellent strength and toughness, and the less thermal deterioration thereof.
【００３９】なお、焼結後の状態では、単斜晶はジルコ
ニア中に実質上含まれない。熱劣化試験後の単斜晶は３
％以下であるが、さらに実質的に０％のものが得られ
る。In the state after sintering, monoclinic crystals are substantially not contained in zirconia. The number of monoclinic crystals after the heat deterioration test is 3
% Or less, but substantially 0% is obtained.
【００４０】本発明の組成を有するジルコニア焼結体は
主として正方晶より成る部分安定化ジルコニアであるの
で、高強度・高靱性を示す。本来正方晶は準安定相であ
るため試料表面の研削によって一部が単斜晶へ転移を生
じ表面相の残留圧縮応力により焼結体の強化に寄与す
る。この強化の程度は研削による表面粗さと焼結体の粒
径に依存している。このため、本発明による主として正
方晶より成る部分安定化ジルコニアとは、Ｘ線回折によ
る結晶相の測定において鏡面状態で正方晶系を少なくと
も５０％以上含むジルコニアをいう。正方晶系が５０％
以下になると、靱性が低下するので正方晶系は５０％以
上含まれることが必要である。Since the zirconia sintered body having the composition of the present invention is a partially stabilized zirconia mainly composed of tetragonal crystals, it exhibits high strength and high toughness. Since the tetragonal phase is a metastable phase by nature, a part of the sample surface is transformed into a monoclinic structure by grinding, and the residual compressive stress of the surface phase contributes to strengthening of the sintered body. The degree of this strengthening depends on the surface roughness due to grinding and the grain size of the sintered body. Therefore, the partially stabilized zirconia mainly composed of tetragonal crystals according to the present invention means zirconia containing at least 50% or more of tetragonal system in a mirror state in the measurement of the crystal phase by X-ray diffraction. Tetragonal system is 50%
If it is less than the above range, the toughness decreases, so it is necessary that the content of the tetragonal system is 50% or more.
【００４１】本発明の焼結体は、焼結体に含まれる正方
晶ジルコニアの平均結晶粒子径が２μｍ以下であること
が必要である。好ましくは１μｍ以下であることが良
い。さらに好ましくは０．５μｍ以下が良い。平均結晶
粒子径が２μｍを越えると単斜晶に変わり靱性が低下す
る。また、正方晶ジルコニアの平均粒子径が小さいほ
ど、安定性が向上し耐熱性に優れたものとなる。In the sintered body of the present invention, the average crystal grain size of tetragonal zirconia contained in the sintered body needs to be 2 μm or less. It is preferably 1 μm or less. More preferably, it is 0.5 μm or less. If the average crystal grain size exceeds 2 μm, it changes to monoclinic and the toughness decreases. Further, the smaller the average particle size of the tetragonal zirconia, the higher the stability and the better the heat resistance.
【００４２】本発明において、ジルコニアの平均結晶粒
子径はＣｕＫα線を用いたＸ線回折法で行い、式として Ｄ＝０．８９λ／（Ｂ−ｂ）ｃｏｓθ より求めた。ここでＤは求めるジルコニアの結晶粒子
径、λはＣｕＫα線の波長で１．５４１Å、Ｂはジルコ
ニアの単斜晶（１１１）面あるいは正方晶（１１１）面
の回折線の半減値幅（ラジアン）のうち大きい方の値、
ｂは内部標準として添加する結晶粒子径３０００Å以上
のα石英の（１０１）面の半減値幅（ラジアン）、θは
ジルコニアの半減値幅の測定に用いた回折線の回折角２
θの１／２の値である。In the present invention, the average crystal grain size of zirconia was determined by an X-ray diffraction method using CuKα rays, and was obtained from the equation D = 0.89λ / (Bb) cosθ. Here, D is the crystal grain size of the zirconia to be obtained, λ is the wavelength of the CuKα line of 1.541Å, and B is the half-value width (radian) of the diffraction line of the monoclinic (111) plane or tetragonal (111) plane of zirconia. The larger value,
b is the half-value width (radian) of the (101) plane of α-quartz with a crystal grain size of 3000 Å or more, which is added as an internal standard, and θ is the diffraction angle 2 of the diffraction line used to measure the half-value width of zirconia.
It is a value of 1/2 of θ.
【００４３】本発明のジルコニア焼結体のＺｒＯ2は、
その一部以上全部までＨｆＯ2によって置換しても、全
く同様の特性を示すものである。ZrO 2 of the zirconia sintered body of the present invention is
Even if a part or more of them are replaced with HfO 2 , the same characteristics are exhibited.
【００４４】[0044]
【実施例】以下に本発明の実施例を説明し、本発明の効
果を明らかにする。EXAMPLES Examples of the present invention will be described below to clarify the effects of the present invention.
【００４５】（実施例１） ２５ｍ2／ｇの比表面積を有する純度９９％以上の単斜
晶系ジルコニアに対し、安定化剤としてＹ2Ｏ3、ＣｅＯ
2を表１の割合で添加し、これに第２成分として、平均
粒径０．３μｍ、純度９９．９％のＡｌ2Ｏ3、平均粒径
０．３μｍ、純度９９．９％のＭｇＯ・Ａｌ2Ｏ3（スピ
ネル）、比表面積２８ｍ2／ｇ、Ａｌ2Ｏ3／ＳｉＯ2比が
７１．８／２８．２の合成ムライト（３Ａｌ2Ｏ3・２Ｓ
ｉＯ2）を表１の割合で加え、湿式混合後乾燥させた粉
末を２００ｋｇ／ｃｍ2、１４００〜１５００℃の条件
で、ホットプレス法により約１時間焼成した。Example 1 For monoclinic zirconia having a specific surface area of 25 m 2 / g and a purity of 99% or more, Y 2 O 3 and CeO were used as stabilizers.
2 was added at the ratio shown in Table 1, and as the second component, Al 2 O 3 having an average particle size of 0.3 μm and a purity of 99.9%, MgO having an average particle size of 0.3 μm and a purity of 99.9% were added. Al 2 O 3 (spinel), a specific surface area of 28m 2 / g, Al 2 O 3 / synthetic mullite SiO 2 ratio is 71.8 / 28.2 (3Al 2 O 3 · 2S
iO 2 ) was added at the ratio shown in Table 1, and the powder obtained by wet-mixing and then drying was fired under a condition of 200 kg / cm 2 and 1400-1500 ° C. for about 1 hour by a hot pressing method.
【００４６】得られた焼結体に含まれる正方晶ジルコニ
アの平均結晶粒子は、総て２μｍ以下であった。得られ
た焼結体は、３×４×４０ｍｍに切断研磨加工し、嵩密
度、結晶相、抗折強度、及び破壊靱性並びに熱劣化試験
後の焼結体表面の結晶相及び抗折強度を測定しその結果
を表１に示す。The average crystal grains of tetragonal zirconia contained in the obtained sintered body were all 2 μm or less. The obtained sintered body was cut and polished to 3 × 4 × 40 mm, and the bulk density, crystal phase, bending strength, fracture toughness, and crystal phase and bending strength of the surface of the sintered body after the heat deterioration test were performed. The results are shown in Table 1.
【００４７】なお、各物性の測定方法として、抗折強度
はＪＩＳ規格に従い、３×４×４０ｍｍ試料片を用い、
スパン３０ｍｍ、クロスヘッド速度０．５ｍｍ／ｍｉｎ
の３点曲げにより１０本の平均値を示した。As a method of measuring each physical property, a bending strength of 3 × 4 × 40 mm sample piece was used in accordance with JIS standard.
Span 30mm, Crosshead speed 0.5mm / min
The average value of 10 pieces was shown by 3-point bending.
【００４８】破壊靱性は、マイクロインデンテーション
法により、荷重５０ｋｇで圧痕を入れて測定を行い、Ｋ
ＩＣ値は新原らの式を用いた。The fracture toughness was measured by the microindentation method with an indentation with a load of 50 kg.
The IC value used the formula of Niihara et al.
【００４９】結晶相の定量測定は、Ｘ線回折法によって
行った。すなわち、ダイヤモンドペーストにて鏡面研磨
した試料の単斜晶の（１１１）面と（１１１）面の積分
強度ＩＭと正方晶の（１１１）面及び立方晶の（１１
１）面の積分強度ＩＴ、ＩＣより単斜晶量は、The quantitative measurement of the crystal phase was carried out by the X-ray diffraction method. That is, the integrated intensity IM of the monoclinic (111) plane and the (111) plane of the sample mirror-polished with diamond paste, and the tetragonal (111) plane and cubic (11)
1) From the integrated strengths IT and IC of the plane, the amount of monoclinic crystal is
【００５０】[0050]
【数１】 [Equation 1]
【００５１】の式により決定した。次に焼結体を５μｍ
以下に微粉砕し、Ｘ線回折により同条件で単斜晶ＺｒＯ
2と立方晶ＺｒＯ2の積分強度ＩＭ*及びＩＣ*を求めた。
この微粉砕の過程で焼結体中に存在していた正方晶Ｚｒ
Ｏ2は機械的応力によりすべて単斜晶ＺｒＯ2へ変態する
と考えられる。よって立方晶量は、It was determined by the formula: Next, the sintered body is 5 μm
Finely pulverized into the following, and monoclinic ZrO 2 under the same conditions by X-ray diffraction.
The integrated intensities IM * and IC * of 2 and cubic ZrO 2 were determined.
Tetragonal Zr that was present in the sintered body during this pulverization process
It is considered that O 2 is transformed into monoclinic ZrO 2 by mechanical stress. Therefore, the cubic amount is
【００５２】[0052]
【数２】 [Equation 2]
【００５３】により決定し、これより正方晶は、 （正方晶量）＝１００−｛（単斜晶量）＋（立方晶
量）｝ により決定した。From this, the tetragonal crystal was determined by (tetragonal crystal amount) = 100-{(monoclinic crystal amount) + (cubic crystal amount)}.
【００５４】熱劣化試験は、３００℃の電気炉内に３０
００時間保持した後、試料を取り出し物性を測定した。
熱劣化試験後の単斜晶量は、試料表面のＸ線回折により
同様に上記式（１）より求めた。The heat deterioration test was conducted in an electric furnace at 300 ° C. for 30 hours.
After holding for 00 hours, the sample was taken out and the physical properties were measured.
The amount of monoclinic crystals after the heat deterioration test was similarly obtained from the above formula (1) by X-ray diffraction of the sample surface.
【００５５】[0055]
【表１】 [Table 1]
【００５６】本実施例では、安定化剤としてＹＯ1.5を
３ｍｏｌ％、ＣｅＯ2を６ｍｏｌ％添加し、これに種々
の第２成分を３０重量％加えたものである。In this example, 3 mol% of YO 1.5 and 6 mol% of CeO 2 were added as stabilizers, and 30 wt% of various second components were added thereto.
【００５７】試料Ｎｏ．１〜３はＡｌ2Ｏ3、ＭｇＯ・Ａ
ｌ2Ｏ3（スピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライ
ト）を単独で３０重量％添加したものである。Sample No. 1 to 3 are Al 2 O 3 and MgO · A
30% by weight of 1 2 O 3 (spinel) and 3Al 2 O 3 .2SiO 2 (mullite) were added alone.
【００５８】表１から明らかなように、いずれも相対密
度、破壊靱性及び曲げ強度が高く、熱劣化試験によって
も単斜晶への転移が見られず、曲げ強度も殆ど劣化しな
い。As is clear from Table 1, the relative densities, fracture toughness and bending strength are all high, no transition to monoclinic crystals is observed by the heat deterioration test, and bending strength is hardly deteriorated.
【００５９】（実施例２） 得られる粉末が表２の割合になるように、純度９９．９
％のオキシ塩化ジルコニウムの水溶液の加水分解によっ
て得られたジルコニアゾル溶液に、純度９９．９％の塩
化イットリウム、純度９９．９％の塩化セリウムを加
え、均一に混合した溶液をアルカリで凝結させ、水酸化
物の沈澱とし、これを脱水乾燥し９００℃にて仮焼して
部分安定化ジルコニア粉末を得た。この粉末は２５ｍ2
／ｇの比表面積を示す。Example 2 The purity of the obtained powder was 99.9 so that the ratio shown in Table 2 was obtained.
% Zirconia sol solution obtained by hydrolysis of an aqueous solution of zirconium oxychloride, yttrium chloride having a purity of 99.9% and cerium chloride having a purity of 99.9% are added, and the uniformly mixed solution is condensed with an alkali, The precipitate of hydroxide was dehydrated, dried, and calcined at 900 ° C. to obtain a partially stabilized zirconia powder. 25m 2 of this powder
The specific surface area of / g is shown.
【００６０】この粉末に、平均粒径０．３μｍ、純度９
９．９％のＡｌ2Ｏ3を、第２成分として表２の割合で加
え、湿式混合後乾燥させた粉末を、１．５ｔｏｎ／ｃｍ
2の圧力で等方的に成形し、１３５０〜１５００℃の温
度で２時間予備焼結し、理論密度の９５％以上の非通気
性焼結体を得た。この焼結体をＡｒガス雰囲気中で２０
００ｋｇ／ｃｍ2の圧力下１４５０〜１６００℃で１時
間、熱間静水圧プレス内にて焼成を行った。得られた焼
結体に含まれる正方晶ジルコニアの平均粒子は総て２μ
ｍ以下であった。This powder had an average particle size of 0.3 μm and a purity of 9
9.9% Al 2 O 3 was added as a second component in a ratio shown in Table 2, wet-mixed and dried to obtain a powder of 1.5 ton / cm 2.
It was isotropically molded under a pressure of 2 and pre-sintered at a temperature of 1350 to 1500 ° C. for 2 hours to obtain a non-breathable sintered body having a theoretical density of 95% or more. This sintered body is placed in an Ar gas atmosphere for 20
Firing was performed in a hot isostatic press at 1450 to 1600 ° C. for 1 hour under a pressure of 00 kg / cm 2 . The average particles of tetragonal zirconia contained in the obtained sintered body were all 2 μm.
It was m or less.
【００６１】得られた焼結体は実施例１と同様にして嵩
密度、結晶相、抗折強度、及び破壊靱性並びに熱劣化試
験後の焼結体表面の結晶及び抗折強度を測定しその結果
を表２に示した。The obtained sintered body was measured for bulk density, crystal phase, flexural strength, fracture toughness, and crystal and flexural strength on the surface of the sintered body after the heat deterioration test in the same manner as in Example 1. The results are shown in Table 2.
【００６２】[0062]
【表２】 [Table 2]
【００６３】表２において、試料Ｎｏ．４〜８は安定化
剤としてＹＯ1.5 ４ｍｏｌ％とＣｅＯ2 ４ｍｏｌ％を
添加し、これに第２成分としてＡｌ2Ｏ3を５〜７０重量
％加えたものである。In Table 2, sample No. Nos. 4 to 8 are obtained by adding YO 1.5 4 mol% and CeO 2 4 mol% as stabilizers and adding Al 2 O 3 as 5 to 70 wt% as a second component.
【００６４】いずれの試料も相対密度、破壊靱性及び抗
折強度共に高い数字を示し、さらに熱劣化試験後におい
ても単斜晶への転移が測定されず、抗折強度も殆ど劣化
せず本発明の効果が確認された。なお、試料Ｎｏ．９は
安定化剤としてそれぞれ４ｍｏｌ％のＹＯ1.5及びＣｅ
Ｏ2を添加し、第２成分として本発明の組成範囲以上の
Ａｌ2Ｏ3を添加した比較例であるが、相対密度は高いも
のの破壊靱性、曲げ強度に充分な値が得られない。All of the samples showed high relative density, fracture toughness, and bending strength, and after the thermal deterioration test, the transition to monoclinic crystals was not measured, and the bending strength was hardly deteriorated. The effect of was confirmed. Sample No. 9 is a stabilizer of 4 mol% of YO 1.5 and Ce, respectively.
This is a comparative example in which O 2 is added and Al 2 O 3 in the composition range of the present invention or more is added as the second component. However, although the relative density is high, sufficient values for fracture toughness and bending strength cannot be obtained.
【００６５】試料Ｎｏ．１０〜１６では、安定化剤とし
てＹＯ1.5を６ｍｏｌ％と一定にしＣｅＯ2を無添加の場
合と添加した場合について、第２成分の添加量を変えた
ものである。ＣｅＯ2を全く添加しない試料Ｎｏ．１０
〜１２では、第２成分を添加しても、熱劣化が甚だし
く、熱劣化試験後に単斜晶へ転移してしまって、曲げ強
度が著しく劣化してしまう。試料Ｎｏ．１３は、安定化
剤としてＣｅＯ2 １．５ｍｏｌ％添加し、第２成分を
全く添加しない比較例であるが、同様に熱劣化が生じ
る。Sample No. In Nos. 10 to 16, YO 1.5 as a stabilizer was kept constant at 6 mol%, and the addition amount of the second component was changed with and without addition of CeO 2 . Sample No. in which CeO 2 was not added at all. 10
In Nos. 12 to 12, even if the second component was added, the thermal deterioration was so great that it was transformed into a monoclinic crystal after the thermal deterioration test, and the bending strength was significantly deteriorated. Sample No. No. 13 is a comparative example in which 1.5 mol% of CeO 2 is added as a stabilizer and the second component is not added at all, but thermal deterioration similarly occurs.
【００６６】これに対して、試料Ｎｏ．１４〜１６は安
定化剤としてＹ2Ｏ3及びＣｅＯ2を含み、第２成分とし
てＡｌ2Ｏ3を１０〜４０重量％添加した実施例である
が、いずれも破壊靱性、曲げ強度共に高い値が得られ、
熱劣化試験によっても単斜晶への転移が起こらず強度の
劣化が見られないことが確認された。On the other hand, sample No. Nos. 14 to 16 are examples containing Y 2 O 3 and CeO 2 as stabilizers and adding 10 to 40% by weight of Al 2 O 3 as a second component, but both have high fracture toughness and high bending strength. Is obtained,
It was also confirmed by the heat deterioration test that the transition to the monoclinic crystal did not occur and the strength was not deteriorated.
【００６７】また、本実施例の試料のうち、Ｎｏ．５〜
６、１０について、ロックウエルスーパーフィッシャル
硬度計を用いて荷重４５ｋｇで硬度を測定しその結果を
表３に示した。Of the samples of this example, No. 5-
For Nos. 6 and 10, the hardness was measured with a load of 45 kg using a Rockwell Superficial hardness meter, and the results are shown in Table 3.
【００６８】[0068]
【表３】 [Table 3]
【００６９】表３より、安定化剤として４ｍｏｌ％のＹ
Ｏ1.5とＣｅＯ2を添加し、さらに第２成分としてＡｌ2
Ｏ3等を添加した実施例である試料Ｎｏ．５〜６は、安
定化剤として６ｍｏｌ％のＹＯ1.5のみを添加し、分散
成分を全く添加しない比較例である試料Ｎｏ．１０の部
分安定化ジルコニア焼結体よりも、著しく硬度が改善さ
れていることが判る。From Table 3, 4 mol% Y was added as a stabilizer.
O 1.5 and CeO 2 were added, and Al 2 was added as the second component.
Sample No. which is an example in which O 3 and the like are added. Sample Nos. 5 to 6 are comparative examples in which only 6 mol% of YO 1.5 was added as a stabilizer and no dispersion component was added. It can be seen that the hardness is remarkably improved over the partially stabilized zirconia sintered body of No. 10.
【００７０】また表４に熱間プレス処理あるいは熱間静
水圧プレス処理を施さずに、常圧焼結した参考例試料Ｎ
ｏ．１７〜３０の特性値を示す。Further, in Table 4, reference example sample N which was sintered under normal pressure without hot pressing or hot isostatic pressing was used.
o. The characteristic values of 17 to 30 are shown.
【００７１】[0071]
【表４】 [Table 4]
【００７２】表４の結果より、本実施例試料の曲げ強度
および熱劣化試験後の曲げ強度の値は、常圧焼結した参
考例試料の値よりも極めて優れていることが確認され
た。From the results in Table 4, it was confirmed that the flexural strength values of the samples of this example and the flexural strength values after the thermal deterioration test were significantly superior to those of the reference example samples sintered under normal pressure.
【００７３】（実施例３） 実施例１及び実施例２の方法により調整した焼結体のう
ち試料Ｎｏ．１、６、１５を、比較例として試料Ｎｏ．
１０、１１、１３を用い、３００℃の電気炉中に所定時
間保持し、熱劣化試験を行い、焼結体表面の単斜晶量を
測定し、保持時間と単斜晶量の関係を図２に示した。Example 3 Of the sintered bodies prepared by the methods of Example 1 and Example 2, sample No. Sample Nos. 1, 6 and 15 were used as comparative examples.
Using 10, 11, 13 and holding it in an electric furnace at 300 ° C for a predetermined time, performing a thermal deterioration test, measuring the amount of monoclinic crystal on the surface of the sintered body, and showing the relationship between the holding time and the amount of monoclinic crystal. Shown in 2.
【００７４】図２において、本実施例である試料Ｎｏ．
１、６、１５は１５００時間保持したにも拘らず、単斜
晶への転移が殆ど起こっていない。これに対してＹ2Ｏ3
−ＺｒＯ2系で第２成分を含まない比較例Ｎｏ．１０、
Ｙ2Ｏ3−ＺｒＯ2−Ａｌ2Ｏ3系でＣｅＯ2を含まない比較
例Ｎｏ．１１、及びＹ2Ｏ3−ＣｅＯ2−ＺｒＯ2系で第２
成分を全く添加しない比較例Ｎｏ．１３は、３００℃空
気中で保持する間に単斜晶への転移が起こり、熱劣化す
ることが判る。これより本発明の組成の高靱性セラミッ
ク焼結体は、比較例の各焼結体に比べて極めて優れた熱
安定性を示すことが確認された。In FIG. 2, the sample No.
Although 1, 6, and 15 were held for 1500 hours, the transition to monoclinic crystals hardly occurred. On the other hand, Y 2 O 3
Comparative Example -ZrO 2 system does not include the second component No. 10,
Comparative Example does not contain CeO 2 with Y 2 O 3 -ZrO 2 -Al 2 O 3 system No. 11 and Y 2 O 3 —CeO 2 —ZrO 2 system second
Comparative example no. It can be seen that No. 13 undergoes a transition to a monoclinic crystal while being held in air at 300 ° C. and is thermally deteriorated. From this, it was confirmed that the high toughness ceramic sintered body having the composition of the present invention exhibits extremely excellent thermal stability as compared with the respective sintered bodies of Comparative Examples.
【００７５】[0075]
【発明の効果】第１、２の発明（請求項１、２）の耐熱
安定性に優れた高靱性セラミック焼結体は、Ｙ2Ｏ3とＣ
ｅＯ2を所定量安定化剤として含む主として正方晶より
成る部分安定化ジルコニアと、Ａｌ2Ｏ3、ＭｇＯ・Ａｌ
2Ｏ3（スピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライ
ト）より選ばれた１種又は２種以上の第２成分（分散成
分）とから成り、熱間プレス法あるいは熱間静水圧プレ
ス法等により高密度にかつ平均２μｍ以下のジルコニア
結晶粒子径となるよう製造された加圧焼結体であるの
で、極めて高強度でしかも同時に熱安定性に著しく優れ
る。すなわち、強度、靱性の熱経時劣化が極めて少ない
高靱性セラミック焼結体であり、このようなジルコニア
系焼結体は従来かつてないものである。なお、加圧焼結
の効果は、そうでない常圧焼結の場合に比して通常強度
が約１．５倍増という予期せざる顕著な効果を奏する。The high toughness ceramic sintered body excellent in heat resistance stability according to the first and second inventions (claims 1 and 2) comprises Y 2 O 3 and C.
Partially stabilized zirconia mainly composed of tetragonal crystals containing eO 2 as a stabilizer in a predetermined amount, and Al 2 O 3 and MgO.Al.
2 O 3 (spinel), 3Al 2 O 3 · 2SiO 2 become from the one or more second component selected from (mullite) (dispersion component), a hot press method or a hot isostatic pressing method Since the pressure-sintered body is manufactured to have a high density and an average zirconia crystal grain size of 2 μm or less, the strength is extremely high and at the same time the thermal stability is remarkably excellent. That is, it is a high-toughness ceramic sintered body with extremely little deterioration of strength and toughness due to heat, and such a zirconia-based sintered body has never been seen before. The effect of pressure sintering has an unexpectedly remarkable effect that the normal strength is increased by about 1.5 times as compared with the case of normal pressure sintering that is not the case.
【００７６】第１、２の発明（請求項１、２）の耐熱安
定性に優れた高靱性セラミック焼結体を摺動部材として
使用する場合は、３モルＹ2Ｏ3部分安定化ジルコニア焼
結体と比較して、約１０倍以上の耐摩耗性が得られる。
本発明はこのように部分安定化ジルコニア焼結体の硬度
を改善し、耐摩耗性も一段と優れるものである。さらに
主として分散成分をなす第２成分の添加により、高温に
おいて従来のジルコニア焼結体と比較し、硬度、強度、
クリープ等の機械的特性にも優れる。When the high toughness ceramic sintered body having excellent heat resistance stability of the first and second inventions (claims 1 and 2) is used as a sliding member, 3 mol Y 2 O 3 partially stabilized zirconia firing is carried out. The wear resistance is about 10 times higher than that of the bonded body.
As described above, the present invention improves the hardness of the partially stabilized zirconia sintered body and further improves the wear resistance. Furthermore, the addition of the second component, which mainly constitutes the dispersion component, makes it possible to obtain hardness, strength, and
Excellent mechanical properties such as creep.
【００７７】第１、２の発明（請求項１、２）の耐熱安
定性に優れた高靱性セラミック焼結体は、このように常
温及び高温において優れた特性を有するので、熱可塑性
樹脂やセラミックスの射出成型機用の耐摩耗性セラミッ
クススクリュウ、真ちゅうロッドや銅管シェル等の熱間
押出しダイス、ガスタービン部品、ディーゼルエンジン
部品等の内燃機関、ポンプ部品、工業用カッター、切削
工具、粉砕機械用部品、摺動部材、人工骨、人工歯、鋳
造セラミックによる人工歯のブリッジ芯材料、人工歯
根、ゲージ等の機械工具、固体電解質等への応用及び実
用化と、性能向上に大きく寄与するものである。The high toughness ceramic sintered body of the first and second inventions (Claims 1 and 2) having excellent heat resistance stability has excellent characteristics at room temperature and high temperature as described above. Wear-resistant ceramics screws for injection molding machines, hot extrusion dies such as brass rods and copper tube shells, gas turbine parts, internal combustion engines such as diesel engine parts, pump parts, industrial cutters, cutting tools, crushing machines Parts, sliding members, artificial bones, artificial teeth, bridge core materials for artificial teeth made of cast ceramics, artificial roots, mechanical tools such as gauges, application and practical application to solid electrolytes, etc., and contribute greatly to performance improvement. is there.
【００７８】上記効果は、部分安定化ジルコニアに含ま
れるＹ2Ｏ3とＣｅＯ2の組成を、添付図面のＡＢＣＤの
４組成点を結ぶ点で囲まれた範囲内の組成にすることで
より確実に達成される（請求項２）。The above effect can be more surely achieved by making the composition of Y 2 O 3 and CeO 2 contained in the partially stabilized zirconia within the range surrounded by the points connecting the four composition points of ABCD in the attached drawings. (Claim 2).
【００７９】また、第３の発明（請求項３）の耐熱安定
性に優れた高靱性セラミック焼結体の製造方法では、特
定の組成と特定の加圧焼結法の適用に基づき上記の耐熱
安定性に優れた高靱性セラミック焼結体を容易に得るこ
とができる。Further, in the method for producing a high toughness ceramic sintered body excellent in heat resistance stability of the third invention (Claim 3), the above heat resistance is applied based on the application of a specific composition and a specific pressure sintering method. It is possible to easily obtain a high toughness ceramic sintered body having excellent stability.
【００８０】加うるに、Ｙ2Ｏ3とＣｅＯ2を安定化剤と
して含むＺｒＯ2粉末を、ＺｒＯ2のゾルおよび／または
水溶性の塩をＹ2Ｏ3、ＣｅＯ2を生ずる水溶性の塩と共
に溶液の状態で均一に混合した後、沈澱の形で分離して
得られたものとすることにより、ＺｒＯ2に安定化剤が
均一分散し、極めて微粒子からなる易焼結性の粉体の原
料となるため、微粒で均一な組成を有し、マイクロポア
の殆どない焼結体が得られ、強度及び靱性値の優れたも
のとなる（請求項３）。In addition, a ZrO 2 powder containing Y 2 O 3 and CeO 2 as stabilizers, a ZrO 2 sol and / or a water-soluble salt is converted into a water-soluble salt which produces Y 2 O 3 and CeO 2. After uniformly mixing with the solution in the form of a solution, the mixture is obtained by separating in the form of a precipitate, whereby the stabilizer is uniformly dispersed in ZrO 2 , and a sinterable powder of extremely fine particles is obtained. Since it is used as a raw material, a sintered body having fine particles and a uniform composition and almost no micropores can be obtained, and the strength and toughness are excellent (claim 3).
【図１】ＺｒＯ2、ＹＯ1.5、ＣｅＯ2の組成範囲を示す
三角座標である。FIG. 1 is a triangular coordinate showing the composition range of ZrO 2 , YO 1.5 , and CeO 2 .
【図２】実施例３の熱劣化試験の時間と単斜晶量との関
係を示したグラフである。FIG. 2 is a graph showing the relationship between the time of the heat deterioration test of Example 3 and the amount of monoclinic crystals.
Claims (3)
む主として正方晶より成る部分安定化ジルコニアに対し (b) 第２成分として、Ａｌ2Ｏ3、又はＡｌ2Ｏ3とＭｇＯ
・Ａｌ2Ｏ3（スピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ム
ライト）から選ばれた１種又は２種とを１〜７０内部重
量％含み、 (c) 熱間プレス法あるいは熱間静水圧プレス法で焼結さ
れた焼結体であって、 (d) 焼結体中に含まれる正方晶ジルコニアの結晶粒子の
平均粒子径が２μｍ以下であり、 (e) かつ３点曲げ強度が１４９ｋｇ／ｍｍ2以上で、 (f) 焼結体のかさ密度が理論密度の９９％以上であり、 (g) ３００℃大気中に３０００時間保持試験後の焼結体
に含まれるジルコニアの単斜晶量が３％以下でありかつ
３点曲げ強度が１４７ｋｇ／ｍｍ2以上であること、 (h) 前記部分安定化ジルコニアは、これに含まれるＹ2
Ｏ3、ＣｅＯ2が添付図面に示すように正三角形に交わる
三軸にそれぞれＺｒＯ2、ＹＯ1.5、ＣｅＯ2のｍｏｌ％
を表示した三角座標において、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｂ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｃ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５．０ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 １３．０ｍｏｌ％） で示された特定４組成点を結ぶ点で囲まれた範囲内の組
成にあること、 を特徴とする耐熱安定性に優れた高靱性セラミック焼結
体。1. A partially stabilized zirconia mainly composed of tetragonal crystals containing (a) Y 2 O 3 and CeO 2 as stabilizers, and (b) Al 2 O 3 or Al 2 O 3 as the second component. And MgO
· Al 2 O 3 (spinel), 3Al 2 O 3 · 2SiO 2 and a one or more of the compounds selected from (mullite) 1-70 Internal wt%, (c) hot pressing method or a hot isostatic (D) The average particle size of the tetragonal zirconia crystal particles contained in the sintered body is 2 μm or less, and (e) the three-point bending strength is 149 kg. / F 2 or more, (f) the bulk density of the sintered body is 99% or more of the theoretical density, and (g) the monoclinic crystal of zirconia contained in the sintered body after 3000 hours of holding test in the air at 300 ° C. The amount is 3% or less, and the three-point bending strength is 147 kg / mm 2 or more, (h) the partially stabilized zirconia contains Y 2
O 3 and CeO 2 are mol% of ZrO 2 , YO 1.5 , and CeO 2 , respectively, on the three axes intersecting the equilateral triangle as shown in the attached drawing.
In the triangular coordinate displaying, point A (ZrO 2 87.5 mol%, YO 1.5 12mo
1%, CeO 2 0.5 mol%) Point B (ZrO 2 95.5 mol%, YO 1.5 4 mol
%, CeO 2 0.5 mol%) Point C (ZrO 2 95.5 mol%, YO 1.5 2 mol
%, CeO 2 2.5 mol%) Point D (ZrO 2 85.0 mol%, YO 1.5 2 mol
%, CeO 2 13.0 mol%), which has a composition within a range surrounded by the points connecting the four specific composition points, and a high toughness ceramic sintered body excellent in heat stability.
む主として正方晶より成る部分安定化ジルコニアに対し (b) 第２成分として、ＭｇＯ・Ａｌ2Ｏ3（スピネル）、
３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）から選ばれた１種
又は２種を１〜７０内部重量％含み、 (c) 熱間プレス法あるいは熱間静水圧プレス法で焼結さ
れた焼結体であって、 (d) 焼結体中に含まれる正方晶ジルコニアの結晶粒子の
平均粒子径が２μｍ以下であり、 (e) かつ３点曲げ強度が１３７ｋｇ／ｍｍ2以上で、 (f) 焼結体のかさ密度が理論密度の９９％以上であり、 (g) ３００℃大気中に３０００時間保持試験後の焼結体
に含まれるジルコニアの単斜晶量が３％以下でありかつ
３点曲げ強度が１３５ｋｇ／ｍｍ2以上であること、 (h) 前記部分安定化ジルコニアは、これに含まれるＹ2
Ｏ3、ＣｅＯ2が添付図面に示すように正三角形に交わる
三軸にそれぞれＺｒＯ2、ＹＯ1.5、ＣｅＯ2のｍｏｌ％
を表示した三角座標において、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｂ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｃ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５．０ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 １３．０ｍｏｌ％） で示された特定４組成点を結ぶ点で囲まれた範囲内の組
成にあること、 を特徴とする耐熱安定性に優れた高靱性セラミック焼結
体。2. For (a) partially stabilized zirconia mainly composed of tetragonal crystals containing Y 2 O 3 and CeO 2 as stabilizers, (b) MgO.Al 2 O 3 (spinel) as the second component,
Sintered body containing 1 to 70% by weight of 1 type or 2 types selected from 3Al 2 O 3 .2SiO 2 (mullite) and sintered by the hot pressing method or the hot isostatic pressing method. And (d) the average particle size of the tetragonal zirconia crystal particles contained in the sintered body is 2 μm or less, (e) and the three-point bending strength is 137 kg / mm 2 or more, The bulk density of the aggregate is 99% or more of the theoretical density, and (g) the monoclinic crystal content of zirconia contained in the sintered body after the 3000-hour holding test at 300 ° C in the atmosphere is 3% or less and 3 points. Bending strength is 135 kg / mm 2 or more, (h) The partially stabilized zirconia contains Y 2
O 3 and CeO 2 are mol% of ZrO 2 , YO 1.5 , and CeO 2 , respectively, on the three axes intersecting the equilateral triangle as shown in the attached drawing.
In the triangular coordinate displaying, point A (ZrO 2 87.5 mol%, YO 1.5 12mo
1%, CeO 2 0.5 mol%) Point B (ZrO 2 95.5 mol%, YO 1.5 4 mol
%, CeO 2 0.5 mol%) Point C (ZrO 2 95.5 mol%, YO 1.5 2 mol
%, CeO 2 2.5 mol%) Point D (ZrO 2 85.0 mol%, YO 1.5 2 mol
%, CeO 2 13.0 mol%), which has a composition within a range surrounded by the points connecting the four specific composition points, and a high toughness ceramic sintered body excellent in heat stability.
む第１成分としてのＺｒＯ2粉末材料であって、 該ＺｒＯ2粉末材料は、ＺｒＯ2のゾルおよび／または水
溶性の塩をＹ2Ｏ3、ＣｅＯ2を生ずる水溶性の塩と共に
溶液の 状態で均一に混合した後、沈澱の形で分離して
得られ、 Ｙ2Ｏ3、ＣｅＯ2が正三角形に交わる三軸にそれぞれＺ
ｒＯ2、ＹＯ1.5、ＣｅＯ2のｍｏｌ％を表示した三角座
標において、 点Ａ（ＺｒＯ2 ８７．５ｍｏｌ％、ＹＯ1.5 １２ｍｏ
ｌ％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｂ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ４ｍｏｌ
％、ＣｅＯ2 ０．５ｍｏｌ％） 点Ｃ（ＺｒＯ2 ９５．５ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 ２．５ｍｏｌ％） 点Ｄ（ＺｒＯ2 ８５．０ｍｏｌ％、ＹＯ1.5 ２ｍｏｌ
％、ＣｅＯ2 １３．０ｍｏｌ％） で示された特定４組成点を結ぶ点で囲まれた範囲内の組
成にあるＺｒＯ2粉末材料に対し、 (b) 第２成分として、Ａｌ2Ｏ3、ＭｇＯ・Ａｌ2Ｏ3（ス
ピネル）、３Ａｌ2Ｏ3・２ＳｉＯ2（ムライト）から選
ばれた１種又は２種以上との粉末を合計で１〜７０内部
重量％の範囲で含む混合粉末を (c) 温度１１００℃以上１６００℃以下で熱間プレス法
あるいは熱間静水圧プレス法で、 (d) 含まれる正方晶ジルコニアの結晶粒子の平均粒子径
が２μｍ以下であり、焼結体のかさ密度が理論密度の９
９％以上であり、かつ３００℃大気中に３０００時間保
持試験後の焼結体に含まれるジルコニアの単斜晶量が３
％以下となるように焼結することを特徴とする耐熱安定
性に優れた高靱性セラミック焼結体の製造方法。3. A ZrO 2 powder material as a first component containing (a) Y 2 O 3 and CeO 2 as stabilizers, wherein the ZrO 2 powder material is a ZrO 2 sol and / or a water-soluble material. salts of Y 2 O 3, were uniformly mixed with CeO 2 with a water-soluble salt resulting solution state obtained by separating in the form of precipitation, the three of Y 2 O 3, CeO 2 intersects the equilateral triangle Z on each axis
In the triangular coordinates showing the mol% of rO 2 , YO 1.5 , and CeO 2 , the point A (ZrO 2 87.5 mol%, YO 1.5 12mo
1%, CeO 2 0.5 mol%) Point B (ZrO 2 95.5 mol%, YO 1.5 4 mol
%, CeO 2 0.5 mol%) Point C (ZrO 2 95.5 mol%, YO 1.5 2 mol
%, CeO 2 2.5 mol%) Point D (ZrO 2 85.0 mol%, YO 1.5 2 mol
%, CeO 2 13.0 mol%), for a ZrO 2 powder material having a composition within the range surrounded by the points connecting the four specific composition points, (b) as the second component, Al 2 O 3 , A mixed powder containing a powder of one or more selected from MgO.Al 2 O 3 (spinel) and 3Al 2 O 3 .2SiO 2 (mullite) in a total amount of 1 to 70 internal weight% ( c) Hot pressing method or hot isostatic pressing method at a temperature of 1100 ° C or higher and 1600 ° C or lower. Is the theoretical density of 9
9% or more, and the amount of zirconia monoclinic crystal contained in the sintered body after the holding test at 300 ° C. in the atmosphere for 3000 hours is 3
%, And a method for producing a high-toughness ceramic sintered body excellent in heat stability, characterized in that the sintered body is sintered.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5227826A JP2537132B2 (en) | 1993-08-23 | 1993-08-23 | High toughness ceramic sintered body excellent in heat resistance stability and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5227826A JP2537132B2 (en) | 1993-08-23 | 1993-08-23 | High toughness ceramic sintered body excellent in heat resistance stability and method for producing the same |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60182726A Division JPH06102574B2 (en) | 1985-08-20 | 1985-08-20 | High toughness ceramic sintered body excellent in heat resistance stability and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06263533A JPH06263533A (en) | 1994-09-20 |
| JP2537132B2 true JP2537132B2 (en) | 1996-09-25 |
Family
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| KR100840777B1 (en) * | 2007-01-25 | 2008-06-23 | (주)에큐세라 | Tetragonal zirconia composite powder, tetragonal zirconia-alumina composite, preperation method thereof |
| WO2010114126A1 (en) | 2009-04-03 | 2010-10-07 | 株式会社住友金属エレクトロデバイス | Sintered ceramic and substrate comprising same for semiconductor device |
| US9545363B2 (en) * | 2013-12-27 | 2017-01-17 | Acucera Inc. | Machinable zirconia comprising titania nanopowder |
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| JPS58202711A (en) * | 1982-05-18 | 1983-11-26 | Mitsubishi Metal Corp | Circular tool |
| JPS59199236A (en) * | 1983-04-27 | 1984-11-12 | アイカ互業株式会社 | Method of reinforcing end section of scagliola board |
| JPS6059154A (en) * | 1983-09-02 | 1985-04-05 | 日産自動車株式会社 | Stopping of loom at constant position |
| JPS60215571A (en) * | 1984-04-12 | 1985-10-28 | 東ソー株式会社 | Manufacture of high strength zirconia sintered body |
| JPS60141671A (en) * | 1983-12-27 | 1985-07-26 | 日立化成工業株式会社 | Manufacture of zirconia sintered body |
| JPS60141673A (en) * | 1983-12-27 | 1985-07-26 | 日本碍子株式会社 | Zirconia ceramic and manufacture |
| JPS6126562A (en) * | 1984-07-18 | 1986-02-05 | 東ソー株式会社 | Zirconia sintered body |
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