JPS63134561A - Zirconia ceramic composition - Google Patents

Abstract

(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は低価格で、かつ高強度を有する焼結体を生成ス
るジルコニアセラミックス組成物に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a zirconia ceramic composition that produces a sintered body that is inexpensive and has high strength.

（従来の技術） 正方晶ジルコニア結晶を主成分とするジルコニアセラミ
ックス（以下正方晶ジルコニアセラミックスという）は
強度、靭性が高く、摩耗性、摩擦係数が小さい材料とし
て注目され、構造材、刃物。(Prior art) Zirconia ceramics, which are mainly composed of tetragonal zirconia crystals (hereinafter referred to as tetragonal zirconia ceramics), are attracting attention as materials with high strength, toughness, and low abrasion resistance and coefficient of friction, and are used as structural materials and cutlery.

摺動材等としての応用・開発が進められてきている。Its application and development as a sliding material, etc. is progressing.

正方晶ジルコニアセラミックスは、従来、ＭｇＯ又はＣ
ａＯを安定化剤として高温（１７００’Ｃ以上）で焼結
し、ついで約１５００℃の温度で熱処理すること罠よシ
、正方晶ジルコニア結晶を析出させて、製造していた。Tetragonal zirconia ceramics are conventionally made using MgO or C.
It was manufactured by sintering at high temperature (1700'C or higher) using aO as a stabilizer and then heat-treating at a temperature of about 1500C to precipitate tetragonal zirconia crystals.

　　　゛ このような方法で製造した正方晶ジルコニアセラミック
スを析出型正方晶ジルコニアセラミックスという。``The tetragonal zirconia ceramics produced by this method are called precipitated tetragonal zirconia ceramics.

これに対し最近は、安定化剤としてＹ２Ｏ３を用いたジ
ルコニア原料粉を焼結すれば、高強度、高靭性な正方晶
ジルコニアセラミックスが得られるということが知られ
てきた。以下このような正方晶ジルコニアセラミックス
を焼結型正方晶ジルコニアセラミックスという。On the other hand, it has recently become known that tetragonal zirconia ceramics with high strength and high toughness can be obtained by sintering zirconia raw material powder using Y2O3 as a stabilizer. Hereinafter, such tetragonal zirconia ceramics will be referred to as sintered tetragonal zirconia ceramics.

（発明が解決しようとする問題点） しかしながら焼結型正方晶ジルコニアセラミックスにお
ける正方晶ジルコニア結晶粒子は５００℃以下の低温で
は不安定で、結晶粒子径が大きい場合、単斜晶ジルコニ
ア結晶に相転移し、得られる正方晶ジルコニアセラミッ
クスの強度等の性能を著しく劣化させるという欠点があ
る。このため焼結型正方晶ジルコニアセラミックスの製
造においては、超微粉ジルコニア原料粉を用い、さらに
これを比較的低温で焼結させ、正方晶ジルコニア結晶粒
子の成長を抑えなければならない。しかし超微粉ジルコ
ニア原料粉を用いると、中和共沈法。(Problems to be solved by the invention) However, the tetragonal zirconia crystal particles in sintered tetragonal zirconia ceramics are unstable at low temperatures below 500°C, and when the crystal particle size is large, the phase transitions to monoclinic zirconia crystals. However, it has the disadvantage that the strength and other properties of the resulting tetragonal zirconia ceramics are significantly deteriorated. Therefore, in the production of sintered tetragonal zirconia ceramics, it is necessary to use ultrafine zirconia raw material powder and sinter it at a relatively low temperature to suppress the growth of tetragonal zirconia crystal particles. However, when using ultrafine zirconia raw material powder, the neutralization coprecipitation method is possible.

アルコキシド法、加水分解法等の複雑な工程を経て製造
しなければならないため得られる正方晶ジルコニアセラ
ミックスは高価なものとなる。また超微粉ジルコニア原
料粉を用いると成形および焼結時の収縮率が大きいため
、クラック、気孔等が発生し易く大形の製品を得ること
は困難であった。The resulting tetragonal zirconia ceramics are expensive because they must be manufactured through complicated processes such as an alkoxide method and a hydrolysis method. Furthermore, when ultrafine zirconia raw material powder is used, the shrinkage rate during molding and sintering is large, so cracks, pores, etc. are likely to occur, making it difficult to obtain large-sized products.

本発明はかかる欠点のない正方晶ジルコニアセラミック
スを得るためのジルコニアセラミックス組成物を提供す
ることを目的とするものである。The object of the present invention is to provide a zirconia ceramic composition for obtaining a tetragonal zirconia ceramic free of such drawbacks.

（問題点を解決するための手段） 本発明者らは上記の欠点について種々検討した結果、Ｃ
ｅ０ｚを３〜１５モル％、　Ｇｄ、０．をｏ、５〜４モ
ルチおよび残部がＺｒ０１からなる中間混合物を８０〜
９９．９重量％並びにＷＯｓおよびＭｏＯ３の１種以上
を０．１〜２０重量％含有したジルコニア組成物を用い
て焼結体（正方晶ジルコニアセラミックス）を得たとこ
ろ、正方晶ジルコニア結晶が７０重量−以上含有され、
超微粉ジルコニア原料粉を用いなくても高い強度が得ら
れることを見い出した。(Means for solving the problem) As a result of various studies on the above-mentioned drawbacks, the inventors found that C.
3 to 15 mol% of e0z, Gd, 0. o, an intermediate mixture consisting of 5 to 4 molti and the remainder Zr01 to 80 to
When a sintered body (tetragonal zirconia ceramics) was obtained using a zirconia composition containing 99.9% by weight and 0.1 to 20% by weight of one or more of WOs and MoO3, the tetragonal zirconia crystal was 70% by weight. - Contains more than
It has been discovered that high strength can be obtained without using ultrafine zirconia raw material powder.

本発明はＣｅＯｘを３〜１５モル％、Ｇａ、０３を０．
５〜４モルチおよび残部がＺｒＯ雪からなる中間混合物
を８０〜９９．９重量％並びにＷＯｓおよびＭｏＯ３の
１種以上を０．１〜２０重量％含有してなるジルコニア
セラミックス組成物に関する。The present invention contains 3 to 15 mol% of CeOx and 0.00% of Ga and 03.
The present invention relates to a zirconia ceramic composition containing 80 to 99.9% by weight of an intermediate mixture consisting of 5 to 4 molti and the balance being ZrO snow, and 0.1 to 20% by weight of one or more of WOs and MoO3.

本発明において、中間混合物中のＣｅＯ２の含有量は３
〜１５モルチおよびＧｄ２ｏ３の含有量は０．５〜４モ
ルチの範囲とされ、Ｃｅｎｔの含有量が３モルチ未満お
よび／またはＧ　ａ、ｏ、の含有量が０．５モルチ未満
であると正方晶ジルコニア結晶が不安定で、焼成後の冷
却過程で単斜晶ジルコニア結晶に転移し易いため、得ら
れた焼結体の強度が著しく低下する。またＣｅＯ！の含
有量が１５モルチを越見るかおよび／またはＧ　ｄ、　
Ｏ，の含有量が４モルチを越えると立方晶ジルコニア結
晶の含有量が増加し、焼結体の強度が低下する。In the present invention, the content of CeO2 in the intermediate mixture is 3
~15 molti and the content of Gd2o3 is in the range of 0.5 to 4 molti, and if the Cent content is less than 3 molti and/or the Ga, O content is less than 0.5 molti, it is tetragonal. Since zirconia crystals are unstable and easily transform into monoclinic zirconia crystals during the cooling process after firing, the strength of the obtained sintered body is significantly reduced. CeO again! and/or the content of G d exceeds 15 molt,
If the content of O exceeds 4 molty, the content of cubic zirconia crystals will increase and the strength of the sintered body will decrease.

焼結体中のＷＯｓおよびＭｏＯ３の１種以上の含有量は
０．１〜２０重量−の範囲とされ、０．１重量−未満で
あると焼結後の焼結体中におけるジルコニア結晶粒子同
志の焼結が困難となり、また２０重量％を越えると焼結
体の強度が著しく低下する。The content of one or more of WOs and MoO3 in the sintered body is in the range of 0.1 to 20% by weight, and if it is less than 0.1% by weight, the zirconia crystal particles in the sintered body will not be contained together. Sintering becomes difficult, and if the content exceeds 20% by weight, the strength of the sintered body decreases significantly.

本発明に示すような組成および割合にすることにより、
焼結体中に正方晶ジルコニア結晶が７０重量％以上含有
され、もし上記範囲外の組成および割合であると正方晶
ジルコニア結晶が７０重量％未満となり、焼結体にクラ
ックが生じ９強度が低下したり、低い応力で破断するよ
うになる。By having the composition and proportions as shown in the present invention,
The sintered body contains 70% by weight or more of tetragonal zirconia crystals, and if the composition and proportion are outside the above range, the tetragonal zirconia crystals will be less than 70% by weight, which will cause cracks in the sintered body and reduce its strength. or break under low stress.

（実施例） 以下本発明を実施例によシ説明する。(Example) The present invention will be explained below using examples.

実施例１ 平均粒径が２μｍのＺｒ０ｚ粉末（第−希元素製。Example 1 Zr0z powder with an average particle size of 2 μm (manufactured by Rare Elements Co., Ltd.).

Ｅｐグレード）、平均粒径が５μｍのＣｅＯ鵞粉末（信
越化学製、純度９９．９％）および平均粒径が５μｍの
Ｇｄ２Ｏ，粉末（信越化学製、純度９９．９％）を第１
表に示す配合割合で秤量し、ボールミルで平均粒径が０
．５μｍ以下になるまで湿式混合、粉砕して中間混合物
を得た。得られた中間混合物を大気中１４００℃で２時
間仮焼して中間原料粉を得た。この中間原料粉に平均粒
径が１．５μｍのＷＯｓ粉末（和光純薬製、試薬１級）
を１重量％を添加し、再びボールミルで平均粒径が０．
５μｍ以になるまで湿式混合、粉砕した。得られた泥漿
にポリビニルアルコール（クラレ製、商品名ポバール）
およびワックス（中京油脂製、商品名アルデツクス２０
９）を添加し、粉霧乾燥して成形粉を得た。成形粉を１
．０トン／ａｍ”の圧力でラバープレス成形後、電気炉
を用い大気中１６００℃で２時間焼成して焼結体を得た
。Ep grade), CeO powder (manufactured by Shin-Etsu Chemical, purity 99.9%) with an average particle size of 5 μm and Gd2O powder (manufactured by Shin-Etsu Chemical, purity 99.9%) with an average particle size of 5 μm were used as the first
Weigh the blending ratio shown in the table and use a ball mill to reduce the average particle size to 0.
．． An intermediate mixture was obtained by wet mixing and pulverizing until the particle size was 5 μm or less. The obtained intermediate mixture was calcined in the air at 1400° C. for 2 hours to obtain an intermediate raw material powder. This intermediate raw material powder is WOs powder with an average particle size of 1.5 μm (Wako Pure Chemical Industries, Ltd., reagent grade 1).
1% by weight was added and milled again with a ball mill until the average particle size was 0.
Wet mixing and pulverization were performed until the particle size was 5 μm or more. Polyvinyl alcohol (manufactured by Kuraray, trade name Poval) is added to the resulting slurry.
and wax (manufactured by Chukyo Yushi Co., Ltd., product name Aldex 20
9) was added and powder mist-dried to obtain a molded powder. 1 molding powder
．． After rubber press molding at a pressure of 0 ton/am'', the product was fired in the air at 1600° C. for 2 hours using an electric furnace to obtain a sintered body.

次に得られた焼結体を切断し、ついで表面を研磨（す８
００ダイヤモンド砥石）して３×４×５０ｍｍ寸法の試
料を得た。この各試料について。Next, the obtained sintered body is cut, and the surface is polished (
00 diamond grindstone) to obtain a sample with dimensions of 3 x 4 x 50 mm. For each sample.

スパン４０ｍｍの３点曲は試験で曲げ強度を測定した。The bending strength of the three-point bend with a span of 40 mm was measured in a test.

その結果を第１表に示す。なお曲げ強度の値は試料数６
本の平均値である。第１表から明らかなように本発明に
なるジルコニアセラミックス組成物を用いた焼結体は６
５ｋｇ／ｍｍ”以上の高い値を示すことが示される。　
　　　　　　　　　以下余白実施例２ 実施例１と同じＺｒ０１粉末、　ＣｅＯｘ粉末およびＧ
ｄ２Ｏ３粉末を第２表に示す配合割合に秤量し、以下実
施例１と同様の工程を経て中間原料粉を得た。The results are shown in Table 1. The bending strength value is based on 6 samples.
This is the average value of the book. As is clear from Table 1, the sintered body using the zirconia ceramic composition of the present invention is 6
It is shown that a high value of 5 kg/mm'' or more is exhibited.
Below is the margin Example 2 Same as Example 1 Zr01 powder, CeOx powder and G
The d2O3 powder was weighed in the proportion shown in Table 2, and the same steps as in Example 1 were carried out to obtain an intermediate raw material powder.

ついでこの中間原料粉に実施例１と同じＷＯｓ粉末を第
２表に示す割合で添加し、以下実施例１と同様の工程を
経て焼結体を得た。得られた焼結体について実施例１と
同様の方法で曲げ強度を測定したところ、第２表から明
らかなように本発明になるジルコニアセラミックス組成
物を用いた焼結体は６５　ｋｇ／ｗｎ”以上の高い値を
示すことが示される。Next, the same WOs powder as in Example 1 was added to this intermediate raw material powder in the proportions shown in Table 2, and the same steps as in Example 1 were followed to obtain a sintered body. The bending strength of the obtained sintered body was measured in the same manner as in Example 1, and as is clear from Table 2, the sintered body using the zirconia ceramic composition of the present invention had a bending strength of 65 kg/wn. It is shown that it shows a high value above.

第２表 ※印は本発明に含まれないものを示す。Table 2 *mark indicates something not included in the present invention.

上記焼結体中の正方晶ＺｒＯ雪含有率は１００重量％で
ある。The tetragonal ZrO snow content in the sintered body is 100% by weight.

実施例３ 実施例１と同じＺｒＯｘ粉末、ＣｅＯｘ粉末およびＧ　
ｄ２Ｏ３粉末を第３表に示す配合割合に秤量し、以下実
施例１と同様の工程を経て中間原料粉を得た。Example 3 Same ZrOx powder, CeOx powder and G as in Example 1
The d2O3 powder was weighed in the proportion shown in Table 3, and the same steps as in Example 1 were carried out to obtain an intermediate raw material powder.

ついでこの中間原料粉にＭｏ５ｓ粉末（和光紬薬製。Next, Mo5s powder (manufactured by Wako Tsumugi Pharmaceutical Co., Ltd.) is added to this intermediate raw material powder.

試薬１級）を第３表に示す割合で添加し、以下実施例１
と同様の工程を経て焼結体を得た。得られた焼結体につ
いて実施例１と同様の方法で曲げ強度を測定したところ
、第３表から明らかなように本発明になるジルコニアセ
ラミックス組成物を用い九焼結体は６２　ｋｇ／ａｎ　
”以上の高い値を示すことが示される。　　　　　　　
　　　　　　　以下余第３表 ※印は本発明に含まれないものを示す。Example 1
A sintered body was obtained through the same process. The bending strength of the obtained sintered body was measured in the same manner as in Example 1, and as is clear from Table 3, the 9 sintered body using the zirconia ceramic composition of the present invention had a bending strength of 62 kg/an.
” is shown to exhibit a high value of ” or higher.
In the following Table 3, *marks indicate those not included in the present invention.

上記焼結体中の正方晶ＺｒＯ＊含有率は１００重量％で
ある。The tetragonal ZrO* content in the sintered body is 100% by weight.

（発明の効果） 本発明になるジルコニアセラミックス組成物は。(Effect of the invention) The zirconia ceramic composition according to the present invention is as follows.

大型品においても安定した特性を有し、クラック。It has stable characteristics even in large products and does not crack.

気孔等が生ぜず、常に高い機械強度の正方晶ジルコニア
セラミックスを安価に製造することができるジルコニア
セラミックス組成物である。This is a zirconia ceramic composition that does not produce pores and allows the production of tetragonal zirconia ceramics with consistently high mechanical strength at low cost.

手シ□続補正書（自発）Procedure □Continuation amendment (voluntary)

Claims (1)

【特許請求の範囲】[Claims] １、ＣｅＯ＿２を３〜１５モル％、Ｇｄ＿２Ｏ＿３を０
．５〜４モル％および残部がＺｒＯ＿２からなる中間混
合物を８０〜９９．９重量％並びにＷＯ＿３およびＭｏ
Ｏ＿３の１種以上を０．１〜２０重量％含有してなるジ
ルコニアセラミックス組成物。1, 3 to 15 mol% of CeO_2, 0 of Gd_2O_3
．． An intermediate mixture consisting of 5 to 4 mol % and the balance ZrO_2 was mixed with 80 to 99.9 wt % and WO_3 and Mo
A zirconia ceramic composition containing 0.1 to 20% by weight of one or more O_3.