| 摘要 |
PURPOSE:To improve the strength and fracture toughness of the above-mentioned body by incorporating a La2O3-beta.11Al2O3 crystal at a specific ratio into the body. CONSTITUTION:This mullite sintered body contains 10 to 30wt.% La2O3-beta.11Al2 O3 crystal. The sintered body can be produced by mixing La2O3 powder as an assistant and Al2O3 powder with mullite powder and molding and calcining the mixture. While the amt. of the La2O3 powder and the Al2O3 powder to be added varies with the content, etc., of the La2O3-beta.11Al2O3 crystal of the mullite sintered body to be produced, 2 to 12wt.% La2O3 powder and 7 to 40wt.% Al2O3 powder are usually added to the mullite powder in order to produce the mullite sintered body contg. 10 to 30wt.% La2O3-beta.11Al2O3 crystal. The desired effect is not obtd. if the content of the La2O3-beta.11Al2O3 crystal is below 10wt.%. The bending strength and fracture toughness are degraded on the contrary if the content exceeds 30wt.%. |
