Al2O3-Y2O3为助剂SiC液相烧结及其机理的研究

Abstract

摘要 本论文选用不同的液相烧结助剂、采用不同的工艺烧结SiC。测量烧结体的线收缩率、质量变化率、密度，X-射线衍射分析烧结体的晶相组成，定量分析烧结体中元素含量变化，SEM观察烧结体显微结构。 以Al2O3、Y2O3、不同配比的Al2O3–Y2O3、SiO2–YAG为助剂在1950℃、Ar气氛中烧结β-SiC。实验结果显示Al2O3对坯体致密化的促进效果较差；Y2O3不能有效促进致密化；Al2O3–Y2O3能有效促进坯体致密；SiO2–YAG对坯体致密化的促进效果不如YAG。 以YAG为助剂在1800℃~1950℃烧结β-SiC和α-SiC。实验结果显示Al2O3与Y2O3发生固相反...

Abstract SiC is sintered using different additives and at different conditions. The weight loss, density, crystal phase compositions by X-Ray Diffraction, chemical compostions, and microstructures by SEM are characterized. β-SiCcontaining Al2O3 ，Y2O3 ，Al2O3–Y2O3 or SiO2–YAG as additives is sintered at 1950℃. It is found that Al2O3 is not a very effective sinterin...