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采用热压烧结 -高温气压处理的方法研究了棒状 β- Si3N4 晶种对 La2 O3- Y2 O3系自增韧 Si3N4 显微结构和性能的影响。结果表明 ,加入晶种将在组织中引入粗大柱状 β- Si3N4 晶粒 ,分布均匀 ;随着晶种加入量的增加 ,粗大柱状 β-Si3N4 晶粒数量增加 ,组 3织明显粗化。当晶种加入量较小时 ( 1 0 vol% ) ,材料具有较高的断裂韧性 (～ 1 2 MPam1/2 ) ,同时保持较高的强度 ( 80 0～ 90 0 MPa) ,而当晶种加入量较大时 ,则表现为抗弯强度的明显下降。分析表明 ,大晶粒直径及其面积百分数是影响断裂韧性的主要因素。
The effects of rod-like β-Si3N4 seed crystals on the microstructures and properties of self-toughened Si3N4 La2 O3-Y2 O3 system were studied by hot pressing and high temperature atmospheric pressure treatment. The results show that the addition of seeds will introduce coarse columnar β-Si3N4 grains into the microstructure, and the distribution is even. With the increase of the seed addition, the number of coarse columnar β-Si3N4 grains increases and the coarse grains of the group 3 become coarse. The material has a higher fracture toughness (~ 12 MPam1 / 2) while maintaining a higher strength (80 0 ~ 90 0 MPa) when the seed addition is small (10 vol%), whereas when the seed is added When the amount is large, it shows a significant decrease in flexural strength. The analysis shows that the large grain diameter and its area percentage are the main factors affecting the fracture toughness.