摘要
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。
WT5BZ]The effect of seeds on the microstructure and mechanical properties of selfreinforced Si_3N_4 with La_2O_3Y_2O_3 was investigated The results show that with the adding of seeds, large elongated βSi_3N_4 grains increased The higher the seeds content, the larger the area ratio of large elongated grains, the coarser the microstructure The fracture toughness of selfreinforced Si_3N_4 could be improved without affecting the strength, producing a microstructure having coarse elongated β Si_3N_4 grains distributed without contact each other by adjusting the content of seeds It is also shown that, the bridging caused by coarse columnar grains is the predominant mechanism The improvement of fracture toughness could be related quantitatively with diameter and area ratio of columnar βSi_3N_4 grains
出处
《材料工程》
EI
CAS
CSCD
北大核心
2000年第4期3-5,10,共4页
Journal of Materials Engineering
关键词
晶种
显微结构
力学性能
自增韧
氮化硅材料
seeds
selfreinforced Si_3N_4
microstructure
mechanical properties
