长柱状β-Si_3N_4晶粒与SiC晶须在层状Si_3N_4/BN复合材料中的作用  

Effect of the Rod-like β-Si_3N_4 Grain and SiC Whisker in the Si_3N_4/BN Multilayer Materials

作　　者：昝青峰[1] 黄勇[1] 汪长安[1] 李淑琴[1] 李翠伟[1] 

机构地区：[1]清华大学新型陶瓷与精细工艺国家重点实验室,北京100084

出　　处：《材料工程》2001年第5期22-26,共5页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目 (5 963 2 0 90 )

摘　　要：用 Si C晶须和长柱状β- Si3N4对 Si3N4/ BN层状材料的基体层和分隔层进行了强化。轧膜工艺对 Si C晶须和原料中存在的少量 β- Si3N4晶粒有一定的定向作用 ,而基体层中定向分布的 Si C晶须和长柱状的 β- Si3N4晶粒对基体层的强韧化作用类似于块体材料 ,其抗弯强度和断裂韧性的提高幅度都大于 5 0 % ;分隔层中β- Si3N4的定向度较差 ,但这有利于形成网状结构 ,在分隔层中起到骨架的作用 ,同时还可以增加裂纹的扩展长度 ,改善分隔层与基体层的界面结合状态。最终得到性能最佳的材料的成分为 Si3N4+2 0 wt% Si C晶须 (基体层 ) ,BN+15 vol% β- Si3N4(分隔层 ) ,其断裂功可达 482 0 J/ m2 ,抗弯强度仍可保持在 6 5 0WT5BZ]The matrix layer and the rod like β Si 3N 4 strengthened the matrix layer and the separating layer of the Si 3N 4/BN multilayer materials were strengthened using SiC whicker and rod like β Si 3N 4 The rolling process would orient them in the matrix layer, and they can improve the bending strength and toughness by above 50% as well as the effect in the monolithic materials When they were in the separating layer, the orientation of β Si 3N 4 was poor It would form the net structure, and their effect was similar to the framework Moreover, they could increase the delaminating crack length and improve the bonding between the separating layer and matrix layer The materials were obtained,in which the matrix layer component was Si 3N 4+20wt%SiCw, the separating layer component was BN+15vol%β Si 3N 4 The work of fracture could achieve 4820J/m 2 with the bending strength retaining 650MPa

关 键 词：层状材料 分隔层 复合材料 碳化硅晶须 长柱状β-氮化硅 陶瓷 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程] TQ174.758[化学工程—陶瓷工业]