原位生长β-Si_3N_4增强BAS基体复合材料  

Composite of Barium Aluminosilicate Reinforced in situ with Silicon Nitride

作　　者：顾建成[1] 吴建生[1] 曹光宇[2] 周玉[2] 雷廷权[2] 

机构地区：[1]上海交通大学材料科学与工程学院,上海200030 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《上海交通大学学报》2001年第3期397-401,共5页Journal of Shanghai Jiaotong University

摘　　要：用溶胶 -凝胶法合成化学定比 BAS(Ba O- Al2 O3- 2 Si O2 )粉末 ,并用差热分析和 XRD法分析基相变过程、氧化锂对 BAS相变过程影响、晶种对 BAS相变过程的影响 ,考察了 BAS对氮化硅相变的影响以及加入晶种后对氮化硅相变的影响 .用热压氮气保护法制备了自生 β- Si3N4 增强 BAS的复合材料 ,并比较了其力学性能与 BAS的力学性能 .结果表明 ,纯 BAS相变产物是六方相 ,氧化锂与氟化物的加入 ,促进了 BAS单斜相的形成 ,BAS单斜晶种能有效地促进 BAS单斜相的形成 ;BAS能够促进氮化硅由 α- Si3N4 →β- Si3N4 的相变 ,β- Si3N4 能有效地提高 BAS微晶玻璃的强度和断裂韧性 ,分析了增强和增韧机理 .BAS glass-ceramic powders were prepared by sol-gel processing. The procedure of transformation of BAS was investigated by DTA and XRD. Effects of additional Li2O with NH4F on transformation from H&rarrM of Barium aluminosilicate were also studied. No evidence is found that the addition of BAS or Si3N4 can influence the transformation from α-Si3N4&rarrβ-Si3N4 or from H&rarrM of Barium aluminosilicate. The results show that the flexural strength and fracture toughness value of the BAS glass-ceramic matrix composites can be effectively improved by in situ rod-like silicon nitride. The main toughening mechanism is crack deflection, pull-out and bridging. The increased value of flexural strength is contributed to the load transition effect from matrix to rod-like silicon nitride.

关 键 词：陶瓷基复合材料 玻璃陶瓷 力学性能 自增韧 钡长石 四氮化三硅 原位生长 

分 类 号：TQ174.758[化学工程—陶瓷工业]