Al_2O_3/BN复相陶瓷的R曲线特性  

R-CURVE BEHAVIOR OF Al_2O_3/BN CERAMIC COMPOSITES

作　　者：李永利[1] 张久兴[1] 乔冠军[2] 金志浩[2] 

机构地区：[1]北京工业大学 [2]西安交通大学

出　　处：《硅酸盐学报》2005年第6期723-726,共4页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(50072017);北京市优秀人才培养专项经费(20041D0501509)资助项目。

摘　　要：采用压痕强度法测定了Al2O3/BN复相陶瓷的阻力曲线。结果表明:该复相陶瓷具有良好的耐接触损伤性能,呈现出上升的阻力曲线效应,显示出增强的抗裂纹扩展能力。而对应的Al2O3单相陶瓷的阻力曲线为一水平直线。分析认为:超细弥散的hBN与基体之间模量及热膨胀失配会在h-BN的弱结合层间产生微开裂,有助于抑制主裂纹的失稳扩展,这是Al2O3/BN复相陶瓷具有优良耐损伤性能和上升型R曲线效应的主要原因。The R-curve of Al2O3/BN ceramic composites was evaluated by the indentation strength method and compared with the R-curve of monolithic Al2O3. The results indicate that the Al2O3/BN ceramic composites possess rising R-curve behavior, which exhibit an excellent crack growth resistance. The monolithic Al2O3 shows a plateau R-curve behavior. The considerable improvement of crack growth resistance is closely related with h-BN super fine particulates toughening mechanism, which is chiefly attributed to the microcracks in the weak layer structure of h-BN caused by the elastic modulus and thermal expansion mismatch between Al2O3 and BN.

关 键 词：R曲线 增韧 氧化铝 氮化硼 复相陶瓷 

分 类 号：TQ174[化学工程—陶瓷工业]