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.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
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。
