摘要
根据共晶界面复合陶瓷的细观结构特性,考虑棒状共晶体边界处的微观滑移确定了棒状共晶体的桥联应力。考虑棒状共晶体的方位随机性,通过桥联应力计算出棒状共晶体的桥联载荷(共晶体桥联载荷使裂纹产生闭合效应,减小裂纹尖端的应力集中),并得到了桥联载荷的能量耗散值。根据断裂韧性和能量耗散的关系,分析了棒状共晶体桥联增韧结果及其尺度效应。分析结果表明:复合陶瓷的桥联增韧值随共晶体内纤维夹杂直径的增大而减小,共晶体直径接近纳米尺度时,桥联增韧值的尺度效应更加明显。
According to the microstrcture characteristics of composite ceramic with eutectic interphase,considering the micro slipping on the boundaries of eutectic rods,the bridging stress of eutectic rod was determined.Considering the random orientation of the eutectic rods,the bridging load of eutectic rods was computed by the bridging stress.The bridging load can make crack closure and reduce the stress concentration of the crack tip,the energy dissipative value of the bridging load was obtained.Based on the relationship between fracture toughness and energy dissipation,the bridging toughening result of the eutectic rod and its size dependence were analyzed.The results show that as the diameter of fiber inclusion increases,the bridging toughening value may lessen,especially when the diameter is in nanometer scale,the size dependence can be more apparent.
出处
《中国机械工程》
EI
CAS
CSCD
北大核心
2011年第3期360-363,共4页
China Mechanical Engineering
基金
国家自然科学基金资助项目(10872216
51072229)
关键词
棒状共晶体
纤维夹杂
桥联应力
桥联增韧
尺度效应
eutectic rod
fiber inclusion
bridging stress
bridging toughening
size dependence
