【作者】 陈良贤； 李成明； 陈飞； 刘政； 黑立富； 吕反修；

【Author】 CHEN Liang-xian,LI Cheng-ming,CHEN Fei,LIU Zheng,HEI Li-fu,L Fang-xiu (School of Material Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

【机构】 北京科技大学材料科学与工程学院；

【摘要】 对利用等离子体喷射法制备的金刚石自支撑膜应用激光制备了带缺口的预裂纹试样,并利用柔性约束法在缺口顶端引入尖端预裂纹,应用带扫描电子显微镜的高温电液伺服疲劳试验机进行了疲劳试验,原位观察到了裂纹的稳态扩展,裂纹稳态扩展的力为63 N,失稳扩展的力为67 N。自支撑金刚石膜的柱状晶生长特征和晶界形成的阻力是造成裂纹稳态扩展的主要原因。更多还原

【Abstract】 Freestanding diamond films prepared by DC plasma jet were cut by laser into notched and precracked samples.Stable crack propagation was observed in situ under cyclic loading in three points bending using a fatigue machine incorporated with the scanning electron microscope.Crack growth was found to be discontinuous; there was generally a break after each growth.Mechanisms for the observed stable crack propagation in freestanding diamond film samples under cyclic loading were discussed.The columnar grain feature of the freestanding diamond films and the grain boundary may be responsible for the stable crack propagation under cyclic loading.更多还原