MoSi_(2)/Mo涂层热震过程中界面应力分布和裂纹扩展的有限元模拟  

Finite Element Simulation of Stress Distribution and Crack Propagation of MoSi_(2)/Mo Coating During Thermal Shock Cycles

作　　者：吴壮志[1] 陈浩[1] 蔡圳阳[1] 刘新利 王德志[1] Wu Zhuangzhi;Chen Hao;Cai Zhenyang;Liu Xinli;Wang Dezhi(School of Materials Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《稀有金属材料与工程》2021年第11期3934-3941,共8页Rare Metal Materials and Engineering

基　　金：National Key R&D Program of China(2018YFC1901700)。

摘　　要：在氢气保护下将MoSi_(2)/Mo涂层加热至1000℃,再迅速冷却至室温进行热震循环,表征了材料在热震循环过程中裂纹的演变过程并评估了MoSi_(2)/Mo涂层的热冲击行为。采用Abaqus软件计算了MoSi_(2)/Mo涂层在热冲击过程中的应力分布,讨论了热震循环中裂纹的发展过程。结果表明:Mo基体与MoSi_(2)涂层之间存在较高的热冲击应力,这将导致裂纹的萌生和扩展。计算结果显示:在最初的10次热震循环中,涂层产生了垂直于界面的裂纹,在界面上没有出现裂纹,涂层与基体仍结合良好;在随后的热震循环中开始出现界面裂纹,界面裂纹开始于垂直裂纹的末端区域,当垂直裂纹与界面裂纹汇聚,会导致涂层剥离和涂层失效。The thermal shock behavior of molybdenum disilicide(MoSi_(2))/molybdenum(Mo)coating and the crack propagation were evaluated by heating the coating to 1000℃,and then cooling it down to room temperature under the protection atmosphere of hydrogen during the thermal shock cycle.Meanwhile the thermal stress distribution of MoSi_(2)/Mo coating during thermal shock was calculated by Abaqus software.The development process of crack during thermal shock cycles was discussed.The results show that there is a high thermal shock stress between the Mo substrate and Mo Si_(2) coating,which can lead to the crack initiation and propagation.According to the extended finite element simulation results,the cracks appear perpendicular to the interface during the first ten thermal shock cycles,while the coating is still well bonded with the substrate and shows no signs of crack along the interface.The interfacial crack appears in the subsequent thermal shock cycles.The interfacial crack begins at the end zone of the vertical crack.When the vertical crack and the interfacial crack converge,the coating peels off and the coating failure occurs.

关 键 词：MoSi_(2)涂层 热冲击 有限元模拟 应力分布 

分 类 号：TG174.4[金属学及工艺—金属表面处理]