基于热-结构耦合等离子喷涂热障涂层循环应力分布  

Thermo-mechanical coupled modeling for analysis of cyclic stress distribution in plasma-sprayed thermal barrier coatings

作　　者：陈宇慧[1] 陈丹阳[2] 钟舜聪[3,4] 杨天雪 杨晓翔[3] 涂善东[4] 轩福贞[4] 

机构地区：[1]福州大学化学化工学院,福建福州350108 [2]漳州职业技术学院,福建漳州363000 [3]福州大学机械工程及自动化学院,福建福州350108 [4]华东理工大学承压系统安全科学教育部门重点实验室,上海200237 [5]福建省特种设备监督检验院,福建福州350001

出　　处：《机电工程》2013年第8期905-908,946,共5页Journal of Mechanical & Electrical Engineering

基　　金：国家自然科学基金资助项目(51005077);教育部回国留学人员启动基金资助项目(教外司留[2008]890号);福建省杰出青年基金资助项目(2011J06020);福建省质量技术监督局资助项目(FJQI2009039;FJQI201014);福州大学人才基金资助项目(XRC-1024)

摘　　要：针对等离子喷涂热障涂层在升温-恒温-降温过程中涂层应力沿层深分布情况及相关力学性能的影响,首先,将氧化层简化为正弦波形式,采用热-结构耦合瞬态计算周期边界条件,考虑了涂层系统上下表面与环境对流传热、涂层系统各层间热传导以及各层材料热机属性随温度变化等非线性关系,建立了热障涂层分析模型;然后,分析比较了涂层蠕变对残余应力的影响,以及随着氧化层厚度的变化,应力的再分布情况;最后,对循环过程与单独降温过程结果进行了比对。研究结果表明,由于恒温阶段蠕变的影响,应力大幅减小;应力增长主要集中在降温过程中,其中最大应力出现在氧化层与粘结层界面波峰处;随着氧化层厚度的增加,氧化层/粘结层内部拉应力显著增加,膜基结合力大幅下降,对涂层的稳定性产生影响。Aiming at the stress distribution in the depth direction of the TBCs and the influence of mechanical properties in heating, dwelling and cooling thermal cycles, the oxide layer surface was simplified to sine wave, thermo-mechanical coupled modeling of periodic boundary conditions of air-plasma-sprayed （APS）thermal barrier coatings （TBCs） on Ni-based alloy was investigated. In the computational models, nonlinear relationships （e.g., convective heat transfer between surrounding environment and coatings, and thermal transfer between the different layers etc.）were considered in the modeling. After the analysis of residual stress influenced by coating creep, the stress redistributed as the change of the thickness of oxide layer, and the results of the cycle and the separate cooling process were compared. The results indicate that the stress significantly is reduced in the dwelling stage because of stress relaxation. The maximum stress occurrs in the peak at the BC/TGO interface and it is amplified at the cooling stage. Moreover, the internal stress in the BC and TGO layer has been increased,when TGO＇s thickness increased,whilst film adhesion had fallen sharply.

关 键 词：热障涂层 热-结构耦合 蠕变 有限元分析 

分 类 号：TG174[金属学及工艺—金属表面处理] TH142.4[金属学及工艺—金属学]