Experiments and inelastic finite element analyses of plasma sprayed graded coatings under cyclic thermal shock
Experiments and inelastic finite element analyses of plasma sprayed graded coatings under cyclic thermal shock
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DOI：
10.1016/j.msea.2004.06.053
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发表时间：
2004-11-15
期刊：
影响因子：
6.4
通讯作者：
Ng, HW
中科院分区：
文献类型：
--
作者：
Gan, ZH;Ng, HW
建立了等离子喷涂多层梯度涂层的弹塑性有限元模型，模拟了涂层在热冲击循环过程中的应力变化。在模型中，已有的数值“沉积模型”中的沉积应力和应变[z.hGan，模型的沉积和热冲击等离子喷涂涂层，博士论文，南洋理工大学，新加坡，2002]被认为是初始应力和应变条件。同时，进行传热分析，计算试样的温度分布，并将其作为热负荷输入到应力模型中。通过现场曲率和温度测量对模型进行了验证。此外，利用声发射（AE）系统实验确定了涂层在热冲击载荷下的性能，该性能与使用通用商业有限元软件ANSYS （ANSYS Inc., Southpointe， PA， USA）的上述模型预测的热冲击期间的应力和应变曲线相关。在热冲击循环前后对试样表面进行扫描电镜观察，发现涂层剥落、裂纹萌生和扩展。本文提出了一种评估梯度层数对循环热冲击过程中残余应力和构件应力影响的方法。(C) 2004 Elsevier B.V.版权所有
Elastic-plastic finite element models of plasma sprayed multi-layered graded coatings were developed to simulate the stress development during thermal shock cycling. In the models, the as-deposited stress and strain in an existing numerical "deposition model" [Z.H. Gan, Modeling of deposition and thermal shock of plasma spray coatings, Ph.D. Thesis, Nanyang Technological University, Singapore, 2002] is considered as the initial stress and strain conditions. In parallel, a heat transfer analysis was performed to calculate the temperature distribution in the specimen, which was input into the stress models as thermal load. The models were verified by in situ curvature and temperature measurement. Additionally, the performance of the coatings under thermal shock loading was experimentally determined using acoustic emission (AE) system, which is correlated to the stress and strain profiles during thermal shock predicted by the above models using a general purpose commercial FEM software ANSYS (ANSYS Inc., Southpointe, PA, USA). The samples' surfaces were examined by SEM prior to and after thermal shock cycling, indicating coating spallation, crack initiation and propagation. This article presents a method for assessing the influence of the number of graded layers on the residual and component stresses during cyclic thermal shock. (C) 2004 Elsevier B.V. All rights reserved.