An experimental and numerical study of a CoNiCrAlY coating using miniature specimen testing techniques
An experimental and numerical study of a CoNiCrAlY coating using miniature specimen testing techniques
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DOI：
10.1016/j.ijmecsci.2019.04.001
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发表时间：
2019-07
影响因子：
7.3
通讯作者：
W. Wen;G. Jackson;H. Li;Wei Sun
中科院分区：
文献类型：
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作者：
W. Wen;G. Jackson;H. Li;Wei Sun
在室温 (RT)、500°C 和 700°C 下对 CoNiCrAlY 涂层进行了小冲头拉伸 (SPT) 测试。 SPT 在 700°C 下获得了高度可重复的结果，而在较低温度下形成的早期裂纹往往会损害测试的可重复性。我们开发了另一种新型微型样品测试方法，并用于在相同温度范围内对 CoNiCrAlY 涂层进行微型拉伸测试。 SPT 和微型拉伸试验结果在延性至脆性转变温度 (DBTT) 方面取得了良好的一致性。微型拉伸试验在整个温度范围内都实现了出色的重复性。已经开发出一种逆向方法，并使用温度相关的 Johnson-Cook 模型从微型拉伸测试中提取材料的机械性能。使用提取的材料特性对 SPT 测试（包括损伤演化）进行有限元 (FE) 建模，以给出 SPT 测试结果的可比预测，例如载荷-位移曲线和断裂失效的大致位置。
Small punch tensile (SPT) tests have been carried out for a CoNiCrAlY coating at room temperature (RT), 500°C and 700°C. Highly re-producible results have been obtained for SPT at 700°C while the formation of early cracking at lower temperatures tends to compromise the repeatability of the tests. An alternative novel miniature specimen testing method has been developed and used for the miniature tensile tests of the CoNiCrAlY coating in the same temperature range. Good agreements have been achieved between the SPT and miniature tensile testing results regarding the ductile to brittle transition temperature (DBTT). Excellent repeatability has been achieved over the full range of the temperature for the miniature tensile tests. An inverse approach has been developed and used to extract the mechanical properties of the material from the miniature tensile tests, using a temperature-dependent Johnson-Cook model. Finite element (FE) modelling of the SPT tests, including damage evolution, has been carried out using the extracted material properties to give comparable predictions of the SPT testing results, such as the load-displacement curves and the approximate locations of the fracture failures.