Thermal barrier coating systems — analysis of nanoindentation curves
Thermal barrier coating systems — analysis of nanoindentation curves
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DOI：
10.1016/j.surfcoat.2009.02.008
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发表时间：
2009-04
影响因子：
5.4
通讯作者：
N. Zotov;M. Bartsch;G. Eggeler
中科院分区：
文献类型：
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作者：
N. Zotov;M. Bartsch;G. Eggeler
机械性能（杨氏模量E，硬度H，塑性度）的所有三个组成部分的热障涂层系统，由电子束物理气相沉积（EB PVD）制备的，已通过纳米压痕法进行了研究。幂律指数n和m，描述的加载和卸载纳米压痕曲线的形状，增加与钇稳定的氧化锆顶涂层（TC），含有4摩尔%的Y2O3，和NiCoCrAlY粘结涂层（BC）的峰值负荷。m的变化与塑性程度有关。随着峰值载荷的增加，硬度降低，通常称为压痕尺寸效应（伊势），只观察到TC和BC。利用基于弹性恢复概念的新经验公式解释了TC中的伊势。Ni基高温合金基体、BC和TC的平均杨氏模量分别为189±11 GPa、166±7 GPa和126±25 GPa。相应的平均硬度值分别为3.3±0.3 GPa、5.5±0.2 GPa和6.2±1.7 GPa。TC的机械性能在1000°C空气中退火时表现出复杂的行为，这可以通过孔隙率和残余应力的变化来解释。
Mechanical properties (Young's modulus E, hardness H, degree of plasticity) of all three components of thermal barrier coatings systems, prepared by electron beam physical vapour deposition (EB PVD), have been investigated by nanoindentation. The power-law exponents n and m, describing the shapes of the loading and unloading nanoindentation curves, increase with peak load for the yttrium-stabilized zirconia top coat (TC), containing 4 mol% Y2O3, and the NiCoCrAlY bond coat (BC). The variations of m are correlated to the degree of plasticity. Decrease of the hardness with increasing peak load, generally known as indentation size effect (ISE), is observed only for the TC and the BC. The ISE in the TC is explained using a new empirical equation based on the concept of elastic recovery. The average Young's moduli of the Ni-based superalloy substrate, the BC and the TC are 189±11 GPa, 166±7 GPa, and 126±25 GPa, respectively. The corresponding average hardness values are 3.3±0.3 GPa, 5.5±0.2 GPa, and 6.2±1.7 GPa, respectively. The mechanical properties of the TC show complex behaviour upon annealing at 1000°°C in air, which can be explained by changes in the porosity and the residual stresses.