采用纳米压入方法表征了热浸镀铝钢表面由Al2O3 层、 Al层和FeAl层组成的复合涂层的纳米硬度、弹性模量及断裂韧 性等微观力学性能，采用扫描电镜(SEM)观察了纳米压痕形貌，并 分析了孔洞对陶瓷层的纳米压入行为和压痕裂纹扩展的影响. 结果表明：等离子体电解氧化(PEO)陶瓷层中包含许多微米和 亚微米尺度的细小孔洞，陶瓷层弹性模量约为226.4 GPa，纳米 硬度约为19.6 GPa. 当纳米压入深度为250 nm时，所测得陶瓷层的 力学参数分散性较大. 与FeAl层比较, PEO陶瓷层具有较高的裂 纹扩展阻力. FeAl层纳米压痕顶端产生了沿直线扩展的 径向裂纹；而陶瓷层纳米压痕中除径向裂纹外 出现了侧边裂纹.
Micro-mechanical properties such as nanohardness, elastic modulus, fracture toughness, etc. of composite coatings which consist of Al2O3 layer, Al layer and FeAl layer were evaluated by using nanoindentation method. The micrographs of nanoindentation were observed using a scanning electron microscopy (SEM). The effect of pores on Load-displacement response and crack propagation was investigated. The results show that there are some pores at micron scale or sub-micron scale within ceramic coatings. Elastic modulus and hardness of ceramic coating are about 226.4Gpa, 19.6Gpa, respectively. Mechanical properties of ceramic coatings are very discrete when the nanoindentatin depth is set as 250nm. The resistance of crack propagation of Al2O3 layer is large than that of FeAl layer. Radial crack emerges from the corner of residual impression of FeAl layer and propagates along straight line. Radial crack and lateral crack appear at nanoindentation of PEO coating and the cracks’ paths are deflected.
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