弯曲载荷下涂层断裂行为

Fracture behavior of coatings under bend loading

采用静载下的三点弯曲试验,详细分析观察了高速电弧喷涂LX88A金属基陶瓷涂层的断裂行为。研究发现涂层中某位置所受力矩达到一定值时,该处会产生垂直于界面的裂纹,故可将力矩是否达到临界值作为该位置产生裂纹的条件。有限元分析结果也证明了上述结论,对于三个不同位置的裂纹,当裂纹产生时该位置处界面附近的应力水平基本接近。研究结果可以为涂层构件的设计提供参考。

The fracture behavior of LX88A metal-based ceramic coatings by high velocity arc spraying technology in 3-point bend specimens had been observed.It was found that the crack normal to the interface in the coatings occurrs where a fixed moment of force was reached.So whether the moment reached to the critical value or not can be used as the condition of crack occurrence.The finite element analysis results proved the previous conclusion.The stress levels at the three different locations where the cracks occurred near the interface almost were same.The results will provide the help for the design of coatings and the structure integrity evaluation of coatings/substrates systems.