等离子喷涂涂层的冲击响应频谱分析

Frequency spectrum analysis of impact response for plasma sprayed coatings

介绍了一种具有摆杆结构的材料表面冲击试验机，对等离子喷涂Ａｌ２Ｏ３－１３％ＴｉＯ２，Ｃｒ２Ｏ３，ＷＣ－１７％Ｃｏ涂层进行了冲击试验研究，测试了在不同冲击能量下涂层－基体系的冲击响应频谱，借助扫描电镜对涂层冲击后的表面进行了观察，结合表面形貌观察结果对涂层冲击过程中的频域和时域信号进行了对比分析。结果表明，涂层在冲击过程中所表现出的频谱特征和涂层受冲击载荷作用后的形态存在相互对应关系。对于所研究的涂层，存在一个临界转变能量值范围，以小于和大于此能量值范围进行冲击试验时其频谱特征会表现出明显的不同。根据对涂层冲击痕表面形貌的扫描电镜观察，此转变值实际上也对应着涂层开始出现破坏的冲击能量。初步的试验结果表明，将频谱分析用于等离子喷涂涂层冲击性能研究是可行的。

An impact test machine, in which the impact load is generated by a pivot lever system, is introduced. The impact wear performance of some plasma sprayed coatings (Al 2O 3+13%TiO 2,Cr 2O 3 and WC 17%Co) is investigated. The frequency spectrum of the coating substrate composite under different impact energy is recorded in the course of impact. The surface morphology of the coating after impact is also observed under scanning electron microscopy. The results show that there is an obvious relationship between the impact effect and the frequency spectrum characteristics of the coating. For the coatings studied, there exists a transformation value of impact energy. The frequency spectrum characteristics while the impact energy is larger or less than this value, are quite different. This transformation value also corresponds the impact energy under the action of which the coating damages begin to occur. The preliminary results show that the frequency spectrum analysis is a feasible method for impact evaluation of plasma sprayed coating.