低温超音速火焰喷涂铜涂层断裂特性的研究

The Mechanisms of Fracture of Copper Coatings Produced by Low-Temperature High-Velocity Air Fuel Spray

采用低温超音速火焰喷涂技术在不锈钢、防锈铝基体上制备了铜涂层，并采用拉伸试验研究了铜涂层在单轴拉伸应力下的断裂情况。结果表明，涂层的结合强度在10～20MPa分布，基体对涂层的结合强度有一定影响；喷涂过程中，塑性变形的粒子铺展沉积于涂层表面，粒子与基体、粒子与粒子之间的边界和微孔成为涂层断裂源，裂纹源沿粒子边界扩展造成断裂；涂层的断裂过程为弹性断裂，没有明显的塑性变形过程，表明涂层与基体、涂层内部的结合主要以机械结合为主。

A series of copper coatings on different substrates were prepared and the fracture behaviors of the coatings were studied by utilizing the Low-Temperature High-Velocity Air Fuel ( LTHVAF) spraying system. Experiment results showed that the coating was mainly the machinery combination, the adhesive strength of coatings ranged between 10 MPa and 20 MPa, and the stress-strain process was linear elasticity. During the fracture process, cracks initiated in the pores of the coating,the grain boundary, the boundary of grain and substrate, and cracks propagated along the grain boundary resulting in fracture.