利用脉冲激光对含Ni不锈钢防护涂层进行离散划痕, 通过X350A残余应力测试仪对激光离散划痕区残余应力进行测试, 研究离散划痕后涂层表面残余应力状况, 并分析激光冲击应力波对涂层结合强度的影响。结果显示, 在激光加载的中心区域内涂层产生均匀的残余压应力, 但该区域的边缘残余压应力急剧减小, 甚至出现了残余拉应力; 研究还表明, 在激光加载区域涂层的残余压应力值随着激光功率密度的增加而增加, 但当激光功率密度接近阈值时, 涂层的残余压应力因脱黏鼓包开始减小, 当激光功率密度足够大时, 含Ni不锈钢涂层在拉应力作用下于激光加载光斑边缘发生断裂剥离。

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coating, and measured residual stress of the area, which discrete scratched by laser ,by the X350A ray diffraction system. We studied the residual stress status and analyzed the effects of laser shock waves stress on interfacial binding strength of film coating. The results show that in the center region of coating by laser loaded produced a uniform residual compressive stress, however, compressive residual stress decreases sharply even lead to surface tensile residual stress at the edge of the region. The study also indicates that the value of the residual compressive stress of coating, discrete scratching by laser, increase with increasing power density of laser. However, when the power density of laser is near to the threshold value, the residual compressive stress has decreased because the film begin to crack initiation and de-bonding. When the laser energy density is large enough, the strong shock waves can lead to tensile stress, crazed and broken of interface between Ni-containing and substrate at the spot edge of the region.