【摘要】 以镀锌钢板点焊用铬锆铜球型电极为基体,进行了电火花沉积TiC涂层工艺试验,并分别进行了沉积前处理(清洗与粗化)与沉积后热扩散处理的对比试验,采用SEM、OM、显微硬度计等分析了涂层的微观形貌,测定了涂层的平均硬度与厚度。结果表明,前处理活化了基体表面,减少涂层与基体界面的分层,但不影响涂层内部结构,涂层的厚度和硬度变化不大。后处理促进了元素扩散,明显改善了涂层内部以及界面的微观结构,减少了裂纹和分层,使涂层的厚度减小。后处理释放了涂层内应力,导致涂层硬度降低。更多还原

【Abstract】 TiC coating was deposited on the surface of CrZrCu spot welding electrode for Zinc coated steel by electrospark.The contrast test was conducted for the substrate with/without pre-treatment(clean and polish),thermal diffusion post-treatment separately.Microstructure of the coatings were characterized by SEM,hardness and depth were measured by microhardness tester and OM respectively.The results indicate that pre-treatment activates the surface of the substrate so as to eliminate the lamination and the hardness and depth of the coating are not obvious change.Post-treatment promotes the element diffusion,reduces the micro crack within the coating and lamination along the interface.Depth of the coating decreases and hardness goes down due to coating residual stress relief.更多还原