电沉积镍涂层中的残余应力及激光热冲击的影响

着重研究了电沉积镍涂层中的残余应力，首先介绍了用X射线衍射法(XRD)测量残余应力的基本原理，研究并得出了电镀工艺参数如厚度、电流密度等对残余应力的影响，并用XRD和扫描电镜对其微观结构进行了分析观察，分析了残余应力的形成机制，为了改善电沉积镍涂层的力学性能，采用激光热冲击的方法对镍涂层进行了表面处理，结果发现，经过激光束热冲击之后，涂层中的残余应力由处理前的拉应力变为压应力，而且随激光参数，如扫描速度与光斑直径、激光能量密度的变化而变化。

Residual Stress and its Redistribution Induced by Laser Beam Thermal Shock in Electrodeposited Nickel Coatings

A uniform nickel coating on the substrate of low carbon steel was prepared by electrodeposition.The residual stress in the electrodeposited nickel coating was measured by X-ray diffraction (XRD). The residual stress in the original electrodeposited nickel coating without any treatment was tensile. The mechanism of residual stress in nickel coating is discussed based on free energy. Laser beam thermal shock was used to modify the mechanical properties of the nickel coating. Laser beam thermal shock could redistribute the residual stress in the nickel coating. The residual stress could be converted from tensile to compressive. The mechanism of residual stress' redistribution induced by laser beam thermal shock is discussed and it was due to the residual thermal plastic deformation in the coating.