激光强化电刷镀n-Al_2O_3/Ni复合镀层残余应力研究

Study of residual stress of n-Al_2O_3/Ni composite coatings prepared by laser-enhanced electro-brush plating

利用Nd3+:YAG激光器对电刷镀过程进行强化,在45钢上制备了n-Al2O3/Ni复合镀层。采用X射线衍射法测定了镀层的轴向残余应力及其随镀层厚度变化情况。结果表明,镀层厚度从10μm增加到200μm,激光强化电刷复合镀层的轴向残余应力由压应力逐渐转变为拉应力。当激光功率为600W时,厚度为200μm的镀层的残余应力为103MPa,比普通电刷镀层降低约255MPa。分析了激光对n-Al2O3/Ni电刷复合镀层轴向残余应力的影响机理。

n-Al2O3/Ni composite coatings were prepared on 45 steel by electro-brush plating with the enhancement of Nd^3＋：YAG laser. The residual stress in axis direction of the composite coating and its variation with coating thickness were studied by X-ray diffraction. The results showed that the residual stress in axis direction of n-Al2O3/Ni composite coating is changed from compressive stress to tensile one with its thickness changing from 10 μm to 200 μm. The residual stress is 103 MPa for the 200 μm thick coating prepared at a laser power of 600 W, which is 255 MPa lower than that of ordinary electro-brush plated coating. The effect mechanism of laser on residual stress in axis direction of laser-enhanced electro-brush plated （LEBP） n-Al2O3/Ni composite coating was analyzed.