ABSTRACT

This paper reports the effect of coating thickness on adhesive properties, and residual stresses by the electric discharge coating (EDC) process on Mg alloy with copper (Cu) nickel (Ni) powder metallurgical (P/M) electrodes. The composite coating layer thickness was measured by optical microscope and it ranges from 10.2 to 102.4 µm. The coating layer was characterized by a Field emission scanning microscope (FESEM) and Energy-dispersive spectroscopy (EDS). X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses were made to identify the chemical composition and functional group. Residual stresses were evaluated by an ETA diffractometer and it revealed that compressive residual stress increases with a range of −458 ± 118 MPa to −1078 ± 125 MPa and tensile residual stresses decrease from 656 ± 113 MPa to 27 ± 11 MPa. The critical load is measured by scratch test. The result shows the adhesive strength of the coated surface was improved with an increase in layer thickness.

摘要

本文报道了采用铜 (Cu) 镍 (Ni) 粉末冶金 (P/M) 电极对镁合金进行放电涂层 (EDC) 工艺时涂层厚度对粘合性能和残余应力的影响。通过光学显微镜测量复合涂层厚度为10.2～102.4μm。通过场发射扫描显微镜（FESEM）和能量色散光谱（EDS）对涂层进行表征。通过 X 射线衍射 (XRD) 和傅里叶变换红外光谱 (FTIR) 分析来鉴定化学成分和官能团。通过ETA衍射仪评估残余应力，结果表明，残余压应力在-458±118 MPa至-1078±125 MPa的范围内增加，残余拉应力从656±113 MPa下降至27±11 MPa。临界载荷通过划痕试验来测量。结果表明，涂​​层表面的粘合强度随着层厚度的增加而提高。