摘要
针对镁合金表面耐磨性和耐蚀性差的问题,利用横流CO2激光器在AZ31B镁合金表面激光熔覆Cu-Ni合金层,并利用光学显微镜（OM）、扫描电镜（SEM）和能谱分析仪（EDS）分析熔覆层与基体的结合界面特征以及显微组织和成分分布情况,测试合金层的显微硬度和耐蚀性。结果表明：合金层与基体结合良好,缺陷较少,但局部存在不均匀的Cu-Ni富集区,且在其边缘区域的枝晶间均匀分布着1～1.5μm的十字状Laves相;合金层的硬度分布比较均匀,约为75HV0.05,明显高于基体的显微硬度45HV0.05;Cu-Ni合金层比AZ31B镁合金基体的腐蚀电位正移317mV,腐蚀电流降低78mA/cm2,耐蚀性也得到较大改善。
To improve the wear resistance and corrosion resistance of the surface of magnesium alloy,the laser alloying experiment was carried out on the AZ31B magnesium alloy with pre-placed Cu-Ni powder using transverse flow CO2 laser.The microstructures,interface features and composition distribution of laser cladding layer were studied through OM,SEM and EDS.The results show that the Cu-Ni cladding layer and the substrate achieve a good metallurgical bonding without obvious defects.But there is uneven local Cu-Ni-rich region,and cross-like Laves phases with size of 1-1.5 μm evenly distribute between dendrites and in their edge regions.The microhardness of Cu-Ni cladding layer is more evenly distributed,about 75HV0.05,significantly higher than the matrix hardness（45HV0.05）.Compared with AZ31B magnesium alloy,the corrosion potential of Cu-Ni alloy layer is shifted by 317 mV and corrosion current is reduced by 78 mA/cm2.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2010年第9期1665-1670,共6页
The Chinese Journal of Nonferrous Metals
基金
山西省自然科学基金资助项目(2008011044)
