铝合金汽车零部件表面金属陶瓷复合涂层的制备与研究

Preparation and Study of Cermet Composite Coating on Aluminum AlloySurface of Automobile Parts

采用激光熔覆技术在铝合金汽车零部件表面制备了金属陶瓷复合涂层,研究了激光熔覆工艺参数对熔覆层成形效果的影响。采用SEM、EDS等分析技术研究了熔覆层的微观组织和元素分布,用显微硬度计测试了熔覆层的显微硬度,利用摩擦磨损试验机试验了熔覆层的耐磨性能。结果表明,当激光功率为1.2 kW时,熔覆层的成形效果良好,无明显缺陷产生,熔覆层与基体呈现良好的冶金结合;增大激光功率,熔覆层稀释率变大。熔覆层的微观结构主要为胞状晶、定向枝晶和细小的等轴晶。与基体相比,熔覆层的显微硬度和耐磨性显著提高,硬度提高了8倍,耐磨性能提高了8.8倍。

Cermet composite coating was prepared on the surface of aluminum alloy automobile parts by laser cladding technology,and the influence of laser cladding process parameters on the forming of cladding layer was studied.The microstructure and element distribution of the cladding layer were studied by SEM and EDS.The microhardness of the cladding layer was tested by the microhardness tester,and the wear resistance of the cladding layer was tested by the friction and wear tester.The results show that when the laser power is 1.2 kW,the macroscopic morphology of cladding layer is good without obvious defects and the cladding layer has good metallurgical bonding with the substrate.With increasing laser power,the dilution ratio of cladding layer increases.The microstructure of cladding layer is mainly composed of cellular crystal,directional dendrite and fine equiaxed crystal.Compared with the substrate,the microhardness and wear resistance of the cladding layer are significantly improved,the microhardness is increased by 9 times,and the wear resistance is increased by 9.8 times.