稀土Y2O3对6063Al激光熔覆镍基熔覆层耐磨性的影响

利用激光熔覆技术,在6063铝合金表面制备了添加有不同含量Y₂O₃的Ni60合金熔覆层,并对熔覆层进行了耐磨性试验. 通过分析熔覆层组织、熔覆层表面磨痕形貌、磨损量及摩擦系数,研究Y₂O₃含量对铝合金表面激光熔覆Ni基涂层耐磨性能的影响. 结果表明,添加5%Y₂O₃的Ni60熔覆层组织呈现明显的网状分布的枝晶和细小的等轴晶,稀土Y₂O₃可以改善铝合金表面Ni60熔覆层的组织,促进晶粒细化和成分分布均匀;添加稀土Y₂O₃的Ni60基熔覆层较Ni60熔覆层的磨损面崩损程度减小了,摩擦稳定性得到提高;随着稀土含量提高,熔覆层的磨损量减小,但Y₂O₃含量高于5%时磨损量基本不会大幅变化;5%Y₂O₃+Ni60熔覆层具有良好的磨损形貌、较低的磨损量以及较稳定的摩擦系数,其熔覆层的耐磨性是Ni60熔覆层的6.1倍,是6063Al合金基体耐磨性的20.1倍.

Effect of rare earth Y2O3 on abrasion resistance of 6063 Al laser cladding Ni-based cladding layer

Ni60 alloy cladding layer with different contents of rare earth Y₂O₃ was prepared on the surface of 6063 aluminum alloys using laser cladding technology, and the wear resistance of cladding layers was investigated. By analyzing the microstructure of cladding layers, the surface morphology of grinding cracks, wear loss and friction coefficient, the effect of Y₂O₃ contents on the wear resistance of laser cladding Ni-based coating was studied. The results show that Ni60 cladding layer with 5% Y₂O₃ displayed significant network distribution of dendrites and fine equiaxed grains. The rare earth Y₂O₃ could improve the microstructure of Ni60 cladding layer on the surface of aluminum alloy, promote grains refinement and uniform distribution of composition. The chipping degree of wear surface was smaller on Ni60 cladding layers with Y₂O₃ than on Ni60 cladding layer, and the friction stability were improved. With increasing the content of rare earth, the amount of wear loss decreased, but the wear loss did not change substantially when the Y₂O₃ content was higher than 5%. Ni60 cladding layer with 5% Y₂O₃ had better wear morphology, lower wear loss and more stable friction coefficient, and its wear resistance was 6.1 times of that of Ni60 cladding layer and 20.1 times of that of 6063 Al alloy matrix.