稀土 CeO2 含量对 Al 合金激光熔覆层组织形貌的影响

目的研究稀土氧化物CeO2的含量对铝合金表面Ni基激光熔覆层组织形貌的影响,降低Ni60熔覆层的气孔、开裂等组织缺陷。方法采用激光熔覆技术,在6063Al表面制备CeO2含量不同的Ni60熔覆层,对熔覆层的表面形貌、截面形貌及微观组织进行对比分析。结果 CeO2质量分数低于3%时,难以获得表面良好的熔覆层,0%~2%时易出现裂纹;CeO2质量分数在4%~5%的熔覆层形貌最好,无明显气孔和裂纹,尤其4%时具有相对较好的截面形貌;CeO2质量分数在5%~10%的熔覆层主要缺陷为气孔,且气孔、脱落等缺陷较少。结论添加CeO2可以改善铝合金表面Ni60熔覆层的组织形貌,尤其4%的CeO2可以改善Ni60熔覆层的组织结构,促进熔覆层的晶粒细化和组织分布均匀,是较佳的添加量。

Effect of Rare Earth CeO2 Contents on the Tissue Morphology of Laser Cladding on Al Alloy Layers

Objective To study the effect of rare earth oxide CeO2 contents on the tissue morphology of aluminum surface Ni-based laser cladding layers, and to lower the porosity, cracking and other tissue defects of Ni60 cladding layer. Methods Ni-Based alloy coatings with different contents of rare-earth CeO2 were prepared on the surface of 6063 aluminum alloy using laser cladding, and the surface morphology, the cross section morphology and microstructure of the cladding layer were analyzed. Results It was difficult to obtain a good cladding layer when the CeO2 content was less than 3% , the cladding layers were prone to cracking at 0% to 2% CeO2 content. Cladding layers with 4% ~ 5% CeO2-Ni60 had the best morphology without pores and cracks, especially addition of 4% CeO2 led to relatively good cross-section morphology. The main defects were pores when the CeO2 content was 5% to 10% , but there were less porosity, loss and other defects. Conclusion Addition of CeO2 could improve the aluminum surface morphology in Ni60 cladding layers, especially addition of 4% CeO2 could improve the organizational structure of Ni60 cladding layers, and promote the grain refinement and even distribution of the structure. Therefore, the preferred addition amount of rare earth CeO2 was 4% .