激光重熔NiCrAlY涂层研究

采用空气等离子喷涂技术(APS)将NiCrAlY粉末作为粘结层材料喷涂在IN718镍基合金上,再用5 kW CO2连续激光器对其进行激光重熔处理,利用扫描电镜(SEM)、能谱分析(EDX)和X射线衍射(XRD)等手段对等离子喷涂层和激光重熔层的微观组织与成分进行了比较分析.结果表明:应用优化激光重熔工艺进行重熔后,涂层...

Study on laser remelting NiCrAlY coating

The bond coatings of NiCrAlY powder was coated on the substrate material of IN718 nickel alloy by air plasma spraying(APS),and then it was remelted by 5 kW CO2 laser.The microstructure of the bond coatings was characterized by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDX) and X-ray diffraction(XRD).The experimental results show that with the optimized remelting process,the bond coating displays superior metallurgical bonding with its substrate,and the mechanical bonding and layer structure of coatings by plasma spraying are changed,which is good for improving the mechanic performance of the coatings.Typical dendritic structure growing in cladding zone in the direction perpendicular to the substrate could strengthen the bond coating with its substrate.The dendritic structure is primarily made of metal Ni and Ni3Al compounds,while some impurities and oxides such as Al2O3,Cr3O4 survived in flake exist in interdendritic structure.A dense oxide layer formed on the bonding surface can avoid O2 diffusion,and effectively prevent the further oxidation of coatings and substrate,and improve the oxidation resistance of bond coatings.