镍基合金表面激光熔覆MoSiNi-SiC复合涂层的组织与性能

Microstructure and Properties of MoSiNi-SiC Composite Coating on Nickel-based Alloy by Laser Cladding

利用激光熔覆技术在镍基合金表面制备了SiC增韧增强的硅化钼复合涂层,研究SiC含量对涂层的裂纹与气孔的形成、组织结构特征、物相组成及硬度、高温摩擦磨损和高温抗氧化性能的影响。结果表明,随着混合粉末中SiC含量的增加,涂层的显微硬度值逐渐增大,高温摩擦磨损性能和高温氧化性能增强,但过高的SiC加入量会使熔覆层的气孔和裂纹倾向明显增大。在SiC含量最高为15%时,涂层无明显成形缺陷,熔覆层组织主要由γ-Ni、Mo_(2)Ni_(3)Si、MoSi_(2)及SiC等相组成,显微硬度值可达814 HV,是基体的5.4倍。

The SiC toughened and reinforced molybdenum silicide composite coating on the surface of nickel-based alloys was prepared by laser cladding.The effect of SiC content on the formation of cracks and pores,structural characteristics,phase composition and hardness,high temperature friction and wear,and high temperature oxidation resistance of the composite coating were studied.Results show that with the increasing of SiC content,the microhardness value increases.The high temperature friction and wear performance and high temperature oxidation performance were enhanced.When the SiC content is up to 15%,the coating has no obvious forming defects.The laser cladding layer is mainly composed of Mo_(2)Ni_(3)Si,MoSi_(2),SiC andγ-Ni phases.Its microhardness value is up to 814 HV,which is 5.4 times that of the substrate.