钛合金表面激光熔覆NiCrBSi(Ti)-TiC涂层

在TC4合金表面进行了激光熔覆NiCrBSi-TiC,Ti-TiC金属陶瓷复合涂层的试验,对涂层的组织和显微硬度进行了分析和测试。结果表明,NiCrBSi-TiC涂层的组织是在初晶γ-Ni和γ-Ni,Ni3B,M23(CB)6,CrB多元共晶的基底上均匀地分布着TiC颗粒,在激光熔覆过程中TiC颗粒只是边缘发生了溶解或熔化;在Ti-TiC涂层中,TiC颗粒全部溶解或熔化,冷却时以枝晶形式重新析出。NiCrBSi-TiC涂层的显微硬度(HV900～1100)明显高于Ti-TiC的涂层的显微硬度(HV500～700)。

Study on laser cladding of NiCrBSi (Ti)-TiC metal-ceramic composite coatings on titanium alloy

NiCrBSi-TiC and Ti-TiC metal-ceramic composite coatings have been respectively cladded on the surface of TC4 alloys by laser.The microstructure and microhardness of coating has been analyzed.The results show that the NiCrBSi-TiC coating is consisted of γ-Ni primary dendrites,γ-Ni and Ni₃B,M₂₃(CB)₆,CrB eutectics and TiC particles uniformly distributing in the substrate. Partial dissolution or melting appearing on the edges of TiC particles in the cladding process is observed. While in the Ti-TiC coating,total dissolution melting of TiC particles and their regrowth in the form of dendrites during cooling are found. The microhardness of NiCrBSi-TiC coating (HV900～1200) is distinctly higher than that of Ti-TiC coating (HV600～700).