Ti—TiC激光熔覆层的形成及其表征

为分析激光熔覆法制备TiC／Ti复合材料显微形貌的成因，对功率密度为21．2kW／cm^2、扫描速度15mm／s的CO2激光作用下的Ti-6A1—4V合金表面进行了Ti＋TiC激光熔覆实验，并对其熔覆层温度波动进行了分析。采用XRD、SEM对Ti-4-TiC熔覆层进行表征，并测定熔覆层的显微维氏硬度。分析表明：用激光熔覆制备TiC／Ti复合材料时，熔覆层在数毫秒内熔化，并以约10^4℃／s速率初始冷却。熔覆层的维氏硬度高达10．8GPa，Ti填充杂乱的TiC枝晶间。熔覆层与基体具有良好的冶金结合，且热影响区厚度与经验计算值相近。

Ti-TiC laser cladding layer formation and its characteristics

Aimed at analyzing the formation of microstructure of Ti ＋ TiC mixture prepared by laser cladding, this paper describes Ti ＋ TiC laser cladding experiment on Ti -6A1 -4V（ mass ratio）alloy sur- face subjected to C02 laser with 21.2 kW/cm2 power density and 15 mm/s scanning velocity and an anal- ysis of the temperature variation of cladding layer. The paper introduces the characterization of the Ti ＋ TiC clad layer by using XRD, SEM and the determination of microstructure and micro-hardness of cladding layer. The results shows that： in the case of TiC/Ti composite materials in cladding layer synthesized by Ti ＋ TiC mixture, the mixture is found to melt in several microseconds, and cool down in 104 ℃/s. In clad layer, its micro hardness is up to 10.8 GPa, and Ti fills up TiC dendrite. Cladding layer has a better metallurgical bonding with Ti -6A1-4V alloy matrix, and the depth of heat affected zone is close to empirical calculating value.