Ti3SiC2-TiSi2-TiB2熔覆复合材料在氩气退火过程中的相稳定性分析

采用氩弧熔敷法制备了Ti3SiC2-TiSi2-TiB2复合材料，并对其在高温氩气退火过程中的相稳定性进行了分析. 结果表明，Ti3SiC2相在氩气保护和1 450℃高温条件下具有稳定性，而原位合成的含碳的TiSi2(Cx)固溶体相在退火过程中通过原子扩散而发生分解，其转化产物主要为Ti3SiC2及少量的SiC稳定相. 退火后，熔覆样品中Ti3SiC2的体积含量比退火前增加了4.8%. 热力学计算结果表明，样品在退火过程中通过原子扩散引起的反应机制为TiSi2(Cx)→Ti3SiC2+SiC,并提出了Ti3SiC2-TiSi2-TiB2熔覆复合材料在退火过程中的原子扩散反应模型. 退火试验分析结果表明，钨极氩弧熔敷法与高温退火相结合的复合工艺可以提高Ti3SiC2-TiSi2-TiB2熔覆复合材料的整体热稳定性.

Analysis of phase stability for Ti3SiC2-TiSi2-TiB2 deposition composites during argon annealing

The stability of phases in the Ti3SiC2-TiSi2-TiB2composites prepared by argon arc deposition during the high temperature annealing in argon was analyzed in this study. The results showed that the Ti3SiC2phase was stable during annealing at 1 450 ℃ in argon, but in-situ synthesized solid solution phases such as TiSi2Cxdecomposed through atom diffusion during annealing. The transformed products were mainly composed of stable Ti3SiC2and a small amount of SiC. After annealing, the volume content of Ti3SiC2in the sample increased by 4.8% comparing with non-annealing. The thermodynamic calculation results showed that the reaction mechanism through atom diffusion during annealing was TiSi2Cx→Ti3SiC2+SiC. The atom diffusion reaction model of the Ti3SiC2-TiSi2-TiB2composites during annealing was proposed. The annealing experiment analysis results showed that the tungsten argon arc deposition combined with annealing process could improve the whole thermal stability of Ti3SiC2-TiSi2-TiB2composites.