反应合成Ti_3Al/TiC+Al_2O_3复合材料烧结过程热力学分析

Thermodynamic Analysis in Reaction Syntheses of Ti_3Al/TiC+Al_2O_3 Composite

将高能球磨后的Ti-Al粉末和TiC,Al2O3粉末混合进行热压烧结,在烧结的过程中反应生成金属间化合物为增强相的复合材料。通过对粉料的X射线衍射分析、热分析(DSC)和烧结体的成分分析表明,最终的金属间化合物只有Ti3Al而没有其它金属间化合物相。通过热力学计算,分析了反应烧结过程并发现在低温由固相间原子扩散控制生成TiAl3,TiAl,Ti3Al的渐进过程,和在高温下金属间化合物的合成机理,而且增强相和基体界面间处于稳定状态。

The intermetallic-compounds-strengthened composite was reaction synthesized by hot pressing sintering the mixture of ball-milled Ti-AI powder and TiC＋Al2O3 powder. According to the X-ray analysis and thermal analysis （DSC） of the powder and its components analysis of the sintering product, it shows that there are no other compounds but Ti3Al.Through thermodynamic calculation, the author analysized the reaction synthesized process, and found the gradual synthesis process from TiAl3 to TiAI, then to Ti3Al controlled by the diffusion under lower temperature and the formation mechanism of intermetallics compounds at high temperature, and it is in stable state at the interface between matrix and strengthening phases.