Si对铝基复合材料中Ti_p芯-壳结构形成的影响

Effects of Si Element on the Formation of Ti Particle Core-Shell Structure in Al Matrix Composite

采用Miedema生成热模型分析了Al-Ti-Si体系可能析出的热力学平衡相。研究了随Si含量变化的Ti_p芯-壳结构形态的变化及反应壳层相的变化情况,并探讨了反应壳层裂纹形成机理。结果表明,当Si含量不大于7%时,壳层厚度随着Si含量的增加而增大,致密的τ1壳层是在Si含量为9%时获得的;随着Si含量的增加,壳层中相的变化过程为(Al,Si)_3Ti→(Al,Si)_3Ti+τ1→τ1;反应壳层裂纹的形成主要是由体积膨胀产生的应力引起的。

The possible thermodynamics equilibrium phases of Al-Ti-Si system were analyzed by computing program of Miedema model. The change of Tip core-shell morphology and phase with different Si addition were researched, in addition, the mechanism of formation of cracks in the shell was researched. The results show that, reaction shell thickness increased with the increase of Si addition when the Si addition was less than 7wt.%. A composite rlshell was obtained with the addition of 9wt.% Si. The phase evolution can be summarized as follows： （A1, Si）3Ti→（Al, Si）3Ti＋τr 1→ τ1 as the Si addition varied from 2wt.% to 9wt.%. The presence of cracks in the shell was mainly due to stress that generates from volume expansion.