TiC+TiB_2协同增强Al-Cu原位复合材料

In situ TiC and TiB_2 cooperatively reinforced Al-Cu composites

为利用TiC和TiB2的协同增强作用,采用基于熔体接触反应法和混合盐反应法的新工艺"两步法"制备了(TiC+TiB2)/Al-2Cu原位复合材料.利用扫描电子显微镜及差式扫描量热计对热处理前后的原位复合材料进行了组织及热分析,结果表明:组织中两相粒子的分布比单相粒子增强的情况更加均匀,而且T4处理实现了两相粒子真正意义上的均匀相间分布;相对于单一的Al-2Cu合金,(TiC+TiB2)/Al-2Cu的熔化开始温度和凝固开始温度升高,熔化潜热和凝固潜热增大,体系稳定性从而得以提高,T4处理进一步增大了这一趋势.

（TiC ＋ TiB2 ）/Al -2Cu composites have been prepared by a new technology, ＂two-step method＂, based on MCR and LSM methods. The distribution of TiC and TiB2 particles is more homogeneous than that of single particulate reinforced composites, and the real homogeneous inter-phase distribution of TiC and TiB2 particles in Al- 2Cu matrix is realized by T4 heat treatment. The melting-start temperature, solidifying-start temperature, melting latent heat and solidifying latent heat of （TiC ＋ TiB2 ）/Al -2Cu are enlarged compared with Al- 2Cu, which implies the system stability is increased, and T4 heat treatment further increases this tendency.