合金元素对电弧熔炼TiC/Ti-6Al-4V复合材料中TiC生长形态的影响

Effects of Alloying Elements on Growth and Morphology of TiC in Arc-Melted TiC/Ti-6Al-4V Composites

摘要:

采用非自耗电弧熔炼制备含不同微合金元素的10vol%TiC/Ti-6Al-4V复合材料，研究不同的微量合金元素对复合材料中TiC形态的影响。结果表明，原始铸态复合材料中TiC形态主要是粗大且发达的枝晶状。而基体中加入0.3%(质量分数, 下同)的Sn元素后，TiC生长被抑制，TiC形态变为细小分散的颗粒状；0.3%的Ni被加入后，增大了TiC的结晶区间，使TiC枝晶生长变得更加发达；而0.3%的Nb元素的加入，则减小了TiC的结晶区间，从而减少了初晶TiC数量，促进了共晶TiC的形成

Abstract:

10vol%TiC/Ti-6Al-4V composites with various alloying elements were prepared by arc-melting. The effects of different trace alloying elements on the morphology of TiC in the composites were investigated. The results indicate that coarse and developed dendritic is the primary form of TiC in as-cast 10vol%TiC/Ti-6Al-4V composites. However, as 0.3% Sn (mass fraction, similarly hereinafter) is added in the composites, the growth of TiC is restrained and TiC become fine and dispersed particles. The addition of 0.3% Ni element increases the crystallization interval of TiC and promotes the growth of dendritic TiC. In contrast to Ni element, 0.3% Nb addition to the composites decreases the crystallization interval of TiC, so the amount of dendritic TiC is reduced and the formation of eutectic TiC is promoted