生长速度对Ti-45%Al包晶合金定向凝固组织的影响  

Influence of Different Growth Velocities on Directional Solidification Microstructure of Ti-45%Al Peritectic Alloy

作　　者：李庆林[1] 沈军[1] 罗文忠[1] 满伟伟[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室

出　　处：《热加工工艺》2007年第4期14-16,共3页Hot Working Technology

基　　金：国家自然科学基金资助项目(50474054)

摘　　要：通过电磁感应加热和液态金属冷却相结合的实验方法制备了Ti-45%Al(at%)包晶合金的定向凝固试样,并观察在不同生长速度下的微观组织和界面形态。结果发现,抽拉速度为10μm/s时,界面以胞晶形式生长,最终组织的α2+γ片层与生长方向垂直;抽拉速度为50μm/s时,观察到明显的枝晶生长界面,α2+γ片层与生长方向成45°夹角。低速下的胞状间距明显大于高速下的枝晶间距,说明快速凝固有利于减小枝晶间距。The experimental method connecting electromagnetic induction heating with liquid melting cooling was used to study microstructure and morphologies of directionally solidified Ti-45%Al （at%）peritectic alloy at different growth velocities.The results show that the interface morphology grows in cellular form when growth velocity is 10 μm/s, and the angel between the lamellar boundaries （α2＋γ） and growth direction is 90°. However, when growth velocity is 50μm/s, the crystals grow in dendritic form, and the angel between the lamellar boundaries （α2＋γ） in the grains and growth direction is 45° .The cellular spaces are bigger than dendritic spaces,which shows that the rapidly solidified process is good for minishing grain spaces in the directional solidification.

关 键 词：Ti-45%Al包晶合金 定向凝固 生长速度 界面形态 片层组织 

分 类 号：TG111.4[金属学及工艺—物理冶金]