Lamellar morphology of directional solidified Ti–45Al–6Nb–xW alloys  

作　　者：Zhi-Yuan Hou Yong-Sheng Li Hao-Jie Mei Kai Hu Guang Chen 

机构地区：[1]School of Materials Science and Engineering,Nanjing University of Science and Technology [2]Engineering Research Center of Materials Behavior and Design,Ministry of Education

出　　处：《Rare Metals》2016年第1期65-69,共5页稀有金属（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2011CB605504);the National Natural Science Foundation of China(No.51571122);the Fundamental Research Funds for the Central Universities(No.30920130121012)

摘　　要：Directional solidification of Ti-45Al-6Nb-xW（x=0,0.4,0.8;at%） alloys was performed by Bridgeman method with the stable growth rate of 5,10,and 20 μm·s^（-1）.The differential scanning calorimeter（DSC） results indicate that both the eutectic temperature and the transition temperature of α（Ti_3Al） to γ（TiAl） increase with W content increasing from 0 at%to 0.8 at%.For the stable growth rate of 10 μm·s^（-1）,the orientations of α_2（Ti_3Al）/γ（TiAl）lamellae change from 45°（0 at%W） to 0° and near 0°（0.4at%and 0.8 at%W） to the crystal growth direction,and the spacing of α_2/γ lamellae decreases with W content increasing from 0 at%to 0.4 at%,while it increases when W content is 0.8 at%.With the increase in growth rate from5 to 10 and 20 μm·s^（-1）,the lamellar spacing of α_2/γbecomes smaller,and the lamellar thickness becomes more uniform.Directional solidification of Ti-45Al-6Nb-xW（x=0,0.4,0.8;at%） alloys was performed by Bridgeman method with the stable growth rate of 5,10,and 20 μm·s^（-1）.The differential scanning calorimeter（DSC） results indicate that both the eutectic temperature and the transition temperature of α（Ti_3Al） to γ（TiAl） increase with W content increasing from 0 at%to 0.8 at%.For the stable growth rate of 10 μm·s^（-1）,the orientations of α_2（Ti_3Al）/γ（TiAl）lamellae change from 45°（0 at%W） to 0° and near 0°（0.4at%and 0.8 at%W） to the crystal growth direction,and the spacing of α_2/γ lamellae decreases with W content increasing from 0 at%to 0.4 at%,while it increases when W content is 0.8 at%.With the increase in growth rate from5 to 10 and 20 μm·s^（-1）,the lamellar spacing of α_2/γbecomes smaller,and the lamellar thickness becomes more uniform.

关 键 词：Ti-Al-Nb--W alloy Directionalsolidification Lamellar morphology Lamellar spacing 

分 类 号：TG146.23[一般工业技术—材料科学与工程]