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） result...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.展开更多
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)
文摘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.
