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

作者：Hou, Zhi-Yuan; Li, Yong-Sheng^*; Mei, Hao-Jie; Hu, Kai; Chen, Guang

来源：Rare Metals, 2016, 35(1): 65-69.

DOI：10.1007/s12598-015-0631-1

• Ti-Al-Nb-W alloy
• Directional solidification
• Lamellar morphology
• Lamellar spacing

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 mu m center dot s(-1). The differential scanning calorimeter (DSC) results indicate that both the eutectic temperature and the transition temperature of alpha(Ti3Al) to gamma(TiAl) increase with W content increasing from 0 at% to 0.8 at%. For the stable growth rate of 10 mu m center dot s(-1), the orientations of alpha(2)(Ti3Al)/gamma(TiAl) lamellae change from 45A degrees (0 at% W) to 0A degrees and near 0A degrees (0.4 at% and 0.8 at% W) to the crystal growth direction, and the spacing of alpha(2)/gamma 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 from 5 to 10 and 20 mu m center dot s(-1), the lamellar spacing of alpha(2)/gamma becomes smaller, and the lamellar thickness becomes more uniform.

• 出版日期2016-1
• 单位南京理工大学