中國(guó)有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 30 No. 11 November 2020 |
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083, China）
Abstract:Near net shaped Ti-45Al-7Nb-0.3W alloy (at.%) parts were manufactured by hot isostatic pressing (HIP). The microstructure and high-temperature mechanical properties of the alloy were investigated by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results show that at a temperature of 700 °C, the peak yield stress (YS) and ultimate tensile stress (UTS) of alloy are 534 and 575 MPa, respectively, and the alloy shows satisfactory comprehensive mechanical properties at 850 °C. The alloy exhibits superplastic characteristics at 1000 °C with an initial strain rate of 5×10-5 s-1. When the tensile temperature is below 750 °C, the deformation mechanisms are dislocation movements and mechanical twinning. Increasing the tensile temperature above 800 °C, grain boundary sliding and grain rotation occur more frequently due to the accumulation of dislocations at grain boundary.
Key words: TiAl alloy; near net shape; powder metallurgy; high-temperature mechanical properties
