Microstructure and Nanohardness of Ti-48Al-2Cr Alloy Solidified under High Pressure

Duo Dong, Li Liu, Dongdong Zhu, Yang Liu, Ye Wang, Xiaohong Wang, Zunjie Wei
2020 Applied Sciences  
In this work, the Ti-48Al-2Cr alloy, solidified under different pressures and temperatures, was investigated in detail. The effect of high pressure on the microstructure and nanohardness of the Ti-48Al-2Cr alloy was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and a nanoindenter XP testing machine. The results showed that the B2 phase disappeared after high-pressure solidification. Compared with ambient pressure solidification, high pressure
more » ... tion, high pressure led to the increase of (α2 + γ) lamellar structure and the decrease of γ phase. The nanohardness of the lamellar structure was discussed based on the microstructure observation. When solidified at 5 GPa/1873 K, the hardness rose to 5.54 GPa, an increase of 60.5% compared with that solidified at ambient pressure. However, the increased holding temperature of 1973 K made the dislocation density in the lamellar structures greatly decrease, and reduced the structure's hardness to 4.48 GPa.
doi:10.3390/app10155394 fatcat:5gbkxfavzfbb3ov5gmznigw7hq