Effect of pressure on the structure of Ti75Al25 alloy during rapid- quenching process

XY Wang and SL Zhang and SD Feng and L Qi and RP Liu, JOURNAL OF NON- CRYSTALLINE SOLIDS, 502, 136-141 (2018).

DOI: 10.1016/j.jnoncrysol.2018.08.001

The structures of the Ti75Al25 alloy during rapid-quenching with and without external pressure are investigated by using molecular dynamic techniques. The amorphous phase can be obtained at the cooling rate 10.0 K/ps without pressure. The alloy is composed of crystal and amorphous phase at the cooling rate 0.1 and 1.0 K/ps without pressure, but the pure amorphous phase can be formed when the pressure exceeds the critical value. The critical pressure is about 20 and 30 GPa when the cooling rate is 0.1 and 1.0 K/ps, respectively. H-A indices analysis indicates that high pressure favors the formation of the ideal icosahedral structures in the amorphous Ti75Al25 alloy, and the content of 1551 bond-type can reach near to 50% when the pressure is 30 GPa. The amorphous state can be maintained if the external pressure is removed from the alloy step-by-step. The content of 1551 bond-type decreases with the deceasing of the pressure, but the 1541 and 1431 bond-types increase in this process.

Return to Publications page