Abstract
? 2022 Elsevier B.V.The effect of high pressure on the composition and grain size of the Mg-xAl alloy was studied, and the mechanism of structure refinement from the viewpoint of solute redistribution was discussed. The results show that the amount of Al in the solid solution in the α-Mg matrix increased due to the higher solute distribution coefficient caused by high pressure. The Al content of the original alloy required for the initial eutectic transformation was increased from 5 wt% at atmospheric pressure to 9 wt% at 4 GPa, and the Al content at the eutectic point increased from 32.3 wt% at atmospheric pressure to 38.3 wt% at 4 GPa. Under high pressure, the large increase in the number of α-Mg crystals is related not only to the increase in nucleation rate and the inhibition of crystal growth caused by high pressure but also to the higher Al content, which enhances constitutional supercooling, further increasing the nucleation rate and inhibiting crystal growth.
NSTL
Elsevier