Microstructural stability of Bi–Sb20 alloy enhanced via liquid structural transition

Abstract

This study investigated the microstructural stability of Bi–Sb20 alloy under the influence of liquid structural transition combined with repeated melting. Liquid structural transition rendered the solidified microstructure dendritic regardless of the number of times the alloy was remelted, whereas the morphology of grains solidified from the original melt changed from equiaxed crystal to dendrite as the number of recycling times increased. Liquid structural transition improved the crystalline quality of the Bi–Sb alloy and decreased the strain in the lattice. Moreover, the microhardness of the samples after liquid structural transition remained steady at approximately 520 MPa for the different recycling times, while it obviously increased with the recycling times before liquid structural transition. These observations indicated that the microstructural stability and Vickers microhardness of the Bi–Sb20 alloy can be controlled through liquid structural transition.