An Innovative Two-Stage Reheating Process for Wrought Aluminum Alloy During Thixoforming

Abstract

An innovative two-stage reheating process has been developed to improve the thixotropic behavior of semi-solid wrought aluminum alloy during thixoforming. The variation of the microstructural evolution mechanisms with temperature and holding time during a traditional process and two-stage reheating process are investigated in this paper. A desirable semi-solid microstructure with spherical-like grains surrounded by a uniform liquid film is obtained in the two-stage reheating process. The semi-solid microstructure obtained via this two-stage reheating process has more refined equivalent diameters, a better spherical degree, a lower coarsening rate constant of solid grains and a reduced possibility of defects caused by entrapped liquid than that produced by the traditional reheating process. These results prove that the two-stage reheating process is a promising method for manufacturing wrought aluminum alloy during thixoforming.