Thixoforming of Semisolid Slurry with High Fraction Solid Fabricated by Partial Melting of Commerical Wrought Aluminum Alloys

Abstract

Semisolid slurries of four wrought alloys were fabricated via partial melting of commerical wrought aluminum alloy. Thixoforming experiments of four typical parts were performed. The results showed that a large amount of equiaxed grains before soaking in semisolid state were created due to recrystallization occurred in the continuous heating from room temperature to a given temperature above recrystallization temperature. It provides a desirable microstructure to form spheroidal grains during the next soaking process in semisolid state. The microstructure of the 2A12,7A04 and 7075 semisolid slurry consisted of fine and spheroidal grains. The elongation of the thixoformed parts were higher those of the hot-rolled plate. The UTS of the thixoformed parts were close or ever higher than those of the hot-rolled plate. Although the grain size and roundness of the 5A06 semisolid slurry are not very desirable, the mechanical properties of the thixoformed part are close or ever than those of the hot-rolled plate. The high mechanical properties of the thixoformed parts further confirmed the feasibility of short-process thixoforming route