A380铝合金液态与半固态压铸件热处理前后组织性能研究

Study on Microstructure and Mechanical Properties of Liquid Die-castings and Semi-solid Die-castings of A380 Aluminum Alloy

对A380铝合金液态与半固态压铸成形件在压铸态和T6热处理态下的力学性能与微观组织进行了研究。力学性能测试表明:两种不同成形方法所得成形件在压铸态时强度相差无几,但半固态成形件的塑性几乎是液态成形件的2倍。经过同样的T6热处理后,半固态压铸件的抗拉强度有所提高,液态压铸件的抗拉强度却下降很大。伸长率均有所下降,但两者变化的幅度不同,液态压铸件的伸长率下降更多。与液态压铸成形件相比,半固态压铸成形件可以获得更佳的综合力学性能。从微观角度解释了两种不同成形方法产生这一性能差异的内在原因。

The microstructure and mechanical properties of the products made of A380 aluminum alloy by the two different forming methods （semi-solid casting and liquid die casting） under the states of casting and T6 heat-treatment were studied, respectively. The results show that semi-solid die-castings and liquid die-castings have almost the same tensile strength before they are heat-treated. But the ductility of the semi-solid forming parts is almost two times higher than that of liquid forming parts. After T6 heat treatment, the tensile strength of semi-solid die casting parts improves, but the tensile strength of liquid die-casting parts decreases. The ductility inclines for both semi-solid die-casting and liquid die-casting, but they have different variation range. The semi-solid castings increase greater in strength than that of liquid die castings and decrease less in elongation than the later, meanwhile the mechanism by which semi-solid casting is superiors to liquid die casting and the reason that the performance difference produced by the two different method are discussed from the microcosmic view.