Abstract: Al-Cu-Mn is one of typical heat-treatable cast alloys with high strength which has been widely used in aerospace and automobile industries. The complete manufacturing process for AlCu-Mn components includes low pressure die casting, T6 heat treatment and machining. It has been found that the property in former process has been transferred to the sequent step with considerable effect. In this paper, a detailed study has been conducted on precipitation strengthening behavior of Al-Cu-Mn alloy under effects of casting macro-segregation. A plate of 60 mm thickness was prepared by using low pressure die casting and the chemical compositions were measured at different positions. The remarkable segregation was observed in the position close to the sprue. The yield strength and elongation in different aging time were compared. The results showed that the composition of Cu decreased from 5.1% to 3.8% through the thickness, which led to a decrease of the yield strength and an increasing time for aging, while the elongation appeared as a parabolic.
Authors: Yisen Hu, Gang Wang, Qing Jiang, Wenfeng Xiao, and Yiming Rong
Keywords: Al-Cu-Mn Alloys, Precipitation Strengthening, Casting Segregation, Heat Treatment, Mechanical Properties, Whole Manufacturing Process