Effect of two-stage artificial aging on precipitation strengthening of T6-tempered AA7005 aluminum alloys

This study explored the adjustment of traditional T6 heat treatment parameters for enhancing the precipitation strengthening effect of AA7005 aluminum alloys. The 18-day natural aging (NA) was replaced by low-temperature artificial aging (AA). Experimental results show that the most suitable parameter combinations are solid solution treatment at condition of 470°C/40 min, followed by AA at 80°C/72 hr and finally AA at 120°C/70 hr. AA7005 alloys tempered by the adjusted T6 parameters not only show greater hardness of 73 HRB and higher tensile strength of 385 MPa, processing time can also be reduced from 18 days to 72 hr (3 days). Hence, replacing NA with AA is not only feasible but also an attractive procedure for achieving peak aging in industrial applications with less time and lower cost involved.