Ultrahigh-temperature aging response of asymmetrically cold-rolled AA2024 alloy

Abstract

In this research, the effect of ultrahigh-temperature aging time on the microstructure and mechanical behavior of asymmetrically cold-rolled AA2024 aluminum alloy was studied. The cold-rolled samples were solution treated at 500 °C and aged at 500 °C for various times of 5, 10, 30, 60, 120, and 240 min. The microstructures, mechanical properties, and fracture surfaces of samples were investigated. It was found that by increasing the aging time, the elongated grains turned into equiaxed and coarser grains as well as the size and content of precipitates increased. The average hardness value increased up to 128 HV with increasing the aging time to 240 min. Also, the maximum yield strength (199.7 MPa) and ultimate tensile strength (384.4 MPa), as well as the minimum total elongation (20.8%), were achieved for the sample after 240 min of aging. The fracture surfaces of samples showed the ductile mode. The size of dimples increased and the number of dimples reduced with increasing the time of ultrahigh-temperature aging treatment.