The Effect of T6 Heat Treatment on 7075 Aluminum on its Hardness and Tensile Strength

Abstract

This study aimed to determine the effect of T6 heat treatment on 7075 aluminum on its hardness and tensile strength. The T6 heat treatment process was heating the test specimens in an oven at various temperatures of the solution heat treatment (SHT) of 350°C, 400°C, 450°C, and 500°C for 2 hours. This process was then followed by quenching for 45 minutes and an artificial aging process at temperature of 120°C for 48 hours. The tests carried out included: Vickers hardness test, tensile test using ASTM B557-84 standard, microstructure test, and XRD test. The test results showed that the hardness and tensile strength before T6 heat treatment were 59.1 VHN and 235.7 MPa, respectively. After the T6 heat treatment was carried out, the hardness results were 105.8, 87.3, 108.9, and 171 VHN and tensile strength of 318.3, 415, 571.7, and 618.3 MPa, respectively. These results indicated that highest hardness was found in the SHT temperature of 500°C, while the increase in tensile strength was found in the temperature of SHT 500°C. It can be obtained because the formation of precipitate after the artificial aging process was due the formation of Al2CuMg and MgZn2.