Effects of Aging and Deep Cryogenic Treatment on Wear Behavior of Al7075 Alloy

Abstract

This study investigated the effects of aging and deep cryogenic treatment (DCT) on the hardness and wear behavior of Al7075 alloy. In this context, two different categories were created for the aging process. For the first group, after solutionizing the samples at 520 °C for 2 h, aging was applied at 120 °C for 12 h to reach 177 HV hardness. In the second group, after solutionizing at 520 °C for 2 h, the aging process was applied at 200 °C for 8 h to reach a hardness value of 164 HV. In addition, DCT (12 h, 24 h, and 36 h at −140 °C) was applied to the samples after the solutionizing and aging processes. The pin-on-disc wear test was carried out according to the ASTM G99 standard in order to examine the effects of the aging and cryogenic processes on wear behavior. The highest wear resistance was obtained with the Al7075 sample aged at 120 °C for 12 h followed by the 12-h DCT. Hardness values and wear test results showed that the applied cryogenic process had positively affected the wear behavior.