Hot-Pressing Process of 7075 Aluminum Alloy: Microstructure, Corrosion and Wear Properties

Abstract

In this study, 7075 aluminum alloy was fabricated by hot-pressing process with various production temperatures and times. It was also aimed to reveal the effects of hot-pressing process parameters on microstructure, corrosion and wear properties of the 7075 aluminum. Samples were produced at 450 degrees C, 475 degrees C and 500 degrees C with 30-min and 60-min process duration under 200 MPa pressure and 0.1-bar vacuum. Microstructural analysis revealed that the magnesium- and zinc-containing secondary phases decomposed under the enhanced steady cooling conditions, which facilitated sufficient diffusion. It was observed that continuous grain boundary phases transformed into a discontinuous structure via the diffusion of magnesium with increasing process temperature. The corrosion behavior of the samples was dependent on the microstructure, and also the discontinuous morphology of the magnesium- and copper-rich secondary phases decreased the corrosion rate down to 0.1746 mm/year. On the other hand, the formation of secondary phases negatively affected the wear resistance, and lower surface damage was obtained in samples produced at 450 degrees C for 30 minutes and 60 minutes.