Effect of Solution–ECAP–Aging Treatment on Microstructure and Properties of 7075 Aluminum Alloy

Gang Xu, Zhongbo Zhang

DOI: https://doi.org/10.64486/m.65.1.8
Online publication date: September 22, 2025

Abstract: 7075 aluminum alloy is widely used as a high-strength structural mate-rial in aerospace and other fields. However, its traditional casting and rolling pro-cess suffers from coarse grains and uneven distribution of secondary phases, which limits its performance potential. Therefore, this study proposes a mul-ti-process coupling method that combines solution treatment, equal-channel an-gular pressing, and aging treatment. Solution treatment fully dissolves the strengthening phases into the matrix. Equal-channel angular pressing applies segmented temperature-controlled extrusion. Aging treatment promotes the pre-cipitation of nanoscale phases. The L16 (45) orthogonal experiment validates the influence of each process on the alloy’s microstructure and properties and also op-timizes these influences. In performance tests, this method refines grains to the nanoscale (average 28 nm), increases hardness from 85 HV to 112 HV, enhances tensile strength to 562 MPa, improves elongation at fracture by 21.5 %, and raises electrical conductivity to 55 % IACS. These results indicate that the proposed mul-ti-process coupling method effectively improves the microstructure and properties of 7075 aluminum alloy through synergy between low-temperature strengthening and medium-high-temperature plasticity optimization. This study offers technical and practical references for optimizing high-strength aluminum alloys.

Keywords: solution treatment; equal channel angular pressing; aging treatment; 7075 aluminum alloy; alloy microstructure

This article is published online first and will appear in Metalurgija, Vol. 65, Issue 1 (2026).