Elevated Temperature Corrosion of Mechanical Properties and Fatigue Life of 7025 Aluminum Alloy

Abstract

Aluminum alloys are widely used in aircraft industry where good corrosion resistance, light weight and high strength are the primary requirements.In the present study, attempts have been made to extend the application of mechanical and fatigue properties of AA7025 in laboratory with corrosive environment of media and combined corrosive at elevated temperature (ET) 150⁰C. The experimental results and analysis of corrosion and corrosion - elevated temperature mechanical and fatigue behavior of the samples showed that the 3.5%NaCl corrosive media and corrosion - elevated temperature (ET) greatly decrease the properties mentioned. The Ultimate Tensile Strength (UTS) and Yield stress YS of AA 7025 reduced by 5.3% and 14.83% respectively due to combine corrosion and elevated temperature but these properties reduce by 8.7% and 19.35% respectively due to combined actions corrosion (ET). The Brinell hardness also reduced by 4.2% and 11.26% due to corrosion only and corrosion and (ET). Ductility was increased by 10.5% and 16.25% for corrosion and corrosion (ET). The environment and elevated temperature – corrosion have significant effect on reduction the fatigue life and strength of AA 7025. It’s clear that the combine corrosion and (ET) combination reduce safely of the mechanical properties compared with the corrosion only and room temperature conditions.