Influence of Test Temperature and Test Frequency on Fatigue Life of Aluminum Alloy EN AW‐2618A

The aluminum alloy EN AW‐2618A is a high‐strength, precipitation‐hardened material developed for applications at elevated temperatures. In service, components such as radial compressor wheels and pistons are exposed to thermal conditions that cause microstructural overaging, leading to mechanical softening. With future exhaust gas turbochargers expected to operate at temperatures up to 230°C and with increasing demands for efficiency and compression ratio, reliable data on fatigue behavior under these conditions is essential but currently lacking. This study aims to close this gap by conducting fully reversed ( R = −1) high‐cycle fatigue (HCF) tests at room temperature and at 230°C on specimens in an overaged condition (1000 h at 230°C), simulating the degradation that occurs in service due to the coarsening of the strengthening S‐phase. Additionally, the influence of test frequency on fatigue performance is investigated.