Assessment of fatigue and thermal performance in aluminum alloys using Taguchi and ANOVA

This study investigates the mechanical and fatigue performance of AA7075‑T4 aluminum alloy at 25, 100, and 150°C. Tensile and fatigue tests were conducted to evaluate ultimate tensile strength, yield strength, Young’s modulus, and ductility. Results reveal that strength and stiffness decline with increasing temperature, while ductility improves. Fatigue behavior was analyzed using a Taguchi L9 orthogonal array and ANOVA, considering stress amplitude and temperature. Stress amplitude accounted for 93 % of the variation in fatigue life, whereas temperature contributed 6 %. S−N curves confirmed greater sensitivity to stress amplitude with rising temperature. At 150°C, the endurance limit improved under low-stress conditions (22 to 32 MPa) due to stress relaxation and microstructural changes, yet fatigue life at 207 MPa decreased by ≈47 %. Comparison with AA7001‑T6 and AA2024‑T4 alloys showed alloy-specific thermal responses, with AA7001‑T6 displaying superior stability for thermo-mechanical fatigue applications.