Investigating fretting wear behavior of LPBF processed AlSi10Mg alloy under variable frequency and heat treatment conditions

This study examines the fretting wear behavior of AlSi10Mg alloy processed via Laser Powder Bed Fusion (LPBF) under different oscillation frequencies (5 Hz, 10 Hz, and 15 Hz) and heat treatment conditions (as-built, stress-relieved, T5, and T6) under a consistent load of 100 N. The fabricated and heat-treated samples were analyzed using X-ray diffraction, hardness testing, and residual stress measurements to evaluate dislocation density, hardenability, and the nature of residual stress. Fretting wear behavior was further assessed through evaluations of the coefficient of friction (COF), worn surface morphology, and wear volume loss using scanning electron microscopy (SEM) and 3D profilometry to understand the mechanism. Results indicated that the as-built samples exhibited superior resistance against fretting wear across all tested frequencies, a phenomenon attributed to their refined microstructure and higher dislocation density (FWHM: 0.213). The results show that lower frequencies primarily result in adhesive wear, with the oxide layer providing some protection, but higher frequencies accelerate abrasive and fatigue wear due to enhanced crack propagation and thermal softening.