2026 Yagci Shot Peening A356

This study aims to investigate the effect of different shot-peening (SP) intensities, including conventional shot peening (CSP) and severe shot peening (SSP), on the surface characteristics, microstructure, and mechanical behavior of cast A356 aluminum alloy, with a particular focus on wear performance. Although SP has been widely investigated for steels and titanium-based alloys, its systematic evaluation on cast Al-Si alloys, particularly regarding surface modification and tribological response, is still limited. This research addresses this gap by systematically analyzing how varying Almen intensities (8N, 11N, and 18N) affect the near-surface integrity and wear performance of cast A356 components. To comprehensively analyze the structural and mechanical changes caused by SP, diverse experimental techniques were implemented. Surface roughness was quantified using a contact profilometer, while microstructural characterization was carried out by optical microscopy (OM) and scanning electron microscopy (SEM); stereo microscopy (SM) was further used to investigate the wear traces. The amount and distribution of residual stress in the samples after the SSP process was analyzed using the X-ray diffraction (XRD) technique. In addition, tribological performance was assessed under controlled load and speed parameters, with friction coefficients recorded in real time and wear volume calculated through profilometry-based geometrical analysis. The microscopic observations demonstrated that SSP increased surface roughness and produced finer peen imprints, while the slight roughness reduction at the highest coverage levels indicated the onset of surface saturation. Moreover, higher peening intensities enhanced surface hardness (from *75 HV in NP to *118 HV in SP8, *148 HV in SP11, and *181 HV in SP18), which in turn elevated the coefficient of f.