Work

Influence of Laser Shock Peening without Coating on Surface, Mechanical, Corrosion, and Tribological Characteristics of AA7075/h-BN Nanocomposites

Year: 2026

Type: article

Abstract: AA7075 metal matrix composites (MMCs) were widely used for their high strength and low density, but their poor surface and tribological characteristics limit their use in aerospace and automotive applications. This study investigates the impact of laser shock peening without coating (LSPwC) on surface, mechanical, corrosion, and tribological properties of stir-squeeze cast AA7075, AA7075/0.5h-BN, and AA7075/1.0h-BN nanocomposites. LSPwC was applied using a 1064 nm wavelength, 400 mJ laser pulse energy, 7.95 GW/cm² power density, and 75% overlap. LSPwC improved surface hardness by ~7% in AA7075 (as-cast) and ~13% in AA7075/h-BN MMCs due to grain refinement, compressive residual stress (CRS), and intermetallic compounds (IMC) strengthening. The inclusion of h-BN NPS further reduced the surface roughness (Ra) by ~ 12% in LSPwC-treated composites. Contact angles decreased by ~10% (unpeened) and ~8% (LSPwC), while surface energy increased by ~76% and ~38%, respectively, indicating improved wettability. Corrosion resistance was also significantly enhanced, with LSPwC AA7075/1.0h-BN MMCs showing the lowest corrosion rate (0.01447 mm/year), corrosion current (1.675E-8), and highest polarisation resistance (124917.7 Ω). Tribological characteristics improved with both the h-BN inclusion and LSPwC treatment. LSPwC AA7075/1.0h-BN composites recorded the lowest SWR (0.1813 mm3/KN-m) and CoF (0.294) at RT, and 0.8233 mm3/KN-m and 0.314, respectively, at 150 ℃. The dominant abrasive, adhesive, and delamination wear mechanisms were reduced to mild in LSPwC samples. Overall, the combination of h-BN NPs LSPwC offers a promising route to enhance the properties of AA7075 MMCs for advanced aerospace applications.

Source: ACS Omega

DOI: 10.1021/acsomega.5c12393

Authors: Sudheer Reddy Beyanagari, Vaira Vignesh Ramalingam, Jayakrishna Kandasamy, Katerina Skotnicova, Praveenkumar Kesavan

Institutions: Amrita Vishwa Vidyapeetham, Vellore Institute of Technology University, VSB - Technical University of Ostrava

Language: English

Topic: Surface Treatment and Residual Stress

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,935

Funder: European Commission