Influence of submerged fast multiple rotation rolling on the structure, strength, and tribological performance of Al–Si–Cu coatings on AA1010 aluminum

Abstract

The effects of submerged fast multiple rotation rolling (FMRR) on Al–Si–Cu coatings deposited on AA1010 substrates were systematically investigated. Coatings were produced via friction surfacing and subsequently processed under FMRR at traverse speeds of 120, 240, and 360 mm/min, while maintaining a constant load of 15 kN and tool rotation of 3200 rpm. Peak surface temperatures decreased with increasing traverse speed (371, 364, and 350 °C for 120, 240, and 360 mm/min, respectively), reducing dynamic recovery and promoting plastic strain accumulation. Microstructural analysis revealed progressive Si particle refinement from 3.1 to 2.1 μm and Al₂Cu precipitate refinement from 2.1 to 1.2 μm, accompanied by improved distribution uniformity (distribution coefficients from 0.57 to 0.76). Average Al grain size decreased from 3.5 to 1.9 μm, with higher fractions of high-angle grain boundaries enhancing load transfer and strain accommodation. Mechanical properties improved with increasing traverse speed: microhardness rose from 108.6 to 144.7 HV, nano-hardness from 8.01 to 9.76 GPa, and the nano-hardness-to-elastic-modulus ratio from 0.039 to 0.045. Tribological tests demonstrated reduced wear loss (7.5–6.1 µg/m) and friction coefficient (0.41–0.31), with SEM confirming a transition from delamination-dominated wear to mild abrasive and pitting wear.