Regulation mechanisms of entropy synergistic effects on enhancing mechanical properties and thermal conductivity in aluminum alloys

Abstract

The intrinsic trade-off between mechanical strength and thermal conductivity in aluminum alloys presents a significant challenge, limiting their utilization in advanced applications. Traditional alloy design methodologies tend to intensify electron-phonon scattering, leading to deteriorated thermal transport properties. This study introduces a design framework that exploits the combined effects of electronic, configurational, and vibrational entropy, systematically examining entropy influences on alloy performance through integrated experimental and first-principles computational methods. Al-Si, Al-Mn, and Al-Mg alloys with varying compositions (1–5 wt.%) were produced using permanent mold casting, while density functional theory (DFT) calculations were conducted to evaluate electronic, configurational, and vibrational entropy. Additionally, a multi-entropy-properties coupling model was formulated, effectively linking entropy parameters with mechanical and thermal properties. Experimental findings indicate that increasing solute content enhances strength in all three alloys while compromising ductility. DFT calculations suggest that configurational entropy primarily contributes to strength improvement by inducing lattice distortion through solute atoms, whereas electronic entropy decreases thermal conductivity by generating localized states near the Fermi level. Furthermore, both configurational and vibrational entropy suppress thermal transport through electron-phonon scattering. The developed multi-entropy-property coupling model corroborates these findings, highlighting the pivotal role of multiscale entropy interactions in optimizing alloy performance. This research offers valuable insights into designing aluminum alloys with enhanced strength and thermal conductivity, demonstrating considerable potential for applications in electronics thermal management and lightweight structural materials.