Combination of hot plastic deformation and T6 heat treatment for enhancing mechanical properties of an A356 alloy

Abstract

ABSTRACT This study evaluates the relationship between solution heat treatment and hot plastic deformation before aging treatment and its effect on A356 alloys’ mechanical properties and microstructural features. The study employed tensile tests, Vickers microhardness tests, and electron microscopy analysis. The results show that hot plastic deformation before the solution treatment leads to higher elongation, ultimate tensile stress, and yield strength values, which can be attributed to modifications in eutectic Si particles (spheroidisation, aspect ratio and roundness). On the other hand, hot plastic deformation after the solution treatment mainly affects the elongation of the alloy. This effect is due to the fracture of eutectic Si particles and the formation of cracks and voids between these particles, which facilitate crack nucleation. Thus, the combination of hot plastic deformation and subsequent solution treatment significantly improves the mechanical properties of the A356 alloy. The observed changes in microstructure and mechanical behaviour provide valuable insights for optimising the material's properties and refining an established process in the automotive wheel industry.