Enhanced tensile strength and ductility of an Al-6Si-3Cu alloy processed by room temperature rolling

Abstract

Recent studies demonstrate that Al-Si alloys, which are conventionally used in as-cast form, can be transformed to profiles through high temperature plastic deformation. However, rare attention is paid to room temperature deformation of Al-Si alloys. In this work, an Al-6Si-3Cu alloy with excellent mechanical performance was produced through combined heat treatment and room temperature rolling, which is superior to other recently developed Al-Si alloys. Specifically, the alloy processed by a combination of solid solution treatment and room temperature rolling has an ultimate tensile strength (UTS) of 429.8 MPa and an elongation (EL) of 5.8%, exhibiting an improvement of 105% and 76% compared to the as-cast alloy, respectively. Subsequent artificial aging further enhances the EL to 9.9% but decreases the UTS to 387.4 MPa, which exceed that of the as-cast alloy by 200% and 85%, respectively. Detailed microstructure observations were performed to reveal the underlying mechanisms behind the enhancement of strength and ductility. Results presented in this work may shed some light on the development of strong and ductile Al-Si alloys.