Heat Treatment Conditions for High-Performance High-Pressure Die-Cast Al-Si-Cu-Mg Alloy

Random porosity in high-pressure die castings of aluminum alloys poses additional challenges in the form of blistering during follow-on heat treatment process. To avoid blisters, the current industrial practice is to lower solution temperature, but this compromises the strength. Herein, kinetics of eutectic Si spheroidization and coarsening during various solution treatment conditions and maximizing the dissolution of much needed Al2Cu and Al5Cu2Mg8Si6 phases, followed by formation of their precipitates in the aging stage with higher particle number densities, are studied and then higher tensile strength of 435 MPa in most commonly used high-pressure die-cast Al-Si-Cu-Mg alloy without causing blisters is demonstrated.

Results on optimization of heat treatment of a high-pressure die-cast Al-Si-Cu-Mg alloy are presented. During solution treatment, dissolution of the intermetallic phases and disintegration/spheroidization of Si particles occur simultaneously. The optimized treatment results in higher strength compared to the published literature for similar alloys without causing any blisters which is a common problem faced in industry.image (c) 2023 WILEY-VCH GmbH