Shortlisted Investigating Feasibility of Combined Hip and Solution Heat Treat Process for Production of Critical Aluminium Castings

Abstract

Aluminium castings used in cyclically stressed applications need to be produced more economically. The present investigation examines the potential of a combined densification and heat treatment process. Using existing hot isostatic pressing hardware, a combined production process was developed using the Bodycote Densal process and a solution heat treatment. Three different castings were treated: permanent mould Al–Si–Mg alloy ABS master cylinder housing, sandcast Sr modified A356 experimental wedge coupon and sandcast Sr modified A356 steering knuckles. The tensile properties and fatigue behaviour of the castings was investigated using SEM and EDAX analysis. The results for the castings processed with the combined treatment were similar to the castings subjected to the more traditional production process of densification followed by heat treatment. On an industrial scale, energy savings are estimated to be ~50% with timesavings of ~30%.