Centrifugal Casting of Al–Si Scrap

Abstract

Recycling is a sustainability strategy that enables environmental savings as well as energy and cost reduction. Sustainability and reduced energy consumption requirements demand that Al–Si alloys are recycled by re-melting. Industries that use cast Al–Si alloys are increasing, leading to more consumption of these alloys that in turn leads to more scrap. Unfortunately, when cast Al–Si alloys are recycled, detrimental microstructures combined with reduction in the mechanical properties occur. In this work, the limitations of recycling of cast Al–Si scrap are discussed. To overcome some of these limitations, centrifugal casting was adopted and the effect of the centrifugal speed was investigated. The microstructure of Al–Si alloys with high recycled content produced by centrifugal casting using different parameters was studied. The independent variables are the centrifugal speed and scrap material mix. The microstructure of the recycled cast Al–Si alloys was observed to improve by centrifugal casting, resulting a graded microstructure from inner to outer surface of the casting. The centrifugal separation is shown to be a promising method for controlling the Fe-rich enormous structures and the porosity present in the recycled Al–Si alloys.