Effects of melt thermal treatment on cast Al-Si alloys: A review

Abstract

The shape and size of primary phases (α-Al and primary Si in hypoeutectic and hypereutectic alloys, respectively), and that of eutectic Si phase significantly affect the mechanical properties of cast Al-Si alloys. The Al-Si alloys prepared by the conventional casting method have large-sized primary phases and needle-shaped eutectic Si phases along with their uneven distribution in the microstructure. This leads to poor mechanical properties in those alloys. This paper presents a review on a modified casting process known as melt thermal treatment, which has the potential to positively change the shape and size of primary and eutectic phases in Al-Si alloy without any foreign additives. Various researches that have been carried out to study the effect of melt thermal treatment on microstructure and different properties of Al-Si alloys are discussed here.