Effects of primary phase morphology on mechanical properties of Al-Si-Mg-Fe alloy in semi-solid slurry casting process
(1. Department of Industrial Engineering, Faculty of Engineering, Rajamangala University of Technology Srivijaya, Songkhla 90000, Thailand;
2. Department of Mining and Materials Engineering, Faculty of Engineering, Prince of Songkla University,
Songkhla 90112, Thailand)
2. Department of Mining and Materials Engineering, Faculty of Engineering, Prince of Songkla University,
Songkhla 90112, Thailand)
Abstract: The gas induced semi-solid (GISS) process was developed to create semi-solid slurry with fine and uniform globular structure. The combination of local rapid heat extraction and vigorous agitation by the injection of fine inert gas bubbles through a graphite diffuser in molten metal held at a temperature above its liquidus temperature changes the morphology of primary α(Al) from coarse dendritic to rosette-like and finally to fine globular. The GISS process produced semi-solid slurry at low solid fractions and then formed the slurry by a squeeze casting process to produce casting parts. The effects of primary phase morphology on the mechanical properties of Al-Si-Mg-Fe alloy were investigated. The results show that the ultimate tensile strength and elongation are affected by the shape factor and particle size of the primary α(Al).
Key words: gas induced semi-solid (GISS); microstructure; mechanical properties; semi-solid slurry casting; rheocasting