Development of a semi-solid metal processing technique for aluminium casting applications

A semi-solid metal processing technique has been invented and is being developed for aluminium casting applications in Thailand. The technique uses fine gas bubbles to create convection necessary for modifying grain structure. Semi-solid metal processing of three aluminium alloys, A356, Al-4.4%Cu, and ADC12, was investigated. Results show that the novel technique successfully modified A356 and Al-4.4%Cu to become semi-solid slurry with solid fractions up to about 50%. Current developments show a feasibility of applying this technique with gravity casting and the capability to prepare semisolid slurry up to 2 kg of aluminium alloys for industrial production.