Semi-solid alloys processing. Application to hypereutectic Al-Si alloys

Abstract

The processing of alloys in the semi-solid state, known as Rheocasting, Thixoforming, Thixoforging or Thixocasting, is within the new technologies used for the production of materials. This work describes the process as well as the phenomena implied in it. As the forming of alloys in the semisolid state requires of a previous material preparation (in order to obtain a non-dendritic structure) the Osprey process or Spray-forming, used in this work, is briefly described. Finally, both the microstructural results obtained from the combination of the two technologies in hypereutectic Al-Si alloys (Al-25%Si-5%Cu, Al-25%Si-5%Cu-2%Mg and Al-30%Si-5%Cu) and comparison with microstructures obtained from similar alloys processed by conventional methods are shown.