An Overview on the Process Development and the Formation of Non-Dendritic Microstructure in Semi-Solid Processing of Metallic Materials

Semi-solid metal (SSM) processing has been an attractive method for manufacturing near-net-shape components with high integrity due to its distinct advantages over conventional forming technologies. SSM employs a mixture of solid phase and liquid slurries and/or non-dendritic feedstocks as starting materials shaping. Since the original development from 1970s, number processes have developed shaping using unique rheological thixotropic properties alloys in semi-solid state, which globular particles primary are dispersed into matrix. In this paper, progress technologies formation microstructure association scientific understanding microstructural evolution reviewed, emphasis includes new rheomoulding, rheo-mixing, rheo/thixo-extrusion twin roll casting, on top traditional rheocasting, thixoforming thixomoulding. The advanced control methods different also compared. mechanisms form microstructures summarised mechanical shear/bending dendrite multiplication spheroidal growth under intensively forced convection. particular, multiple phases eutectic is discussed. concluding remarks focus current challenges developing trends processing.