Segregation of Liquid Phase in the Extruded Semisolid Metal

摘要

The influence of stress and strain on the solid/liquid segregation formed in deformed semisolid metal was studied. Thecompression experiment at a low constant strain rate was conducted on a Gleeble 1500 thermo-mechanical simulator.The stress and strain fields of the samples were calculated by finite element method. The experiment results and themodeling results prove that the hydrostatic pressure gradient is the driving force for solid/liquid segregation. Thesegregated liquid phase usually agglomerates in the micropores and shear bands are created by sliding of equiaxeddendrite grains. The sliding among the grains is influenced by the solid fraction and grain size of the semisolid slurry,so as the solid fraction and grain size change, the morphology of the segregated liquid changes.