Role of the local stress systems on microstructural inhomogeneity during semisolid injection

High pressure metal die casting is an extremely dynamic process with widely ranging cooling rates and intensifying pressures, resulting in a wide range of solid fractions deformation simultaneously existing the same casting. These parameters their complex interplay dictate formation microstructural solidification defects. In this study, fast synchrotron X-ray imaging experiments simulating high aluminium alloys were conducted to investigate effect fraction, loading conditions semisolid flow on local inhomogeneity. While most literature field reports speeds up 10 µm/s for situ deformation, present work captures much faster filling solidification, at closer 100 different fractions. Semisolid low reveals two typical features: (i) coarser grains middle finer ones near walls, (ii) remelting solid-liquid interface due Cu enrichment liquid by flow. Ex scans digital image correlation analysis higher fraction samples reveal porosity mechanism based state stresses, microstructure feeding. Four characteristics identified: plug flow, dead zone (densified mush), (iii) shear (iv) bulk zones. insights will be used develop zone-specific strategies numerical modelling defect during