Effect of Slurry Temperature Distribution on Semi-Solid Die Casting

Abstract

Semi-solid alloy slurries with different temperature distributions have diverse flow patterns of the slurries during die casting filling process. This different flow patterns can lead to various degrees of front separation of the slurry metal from the die cavity during die filling process. This separation can result in air entrapment, which is one of the origins for gas porosities and blisters occurred during followed heat treatment. Therefore, in this paper, the effects of slurry temperature distribution on filling patterns during die casting process were investigated. Based on partial filling experiments, positive and negative gradient temperature distribution, together with two homogeneous conditions 575°C, 579°C were compared by computer simulation. The results indicate that the positive gradient temperature condition of 357.0 slurry is more suitable for the semi-solid die casting of the connector, and 7 °C temperature gradient in slurry is appropriate for good filling.

Using ProCAST to Study the Effects of SEED Process Parameters on the Radial Temperature Distribution in Semi-Solid Slugs

“…The data calculated by the equation agreed well with the simulation results. Qu et al [12] measured the temperature distribution within 90mm alloy 357 slugs produced by the SEED process by placing a thermocouple tree within the crucible prior to pouring. They measured approximately 7 °C temperature difference between the slug center (572 °C) and surface (579 °C), which corresponds to a solid fraction difference of only about 0.03, as shown in Fig.…”

Using the Phase Field Method to Investigate Microstructural Evolution of Semi-Solid 357.0 Slurries

“…The process uses a cylindrical steel crucible, and after pouring of the liquid alloy into the crucible, a portion of the latent heat of solidification is transferred to the crucible, cooling the alloy into the semi-solid temperature range. However, this produces a temperature gradient across the diameter of the slug, resulting in higher temperatures at the slug's center and lower temperatures at its surface [4]. This suggests that nucleation of the solid will initially occur at the slug's surface, and gradually move to the center of the slug.…”