Self-granulation of Eutectic Si Phase in Thin Al-8% Si Alloy Casting

Abstract

  Currently, there is a demand for techniques for manufacturing ductile die-casting for automobile bodies and frames. One of these techniques is T6 treatment performed after the die-casting of Al-Si alloy which has excellent castability. However, since the Al-Si alloy is thin-walled product, we are struggling to deal with deformation during solution treatment. Therefore, in this report, we attempted to develop a technology that utilizes the self-granulation phenomenon that causes granulation heat by applying heat inside the casting by thermally insulating castings and molds during solidification. As a result, in the casting with a thickness of 4 mm, the eutectic Si phase, which was plate-like, could be divided and granulated.