Effect of solid fraction on formability and mechanical properties in a vertical-type rheo squeeze-casting process

Abstract

This paper demonstrates an electromagnetic stirring (EMS) process which strongly stirs the molten metal at the initial stage of solidification, in order to transform the dendritic microstructure into fine spherical particles close to a globule; the paper accordingly suggests that the vertical squeeze-casting process is suitable for forming rheological material into engineering parts. Thus, this study investigates the performance of the vertical rheological die-casting process for developing highly functional and lightweight engineering parts. The vertical squeeze-casting process was optimized to obtain a high-quality product by controlling the solid volume fraction through EMS, as well as the velocity of injection in the rheological forming process; subsequently, the formability of the product was estimated. As a result, the mechanical characteristics of the product fabricated for each condition could be examined. In this study, the channel type of product was selected because of its feasibility to be adapted to a vehicle component of rheological materials. It is suggested that when rheological materials formed by the EMS process, which controls the solid fraction of rheological material, are manufactured into engineering components by vertical die-casting, the fine microstructure of the product can be fabricated.