Microstructure of Al Alloy Semi-Solid Slurry Made in Metallic Vessel Using Vibrating Plate

Abstract

Recently, semi-solid slurry making method using metallic vessels, called "Cup-method", have been studied by the authors. In this method, semi-solid slurry with globular and fine structure is obtained only by pouring molten metal at certain temperature into a metallic vessel which is designed for desired slurry volume and solid fraction of the slurry. The method provides us shorter slurry making time and finer microstructure of α grain with around 50 μm in its size. However, the cup-method requires precise control in the slurry making condition; therefore it is difficult to obtain the homogeneous microstructure in the slurry, especially for the larger slurry. In this study, mechanical vibration was introduced to enhance homogeneity and fine microstructure generation. As a result, mechanical vibration provides the fine and homogeneous distribution of microstructure for wider slurry making conditions. Fine and non-dendrite structure of the slurry could be obtained even by using higher superheated melt, while the conventional method without vibration showed coarse and dendritic microstructure in the similar conditions.