Effect of Crystal Orientation on Textures of Electromagnetic Stirred Aluminum Alloy

Abstract

Recently, a rheocasting process has been interested to produce a structural part for an automobile industry and so the slurry-on-demand process to make the semi-solid slurry having a fine and globular microstructure has been very important to produce a high quality and cost effective part in the rheocasting process. An electromagnetic (EM) stirrer employing for a slurry making process was designed and prepared to induce simultaneously both a circumferential and vertical fluid flow of a melt in order to control a rotation angle of EM stirring of a poured melt. In the present study, the semi-solid slurry of Al-15%Cu alloy was produced in the EM stirrer and its microstructure and the orientation distribution function calculated from the pole figure data was examined in accordance with a various rotation angle of EM stirring between 0˚ (circumferential flow) and 90˚ (vertical flow). The size and morphology of primary α phase was affected with a rotation angle of EM stirring and the finest and the most globular primary α phase could be obtained at a rotation angle of EM stirring of 45˚ and 60˚. Also, due to the EM stirring the tendency to random orientation was appeared. Also, the tendency of random orientation was the most at a rotation angle of 45˚ and 60˚. Therefore, it was considered that the rotation angle of EM stirring of 45˚ and 60˚ was the most effective to induce the non-dendritic growth of primary solid phase of EM stirred Al-Cu alloy.