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 degrees (circumferential flow) and 90 degrees (vertical flow). The size and morphology of primary a phase was affected with a rotation angle of EM stirring and the finest and the most globular primary a phase could be obtained at a rotation angle of EM stirring of 45 degrees and 60 degrees. 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 degrees and 60 degrees. Therefore, it was considered that the rotation angle of EM stirring of 45 degrees and 60 degrees was the most effective to induce the non-dendritic growth of primary solid phase of EM stirred Al-Cu alloy.