급속응고 Al-20 wt% Si 합금분말 압출재의 ECAP

Abstract

In this paper processing and mechanical properties of Al-20 wt% Si alloy was studied. A bulk form of Al-20Si alloy was prepared by gas atomizing powders having the powder size of 106-145 μm and powder extrusion. The powder extrudate was subsequently equal channel angular pressed up to 8 passes in order to refine grain and Si particle. The microstructure of the gas atomized powders, powder extrudates and equal channel angular pressed samples were investigated using a scanning electron microscope and X-ray diffraction. The mechanical properties of the bulk sample were measured by compressive tests and a micro Vickers hardness test. Equal channel angular pressing was found to be effective in matrix grain and Si particle refinement, which enhanced the strength and hardness of the Al-20Si alloy without deteriorating ductility in the range of experimental strain of 30%.