Mechanical properties of equal channel angular pressed powder extrudates of a rapidly solidified hypereutectic Al-20 wt% Si alloy

Abstract

The processing and mechanical properties of rapidly solidified and consolidated hypereutectic Al-20 wt% Si alloys were studied. A bulk form of rapidly solidified Al-20 wt% Si alloy was prepared by extruding gas atomized powders having a powder size of 106–145 μm. Powder extrudates were subsequently equal channel angular pressed up to eight repetitive route C passes to refine matrix microstructure and Si particles by imposing severe plastic deformation. The microstructures of the gas atomized powders, extrudates and equal channel angular pressed samples were investigated via a scanning electron microscope. The mechanical properties of the bulk samples were measured by compressive tests. Equal channel angular pressing was found to be effective in matrix grain and Si particle refinement, which enhanced the strength of the Al-20 wt% Si alloy without deteriorating ductility in a range of experimental strain of up to 30%.