Simple manufacturing method for A7075 aluminum alloy slurry with fine granules and application to rheo-extrusion

Semi-solid slurry of A7075 aluminum alloy with fine solid granules was tried simply to make by passing the melt through upright tube followed by inclined water-cooled tube. Structures of solidified slurries were granular and mean grain sizes of about 0.06 to 0.11mm could be obtained. When the slurries introduced into an extrusion container kept at semi-solid temperature 873K were extruded to round bars at various extrusion ratios and press ram speed of 10mm/s, just after cooling to 833K, they could easily be extruded to bars with smooth surfaces at lower forces. Although every tensile strength of extruded bars were lower than that of hot-extruded one, there was a tendency that finer the solid granules in slurry, higher the tensile strength of extruded bar.