Rheo-Extrusion of A7075 Aluminium Alloy Utilizing Semi-Solid Slurry Manufactured by Simple Method
In order to extrude A7075 aluminum alloy soundly from melt without using feed stock billet, rheo-extrusion was tried by utilizing semi-solid slurry with fine solid granules made by employing cooling tube. When the melt moving down inside thin tube was adequately cooled in different ways and introduced into an extrusion container kept at semi-solid temperature of 873K, structure of solidified slurries were granular and mean grain sizes of about 60 to 120μm could be obtained. Subsequently, these slurries were extruded to round bars at various extrusion ratios (28 to 64) and press ram speed of 10mm/s, just after cooling to 833K. The newly developed slurries 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.
W.J. Poole, M.A. Wells and D.J. Lloyd
R. Nagata et al., "Rheo-Extrusion of A7075 Aluminium Alloy Utilizing Semi-Solid Slurry Manufactured by Simple Method", Materials Science Forum, Vols. 519-521, pp. 1847-1852, 2006