Solid state recycling of aluminium AA6061 alloy chips by hot extrusion

In the present study, aluminium AA-6061 alloy turning chips recycled using solid-state recycling technique through cold compaction followed by hot extrusion. The effect of the extrusion ratio (ER) and extrusion temperature (ET) on the microstructure evolution, the physical properties and the mechanical properties of the produced samples were studied. Moreover, the results were compared with those of the as-received samples extruded under the same conditions (reference samples extruded under ER = 5.2 and different ET = 350, 450 and 500 °C). Approximately dense samples with reasonable tensile strength, elongation, and microhardness were obtained. The tensile properties (strength and elongation) of recycled samples increased with the increase of the ER and ET those improve the bonding between chips. The chip samples processed under ER of 12.8 and ET of 500 °C have superior mechanical properties compared to the reference samples. The fracture surfaces of the recycled samples consisted of a combination of micro-cracks and equiaxed dimples according to the degree of the bonding of the chips.