Solid-state recycling of aluminum alloy (AA-6061) chips via hot extrusion followed by equal channel angular pressing (ECAP)

Aluminum alloy (AA-6061) chips were recycled using hot extrusion followed by equal channel angular pressing (ECAP) process at room temperature. AA-6061chips were cold compacted into billets, then extruded into rods under extrusion ratio of 5.2 at different extrusion temperatures (ET). Finally, the rods were processed through ECAP die with inner angle Φ of 90°, and outer arc angle Ψ of 32.8°, which impose strain ɛ of 1 per each pass up to different number of passes. The effects of the ECAP number of passes and extrusion temperature on the microstructure evolution and mechanical properties were fully investigated. Furthermore, the microstructure and the mechanical properties of the ECAPed samples were compared with those of the extruded samples. Grain refinement were noted after the ECAP process. Moreover, the ECAPed samples revealed higher mechanical properties than those of the extruded samples. The extrusion temperature (ET) and the number of the ECAP passes have an obvious effect on both the microstructure and mechanical properties of the solid state recycled chips samples.