An experimental study on solid-state recycling of AA6061-T6 machined chips by friction extrusion

The current paper provides an experimental study for the recycling of machining chips waste by Friction Extrusion to produce a wire. AA 6061-T6 block was used to produce machining chips by using a CNC milling machine with length, width, and thickness of 3.2, 0.5, and 0.08 mm respectively. A tool steel chamber and a rotating die with a central hole of 2.4 mm were used to produce an extruded wire by frictional heat in a single step. In order to enhance the wire’s mechanical properties and with a uniform structure, solution heat treatment followed by artificial aging for different periods of time (30, 60, and 90 min.) was done. Results for the tension test, microhardness test, and microstructure test showed that heat treatment contributed to improving mechanical properties; aging for 60 min. provides the highest results. Due to the production of finely dispersed precipitates, precipitation hardening successfully enhanced the UTS to 388 Mpa with an increase of about 41%.