Effect of ECAP Routes on Mechanical Properties and Microstructure of AA6061-T4 Recycled Chips

Abstract

Two routes, BC and C, were scrutinized, and the outcomes displayed significant enhancements in properties for the recycled chips after the hot extruded and ECAP techniques. After the fourth run, route BC exhibited a maximum Ultimate tensile strength of 265 MPa, peak yield strength of 149 MPa, and an elongation to failure of 46%. Meanwhile, the corresponding values for route C were 238 MPa, 136 MPa, and 41%, respectively. For two routes, BC and C, every pass led to elevated strength and hardness while also contributing to increased elongation to failure. The microstructures and mechanical characteristics of the ECAPed samples surpassed those of the extruded sample. The routes and pass numbers substantially impacted the microstructures and mechanical properties of the solid-state recycled AA6061-T4 alloy chip specimens. Scanning electron microscopy pictures showcased a honeybee-type pattern following ECAP through route BC, signifying the final stages of grain refinement. At the same time, the initial sample exhibited a fracture tendency with a mix of brittleness and ductility.