Document Type : Research Paper


Mechanical and Manufacturing Engineering Dept., Technical College of Engineering, Sulaimani Polytechnic University, Sulaimani, Kurdistan Region, Iraq.


Aluminum alloy finds strong suitability in automotive, sporting, goods aerospace, and weight reduction industries. Its blend of lightweight attributes and robust strength make it well-suited for crafting lightweight components and structures while upholding overall strength and performance standards. In this research, AA6061-T4 alloy chips underwent a recycling process involving hot extrusion followed by Equal Channel Angular Pressing. The influence of various routes and varied numbers of cycles on microstructure and mechanical characteristics were examined utilizing a die featuring angles of 90° and 20°. 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.

Graphical Abstract


  • Tensile strength increased substantially by around 67% for route BC, while for route C, it rose by about 50%
  • Strength improved significantly, reaching 265MPa and 238MPa for routes BC and C after four passes
  • Results showed route BC is most effective for generating UFG materials to refine grains from recycled AA6061-T4 chips
  • ECAPed samples with tensile strength rising 67% for route BC and 50% for route C
  • Micro-hardness increased 67% after four passes to 79.36 HV, while for route BC, it reached 62.82 after two passes


Main Subjects

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