Document Type : Research Paper


1 Mechanical Engineering Dept, College of Engineering, Sulaimani Polytechnic University, Sulaimani, Kurdistan Region, Iraq

2 Mechanical Engineering Dept, College of Engineering, University of Tehran, Tehran, Iran.


The oxidation of aluminum machined chips makes successful recycling via the traditional re-melting technique difficult. A viable solution to this problem is to utilize solid-state recycling to transform aluminum machined chips directly into semi-finished goods, eliminating the costs of the re-melting process and minimizing CO2 emissions. In the present study, Al-6061 alloy chips have been recycled using hot extrusion followed by severe plastic deformation at ambient temperature to examine the material's mechanical properties and microstructures. The current study investigates the effects of equal channel angular pressing samples after (1, 2, and 4) cycles using a die with  90° and  20° angles, a strain of 1 was applied each pass for a maximum of four cycles at room temperature, through different routes (BC, C) on the mechanical properties of recycled specimens before and after the process. Observations showed a significant improvement in the characteristics of recycled chips exposed to hot extrusion followed by the ECAP technique. Maximum ultimate tensile strength (265, and 238 MPa) maximum yield strength (149, and 136 MPa), and elongation to failure (46 and 41%) for both routes were obtained. Moreover, each pass increases yield strength ultimate tensile strength, and micro-hardness while increasing elongation to failure. The mechanical characteristics of ECAPed specimens were higher than the extruded specimen. The mechanical properties and microstructures of solid-state recycled Al-6061 alloy chip samples were significantly influenced by the number of passes and route types.

Graphical Abstract


  • Severe plastic deformation was utilized to improve mechanical properties, microstructure, and microhardness.
  • Improvements in tensile strength and yield strength are reported for the ECAPed Al-6061 alloys.
  • Ductility decreased from 27% to 13% after one pass.
  • The micro-hardness increased from 47.55 HV to 79.36 HV, an increase of about 67% after four pass. 


Main Subjects

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