Tailoring twist extrusion process; the better strain behavior at the lower required loads

• Published in: Journal of alloys and compounds 2021-04, Vol.859, p.157855, Article 157855
• Main Authors: Attarilar, Sh, Gode, C., Mashhuriazar, M.H., Ebrahimi, M.
• Format: Article
• Language: English
• Subjects: Coefficient of friction; Copper; Cross-sections; Deformation effects; Extrusion; Friction coefficient; Grain boundaries; Grain refinement; Hardness; Hardness measurement; Length-to-width ratio; Lubricants; Mechanical properties; Microstructure evolution; Plastic deformation; Strain hardening; Twist angle
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2020.157855

This study dealt with discovering the optimal conditions of the twist extrusion parameters for producing materials possess enhanced strain behavior with the least amount of extrusion load. It was found that the twist angle has a dominant influence on the strain behavior of the deformed sample with the contribution percentage of 56%, while the effect of friction coefficient would be the most noticeable if the required extrusion load is considered. Based on above, pure copper with the square cross-section was subjected to the process with the large twist angle at the best lubricant state. The results showed that the strength and hardness of the deformed copper were considerably enhanced compared to the initial condition due to the substantial grain refinement. The uniform plastic deformation zone of the deformed sample is limited which causes the reduction of strain-hardening exponent and ductility. Moreover, the lateral region of the sample’s cross-section endures larger plastic strain compared to the central one, leading to owning higher hardness. A combined microstructure consisting of low angle dislocation walls and high angle grain boundaries was also determined for the deformed copper. •The twist angle has a dominant influence on the strain behavior of the processed sample.•Effect of the friction coefficient is the most noticeable from the required extrusion load point of view.•Lateral region of the cross-section endures larger plastic strain compared to the center.•Strength and hardness of the TEed copper were considerably enhanced.•Uniform plastic deformation zone of the deformed sample is restricted.