Nano-grain refinement and strengthening of copper under room temperature RUE process

Document Type : Research Note

Authors

Faculty of Materials Science and Engineering, K.N. Toosi University of Technology, Tehran, Postal Code: 1999143344, Iran

Abstract

In this investigation repetitive upsetting-extrusion (RUE) process was used to investigate the effect of severe plastic deformation on the microstructural changes and flow behavior of commercial pure copper. Initial material together with two passes, four passes and eight passes of RUE in annealed and non-annealed condition were studied. Results show that grain refinement, in the scale of nano meter, has mostly been achieved only after two passes of RUE which is essentially a combination of one upsetting and one extrusion path. Increasing the number of passes after four passes of RUE did not have discernible effect on the grain refinement. Such a behavior is explained to be due to saturation of dislocations and the formation of high angle grain boundaries after only two passes of RUE. The grains after eight passes of RUE process even became slightly larger than the two and the four passes of RUE. This was related to restoration phenomena occurring during high number of passes of RUE. Flow strength of the material after different passes substantially increased, though the rate at which the flow stress increased declined by increasing the number of passes. ETMB model were used to explain the deformation behavior of the RUE samples.

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References

References:
1. Aghaie-Khafri, M. and Mahmudi, R. "Optimizing homogenization parameters for better stretch formability in an Al-Mn-Mg alloy sheet", Mater. Sci. Eng. A, 399, pp. 173-180 (2005).
2. Saito, Y., Utsunomiya, H., Tsuji, N., and Sakai, T. "Novel ultra-high straining process for bulk materialsdevelopment of the accumulative roll-bonding (ARB) process", Acta Mater., 47, pp. 579-583 (1999).
3. Valiev, R.Z. and Langdon, T.G. "Developing SPD methods for processing bulk nanostructured materials with enhanced properties", Metals Mater. Int., 7, pp. 413-420 (2001).
4. Yoon, E.Y., Lee, D.J., Park, B., Akbarpour, M.R., Farvizi, M., and Kim, H.S. "Grain refinement and tensile strength of carbon nanotube-reinforced Cu matrix nanocomposites processed by high-pressure torsion", Metals Mater. Int., 19, pp. 927-932 (2013).
5. Latypov, M.I., Lee, M.G., Beygelzimer, Y., Kulagin, R., and Kim, H.S. "Simple shear model of twist extrusion and its deviations", Metals. Mater. Int., 21, pp. 569-579 (2015).
6. Fatemi-Varzaneh, S.M. and Zarei-Hanzaki, A. "Accumulative back extrusion (ABE) processing as a novel bulk deformation method", Mater. Sci. Eng. A, 504, p. 104 (2009).
7. Binesh, B. and Aghaie-Khafri, M. "RUE-based semisolid processing: Microstructure evolution and effective parameters", Mater. Des., 95, pp. 268-286 (2016).
8. Zaharia, L., Comaneci, R., Chelariu, R., and Luca, D. "A new severe plastic deformation method by repetitive extrusion and upsetting", Mater. Sci. Eng. A, 595, pp. 135-142 (2014).
9. Aizawa, T. and Tokimutu, K. "Bulk mechanical alloying for productive processing of functional alloys", Mater. Sci. Forum, 312-314, pp. 13-22 (1999).
10. Raghu, I.B. "On the die design for repetitive upsettingextrusion (RUE) process", Int. J. Mater. Form., 6, pp. 289-301 (2013).
11. Balasundar, I., Ravi, K.R., and Raghu, T. "Strain softening in oxygen free high conductivity (OFHC) copper subjected to repetitive upsetting-extrusion (RUE) process", Mater. Sci. Eng., A583, pp. 114-122 (2013).
12. Balasundar, I. and Raghu, T. "Deformation behaviour of bulk materials during repetitive upsetting extrusion (RUE) process", Int. J. Mater. Form., 3, pp. 267-278 (2010).
13. Balasundar, I. and Raghu, T. "On the die design requirements of repetitive upsetting-extrusion (RUE) process", Int. J. Mater. Form., 6, pp. 289-301 (2013).
14. Sheppard, T. Extrusion of Aluminum Alloys, Springer Science+Business Media, B.V. (1999).
15. Balasundar, T. "Severe plastic deformation (SPD) using a combination of upsetting and extrusion", J. Metall. Eng. (ME), 2, pp. 130-139 (2013).
16. Balasundar, I. "Grain refinement in OFHC Cu subjected to repetitive upsetting extrusion (RUE) process", Mater. Sci. Forum, 710, pp. 270-275 (2012).
17. Hosford, W.F. and Caddell, R.M., Metal Forming, Mechanics and Metallurgy, Fourth Edition, Cambridge Univ. Press (2011).
18. Ranaei, M.A. "Microstructure, mechanical and electrical properties of commercially pure copper deformed severely by equal channel angular pressing", Int. J. Nanosci. Nanotech., 10, pp. 266-257 (2014).
19. Aghaie-Khafri, M. and Mahmudi, R. "The effect of preheating on the formability of an Al-Fe-Si alloy sheet", J. Mater. Process. Technol., 169, pp. 38-43 (2005).
20. XU, Y. "Microstructure and mechanical properties of AZ61 magnesium alloy prepared by repetitive upsetting-extrusion", Trans. Nonferrous Metals Soc., China, 25, pp. 381-388 (2015).
21. Lianxi, H., Yuping, L., Erde, W., and Yang, Y. "Ultrafine grained structure and mechanical properties of a LY12 Al alloy prepared by repetitive upsettingextrusion", Materi. Sci. Eng., A422, pp. 327-332 (2006).
22. Habibi, A. and Ketabchi, M. "Enhanced properties of nano-grained pure copper by equal channel angular rolling and post-annealing", Mater. Des., 34, pp. 483- 487 (2012).
23. Kommel, L. "Microstructure and properties development of copper during severe plastic deformation", Mater. Desi., 28, pp. 1221-2128 (2007).
24. Humphreys, F.J. and Hatherly, M., Recrystallization and Related Annealing Phenomena, Elsevier Ltd., (2004).
25. Enikeev, N.A. "Kinetic dislocation model of microstructure evolution during severe plastic deformation", Mater. Sci. Eng., A460, pp. 619-623 (2007).
Scientia Iranica
Volume 26, Issue 1
Transactions on Mechanical Engineering (B)
January and February 2019
Pages 445-454

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