Transactions of Materials Processing (소성∙가공)

The Korean Society for Technology of Plasticity and materials processing (한국소성∙가공학회)
권호 표지
DOI QR코드

DOI QR Code

Effects of Processing Conditions on Microstructure and Mechanical Properties of Mg Alloy Deformed by Differential Speed Rolling

이속 압연된 마그네슘 합금의 미세조직 및 기계적 물성에 미치는 가공 변수의 영향

  • Received : 2017.09.21
  • Accepted : 2017.12.27
  • Published : 2018.02.01
Download PDF
⟨ Previous Next ⟩

Abstract

This paper outlines the research findings on the microstructure and mechanical properties of AZ31 Mg alloy fabricated by differential speed rolling (DSR) with respect to processing variables such as temperature, roll speed ratio (RSR), and deformation route. The resultant microstructure of the sample, deformed by 2-pass DSRs at 473 K, comprised finer grains with more uniform distribution than those at 573 and 623 K. This was due to active recrystallization, which was expected to appear during DSR at temperatures higher than 573 K. When the sample was deformed via DSR with RSR of 1:4 for the upper and lower rolls at 453 K, the values of yield and ultimate tensile strength were observed to be higher than their counterpart with RSR of 1:1. The application of sample rotation around the longitudinal axis would give rise to an excellent combination of tension strength (~330 MPa) and ductility (~20 %) at ambient temperatures. This is discussed based on its uniform fine grained structure and the softening of basal texture.

Keywords

References

  1. D. H. Park, J. J. Yun, Y. H. Tak, C. W. Lee, 2015, Development of Automotive Dash Panel Parts using Warm Drawing of Magnesium Alloy AZ31B, Trans. Mater. Process, Vol. 24, No. 4, pp. 248-255. https://doi.org/10.5228/KSTP.24.4.248
  2. D. J. Lee, Y. Lee, H. K. Kim, Y. N. Kwon, H. S. Kim, E. Y. Yoon, 2016, Analyses of Sever Plastic Deformation Behavior of Hot Isostatic Pressed Nibase Super alloy during High Pressure Torsion Process, Trans. Mater. Process, Vol. 25, No. 4, pp. 254-260. https://doi.org/10.5228/KSTP.2016.25.4.254
  3. R. Z. Valiev, T. G. Langdon, 2006, Principles of Equal-channel Angular Pressing as a Processing Tool for Grain Refinement, Prog. Mater. Sci., Vol. 51, No. 7, pp. 881-981. https://doi.org/10.1016/j.pmatsci.2006.02.003
  4. S. Akramov, M. K. Lee, I. Kim, B. H. Park, 2005, Texture and Plastic Strain Ratio of the Severe Shear Deformed with ECAP and heat-treated AA 1050 Aluminum Alloy Sheet, Trans. Mater. Process, Vol. 14, No. 6, pp. 553-558. https://doi.org/10.5228/KSPP.2005.14.6.553
  5. J. Straska, M. Janecek, J. Gubicza, T. Krajnak, E. Y. Yoon, H. S. Kim, 2015, Evolution of Microstructure and Hardness in AZ31 Alloy Processed by High Pressure Torsion. Mater. Sci. Eng. A, Vol. 625, No. 11, pp. 98-106. https://doi.org/10.1016/j.msea.2014.12.005
  6. Z. Horita, D. J. Smith, M. Furukawa, M. Nemoto, R. Z. Valiev, T. G. Langdon, 1996, An Investigation of Grain Boundaries in Submicrometer-Grained Al- Mg Solid Solution Alloys Using High-Resolution Electron Microscopy, J. Mater. Res., Vol. 11, No. 8, pp. 1880-1890. https://doi.org/10.1557/JMR.1996.0239
  7. Y. S. Kim, 2005, Thermal Stability and Dry Sliding Wear Behavior of Ultra-Fine Grained 6061 Al Alloy Processed by the Accumulative Roll-Bonding Process, Trans. Mater. Process, Vol. 14, No. 1, pp. 71-77. https://doi.org/10.5228/KSPP.2005.14.1.071
  8. H. Watanabe, T. Mukai, K. Ishikawa, 2007, Effect of Temperature of Differential Speed Rolling on Room Temperature Mechanical Properties and Texture in an AZ31 Magnesium Alloy, J. Mater. Process. Tech., Vol. 182, No. 1-3, pp. 644-647. https://doi.org/10.1016/j.jmatprotec.2006.08.010
  9. S. C. Yoon, C. H. Bok, E. J. Kwak, Y. G. Jeong, T. S. Kim, H. S. Kim, 2008, Effect of Equal Channel Angular Pressing Temperature on the Fracture and Mechanical Properties of Magnesium, Trans. Mater. Process, Vol. 17, No. 1, pp. 13-18. https://doi.org/10.5228/KSPP.2008.17.1.013
  10. L. L. Chang, J. H. Cho, S. B. Kang, 2011, Microstructure and Mechanical Properties of AM31 Magnesium Alloys Processed by Differential Speed Rolling, J. Mater. Process. Tech., Vol. 211, No. 9, pp. 1527-1533. https://doi.org/10.1016/j.jmatprotec.2011.04.003
  11. J. B. Lee, T. J. Konno, H. G. Jeong, 2010, Effect of Differential Speed Rolling on the Anisotropy of Mechanical Properties and Texture Evolution of AZ31 Mg Alloys, J. Alloy. Compd., Vol. 499, No. 2, pp. 273-277. https://doi.org/10.1016/j.jallcom.2010.03.186
  12. Loorentz, Y. G. Ko, 2012, Microstructure Evolution and Mechanical Properties of Severely Deformed Al Alloy Processed by Differential Speed Rolling, J. Alloy. Compd., Vol. 536, No. S1, pp. S122-S125. https://doi.org/10.1016/j.jallcom.2011.12.009
  13. H. K. Kim, W. J. Kim, 2004, Microstructural Instability and Strength of an AZ31 Mg Alloy after Severe Plastic Deformation, Mater. Sci. Eng. A, Vol. 385, No. 1-2, pp. 300-308. https://doi.org/10.1016/S0921-5093(04)00882-2
  14. O. B. Kulyasova, R. K. Islamgaliev, Y. H. Zhao, R. Z. Valiev, 2015, Enhancement of the Mechanical Properties of an Mg-Zn-Ca Alloy Using High-Pressure Torsion, Adv. Eng. Mater., Vol. 17, No. 12, pp. 1738-1741. https://doi.org/10.1002/adem.201500176