Measurement of Bauschinger Effect in Ultrafine-Grained A1070 Aluminum Rods

Abstract:

In this study, the Bauschinger effect in ultrafine-grained pure aluminum rods (A1070) was investigated. The samples were produced by multipass equal-channel angular pressing (ECAP) with ‘route BC’, which is known to give nearly equiaxial-shaped crystal grains. Dumbbell-shaped specimens with a circular cross section were machined from the samples subjected to ECAP to carry out uniaxial tensile and compressive tests, which were followed by reversal of the loading direction at a prestrain of 1%. The influence of the grain size on the intensity of the Bauschinger effect was investigated. The Bauschinger effect is interpreted to be a manifestation of internal stresses produced near the grain boundaries by the accumulation of dislocations. On the basic of our experimental results, the roles of the grain boundaries, which are usually at least partially considered as barriers to dislocation motion, are reconsidered.

• Periodical: Key Engineering Materials (Volume 725)
• Pages: 202-207
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.725.202
• Online since: December 2016
• Authors: Takayuki Koizumi*, Mitsutoshi Kuroda
• Keywords: Bauschinger Effect, Equal-Channel Angular Pressing, Tension-Compression Asymmetry, Ultrafine-Grained Material

References

[1] N. Tsuji, Y. Ito, Y. Saito, Y. Minamino, Strength and ductility of ultrafine grained aluminum and iron produced by ARB and annealing, Scripta Materialia 47 (2002) 893–899.

DOI: 10.1016/s1359-6462(02)00282-8

[2] E.A. El-Danaf, M.S. Soliman, A.A. Almajid, M.M. El-Rayes, Enhancement of mechanical properties and grain size refinement of commercial purity aluminum 1050 processed by ECAP, Materials Science and Engineering A 458 (2007) 226–234.

DOI: 10.1016/j.msea.2006.12.077

[3] V.M. Segal, V.I. Reznikov, A.E. Drobyshevskiy, V.I. Kopylov, Plastic working of metals by simple shear, Russian Metallurgy 1 (1981) 99–105.

[4] V.M. Segal, Materials processing by simple shear, Materials Science and Engineering A 197 (1995) 157–164.

[5] M. Haouaoui, I. Karaman, H.J. Maier, Flow stress anisotropy and Bauschinger effect in ultrafine grained copper, Acta Materialia 54 (2006) 5477–5488.

DOI: 10.1016/j.actamat.2006.07.022

[6] Z. Horita, M. Furukawa, M. Nemoto, T.G. Langdon, Development of fine grained structures using severe plastic deformation, Materials Science and Technology 16 (2000) 1239–1245.

DOI: 10.1179/026708300101507091

[7] Y. Iwahashi, Z. Horita, M. Nemoto, T.G. Langdon, The process of grain refinement in equal-channel angular pressing, Acta Materialia 46 (1998) 3317–3331.

DOI: 10.1016/s1359-6454(97)00494-1

[8] K. Oh-ishi, Z. Horita, M. Nemoto, M. Furukawa, T.G. Langdon, Optimizing the rotation conditions for grain refinement in equal-channel angular pressing, Metallurgical and Materials Transactions A 29 (1998) 2011–(2013).

DOI: 10.1007/s11661-998-0027-z

[9] Y. Iwahashi, J. Wang, Z. Horita, M. Nemoto, T.G. Langdon, Principle of equal-channel angular pressing for the processing of ultra-fine grained materials, Scripta Materialia 35 (1996) 143–146.

DOI: 10.1016/1359-6462(96)00107-8

[10] Y.J. Chen, Y.C. Chai, H.J. Roven, S.S. Gireesh, Y.D. Yu, J. Hjelen, Microstructure and mechanical properties of Al–xMg alloys processed by room temperature ECAP, Materials Science and Engineering A 545 (2012) 139–147.

DOI: 10.1016/j.msea.2012.03.012

[11] Y.J. Chen, J. Hjelen, H.J. Roven, Application of EBSD technique to ultrafine grained and nanostructured materials processed by severe plastic deformation: Sample preparation, parameters optimization and analysis, Transactions of Nonferrous Metals Society of China 22 (2012).

DOI: 10.1016/s1003-6326(11)61390-3

[12] Y. Ito, Z. Horita, Microstructural evolution in pure aluminum processed by high-pressure torsion, Materials Science and Engineering A 503 (2009) 32–36.

DOI: 10.1016/j.msea.2008.03.055

[13] J. May, H.W. Höppel, M. Göken, Strain rate sensitivity of ultrafine-grained aluminium processed by severe plastic deformation, Scripta Materialia 53 (2005) 189–194.

DOI: 10.1016/j.scriptamat.2005.03.043

[14] M.S. Mohebbi, A. Akbarzadeh, Y.O. Yoon, S.K. Kim, Stress relaxation and flow behavior of ultrafine grained AA 1050, Mechanics of Materials 89 (2015) 23–34.

DOI: 10.1016/j.mechmat.2015.06.001

[15] D.C. Drucker, Plasticity theory strength-differential (SD) phenomenon, and volume expansion in metals and plastics, Metallurgical Transactions 4 (1973) 667–673.

DOI: 10.1007/bf02643073

[16] J.K. Mahato, P.S. De, A. Sarkar, A. Kundu, P.C. Chakraborti, Effect of deformation mode and grain size on Bauschinger behavior of annealed copper, International Journal of Fatigue 83 (2016) 42–52.

DOI: 10.1016/j.ijfatigue.2015.04.023

[17] M.F. Ashby, The deformation of plastically non-homogeneous materials, Philosophical Magazine 21 (1970) 399–424.

DOI: 10.1080/14786437008238426

[18] L.P. Evers, W.A.M. Brekelmans, M.G.D. Geers, Scale dependent crystal plasticity framework with dislocation density and grain boundary effects, International Journal of Solids Structures 41 (2004) 5209–5230.

DOI: 10.1016/j.ijsolstr.2004.04.021