Effect of alloying elements and processing parameters on the Portevin-Le Chatelier effect of Al-Mg alloys

Abstract

The effects of alloying elements and processing parameters on the mechanical properties and Portevin-Le Chatelier effect of Al-Mg alloys developed for inner auto body sheets were investigated in detail. Tensile testing was performed in various Zn and Mg contents under different annealing and cold-rolling conditions. In the results, the stress drop and reloading time of serrations increase with increasing plastic strain and exhibit a common linear relationship. The increase rates of stress drop and reloading time increase with increasing Mg or Zn content. The alloys with a greater intensity of serrated yielding generally exhibit a greater elongation. The stress drop and reloading time of serrations decrease with increasing grain size in the case of the annealed samples. The cold-rolled sample exhibits the most severe serration because it initially contains a large number of grain boundaries and dislocations.

Keywords

aluminum-magnesium alloys / Portevin-Le Chatelier effect / alloying elements / processing parameters / mechanical properties

References

[1] Burger GB, Gupta AK, Jeffrey PW, Lloyd DJ. Microstructural control of aluminum sheet used in automotive applications. Mater. Charact., 1995, 35(1): 23.

[2] Cole GS, Sherman AM. Light weight materials for automotive applications. Mater. Charact., 1995, 35(1): 3.

[3] Sci. Technol. Adv. Mater., 2011, 12(6)

[4] Jiang HF, Zhang QC, Chen XD, Chen ZJ, Jiang ZY, Wu XP, Fan JH. Three types of Portevin-Le Chatelier effects: experiment and modelling. Acta Mater., 2007, 55(7): 2219.

[5] Bernard C, Coër J, Laurent H, Chauvelon P, Manach PY. Relationship between local strain jumps and temperature bursts due to the Portevin-Le Chatelier effect in an Al-Mg alloy. Exp. Mech., 2013, 53(6): 1025.

[6] Wen W, Morris JG. An investigation of serrated yielding in 5000 series aluminum alloys. Mater. Sci. Eng. A, 2003, 354(1–2): 279.

[7] Darowicki K, Orlikowski J, Zieliński A. Investigation of changes in the type B PLC effect of Al-Mg-Cu type alloy for various strain rates. Mater. Sci. Eng. A, 2008, 496(1–2): 478.

[8] Wen W, Morris JG. The effect of cold rolling and annealing on the serrated yielding phenomenon of AA5182 aluminum alloy. Mater. Sci. Eng. A, 2004, 373(1–2): 204.

[9] Fu SH, Cheng T, Zhang QC, Hu Q, Cao PT. Two mechanisms for the normal and inverse behaviors of the critical strain for the Portevin-Le Chatelier effect. Acta Mater., 2012, 60(19): 6650.

[10] Jiang HF, Zhang QC, Jiang ZY, Wu XP. Experimental investigations on kinetics of Portevin-Le Chatelier effect in Al-4wt.% Cu alloys. J. Alloys Compd., 2007, 428(1–2): 151.

[11] Shabadi R, Kumar S, Roven HJ, Dwarakadasa ES. Effect of specimen condition, orientation and alloy composition on PLC band parameters. Mater. Sci. Eng. A, 2004, 382(1–2): 203.

[12] van den Beukel A, Kocks UF. The strain dependence of static and dynamic strain-aging. Acta Mater., 1982, 30(5): 1027.

[13] Sarkar A, Barat P, Mukherjee P. Investigation of Portevin-Le Chatelier effect in Al-2.5 pct Mg alloy with different microstructure. Metall. Mater. Trans. A, 2013, 44(6): 2604.

[14] Saad G, Fayek SA, Fawzy A, Soliman HN, Nassr E. Serrated flow and work hardening characteristics of Al-5356 alloy. J. Alloys Compd., 2010, 502(1): 139.

[15] Ait-Amokhtar H, Boudrahem S, Fressengeas C. Spatiotemporal aspects of jerky flow in Al-Mg alloys, in relation with the Mg content. Scripta Mater., 2006, 54(12): 2113.

[16] Halim H, Wilkinson DS, Niewczas M. The Portevin-Le Chatelier (PLC) effect and shear band formation in an AA5754 alloy. Acta Mater., 2007, 55(12): 4151.

[17] Kang JD, Mishra RK, Wilkinson DS, Hopperstad OS. Effect of Mg content on Portevin-Le Chatelier band strain in Al-Mg sheet alloys. Philos. Mag. Lett., 2012, 92(11): 647.

[18] Jiang HF, Zhang QC, Wu XP, Fan JH. Spatiotemporal aspects of the Portevin-Le Chatelier effect in annealed and solution-treated aluminum alloys. Scripta Mater., 2006, 54(12): 2041.

[19] Hu Q, Zhang QC, Cao PT, Fu SH. Thermal analyses and simulations of the type A and type B Portevin-Le Chatelier effects in an Al-Mg alloy. Acta Mater., 2012, 60(4): 1647.

[20] Cao PT, Zhang QC, Xiao R, Xiong SM. The Portevin-Le Chatelier effect in Al-Mg alloy investigated by infrared pyrometry. Acta Phys. Sin., 2009, 58(8): 5591.

[21] Reed JM, Walter ME. Observations of serration characteristics and acoustic emission during serrated flow of an Al-Mg alloy. Mater. Sci. Eng. A, 2003, 359(1–2): 1.

[22] Wen W, Zhao YM, Morris JG. The effect of Mg precipitation on the mechanical properties of 5xxx aluminum alloys. Mater. Sci. Eng. A, 2005, 392(1–2): 136.

[23] Kang J, Wilkinson DS, Jain M, Embury JD, Beaudoin AJ, Kim S, Mishira R, Sachdev AK. On the sequence of inhomogeneous deformation processes occurring during tensile deformation of strip cast AA5754. Acta Mater., 2006, 54(1): 209.

[24] Zha M, Li YJ, Mathiesen RH, Bjørge R, Roven HJ. Achieve high ductility and strength in an Al-Mg alloy by severe plastic deformation combined with inter-pass annealing. Mater. Sci. Eng. A, 2014, 598, 141.

[25] Rodriguez P. Serrated plastic flow. Bull. Mater. Sci., 1984, 6(4): 653.

[26] Fujita H, Tabata T. Discontinuous deformation in Al-Mg alloys under various conditions. Acta Metall., 1977, 25(7): 793.

[27] Zhu YT, Langdon TG. The fundamentals of nanostructured materials processed by severe plastic deformation. JOM, 2004, 56(10): 58.

[28] Zhao YH, Liao XZ, Cheng S, Ma E, Zhu YT. Simultaneously increasing the ductility and strength of nanostructured alloys. Adv. Mater., 2006, 18(17): 2280.

[29] Zhao YH, Bingert JF, Liao XZ, Cui BZ, Han K, Sergueeva AV, Mukherjee AK, Valiev RZ, Langdon TG, Zhu YT. Simultaneously increasing the ductility and strength of ultra-fine-grained pure copper. Adv. Mater., 2006, 18(22): 2949.

[30] Lin JP. Effect of Mg content on dynamic recrystallization behaviors of Al-Mg alloys. J. Univ. Sci. Technol. Beijing, 1997, 19(1): 47.

[31] Gubicza J, Chinh NQ, Horita Z, Langdon TG. Effect of Mg addition on microstructure and mechanical properties of aluminum. Mater. Sci. Eng. A, 2004, 387-389, 55.

[32] Robinson JM, Shaw MP. Microstructural and mechanical influences on dynamic strain aging phenomena. Int. Mater. Rev., 1994, 39(3): 113.

[33] Wagenhofer M, Erickson-Natishan MA, Armstrong RW, Zerilli FJ. Influences of strain rate and grain size on yield and serrated flow in commercial Al-Mg alloy 5086. Scripta Mater., 1999, 41(11): 1177.

[34] Han BQ, Huang JY, Zhu YT, Lavernia EJ. Effect of strain rate on the ductility of a nanostructured aluminum alloy. Scripta Mater., 2006, 54(6): 1175.

[35] Chmelík F, Pink E, Król J, Balík J, Pešička J, Lukáč P. Mechanisms of serrated flow in aluminium alloys with precipitates investigated by acoustic emission. Acta Mater., 1998, 46(12): 4435.

[36] McCormick PG. The Portevin-Le Chatelier effect in an Al-Mg-Si alloy. Acta Metall., 1971, 19(5): 463.

[37] Picu RC, Zhang D. Atomistic study of pipe diffusion in Al-Mg alloys. Acta Mater., 2004, 52(1): 161.