Deformation behavior of a magnesium alloy sheet with random crystallographic orientations under various loading paths

Authors

  • Takayuki Hama
  • Tsuyoshi Mayama
  • Hirohiko Takuda

Keywords:

cast magnesium alloy, crystal plasticity finite-element method, twinning, detwinning, yield locus, unloading, contour of plastic work

Abstract

This paper reports deformation behavior under various loading paths at room temperature of a magnesium alloy sheet with random crystallographic orientations both experimentally and numerically. The flow stress under uniaxial tension was larger than that of uniaxial compression. When the sheet was subjected to reverse loading, a slightly sigmoidal curve occurred under compression followed by tension, whereas it did not occur under tension followed by compression. These results demonstrated that the sample showed a tension-compression asymmetry and a strain-path dependency as in the case of rolled Magnesium alloy sheets with strong basal texture. Results of crystal plasticity finite-element simulation depicted that these characteristics occurred because of a tension-compression asymmetry in twinning activity even in the sheet with random crystallographic orientations. These results exhibited that a tension-compression asymmetry and a strain-path dependency were inevitable in the deformation of magnesium alloys at room temperature irrespective of initial textures. An evolution of contour of plastic work was also investigated numerically to support this conclusion.

References

DOEGE, E., DRODER, K., Sheet metal forming of magnesium wrought alloy – formability and process technology, J. Mater. Process. Technol., 115, 1, pp. 14–19, 2001.

KULEKCI, M.K., Magnesium and its alloys applications in automotive industry, Int. J. Adv. Manuf. Technol., 39, 9–10, pp. 851–865, 2008.

LEE, Y.S., KIM, M.C., KIM, S.W., KWON, Y.N., CHOI, S.W., LEE, J.H., Experimental and analytical studies for forming limit of AZ31 alloy on warm sheet metal forming, J. Mater. Process. Technol., 187–188, pp. 103–107, 2007.

KANEKO, J., SUGAMATA, M., Mechanical properties and formability of magnesium alloy sheets (in Japanese), J. Japan Inst. Light Metals, 54, 11, pp. 484–492, 2004.

CHEN, F.K., HUANG, T.B., CHANG, C.K., Deep drawing of square cups with magnesium alloy AZ31 sheets, Int. J. Mach. Tool. Manu., 43, 15, pp. 1553–1559, 2003.

HAMA, T., KARIYAZAKI, Y., OCHI, K., FUJIMOTO, H., TAKUDA, H., Springback characteristics of magnesium alloy sheet AZ31B in draw-bending, Mater. Trans., 51, 4, pp. 685–693, 2010.

LOU, X.Y., LI, M., BOGER, R.K., AGNEW, S.R., WAGONER, R.H., Hardening evolution of AZ31B Mg sheet, Int. J. Plast. 23, 1, pp. 44–86, 2007.

CHINO, Y., KIMURA, K., MABUCHI, M., Twinning behavior and deformation mechanisms of extruded AZ31 Mg alloy, Mater. Sci. Eng. A, 486, pp. 481–488, 2008.

HAMA, T., KITAMURA, N., OCHI, K., FUJIMOTO, H., TAKUDA, H., Unloading behavior of a magnesium alloy sheet under various loading paths, Steel Res. Int., Special edition, pp. 1054–1059, 2011.

HAMA, T., KARIYAZAKI, Y., HOSOKAWA, N., FUJIMOTO, H., TAKUDA, H., Workhardening behaviors of magnesium alloy sheet during in-plane cyclic loading, Mater. Sci. Eng. A, 551, pp. 209-217, 2012.

HAMA, T., NAGAO, H., KUCHINOMACHI, Y., TAKUDA, H., Effect of pre-strain on workhardening behavior of magnesium alloy sheets upon cyclic loading, Mater. Sci. Eng. A, 591, pp. 69–77, 2014.

KIMA, H.J., CHOI, S.C., LEE, K.T., KIMA, H.Y., Experimental Determination of Forming Limit Diagram and Springback Characteristics of AZ31B Mg Alloy Sheets at Elevated Temperatures, Mater. Trans., 49, 5, pp. 1112–1119, 2008.

AGNEW, S.R., DUYGULU, O., Plastic anisotropy and the role of nonbasal slip in magnesium alloy AZ31B, Int. J. Plast., 21, 6, pp. 1161–1193, 2005.

KOIKE, J., Enhanced deformation mechanisms by anisotropic plasticity in polycrystalline Mg alloys at room temperature, Metall. Mater. Trans. A, 36, 7, pp. 1689–1696, 2005.

HUANG, X., SUZUKI, K., YUASA, M., CHINO, Y., Effects of initial microstructure on the microstructural evolution and stretch formability of warm rolled Mg-3Al-1Zn alloy sheets, Mater. Sci. Eng. A, 587, pp. 150–160, 2013.

KOHZU, M., KII, K., NAGATA, Y., NISHIO, H., HIGASHI, K., INOUE, H., Texture randomization of AZ31 Magnesium alloy sheets for improving the cold formability by a combination of rolling and high-temperature annealing, Mater. Trans., 51, 4, pp. 749–755, 2010.

SONG, B., HUANG, G., LI, H., ZHANG, L., HUANG, G., PAN, F., Texture evolution and

mechanical properties of AZ31B magnesium alloy sheets processed by repeated

unidirectional bending, J. Alloys Compd., 489, 2, pp. 475–481, 2010.

CHENG, Y.Q., CHEN, Z.H., XIA, W.J., Drawability of AZ31 magnesium alloy sheet produced by equal channel angular rolling at room temperature, Mater. Charac., 58, 7, pp. 617–622, 2007.

HAMA, T., MAYAMA, T., TAKUDA, H., Deformation behavior of a magnesium alloy sheet with random crystallographic orientations, Key Eng. Mater., 611–612, pp. 27–32, 2014.

KUWABARA, T., KUMANO, Y., ZIEGELHEIM, J., KUROSAKI, I., Tension-compression asymmetry of phosphor bronze for electronic parts and its effect on bending behavior, Int. J. Plast., 25, 9, pp. 1759–1776, 2009.

Published

2015-01-15