Corrosion stress relaxation in pure magnesium and die-cast Mg alloys

Authors

  • Yakov B. Unigovski Dept of Materials Engineering, Ben-Gurion University of the Negev
  • Leonid Riber Dept of Materials Engineering, Ben-Gurion University of the Negev
  • Emmanuel M. Gutman Dept of Materials Engineering, Ben-Gurion University of the Negev

Keywords:

pure magnesium, die-cast Mg alloys, stress relaxation, corrosive solutions, relaxation spectra

Abstract

The effect of corrosive solutions on stress relaxation behavior of pure Mg and its alloys is studied. Pure magnesium shows a crucial corrosion stress relaxation in 3.5wt.% NaCl even at room temperature in comparison with tests in air. Die-cast Mg alloys AZ91D, AM50 and AS21 at room temperature show a relatively small stress decrease both in air and in different corrosive media. At elevated temperature, all studied die-cast Mg alloys show a strong stress relaxation in a 3.5 % NaCl corrosive solution. In a corrosive environment, the highest sensitivity to stress relaxation was observed both in the alloy with the highest Al content (AZ91D), and in AS21 alloy that contains two intermetallics (Mg17Al12 and Mg2Si). It is shown that the stress relaxation method manifests a high sensitivity to structural homogeneity of alloys, especially in corrosive solutions.

According to TEM investigations of pure Mg, an unloaded specimen comprises a few dislocations in the vicinity of such an obstacle as grain boundary. At a constant strain of about 4x10-4, dislocation networks were found with a sharply increasing quantity of dislocations.

Downloads

Download data is not yet available.

References

Bland, D. R. 1980. The theory of Linear Viscoelasticity. New York: Pergamon Press.

Gutman, E. M. 1967. Sov. Mater. Sci. 3(190, 293) : 401.

Gutman, E. M. 1994. Mechanochemistry of solid surfaces. Singapore : World Scientific: 322.

Gutman, E. M., Unigovski, Ya., Aghion, E., Koren Z. and Eliezer, A. 2000. Effect of die-casting conditions on viscoelastic behavior of Mg-alloy. J. Mater. Perform. Eng. 9(3) : 297-301.

Gutman, E. M., Eliezer, A., Unigovski, Ya., and Abramov, E. 2001. Mechanoelectrochemical behavior and creep corrosion of magnesium alloys. Mater. Sci. Eng. A302 : 63-67.

Pettersen, K. and Fairchild, S. 1997. Stress relaxation in bolted joints of die-cast magnesium components. SAE tech. paper series, Paper No. 970326 : Warrendale, Pa. : 23-31.

Tobolsky, A.V. 1960. Properties and structure of polymers. New York : John Wiley & Sons : 331.

Downloads

Published

2017-04-23

How to Cite

[1]
Y. B. . Unigovski, L. Riber, and E. M. . Gutman, “Corrosion stress relaxation in pure magnesium and die-cast Mg alloys”, J Met Mater Miner, vol. 17, no. 1, Apr. 2017.

Issue

Vol. 17 No. 1 (2007)

Section

Original Research Articles

License

Copyright (c) 2017 Journal of Metals, Materials and Minerals

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Authors who publish in this journal agree to the following terms:

    1. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.

 

    1. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.