Precipitation hardening in Mg–Zn–Sn alloys with minor additions of Ca and Si
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S. Cohen
Abstract
Al-free Mg–Zn alloys with alternative alloying elements were investigated in order to form Mg–Zn-based alloys with improved thermal stability. Based on thermodynamic calculations, Zn and Sn additives are expected to form stable intermetallic phases with Mg and cause precipitation hardening. An Mg alloy containing 4.5 wt.% Zn and 3.8 wt.% Sn was examined in detail and subsequently alloyed with Ca and Si, in order to promote additional precipitation. The as-cast microstructure and its stability during exposure to elevated temperatures were investigated. Precipitation hardening was investigated in the temperature range of 175 – 250 °C by Vickers hardness measurements and analysis of the microstructure evolution, using X-ray diffraction and electron microscopy techniques. During aging at 175 °C for 1 to 96 h, two hardness maxima were observed: the first after 2 h, and the second after 16 h. The occurrence of two hardness peaks can be related to a precipitation sequence. Firstly, MgZn2 precipitates form, and secondly Mg2Sn. The results indicate that the precipitation mechanism is most likely diffusion-controlled. The precipitates are uniformly distributed in the Mg matrix with two morphologies: needle- and plate-like shapes. The addition of Si and Ca did not result in the expected effect on the precipitation behavior.
References
[1] M. Regev, A. Rosen, M. Bamberger, in: F.H. Froes, C.M. Ward-Close, D. Eliezer, P. McCormick (Eds.), Synthesis of Lightweight Metals III, TMS (1999) 163.Search in Google Scholar
[2] Z. Zhang, A. Couture, A. Luo: Scripta Mater., 39 (1998) 45.10.1016/S1359-6462(98)00122-5Search in Google Scholar
[3] W. Blum, P. Zhang, B. Watzinger, B. v. Grossmann, H. Haldenwanger: Mater. Sci. and Eng. A 319 (2001) 735.10.1016/S0921-5093(00)02016-5Search in Google Scholar
[4] T. Horie, H. Iwahori, Y. Seno, Y. Awano, in: H.I. Kaplan, J.N. Hryn, B.B. Clow (Eds.), Mg Technology 2000-TMS annual meeting, Nashville, Tennessee, USA (2000) March 12–16, 261.10.1002/9781118808962.ch36Search in Google Scholar
[5] D. Maeng, T. Kim, J. Lee, S. Hong, S. Seo, B. Chun: Scripta Mater. 43 (2000) 385.10.1016/S1359-6462(00)00428-0Search in Google Scholar
[6] T. Massalski: Binary Alloy Phase Diagrams, 2nd Edition, ASM Int. (1992).Search in Google Scholar
[7] A. Finkel, L. Shepeleva, M. Bamberger, E. Rabkin, in: H. Kaplan (Ed.), The Minerals, Metals & Materials Society, Magnesium Technology (2003) TMS annual meeting, San Diego, CA, USA (2003) March 2– 6.Search in Google Scholar
[8] J. Nie, B. Muddle: Scripta Mater. 37 (1997) 1475.10.1016/S1359-6462(97)00294-7Search in Google Scholar
[9] M. Pekguleryuz, M. Avedesian: Mg Alloys and Their Appl. – DGM Conf. (1992) 213.Search in Google Scholar
[10] Y. Lee, A. Dahle, D.St. John, in: H.I. Kaplan, J.N. Hryn, B.B. Clow (Ed.), Mg Technology 2000-TMS annual meeting, Nashville, Tennessee, USA (2000) March 12–16, 211.Search in Google Scholar
[11] A. Strecker, J. Mayer, B. Baretzky, U. Eigenthaler, T. Gemming, R. Schweinfest, M. Rühle: J. Electron Micr. 48 (3) (1999) 235.10.1093/oxfordjournals.jmicro.a023673Search in Google Scholar
[12] H. Mehrer (Ed.): Crystal and Solid State Physics, Vol. 26, Springer-Verlag, Berlin (1990) 93.Search in Google Scholar
© 2005 Carl Hanser Verlag, München
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- Frontmatter
- Kösterpreis
- Award/Preisverleihung
- Editorial
- Editorial
- Articles Basic
- Effect of interface strength on electromigration-induced inlaid copper interconnect degradation: Experiment and simulation
- Application of factor analysis in electron spectrometry (AES, XPS) for materials science
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- Modeling of axial strain in free-end torsion of textured copper
- Vacancies in plastically deformed copper
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- Nanoindentation applied on a tungsten–copper composite before and after high-pressure torsion
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