1. Home
  2. Honda R&D Technical Review Vol.22 N...
  3. Microstructure and Mechanical Prope...

Technical Review e-Book: Summary

Microstructure and Mechanical Properties of Heat-resistant Mg-Zn-Y Cast Alloys with Addition of Fourth Elements

Article of Honda R&D Technical Review Vol.22 No.2

Summary

Extruded Mg-Zn-Y alloys with long-period stacking ordered (LPSO) structures are known to display increased strength at high temperatures, and are therefore useful in achieving weight savings in automotive components. Seeking to realize these attractive properties in cast components, the project discussed in this paper focused on controlling the microstructure of Mg96Zn2Y2 (at.%) cast alloy by the addition of a fourth element. First, the effects of refining the crystal grains through the addition of zirconium and modification of the cooling rate on microstructure and mechanical properties were investigated. With the addition of Zr and the achievement of a high rate of cooling, the resulting Mg95.8Zn2Y2Zr0.2 cast alloy displayed fine equiaxed grains (approx.10 mm in diameter) and excellent tensile and fatigue properties, equivalent to or greater than those of commercial aluminum alloys at high temperatures above 200 deg C. At 250 deg C, this alloy exhibited a tensile strength of 223 MPa, approximately twice that of the A4032-T6 alloy used for automotive pistons. The project also focused on strengthening LPSO structures by means of stacking fault energy (SFE), and used a first principle calculation to select a further element for addition to the alloy. The addition of Ag increased yield strength by 60 percent.

Reference

(1) Yoshimoto, S., Yamasaki, M., Kawamura, Y.: Microstructure and Mechanical Properties of Extruded Mg-Zn-Y Alloys with 14H Long Period Ordered Structure, Mater. Trans., Vol.47, p.959-965 (2006)
(2) Ienaga, Y., Inoue, K., Kawamura, Y.: Mechanical properties of large-scale extruded Mg-Zn-Y alloys, Proceedings of the 110th Conference of Japan Institute of Light Metals, p. 145-146 (2006)
(3) Emley, E. F.: Principles of magnesium technology, Oxford, Pergamon press, p.126-156 (1966)
(4) Yamaguchi, T., Saito, K., Kawamura, Y.: Mechanical properties of continuously consolidated Mg96Zn2Y2 magnesium alloy chips, JILM, Vol. 57, No. 7, p. 286-292 (2007)
(5) Okamoto, H.: Phase diagrams of dilute binary alloys, ASM International, p. 170 (2002)
(6) Ando, S., Toda, K., Tsushida, M., Kitahara, H., Tonda, H., Kawamura, Y.: Fatigue Properties of Mg-Zn-Y Alloys with Long Period Ordered Structure, J. Japan Inst. Metals, Vol. 71, No. 9, p. 699-703 (2007)
(7) Koike, S., Washizu, K., Tanaka, T., Baba, T., Kikawa, K.: Development of Lightweight Oil Pans Made of a Heat-Resistant Magnesium Alloy, HONDA R&D Technical Review, Vol. 12, No. 1, p. 167-174
(8) Shibata, A., Suzuki, M., Maruyama, K.: Effects of Eutectic Compounds Formed along Grain Boundaries in Thixomolded Alloy Mg96Zn2Y2 on Creep Deformation, Mater. Trans., Vol.50, p.1426-1432 (2009)
(9) Busk, R. S.: Magnesium Products Design translated by the association of light metals, The association of light metals, p. 146 (1988)
(10) Abe, E.: Jisedaino koukyoudo/koutainetsusei magunesiumugoukinno tokusyubisaikouzou-HAADF niyorukaiseki, Proceedings of the 10th Conference of the Association of Magnesium Alloy Development and Processing, p. 61-62 (2006) (in Japanese)

The first half of this paper is modified from the earlier paper published in the Journal of Japan Institute of Light Metals, Vol. 60, No. 6 (2010).

Author (organization or company)

Yuichi IENAGA(Fundamental Technology Research Center)、Kenshi INOUE(Fundamental Technology Research Center)、Mitsumoto KAWAI(Fundamental Technology Research Center)

We would like to get your opinion on this research paper. (This is only applicable to registered members.)

The readers of this research paper have also selected these research papers.

Development of Material for Lightweight Catalytic Converter
Article of Honda R&D Technical Review Vol.26 No.1
Mechanical Structure and Performance Evaluation of High Differential Pressure Water Electrolysis Cell
Article of Honda R&D Technical Review Vol.23 No.2
Effects of Low-viscosity Engine Oil on Fuel Economy and Wear
Article of Honda R&D Technical Review Vol.22 No.2