Hostname: page-component-8448b6f56d-t5pn6 Total loading time: 0 Render date: 2024-04-19T14:05:11.662Z Has data issue: false hasContentIssue false
  • English
  • Français

Novel hexagonal structure and ultrahigh strength of magnesium solid solution in the Mg–Zn–Y system

Published online by Cambridge University Press:  31 January 2011

Akihisa Inoue ,
Yoshihito Kawamura ,
Mitsuhide Matsushita ,
Kentaro Hayashi  and
Junichi Koike
Akihisa Inoue*
Affiliation:
Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
Yoshihito Kawamura
Affiliation:
Mechanical Engineering, Kumamoto University, Kumamoto 860–0862, Japan
Mitsuhide Matsushita
Affiliation:
Inoue Superliquid Glass Project, Exploratory Research for Advanced Technology, Japan Science and Technology Corporation, Sendai 982–0807, Japan
Kentaro Hayashi
Affiliation:
Graduate School, Tohoku University, Sendai, Japan
Junichi Koike
Affiliation:
Materials Science and Engineering, Tohoku University, Sendai, Japan
*
a)Address all correspondence to this author. e-mail: ainoue@imr.tohoku.ac.jp
Get access

Abstract

A magnesium (Mg) solid solution with a long periodic hexagonal structure was found in a Mg97Zn1Y2 (at.%) alloy in a bulk form prepared by warm extrusion of atomized powders at 573 K. The novel structure has an ABACAB-type six layered packing with lattice parameters of a = 0.322 nm and c = 3 × 0.521 nm. The Mg solid solution has fine grain sizes of 100 to 150 nm and contains 0.78 at.% Zn and 1.82 at.% Y. In addition, cubic Mg24Y5 particles with a size of about 7 nm are dispersed at small volume fractions of less than 10% in the Mg matrix. The specific density (ρ) of the extruded bulk Mg–Zn–Y alloy was 1.84 Mg/m3. The tensile yield strength (σy) and elongation (δ) are 610 MPa and 5%, respectively, at room temperature, and the specific yield strength defined by the ratio of σy to ρ is as high as 3.3 × 105 Nm/kg. High σy values exceeding 400 MPa are also maintained at temperatures up to 473 K. It is noticed that the σy levels are 2.5 to 5 times higher than those for conventional high-strength type Mg-based alloys. The Mg-based alloy also exhibits a high-strain-rate superplasticity with large δ of 700 to 800% at high strain rates of 0.1 to 0.2 s−1 and 623 K. The excellent mechanical properties are due to the combination of the fine grain size, new long periodic hexagonal solid solution containing Y and Zn, and dispersion of fine Mg24Y5 particles. The new Mg-based alloy is expected to be used in many fields.

Type
Articles
Information
Journal of Materials Research , Volume 16 , Issue 7 , July 2001 , pp. 1894 - 1900
Copyright
Copyright © Materials Research Society 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Kainer, K.U., Magnesium Alloys and their Applications (John Wiley & Sons, New York, 2000).CrossRefGoogle Scholar
2.Inoue, A., Mater. Trans., JIM 36, 866–875 (1995).CrossRefGoogle Scholar
3.Inoue, A., Bulk Amorphous Alloys (Trans Tech Publications, Zurich, Switzerland, 1998), pp. 1–116.Google Scholar
4.Inoue, A., Acta Mater. 48, 279–306 (2000).CrossRefGoogle Scholar
5.Pearson, W.B., Crystal Chemistry and Physics of Metals and Alloys (Wiley, New York, 1972), p. 72.Google Scholar
6.Clark, J.B., Zabdyr, L., and Moser, Z., Phase Diagrams of Binary Magnesium Alloys (ASM, Metals Park, OH, 1988), pp. 353–364Google Scholar
7.Nayeb-Hashemi, A.A. and Clark, J.B., Phase Diagrams of Binary Magnesium Alloys (ASM, Metals Park, OH, 1988), pp. 344–349.Google Scholar
8.Villars, P., Prince, A., Zabdyr, L., and Moser, Z., Handbook of Ter-nary Alloy Phase Diagrams (ASM International, Metals Park, OH, 1995), pp. 12369–12372.Google Scholar