Hostname: page-component-745bb68f8f-b6zl4 Total loading time: 0 Render date: 2025-01-10T21:15:09.977Z Has data issue: false hasContentIssue false
  • English
  • Français

A new high-strength spinodal alloy

Published online by Cambridge University Press:  01 April 2005

James A. Hanna ,
Ian Baker ,
Markus W. Wittmann  and
Paul R. Munroe
James A. Hanna*
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
Ian Baker
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
Markus W. Wittmann
Affiliation:
Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755
Paul R. Munroe
Affiliation:
Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052, Australia
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Preliminary investigations of a new high-strength alloy of composition Fe30Ni20Mn25Al25 (at.%) are described in this paper. The as-cast alloy consisted of a periodic two-phase microstructure of interconnected, ∼50-nm-wide rods with fully coherent {100} interfaces, strongly suggestive of formation by a B2 to [(B2 + body-centered cubic (bcc)] spinodal decomposition. The (Ni,Al)-rich B2 and (Fe,Mn)-rich bcc phases differed in lattice parameter by <0.5%. Hardness and yield strength of the as-cast alloy were found to be approximately 500 VPN and 1500 MPa, respectively, and increased by more than 50% after annealing at 550 °C for several days. (Fe,Mn)-rich precipitates with a β–Mn structure were observed in the annealed material.

Keywords

Intermetallic alloysMechanical propertiesNanoscale
Type
Rapid Communication
Information
Journal of Materials Research , Volume 20 , Issue 4 , April 2005 , pp. 791 - 795
Copyright
Copyright © Materials Research Society 2005

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

REFERENCES

1. Xiao, H. and Baker, I.: Long range order and defect concentrations in NiAl and CoAl. Acta Metall. Mater. 42, 1535 (1994).10.1016/0956-7151(94)90363-8CrossRefGoogle Scholar
2. Wittmann, M., Baker, I. and Munroe, P.: The structure and mechanical properties of Fe2AlMn single crystals. Philos. Mag. A 84, 3169 (2004).CrossRefGoogle Scholar
3. Jantzen, C. and Herman, H.: Spinodal decomposition––phase diagram representation and occurrence, in Phase Diagrams: Materials Science & Technology Vol. 5, edited by Alper, A. (Academic Press, New York, 1978), pp. 127–185.Google Scholar
4. Hanna, J.: Investigations of Fe30Ni20Mn25Al25: A new high-strength spinodal alloy. M.S. Thesis, Thayer School of Engineering, Dartmouth College, Hanover, NH (2004).Google Scholar
5. Cahn, J.: Spinodal decomposition (1967 Institute of Metals Lecture). Trans. Metall. Soc. AIME 242, 166 (1968).Google Scholar
6. Cahn, J.: On spinodal decomposition in cubic crystals. Acta Metall. 10, 179 (1962).CrossRefGoogle Scholar
7. de Fontaine, D.: Configurational thermodynamics of solid solutions, in Solid State Physics Vol. 34: Advances in Research and Applications, edited by Seitz, F. (Academic Press, New York, 1979), pp. 73–273.Google Scholar
8. Soffa, W. and Laughlin, D.: Decomposition and ordering processes involving thermodynamically first-order order → disorder transformations. Acta Metall. 37, 3019 (1989).CrossRefGoogle Scholar
9. Misra, A., Gibala, R. and Noebe, R.: Optimization of toughness and strength in multiphase intermetallics. Intermetallics 9, 971 (2001).CrossRefGoogle Scholar
10. Singh, J. and Wayman, C.: Age-hardening characteristics of a martensitic Fe–Ni–Mn alloy. Mater. Sci. Eng. 94, 233 (1987).CrossRefGoogle Scholar
11. Schwartz, L. and Plewes, J.: Spinodal decomposition in Cu–9 wt% Ni–6 wt% Sn—II. A critical examination of mechanical strength of spinodal alloys. Acta Metall. 22, 911 (1974).CrossRefGoogle Scholar
12. Kato, M., Mori, T. and Schwartz, L.: Hardening by spinodal modulated structure. Acta Metall. 28, 285 (1980).CrossRefGoogle Scholar
13. Munroe, P. and Baker, I.: Brittle fracture in B2 compounds, in George R. Irwin Symposium on Cleavage Fracture, edited by Chan, K. (TMS, Warrendale, PA, 1997), pp. 329–345.Google Scholar
14. Gudladt, H-J., Wunderlich, W. and Costalas, E.: The influence of microstructure on the mechanical properties of a spinodally decomposed Cu–Ni–Fe alloy. Z. Metallkd. 88, 642 (1997).Google Scholar
15. Baker, I., Nagpal, P., Liu, F. and Munroe, P.: The effect of grain size on the yield strength of FeAl and NiAl. Acta Metall. Mater. 39(7), 1637 (1991).CrossRefGoogle Scholar