Skip to main content

A new high-strength spinodal alloy

  • James A. Hanna (a1), Ian Baker (a1), Markus W. Wittmann (a1) and Paul R. Munroe (a2)

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.

Corresponding author
a) Address all correspondence to this author. e-mail:
Hide All
1.Xiao H. and Baker I.: Long range order and defect concentrations in NiAl and CoAl. Acta Metall. Mater. 42, 1535 (1994).
2.Wittmann M., Baker I. and Munroe P.: The structure and mechanical properties of Fe2AlMn single crystals. Philos. Mag. A 84, 3169 (2004).
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. 127185.
4.Hanna J.: Investigations of Fe30Ni20Mn25Al25: A new high-strength spinodal alloy. M.S. Thesis, Thayer School of Engineering, Dartmouth College, Hanover, NH (2004).
5.Cahn J.: Spinodal decomposition (1967 Institute of Metals Lecture). Trans. Metall. Soc. AIME 242, 166 (1968).
6.Cahn J.: On spinodal decomposition in cubic crystals. Acta Metall. 10, 179 (1962). 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. 73273.
8.Soffa W. and Laughlin D.: Decomposition and ordering processes involving thermodynamically first-order order → disorder transformations. Acta Metall. 37, 3019 (1989).
9.Misra A., Gibala R. and Noebe R.: Optimization of toughness and strength in multiphase intermetallics. Intermetallics 9, 971 (2001).
10.Singh J. and Wayman C.: Age-hardening characteristics of a martensitic Fe–Ni–Mn alloy. Mater. Sci. Eng. 94, 233 (1987).
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).
12.Kato M., Mori T. and Schwartz L.: Hardening by spinodal modulated structure. Acta Metall. 28, 285 (1980).
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. 329345.
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).
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).
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
  • URL: /core/journals/journal-of-materials-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 60 *
Loading metrics...

Abstract views

Total abstract views: 139 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 23rd November 2017. This data will be updated every 24 hours.