Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-28T22:14:20.969Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermal decomposition of mechanically alloyed nanocrystalline fcc Fe60Cu40

Published online by Cambridge University Press:  31 January 2011

J. Y. Huang ,
Y. D. Yu ,
Y. K. Wu ,
H. Q. Ye  and
Z. F. Dong
J. Y. Huang
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
Y. D. Yu
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
Y. K. Wu
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
H. Q. Ye
Affiliation:
Laboratory of Atomic Imaging of Solids, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
Z. F. Dong
Affiliation:
Laboratory of RSA, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, People's Republic of China
Get access

Abstract

A ferromagnetic and supersaturated fcc Fe60Cu40 solid solution was prepared by mechanical alloying (MA). The phase transformations of the as-milled Fe60Cu40 powder upon heating to 1400 °C and subsequently cooling to room temperature were characterized by differential thermal analysis (DTA) and thermal magnetic measurement. The fcc Fe60Cu40 solid solution decomposes into α–Fe(Cu) + γ–Fe(Cu) + Cu(Fe) upon heating from 300 to 460 °C, and on further heating, α–Fe(Cu) transforms to γ–Fe(Cu) at 640 → 760 °C; during cooling, the reverse transformation occurs from 800 → 640 °C (obtained from thermomagnetic measurement) or from 700 → 622 °C (obtained from DTA). The γ ⇆ α transformation in mechanically alloyed Fe60Cu40 nanocrystalline occurs in a wide temperature range; the transformation temperature is higher than that of the martensite transformation in as-cast Fe–Cu alloys, but is much lower than that of the allotropic transformation of pure Fe. These differences may be caused by the different fabrication process, the nonequilibrium microstructure of MA, as well as the inhomogeneous grain size in α–Fe(Cu). High resolution transmission electron microscope (HRTEM) observations carried out in the specimen after the DTA run show that N-W or K-S orientation relationships exist between α–Fe(Cu) and Cu(Fe), which also represent the orientation relationship between α–Fe(Cu) and γ–Fe(Cu) due to excellent coherency between γ–Fe(Cu) and Cu(Fe). The grain size of the α–Fe(Cu) is inhomogeneous and varies from 50–600 mm. Energy dispersive x-ray spectroscopy (EDXS) result shows that the Cu content in these α–Fe(Cu) grains reaches as high as 9.5 at. % even after DTA heating to 1400 °C, which is even higher than the maximum solubility of Cu in γ–Fe above 1094 °C. This may be caused by the small grain size of α–Fe(Cu).

Type
Articles
Information
Journal of Materials Research , Volume 11 , Issue 11 , November 1996 , pp. 2717 - 2724
Copyright
Copyright © Materials Research Society 1996

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.Uenish, K., Kobayashi, K.F., Nasu, S., Hatano, H., Ishihara, K.N., and Shingu, P. H., Z. Metallkd. 82(2), 132 (1992).Google Scholar
2.Eckert, J., Holzer, J. C., Krill, C. E. III, and Jonson, W. L., J. Appl. Phys. 73, 2794 (1993).CrossRefGoogle Scholar
3.Eckert, J., Holzer, J. C., and Jonson, W. L., J. Appl. Phys. 73, 131 (1993).CrossRefGoogle Scholar
4.Yavari, A. R., Desré, P. J., and Benameur, T., Phys. Rev. Lett. 68, 2235 (1992).CrossRefGoogle Scholar
5.Crespo, P., Hernando, A., Yavari, R., Drbohlav, O., Garcia Escorial, A., Barandiaran, J. M., and Orue, I., Phys. Rev. B 48, 7134 (1993).CrossRefGoogle Scholar
6.Ma, E., Atzman, M., and Pinkerton, F., J. Appl. Phys. 74, 955 (1993).CrossRefGoogle Scholar
7.Hernando, A., Crepo, P., Garcia Escorial, A., and Barandiaran, J.M., Phys. Rev. Lett. 70, 3521 (1993).CrossRefGoogle Scholar
8.Jiang, J. Z., Gonser, U., Gente, C., and Bormann, R., Appl. Phys. Lett. 63, 1056 (1993); 63, 2768 (1993).CrossRefGoogle Scholar
9.Huang, J. Y., He, A. Q., and Wu, Y. K., Nano. Mater. 4, 1 (1994).CrossRefGoogle Scholar
10.Marci, P. P., Enzo, S., Cowlam, N., Frattini, R., Principi, G., and Hu, W. X., Philos. Mag. B71, 249 (1993).Google Scholar
11.Hansen, M., Constitution of Binary Alloys (McGraw-Hill Book Company, Inc., New York, Toronto, and London, 1958).CrossRefGoogle Scholar
12.Drbohlav, O. and Yavari, A. R., Acta Metall. Mater. 43, 1799 (1994).CrossRefGoogle Scholar
13.Easterling, K. E. and Miekk, H. M., Acta Metall. 15, 1133 (1967).CrossRefGoogle Scholar
14.Kuhrt, C. and Schultz, L., J. Appl. Phys. 73, 1975 (1993).CrossRefGoogle Scholar
15.Cech, R. E. and Turnbull, D., J. Metals 8, 124 (1956).Google Scholar
16.Bando, Y., Trans. Jpn. Inst. Met. 5, 134 (1964).CrossRefGoogle Scholar
17.Easterling, K. and Weatherly, G. C., Acta Metall. 17, 845 (1969).CrossRefGoogle Scholar
18.Shewmon, P. G., Transformations in Metals (McGraw-Hill Book Co., New York, 1969), p. 300.Google Scholar
19.Räsänen, E., Tekn. Lic. Thesis, Institute of Technology, Helsinki (1967).Google Scholar