Hostname: page-component-5f745c7db-nc56l Total loading time: 0 Render date: 2025-01-06T06:19:43.402Z Has data issue: true hasContentIssue false
  • English
  • Français

Tailoring deformation-induced effects in Co powders by milling them with α–Al2O3

Published online by Cambridge University Press:  31 January 2011

E. Menéndez ,
J. Sort ,
S. Suriñach ,
M.D. Baró  and
J. Nogués
E. Menéndez
Affiliation:
Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
J. Sort*
Affiliation:
Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
S. Suriñach
Affiliation:
Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
M.D. Baró
Affiliation:
Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
J. Nogués
Affiliation:
Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The evolution of the structural and magnetic properties of metal-ceramic, cermet, nanocomposite powders, consisting of Co and α–Al2O3 in different proportions, prepared by ball milling has been investigated. The overall microstructure of the system, after long-term milling, is found to be very sensitive to the amount of α–Al2O3, yielding a less refined and faulted hexagonal-close-packed (hcp)-Co structure for the sample with larger α–Al2O3 percentage. The increased presence of the ceramic counterpart also causes a delay of the face-centered-cubic (fcc) to hcp-Co stress-induced transformation during ball milling. The results seem to indicate an evolution of the role of α–Al2O3, from increasing locally the strain rate of the mechanical work for small amounts of ceramic to absorbing milling energy for large amounts of α–Al2O3. The magnetic properties correlate with the obtained microstructure, where the amount of hcp-Co and stacking faults and the isolation of the Co particles by the α–Al2O3 control the coercivity.

Keywords

Mechanical alloyingMicrostructureMagnetic properties
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 11 , November 2007 , pp. 2998 - 3005
Copyright
Copyright © Materials Research Society 2007

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

1Tai, W.P., Kim, Y.S., Kim, J.G.: Fabrication and magnetic properties of Al2O3/Co nanocomposites. Mater. Chem. Phys. 82, 396 2003CrossRefGoogle Scholar
2Oh, S.T., Sando, M., Niihara, K.: Mechanical and magnetic properties of Ni-Co dispersed Al2O3 nanocomposites. J. Mater. Sci. 36, 1817 2001CrossRefGoogle Scholar
3Jia, K., Fischer, T.E., Gallois, B.: Microstructure, hardness and toughness of nanostructured and conventional WC-Co composites. Nanostruct. Mater. 10, 875 1998CrossRefGoogle Scholar
4El-Eskandarany, M. Sherif, Mahday, A.A., Ahmed, H.A., Amer, A.H.: Synthesis and characterizations of ball-milled nanocrystalline WC and nanocomposite WC-Co powders and subsequent consolidations. J. Alloys Compd. 312, 315 2000CrossRefGoogle Scholar
5Ohji, T., Jeong, Y.K., Choa, Y.H., Niihara, K.: Strengthening and toughening mechanisms of ceramic nanocomposites. J. Am. Ceram. Soc. 81, 1453 1998CrossRefGoogle Scholar
6Suryanarayana, C.: Nanocrystalline materials. Int. Mater. Rev. 40, 41 1995CrossRefGoogle Scholar
7Voevodin, A.A., Zabinski, J.S.: Nanocomposite and nanostructured tribological materials for space applications. Compos. Sci. Technol. 65, 741 2005Google Scholar
8Li, J., Ma, L.: Influence of cobalt phase on mechanical properties and thermal shock performance of Al2O3-TiC composites. Ceram. Int. 31, 945 2005CrossRefGoogle Scholar
9Yeo, W.S., Yaacob, I.I.: Mechanical alloying of Al2O3–Co powders mixture. Key Eng. Mater. 306–308, 1109 2006CrossRefGoogle Scholar
10Young, D.A.: Phase Diagrams of the Elements University of California Press Berkeley, CA 1991CrossRefGoogle Scholar
11Granqvist, C.G., Buhrman, R.A.: Ultrafine metal particles. J. Appl. Phys. 47, 2200 1976CrossRefGoogle Scholar
12Kitakami, O., Sakurai, T., Miyashita, Y., Takeno, Y., Shimada, Y., Takano, H.: Fine metallic particles for magnetic domain observations. Jpn. J. Appl. Phys. 35, 1724 1996CrossRefGoogle Scholar
13Ram, S.: Allotropic phase transformations in HCP, FCC and BCC metastable structures in Co-nanoparticles. Mater. Sci. Eng., A 304–306, 923 2001CrossRefGoogle Scholar
14Ram, S.: Self-confined dimension of thermodynamic stability in Co-nanoparticles in fcc and bcc allotropes with a thin amorphous Al2O3 surface layer. Acta Mater. 49, 2297 2001CrossRefGoogle Scholar
15Huang, J.Y., Wu, Y.K., Ye, H.Q.: Phase-transformation of cobalt induced by ball-milling. Appl. Phys. Lett. 66, 308 1995CrossRefGoogle Scholar
16Sort, J., Nogués, J., Suriñach, S., Baró, M.D.: Microstructural aspects of the hcp-fcc allotropic phase transformation induced in cobalt by ball milling. Philos. Mag. 83, 439 2003CrossRefGoogle Scholar
17Sort, J., Zhilyaev, A., Zielinska, M., Nogués, J., Suriñach, S., Thibault, J., Baró, M.D.: Microstructural effects and large microhardness in cobalt processed by high pressure torsion consolidation of ball milled powders. Acta Mater. 51, 6385 2003CrossRefGoogle Scholar
18Sort, J., Mateescu, N.M., Nogués, J., Suriñach, S., Baró, M.D.: Effect of the milling energy on the milling-induced hpc-fcc cobalt allotropic transformations. J. Metastable Nanocryst. Mater. 12, 126 2002Google Scholar
19Menéndez, E., Sort, J., Langlais, V., Zhilyaev, A., Muñoz, J.S., Suriñach, S., Nogués, J., Baró, M.D.: Cold compaction of metal-ceramic (ferromagnetic-antiferomagnetic) composites using high pressure torsion. J. Alloys Compd. 434–435, 505 2007CrossRefGoogle Scholar
20Young, R.A.: The Rietveld Method International Union of Crystallography University Press, Oxford 1995Google Scholar
21Zuo, B., Sritharan, T.: Ordering and grain growth in nanocrystalline Fe75Si25 alloy. Acta Mater. 53, 1233 2005CrossRefGoogle Scholar
22Warren, B.E., Averbach, B.L.: The effect of cold-work distortion on x-ray patterns. J. Appl. Phys. 21, 595 1950CrossRefGoogle Scholar
23Lutterotti, L., Scardi, P.: Simultaneous structure and size-strain refinement by the Rietveld method. J. Appl. Crys. 23, 246 1990CrossRefGoogle Scholar
24Enzo, S., Fagherazzi, G., Benedetti, A., Polizzi, S.: A profile-fitting procedure for analysis of broadened x-ray diffraction peaks. I. Methodology. J. Appl. Crystallogr. 21, 536 1988CrossRefGoogle Scholar
25Lutterotti, L., Gialanella, S.: X-ray diffraction characterization of heavily deformed metallic specimens. Acta Mater. 46, 101 1997CrossRefGoogle Scholar
26Sahu, P.: Lattice imperfections in intermetallic Ti-Al alloys: An x-ray diffraction study of the microstructure by the Rietveld method. Intermetallics 14, 180 2006CrossRefGoogle Scholar
27Moumeni, H., Alleg, S., Djebbari, C., Bentayeb, F.Z., Greneche, J.M.: Synthesis and characterisation of nanostructured FeCo alloys. J. Mater. Sci. 39, 5441 2004CrossRefGoogle Scholar
28Sahu, P., De, M., Kajiwara, S.: Microstructural characterization of Fe-Mn-C martensites athermally transformed at low temperature by Rietveld method. Mater. Sci. Eng., A. 333, 10 2002CrossRefGoogle Scholar
29Manik, S.K., Dutta, H., Pradhan, S.K.: Microstructure characterization and phase transformation kinetics of polymorphic transformed ball milled a-TiO2-10mol%m-ZrO2 mixture by Rietveld method. Mater. Chem. Phys. 82, 848 2003CrossRefGoogle Scholar
30Warren, B.E.: X-ray Diffraction Addison-Wesley Reading, MA 1969Google Scholar
31Ericsson, T.: Temperature and concentration dependence of stacking fault energy in Co-Ni system. Acta Metall. 7, 853 1966CrossRefGoogle Scholar
32Chikazumi, S.: Physics of Ferromagnetism, Oxford University Press, Oxford 1997CrossRefGoogle Scholar
33Montero, M.I., Emura, M., Cebollada, F., González, J.M., González, E.M., Vicent, J.L.: Coercivity analysis in the Co-x/(SiO2)(100-x) nanoparticulate system. J. Magn. Magn. Mater. 203, 205 1999CrossRefGoogle Scholar
34Dieter, G.E.: Mechanical Metallurgy. McGraw-Hill London 1988Google Scholar
35Houska, C.R., Averbach, B.L., Cohen, M.: The cobalt transformation. Acta Metall. 8, 81 1960CrossRefGoogle Scholar
36Yang, H., Liu, Y.: Factors influencing the stress-induced fcc ↔ hcp martensitic transformation in Co-32Ni single crystal. Acta Mater. 54, 4895 2006CrossRefGoogle Scholar
37Sort, J., Suriñach, S., Muñoz, J.S., Baró, M.D., Wojcik, M., Jedryka, E., Nadolski, S., Sheludko, N., Nogués, J.: Role of stacking faults in the structural and magnetic properties of ball-milled cobalt. Phys. Rev. B 68, 014421 2003CrossRefGoogle Scholar
38Bian, B., Yang, W., Laughlin, D.E., Lambeth, D.N.: Stacking faults and their effect on magnetocrystalline anisotropy in Co and Co-alloy thin films. IEEE Trans. Magn. 37, 1456 2001CrossRefGoogle Scholar
39Holloway, L., Laidler, H.: Thermal activation effects in CoCrPtTa media due to stacking faults. IEEE Trans. Magn. 37, 1459 2001CrossRefGoogle Scholar
40Takahashi, Y., Tanahashi, K., Hosoe, Y.: Stacking faults in Co-Cr-Pt perpendicular magnetic recording media. J. Appl. Phys. 91, 8022 2002CrossRefGoogle Scholar
41Sort, J., Nogués, J., Amils, X., Suriñach, S., Muñoz, J.S., Baró, M.D.: Room-temperature coercivity enhancement in mechanically alloyed antiferromagnetic-ferromagnetic powders. Appl. Phys. Lett. 75, 3177 1999CrossRefGoogle Scholar
42Saito, T., Saito, H.: Structures and magnetic properties of Co powder milled with SiO2 powder. J. Mater. Sci. Lett. 21, 1895 2002CrossRefGoogle Scholar
43Skomski, R., Coey, J.M.D.: Permanent Magnetism Institute of Physics Publishing Bristol and Philadelphia 1999Google Scholar