Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-29T07:34:15.131Z Has data issue: false hasContentIssue false

Solidification Behaviour of Al Particles Embedded in an Ni Aluminide Matrix

Published online by Cambridge University Press:  21 February 2011

K.A.Q O'Reilly
Affiliation:
Oxford Centre for Advanced Materials and Composites, Dept. of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
W.T. Kim
Affiliation:
Dept. of Physics, Chong Ju University, 36 Naedok Dong, Chongju, 360-764 Korea
B. Cantor
Affiliation:
Oxford Centre for Advanced Materials and Composites, Dept. of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
Get access

Abstract

A hypereutectic Al-40wt%Ni alloy has been manufactured by melt spinning, and the resulting microstructure examined by transmission electron microscopy. As-melt spun hypereutectic Al-40wt%Ni consists of an Ni aluminide matrix and an A1-rich phase distributed in the form of particles with sizes ∼ 50-100 nm, and as an irregular layer at the cell and grain boundaries. Diffraction analysis of the Ni aluminide matrix is consistent with the ASTM x-ray diffraction standard 2θ values for the orthorhombic NiAl3 phase, a=6.6114 Å, b=7.3662 Å andc=4.8112 Å. The solidification nucleation kinetics of Al-rich particles have been examined by heating and cooling experiments in a differential scanning calorimeter over a range of heating and cooling rates. Solidification of the Al-rich phase at the cell and grain boundaries nucleates catalytically on the surrounding Ni aluminide matrix at an undercooling of ∼ 3 K. Analysis of the solidification nucleation kinetics of the Al-rich phase in Al-40wt%Ni supports the hypothesis [1-4] that the classical spherical cap model of heterogeneous nucleation breaks down at low undercoolings and small contact angles.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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 Moore, K.I., Zhang, D.L. and Cantor, B., Acta Metall. 38, 1327, (1990).Google Scholar
2 Zhang, D.L. and Cantor, B., Phil. Mag. A62, 557, (1990).Google Scholar
3 Kim, W.T. and Cantor, B., Acta Metall. 40, 3339, (1992).Google Scholar
4 O'Reilly, K.A.Q. and Cantor, B., Acta Metall. Acta Met., 43, 405, (1995).Google Scholar
5 Christian, J.W., The Theory of Transformations in Metals and Alloys. (Pergamon Press, Oxford, 1975).Google Scholar
6 Wang, C.C. and Smith, C.S., TMS-AIME 188, 136, (1950).Google Scholar
7 Miller, W.A. and Chadwick, G.A., Proc. R. Soc. A321, 257, (1969).Google Scholar
8 Southin, R.T., PhD. Thesis, Cambridge, (1970).Google Scholar
9 Southin, R.T. and Chadwick, G.A., Acta Metall. 26, 223, (1978).Google Scholar
10 Boswell, P.G. and Chadwick, G.A., Acta Metall. 28, 209, (1980).Google Scholar
11 Boswell, P.G., Chadwick, G.A., Elliott, R. and Sale, F.R., in Solidification and Casting of Metals. (Metals Society, London, 1979), p. 611.Google Scholar
12 Zhang, D.L. and Cantor, B., Scripta Metall. 24, 751, (1990).Google Scholar
13 Zhang, D.L. and Cantor, B., Mater.Sci.Eng. A128, 209, (1990).Google Scholar
14 Zhang, D.L. and Cantor, B., J.Cryst.Growth, 104, 583, (1990).Google Scholar
15 Zhang, D.L., Chattopadhyay, K. and Cantor, B., J.Mater.Sci. 26, 1531, (1991).Google Scholar
16 Kim, W.T., Zhang, D.L. and Cantor, B., Metall. Trans.A 22A, 2487, (1991).Google Scholar
17 Zhang, D.L. and Cantor, B., Acta Metall. 39, 1595, (1991).Google Scholar
18 Kim, W.T. and Cantor, B., J.Mater.Sci. 26, 2868 (1991).Google Scholar
19 Zhang, D.L., and Cantor, B., Acta Metall. 40, 2951, (1992).Google Scholar
20 Eborall, M.D., J.Inst.Metals 76, 295, (1949).Google Scholar
21 Crossley, F.A. and Mondolfo, L.F., AIME Trans. 191, 1143, (1951).Google Scholar
22 Marcantonio, J.A. and Mondolfo, L.F., J.Inst.Metals 98, 23, (1970).Google Scholar
23 Cissé, J., Herr, H.W. and Boiling, G.F., Metall.Trans. 5, 633, (1974).Google Scholar
24 Bradley, A.J. and Taylor, A., Phil.Mag. 23, 1049, (1937).Google Scholar
25 Brandes, E.A. and Smithells, C.J., Metals Reference Book. 6th ed. (Butterworths, London, 1983).Google Scholar
26 Massalski, T.B., Binary Alloy Phase Diagrams. 2nd ed. (ASM International, 1990).Google Scholar
27 Zhang, D.L., Hutchinson, J.L. and Cantor, B., J. Mater. Sci. 29, 2147, (1994).Google Scholar
28 Ho, C.R. and Cantor, B., Phil.Mag.A 66, No.l, 141, (1992).Google Scholar
29 Turnbull, D., J.Appl.Phys. 21, 1022, (1950).Google Scholar
30 Cantor, B. and Doherty, R.T., Acta Metall. 27, 33, (1979).Google Scholar
31 Turnbull, D. and Holloman, J.H., Prog.Metal Phys. 4, 333, (1953).Google Scholar