Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-18T11:19:37.243Z Has data issue: false hasContentIssue false

Microstructure in Rapidly Quenched Al-Ti,Al-B and Al-Ti-B Alloys

Published online by Cambridge University Press:  26 February 2011

A. Majumdar
Affiliation:
Department of Materials Engineering, Monash University, Clayton, Victoria, Australia 3168
R. H. Mair
Affiliation:
Department of Materials Engineering, Monash University, Clayton, Victoria, Australia 3168
B. C. Muddle
Affiliation:
Department of Materials Engineering, Monash University, Clayton, Victoria, Australia 3168
Get access

Abstract

Rapidly quenched ribbons (˜50m thickness) of Al-5wt.%Ti, Al-lwt.%B and a range of Al-Ti-B alloys have been produced by melt spinning under He atmosphere and the microstructures of the ribbons, following solidification and post-solidification heat treatment, characterized using analytical electron microscopy. In the Al-5Ti alloy, the coarse equilibrium primary phase (b.c.t. Al3 Ti) that is observed following conventional casting is replaced by fine (0.1–0. 2μm), cuboidal particles of a metastable cubic (Ll2) Al3Ti in melt-spun ribbon. These metastable particles form directly from the melt and act as nucleation sites for the solid solution which subsequently forms. A refined microstructure with an average grain size of 1–2μm results. A supersaturation of Ti is retained in matrix solid solution following solidification and a variety of solid state precipitate forms, including fine dispersions of coherent, metastable Al3 Ti particles, is observed to emerge during post-solidification heat treatment. For the Al-1B alloy, the coarse distribution of primary AlB2 particles in a chill-cast ingot is replaced by a fine, uniform dispersion of the metastable boride, α-AlB12, in the melt-spun ribbon. Attempts to induce a refined boride dispersion in melt-spun Al-Ti-B alloys have proved largely unsuccessful.

Type
Articles
Copyright
Copyright © Materials Research Society 1987

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

1. Jones, H., J. Mater. Sci., 19, 1043(1984).CrossRefGoogle Scholar
2. Fine, M.E., Met. Trans., 6A, 625(1975).CrossRefGoogle Scholar
3. John, D.H. St., Hogan, L.M., Proc. of the 1985 Metals Congress, Ballarat, Australia, (Australian Institute of Metals, 1985), pp.I1–I3.Google Scholar
4. Sigworth, G.K., Met. Trans., 15A, 277(1984).CrossRefGoogle Scholar
5. Hori, S., Tai, H., Narita, Y., Rapidly Quenched Metals, edited by Steeb, S. and Warlimont, H. (Elsevier Science Publishers B.V., 1985), p. 11.Google Scholar
6. Hori, S., Saji, S., Takehara, A., Proc. 4th Int.Conf. on Rapidly Quenched Metals (Sendai, 1981) edited by Masumoto, T. and Suzuki, K., pp. 13451548; S. Hori, N. Furushiro, Proc. 4th Int.Conf. on Rapidly Quenched Metals (Sendai, 1981) edited by T. Masumoto and K. Suzuki, pp. 1525–1528.Google Scholar
7. Metals Handbook, vol.8, 8th edn., (American Society for Metals, Ohio, 1973), p. 257.Google Scholar
8. Pearson, W.B., A Handbook of Lattice Spacings and Structure of Metals and Alloys (Pergamon Press, 1964), p. 219.Google Scholar