Hostname: page-component-8448b6f56d-gtxcr Total loading time: 0 Render date: 2024-04-18T10:26:34.038Z Has data issue: false hasContentIssue false

Rapid Synthesis of Nanostructural Intermetallics and their Bulk Properties

Published online by Cambridge University Press:  10 February 2011

S. M. Pickard
Affiliation:
Materials Science and Engineering Department, The University of Michigan, Ann Arbor MI 48109
A. K. Ghosh
Affiliation:
Materials Science and Engineering Department, The University of Michigan, Ann Arbor MI 48109
Get access

Abstract

A rapid physical vapor deposition process (PVD) utilizing a high speed rotating substrate and small substrate-to-source spacing has been used to produce bulk sheet of Ti-Al alloys in the compositional range Ti-12% Al to Ti-75% Al1 at a rate of 1–3 μm/minute. Microstructural architectures produced by the method comprise of either fully homogenous phase mixtures of nano-grains, or nanolaminated material, depending on the substrate rotational rate, with lower rotational rate producing a layered microstructure. Defect populations within the as-deposited material are characterized by TEM and SEM, and hot pressing consolidation of the as-deposited material, which retains a grain size < 1000 nm, has been investigated. While indentation hardness of α2+γ(2 phase) alloys exceeded 7 GPa, brittle failure occurred in the elastic regime at nominally lower tensile stress than that for conventionally produced alloys containing Nb and Cr as solute elements. α2+γ alloys can exhibit tensile elongations of more than 100% at 850°C with retention of fine grain size. Elevated temperature failure occurs by the formation of voids in regions of compositional variability in the composite where single phase α2-Ti3Al structure was present.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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. Froes, F. H., Suryanarayana, C., Chen, G.-H., Frefer, Abdulbaset, and Hyde, G. R., JOM, 44 (May 92), p. 26.Google Scholar
2. Kim, Y.-W. and Dimiduk, D. M., JOM, 43 (August 91), p. 40.Google Scholar
3. Kaibyshev, D. A. in Superplasticity of alloys. Intermetallics and Ceramics. Springer-Verlag New York 1992, Chapter 9.Google Scholar
4. Mishra, R. S. and Mukerjee, A. K., to be published in Advances in the Science and Technology of Titanium alloys, edited by Weiss, I., Srinivassan, R., Bania, P. and Eylon, D., TMS, Warrendale, 1996.Google Scholar
5. Liu, C. T., Ser. Metall. Mater., 25, p. 1231 (1991)Google Scholar