Hostname: page-component-8448b6f56d-wq2xx Total loading time: 0 Render date: 2024-04-24T11:58:58.756Z Has data issue: false hasContentIssue false

Mechanical Behavior of a Tri-modal Al Matrix Composite

Published online by Cambridge University Press:  01 February 2011

Jichun Ye
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, CA 95616-5294USA
Bing Q. Han
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, CA 95616-5294USA
Feng Tang
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, CA 95616-5294USA
Julie M. Schoenung
Affiliation:
Department of Chemical Engineering and Materials Science, University of California, Davis, Davis, CA 95616-5294USA
Get access

Abstract

Mechanical milling at cryogenic temperatures (cryomilling) was applied to fabricate a composite powder with 20 wt. % B4C (submicron-to-several microns in size) in a nanocrystalline (NC) 5083 Al matrix. A uniformly blended powder with 50 wt. % cryomilled composite powder and 50 wt. % coarse-grained (CG) 5083 Al powder was degassed, cold isostatic pressed (CIPped) and extruded to form a composite with 10 wt. % B4C, 50 wt. % CG 5083 Al and balance NC 5083 Al. This tri-modal material was then tested for mechanical behavior under compressive and tensile load conditions at various temperatures. The composite exhibited an extremely high yield stress at room temperature, but limited ductility. Although the composite lost its strength at elevated testing temperatures rapidly, the retained strength was still much higher than that of the conventional 5083 Al. The composite exhibits its highest ductility of 26% at 200°C under tensile load. In compression, it plastically deformed uniformly at all the elevated temperatures (≥373 K) and did not fracture even when the deformation exceeded 30%. The microstructure of this composite, including the distribution of each phase, the grain sizes of the Al matrix, the interfaces between these three phases, and the fracture surfaces were characterized using transmission electron microscopy (TEM) and optical microscopy (OM) techniques. The relationship between the microstructures and mechanical properties was discussed.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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 Lloyd, D. J., Inter. Mater. Rev 39, 123 (1994).Google Scholar
2 Shackelford, J. F., Alexander, W., and Park, J. S., CRC Materials Science and Engineering Handbook, 3rd edition. Boca Raton, Fla, (CRC Press, 2001).Google Scholar
3 Weertman, J. R., in Nanostructured materials: processing, properties, and applications, edited by Koch, C.C., NY, Norwich, (William Andrews Publishing, 2002) pp. 397421.Google Scholar
4 Schoenung, J. M., Ye, J., He, J., Tang, F., and Witkin, D., Mater. Forum 29, 123 (2005).Google Scholar
5 Ye, J., He, J., and Schoenung, J.M., submitted.Google Scholar
6 Han, B. Q., Lee, Z., Witkin, D., Nutt, S. R., and Lavernia, E. J., Metall. Mater. Trans. A36, 19, (2005).Google Scholar
7 Davis, J. R., ASM Specialty Handbook-Aluminum and Aluminum Alloys, Materials Park, OH, (ASM International, 1994) pp. 675.Google Scholar