Fatigue crack-growth in shape-memory NiTi and NiTi-TiC composites

Vaidyanathan, R and Dunand, DC and Ramamurty, U (2000) Fatigue crack-growth in shape-memory NiTi and NiTi-TiC composites. In: Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 289 (1-2). pp. 208-216.

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Abstract

An experimental study was conducted to examine the room-temperature Fatigue crack-growth characteristics of shape-memory NiTi matrix composites reinforced with 10 and 20 vol.% of TIC particles. Microstructural characterization of these hot-isostatically-pressed materials shows that the TiC particles do not react with the NiTi matrix and that they lack any texture. Overall fatigue crack-growth characteristics were found to be similar for the unreinforced and reinforced materials. However, a slight increase in the threshold for fatigue crack initiation was noted for the composites. The fracture toughness, as indicated by the failure stress intensity factor range, was found to be similar for all materials. Neutron diffraction studies near the crack-tip of the loaded fracture NiTi specimen detected no significant development of texture at the crack-tip. These results are explained by recourse to fractographic observations. Finally, a comparison is made between the micromechanisms of fracture of metal matrix composites, which deform by dislocation plasticity, and those of the present NiTi-TiC composites, which deform additionally by twinning.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Shape memory alloys;Metal matrix composites;Fatigue and fracture;Micromechanisms;Neutron diffraction.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	20 Jul 2009 11:57
Last Modified:	19 Sep 2010 04:58
URI:	http://eprints.iisc.ac.in/id/eprint/17735

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