Phase formation in Ti/Ni dissimilar welds

Chatterjee, S and Abinandanan, TA and Chattopadhyay, K (2008) Phase formation in Ti/Ni dissimilar welds. In: Materials Science and Engineering A, 490 (1-2). pp. 7-15.

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Abstract

We explore phase formation in Ti/Ni dissimilar welds using a combination of microscopy and composition analysis (TEM, SEM and EDS).Main microstructural features are NiTi dendrites and $Ti_2Ni$ grains in the inter-dendritic space. The high temperature B2 phase of NiTi is found to transform to trigonal 'R'-phase, $B19^{\prime}$ martensite, and rhombohedral $Ni_4Ti_3$ phase; these different transformation products highlight the composition inhomogeneity in the parent B2 phase and probable non-equilibrium solidification events during rapid cooling of the weld. Solidification sequence of NiTi and $Ti_2Ni$ was found to vary depending on local conditions in the weld. Formation of impurity nitride phases of titanium is observed which signify incomplete shielding during welding.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Dissimilar welding;Microstructure;TEM;SEM;Ni–Ti.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	12 Sep 2008 05:53
Last Modified:	22 Feb 2012 08:40
URI:	http://eprints.iisc.ac.in/id/eprint/15728

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