Effect of hydrogen charging on tensile properties of B-modified Ti-6Al-4V alloy

Singh, Gaurav and Bajargan, Govind and Datta, Ranjan and Ramamurty, Upadrasta (2013) Effect of hydrogen charging on tensile properties of B-modified Ti-6Al-4V alloy. In: Materials Science and Engineering: A, 576 . pp. 326-336.

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Abstract

Trace addition of B to Ti and its alloys leads to a marked microstructural refinement, which in turn enhances the tensile and fatigue properties of the as-cast alloys. This can be particularly advantageous in applications wherein Ti alloys are used in the as-cast form. In some of these, the environment containing H and Ti alloy components is susceptible to embrittlement due to H uptake. Whether the addition of B to Ti-6Al-4V improves the relative mechanical performance of such cast components used in H environments is examined in this work. Cast Ti-6Al-4V-xB (0 <= x <= 0.55 wt%) alloys were H charged at 500 and 700 degrees C for up to 4 h. Microstructures and room temperature tensile properties of the resulting alloys have been evaluated. Experimental results show that charging at 700 degrees C for 2 h leads to the formation of titanium hydride in the microstructure, which in turn causes severe embrittlement. For shorter durations of charging, a marginal increase in strength was noted, which is attributed to the solid solution strengthening by H. The mechanical performance of the B modified alloys was found to be relatively higher, implying that B addition not only refines the as-cast microstructure but also is beneficial in applications that involve H environment A direct correlation between the volume fraction of TiB particles in the microstructure and the relative reduction in the strength of H-embrittled alloys suggests that the addition of B to Ti alloys, in optimum quantities, can be utilized as a strategy to design alloys that are more resistant to H embrittlement.

Item Type:	Journal Article
Publication:	Materials Science and Engineering: A
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Titanium Alloys; Titanium Hydride; Hydrogen Embrittlement; Mechanical Properties; Ductility
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	02 Sep 2013 06:23
Last Modified:	02 Sep 2013 06:23
URI:	http://eprints.iisc.ac.in/id/eprint/46949

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