Origin of contamination and role of mechanochemistry during mechanical alloying: the case of Ag–Te alloys

De, Joyita and Umarji, AM and Chattopadhyay, K (2007) Origin of contamination and role of mechanochemistry during mechanical alloying: the case of Ag–Te alloys. In: Materials Science and Engineering A, 449-45 . pp. 1062-1066.

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Abstract

We show that enhanced reaction of the vial materials with the milled samples can take place during the non-equilibrium processing route of mechanical alloying leading to the introduction of significant contamination. The increase in reactivity could be attributed to the grain size reduction to nanoscale during the milling process. Our attempt at mechanical alloying of elemental silver and tellurium powder using agate and zirconia grinding media to obtain contamination-free silver telluride $(Ag_2Te)$ phase with fine grain size has lead to the evolution of silver silicate $(Ag_2SiO_3)$ and zirconium telluride $(ZrTe_2)$ phases,respectively which contaminate the $Ag_2Te$ phase. On the other hand, no contamination could be observed when tungsten carbide (WC) vial and balls are used. Attempts have been made to rationalize the observations in terms of changes in thermodynamics and kinetics at small length scale.

Item Type:	Journal Article
Publication:	Materials Science and Engineering A
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier. This article is also published in Proceedings of the 12th International Conference on Rapidly Quenched & Metastable Materials.
Keywords:	Intermetallics;Mechanical alloying;X-ray diffraction.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	28 Jul 2008
Last Modified:	19 Sep 2010 04:48
URI:	http://eprints.iisc.ac.in/id/eprint/15262

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