Tensile behavior of a free-standing Pt-aluminide (PtAl) bond coat

Alam, Md Zafir and Kamat, SV and Jayaram, V and Das, Dipak K (2013) Tensile behavior of a free-standing Pt-aluminide (PtAl) bond coat. In: ACTA MATERIALIA, 61 (4). pp. 1093-1105.

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Abstract

The tensile behavior of a high activity stand-alone Pt-aluminide (PtAl) bond coat was evaluated by the micro-tensile test method at various temperatures (room temperature to 1100 degrees C) and strain rates (10(-5) s(-1)-10(-1) s(-1).) At all strain rates, the stress strain behavior of the stand-alone coating was significantly affected by the variation in temperature. The stress strain response was linear, indicating brittle behavior, at temperatures below the brittle ductile transition temperature (BDTT). The coating exhibited appreciable ductility (up to 2%) above the BDTT. The strength (both yield stress and ultimate tensile strength) of the coating decreased and its ductility increased with increasing temperature above the BDTT. The tensile behavior of the coating was sensitive to strain rate in the ductile regime, with its strength increasing with increasing strain rate at any given temperature. The BDTT of the coating was found to increase with increasing with increasing strain rate. The coating exhibited two distinct mechanisms of deformation above the BDTT. The transition temperature for the change of deformation mechanism also increased with increasing strain rate. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	ACTA MATERIALIA
Publisher:	PERGAMON-ELSEVIER SCIENCE LTD
Additional Information:	Copyright for this article belongs to the PERGAMON-ELSEVIER SCIENCE LTD, ENGLAND.
Keywords:	Pt-aluminide bond coat; Tensile behavior; Temperature; Strain rate; Thermal barrier coating BRITTLE TRANSITION-TEMPERATURE; MECHANICAL-PROPERTIES; FLOW-STRESS; SUPERALLOY; EVOLUTION; DISLOCATIONS; DEFORMATION; DEPENDENCE; PLATINUM; CRYSTALS
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	03 Apr 2013 10:32
Last Modified:	03 Apr 2013 10:32
URI:	http://eprints.iisc.ac.in/id/eprint/46249

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