Impression creep behaviour of squeeze-cast Ca and Sb added AZ91 magnesium alloy

Bankoti, AKS and Mondal, AK and Dieringa, Hajo and Ray, BC and Kumar, S (2016) Impression creep behaviour of squeeze-cast Ca and Sb added AZ91 magnesium alloy. In: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 673 . pp. 332-345.

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Abstract

Impression creep technique has been employed to investigate creep behaviour of the squeeze-cast AZ91 Mg alloy modified by the addition of Ca and/or Sb. All the modified alloys exhibit superior creep resistance than the base AZ91 alloy. The combined additions of Ca and Sb are more effective in improving creep resistance than the individual additions. Individual Ca added AZX911 results superior creep resistance than the Sb added AZY911 owing to the higher thermal stability of the Al2Ca phase in the former alloy compared to that of the Mg3Sb2 phase in the later one. The AZXY9120 alloy pertaining 2.0Ca and 0.3Sb (wt%) exhibits the best creep resistance due to reduced amount of beta-Mg17Al12 phase and presence of higher amount of dense network of thermally stable Al2Ca phase at grain boundaries. Post creep microstructural observation confirms the ability of the Al2Ca phase to withstand applied high stresses at elevated temperature without undergoing significant changes in its structure. The values of stress exponents and activation energies are in the range of 4.3-6.5 and 111.9 +/- 1.1 to 114.9 +/- 3.0 kJ/mol, which concludes dislocation climb controlled by pipe diffusion is the dominant creep mechanism for all the alloys in the temperature and stress level employed. (C) 2016 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Additional Information:	Copy right for this article belongs to the ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	22 Oct 2016 09:07
Last Modified:	22 Oct 2016 09:07
URI:	http://eprints.iisc.ac.in/id/eprint/54977

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