Evolution of texture and asymmetry and its impact on the fatigue behaviour of an in-situ magnesium nanocomposite

Tekumalla, Sravya and Bibhanshu, Nitish and Shabadi, Rajashekara and Suwas, Satyam and Ha, Thi Mai Hoa and Gupta, Manoj (2018) Evolution of texture and asymmetry and its impact on the fatigue behaviour of an in-situ magnesium nanocomposite. In: MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 727 . pp. 61-69.

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Abstract

A novel in-situ synthesis technique has previously been proposed for the synthesis of magnesium based nano composites, by exploiting the thermodynamic reactions, to fabricate nanoparticles in-situ during the melt processing. Although the microstructural aspects of formation of such nanocomposites have been dealt with previously, the implications of the same on the texture and hence on mechanical properties are not certain. In the present work, the evolution of crystallographic texture and its influence on tension-compression asymmetry (Tensile yield strength divided by Compressive yield strength) and thereby, the impact on fatigue failure mechanisms is studied by comparing the behaviour of Mg-1.8Y/1.53ZnO nanocomposite and its monolithic alloy, Mg-1.8Y. The Mg-1.8Y/1.53ZnO nanocomposite revealed a very strong two component texture, not akin to the weak texture of Mg-1.8Y alloy. The texture was attributed to the loss of Y in the matrix and consumption of Y in formation of Y2O3 nanoparticles in-situ and the formation of the beta(1)' (Mg-Zn') rods during extrusion. Further, this texture exhibited by the nanocomposite favoured high twinning activity under compression, thereby causing strong asymmetry in the tensile and compressive yield strengths. The fatigue tests indicated a superior performance of the nanocomposite as compared to the alloy. The deformation and damage mechanisms, when studied in correlation with the asymmetry revealed that the asymmetric materials exhibit steeper S-N curves as compared to the symmetric materials.

Item Type:	Journal Article
Publication:	MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Publisher:	ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Additional Information:	Copyright of this article belong to ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	02 Aug 2018 15:47
Last Modified:	02 Aug 2018 15:47
URI:	http://eprints.iisc.ac.in/id/eprint/60347

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