Stress states in individual Si particles of a cast Al-Si alloy: Micro-Raman analysis and microstructure based modeling

Joseph, Sudha and Kumar, S and Bhadram, Venkata Srinu and Narayana, Chandrabhas (2015) Stress states in individual Si particles of a cast Al-Si alloy: Micro-Raman analysis and microstructure based modeling. In: JOURNAL OF ALLOYS AND COMPOUNDS, 625 . pp. 296-308.

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Abstract

The stress states in Si particles of cast Al-Si based alloys depend on its morphology and the heat treatment given to the alloy. The Si particles fracture less on modification and fracture more in the heat treated condition. An attempt has been made in this work to study the effect of heat treatment and Si modification on the stress states of the particles. Such understanding will be valuable for predicting the ductility of the alloy. The stress states of Si particles are estimated by Raman technique and compared with the microstructure-based FEM simulations. Combination of Electron Back-Scattered Diffraction (EBSD) and frequency shift, polarized micro-Raman technique is applied to determine the stress states in Si particles with (111) orientations. Stress states are measured in the as-received state and under uniaxial compression. The residual stress, the stress in the elastic-plastic regime and the stress which causes fracture of the particles is estimated by Raman technique. FEM study demonstrates that the stress distribution is uniform in modified Si, whereas the unmodified Si shows higher and more complex stress states. The onset of plastic flow is observed at sharp corners of the particles and is followed by localization of strain between particles. Clustering of particles generates more inhomogeneous plastic strain in the matrix. Particle stress estimated by Raman technique is in agreement with FEM calculations. (C) 2014 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	JOURNAL OF ALLOYS AND COMPOUNDS
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copyright for this article belongs to the ELSEVIER SCIENCE SA, PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Keywords:	Al-Si alloy; Polarized Raman technique; Finite element modeling; Si modification; Heat treatment; Stress analysis
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	14 Feb 2015 13:32
Last Modified:	14 Feb 2015 13:32
URI:	http://eprints.iisc.ac.in/id/eprint/50800

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