Title: Effect of alumina inclusions on microstructure and mechanical properties of 62 WC, 32 (Ti-W) C and 6 Co compacts

Authors: Mushtaq Albdiry; Haydar Alethari

Addresses: Department of Mechanical Engineering, University of Southern Queensland, Toowoomba, Qld, 4350, Australia. ' Department of Materials Engineering, Babylon University, Hilla-Najaf Road, Al-Hilla, Iraq

Abstract: This investigation is aimed at understanding the role of adding ceramic inclusion, alumina (Al2O3) on the densification, microstructure and mechanical properties of cemented carbide cutting inserts. The samples were prepared of an initial mixture of 62 WC, 32 (Ti-W) C and 6 Co wt% particulates; different additions of Al2O3 of 1, 2, 3 and 4 wt% were introduced to that mixture. The testing specimens were compacted via powder metallurgy at 200 MPa and sintered at 1,410°C under vacuum. The green and sintered densities have decreased; the figures of macrohardness, Vickers hardness and transverse rupture strength have also deteriorated with the increase of alumina content. The macrohardness has almost declined of 30% at 3% alumina. This is ascribed to the interfacial grain-boundary decohesion between Al2O3 and carbide particles as can be observed from scanning electron microscopy images which depicts the monolithic clusters in the final consolidation of the compacts.

Keywords: powder metallurgy; cemented carbide; alumina; ceramic inclusion; microstructure; materials properties; densification; cutting inserts; hardness; transverse rupture strength.

DOI: 10.1504/IJMMP.2012.048523

International Journal of Microstructure and Materials Properties, 2012 Vol.7 No.4, pp.329 - 340

Published online: 14 Aug 2012 *

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