Influence of alumina on metallographic and mechanical properties of carbide cutting inserts

Abstract EN

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 6Co wt % particulates; different additions of Al2O3 of 1, 2, 3, 4, 5 and 7 wt % were introduced to that mixture.

The testing specimens were compacted via powder metallurgy at 200 MPa and sintered at 1410°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.