Title: Mechanical properties and fracture characteristics of cemented tungsten carbide with fine microstructure studied by nanoindentation

Authors: R. Irwan, H. Huang

Addresses: School of Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia. ' School of Engineering, The University of Queensland, St. Lucia, QLD 4072, Australia

Abstract: Nanoindentation was used to investigate mechanical properties and fracture characteristics of cemented tungsten carbide with fine microstructure. The elastic modulus and hardness of tungsten carbide grains were found to be significantly greater than those measured in cobalt binder rich regions, respectively. From the indented surfaces, very few evidences of cracking or fragmentation were observed using in-situ atomic force microscopy. However, the pop-in events were observed from the indentation load-displacement relationships and the acoustic emissions were detected during indenting processes, indicating the occurrences of brittle fracture. The latter observations were explained using a hypothesis that the fracture of the material under nanoindentation was mainly via sharp corner breaking due to the crash of individual tungsten carbide grains.

Keywords: nanoindentation; cemented tungsten carbide; elastic modulus; hardness; microstructure; fracture characteristics; mechanical properties; tungsten carbide grains.

DOI: 10.1504/IJSURFSE.2008.018966

International Journal of Surface Science and Engineering, 2008 Vol.2 No.1/2, pp.29 - 40

Published online: 26 Jun 2008 *

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