Effects of surface roughness on the flexural strength of a hardmetal

Jorge  Cruz Fernandes; Carlos Alberto Pacheco da Silva; Luis G. Rosa; Carlos Saraiva

Key information

Authors:

Jorge Cruz Fernandes (José Jorge Lopes da Cruz Fernandes); Carlos Alberto Pacheco da Silva; Luis G. Rosa (Luís Manuel Guerra da Silva Rosa); Carlos Saraiva (Carlos Saraiva Martins)

Published in

April 1, 1994

Abstract

A detailed study to assess the effect of surface roughness on three-point flexural strength of a WC-Co hardmetal was undertaken. Eight different types of surface finish were investigated; R-parameters were determined and Weibull statistics were applied to analyse the fracture strength results. It was concluded that the highest values of rupture stress and Weibull modulus are obtained when the surfaces and the edges of the specimens are submitted to careful and gradual, step-by-step, surface-finishing operations and a 1 mum diamond paste is used as the final abrasive. Only when very fine finish is attained may the results of rupture stress then represent the intrinsic behaviour of the material.