Particle erosion of cemented carbides with low Co content

Cemented carbides are well known for their high erosion resistance and are therefore used in many demanding applications involving erosion, such as grit blasting nozzles. A number of investigations on the erosive wear resistance of conventional cemented carbides have been published. The present paper is aimed at investigating the erosion resistance of a series of modern cemented carbides containing no or very small amounts of Co, so-called binderless carbides, and relating their performance to conventional sorts. A series of binderless carbides with varying grain size (0.6, 2 and 5 μm) and binder content (0.25 and 1 wt.%) has been tested. The materials were eroded by SiC particles of three sizes (80, 200 and 600 μm) from four angles (90, 70, 50 and 30°) with a velocity of 70 m/s. Three conventional WC-Co grades of corresponding grain sizes were also tested, under identical test conditions. The materials are ranked with respect to their erosion rate and scanning electron microscopy is used to analyse the worn surfaces. The influence of carbide grain size and binder amount on the wear behaviour is discussed.