Tribology international vol:43 issue:1-2 pages:40-54
Flat samples of WC-Co hardmetals with 6-12 wt%Co were surface finished by grinding polishing and wire-electro-discharge machining (EDM). Comparative dry reciprocating sliding experiments against WC-6wt%Co pins were performed using a Plint TE77 tribometer. Tribological characteristics were recorded online. Wear Surfaces were characterized by surface scanning topography and scanning electron microscopy. Wire-EDM'ed samples exhibited higher friction and wear compared to ground and polished equivalents. This trend was correlated to X-ray diffraction measurements revealing tensile residual surface stresses in WC after wire-EDM contrary to compressive surface stresses after grinding and polishing. However, finer executed EDM reduces friction and wear significantly. (C) 2009 Elsevier Ltd. All rights reserved.