Cyclic contact fatigue of cemented carbides under dry and wet conditions: Correlation between microstructure, damage and electrochemical behavior

ROA, J.J.; ARCIDIACONO, M.; GARCÍA, J.; GRASSO, J.; SOLDERA, F.; SIMISON, S.; ESCALADA, L.; SOSA, A.D.

INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS

ELSEVIER SCI LTD

Año: 2020 vol. 92

0263-4368

The correlation between the damage induced under cyclic contact fatigue and their electrochemical behavior(anodic polarization curves) for different WC-Co-based cemented carbides grades was investigated at the macrometricand micrometric length scale. Under both, dry (i.e. air atmosphere) and wet (cutting lubricant fluid)conditions, the crack path propagates near the carbide/metallic binder interface, resulting in tortuous cracks ofseveral micrometers. Despite the alkaline conditions imposed by the cutting fluid (pH 9.2), the cobalt binder ispreferentially dissolved, and the carbide-skeleton keeps stable. The presence of cutting fluid in the contactfatigue zone changes the morphology of the cracks due to the partial dissolution of the binder phase. Theaddition of chromium to the WC-Co composition enhances corrosion resistance of the metallic binder phaseresulting in reduced damage of the cemented carbides in environmental assisted cyclic contact fatigue conditions.