Effect of wettability on the friction of a laser-textured cemented carbide surface in dilute cutting fluid

Abstract

To clarify the correlation between the wettability and friction coefficient, the wettability and friction properties of four different laser-induced surface textures on cemented carbide surface were evaluated in this study using droplet angle measuring meter and pin-on-disc reciprocating tribometer. The fluid used was dilute cutting fluid of volume ratio 1:40 emulsified oil to water. The four textures investigated were orthogonal arrays of circular and square dimples and convex. Results suggest a coupled effect of texture shape and area ratio on surface contact angle. A strong correlation between friction coefficient and surface wettability was also found. Friction coefficient decreases with the decrease in contact angle of the textured cemented carbide surface and the increase in delta wettability (Δθ = θwball–θwdisc) between two sliding surfaces in dilute cutting fluid. This finding indicates that the wettability of cemented carbide surface have significant effect on friction coefficient in dilute cutting fluid condition.