On the hardness of submicrometer-sized WC–Co materials.

The hardness–composition–grain size relationships of cemented WC–Co with WC particle sizes in the submicrometer range have been investigated. It is found that the Hall–Petch relations for individual WC and Co phases derived from micrometer-sized WC–Co are still applicable to submicrometer-sized WC–Co, suggesting that the deformation mechanism remains the same when WC particle sizes change from micrometers to submicrometers. However, the measured hardness of submicrometer-sized WC–Co is lower than that predicted using the equation derived from micrometer-sized WC–Co and the principle that the applied loads are transmitted through the carbide skeleton and the continuous binder phase (Lee and Gurland (1978) [7] ). It is proposed that this discrepancy can be addressed by the reduced continuity of WC when WC particle sizes decrease from micrometers to submicrometers at a given WC volume fraction. [ABSTRACT FROM AUTHOR]