Mechanical reliability of FIB-fabricated WC–Co cemented carbide nanowires evaluated by MEMS tensile testing

•MEMS-based tensile testing technique evaluated WC–Co cemented carbide nanowires.•All the WC–Co nanowires showed brittle fracture without plastic deformation.•The Weibull plot suggested that three different fracture mechanisms existed.•The WC segmentalization and shear stress determined the strength.•The non-segmented WC–Co elements can be used as a high strength mechanical component.

In this paper, the mechanical reliability of WC–Co cemented carbide nanowires (NWs) is described. By using focused ion beam (FIB) technique, the NWs are fabricated from the bulk. Specially-developed microelectromechanical systems (MEMS) based tensile testing device is used to directly measure the fracture strength. The volume and Co area fraction of the NWs are adopted to discuss the NWs’ size effect on the strength. The Weibull plot suggests that there are three different fracture mechanisms. From SEM observation results, it is found that WC–Co NWs have failed inside WC grain or Co binder under shear deformation mode. The applicability of WC–Co cemented carbide as mechanical components in MEMS is discussed.