Strength of functionally designed cellular cemented carbides produced by coextrusion

In an effort to improve the wear characteristics of petroleum drill bit inserts, a series of cemented carbide materials with a functionally designed cellular (FDC) architecture were fabricated by a coextrusion process. The FDC architecture characterized in this study was comprised of cemented carbide cells surrounded by a ductile cobalt cell boundary. Property evaluation employed transverse rupture strength (TRS) testing to characterize their mechanical behavior. It was determined that the presence of Co2 + xW4 – xC in the material greatly affected the bonding of the cell to the cell boundary and therefore the strength of the material. Fractography of the FDC materials supported the hypothesis that the interface between the cell and cell boundary was affected by the Co2 + xW4 – xC phase and the consequential reduction in cobalt content of the cell.