cBN–TiC and WC–Co Composites: Optimization of Co‐Extruding Conditions

In this study, double-layer tubes with inner-layer cubic boron nitride–titanium carbide (cBN–TiC) and outer-layer tungsten carbide–cobalt (WC–Co) were fabricated by co-extrusion. The Taguchi method was used to determine the optimal parameters, including extrusion ratio, half-die angle, extrusion speed, and binder amount. The double-layer tube made using these optimal parameters had an inner-layer hardness of 3825 Hv and an outer-layer hardness of 1849 Hv. The porosity of the double-layer tube was 10.4%. Furthermore, the crystalline structures obtained from the inner and outer layers were cBN, TiC, TiB2, and BNi and WC and Co2C phases.