Preparation process of tungsten carbide porous ceramic by gel-casting

Porous tungsten carbide (WC) ceramics were prepared by a gel-casting method, then it was sintered at 1500 for 2 h to get porous WC ceramic. The results show that the maximum solid loading in WC slurry dispersed with polyethyleneimine (PEI) is 45% (in volume fraction). The WC slurry with the minimum viscosity can be obtained under the optimal condition (i.e., pH value of 9.5 and the dispersant content of 0.2% (in mass fraction)). According to the results by mercury-injection test, the pore size distribution of the ceramics presents a unimodal model. The porosity of WC porous ceramics decreases from 61.8% (in volume fraction) to 56.3% when the solid loading of WC slurry increases from 25% to 45%. The flexural strength of WC porous ceramics is 20 to 40 MPa. This ceramic can be used for machining and the subsequent pressureless reactive melt infiltration.