Development of ZrO 2–WC composites by pulsed electric current sintering (original) (raw)

ZrO 2 -WC ceramic composites with 40 vol% WC were consolidated by pulsed electric current sintering (PECS) for 4 min at 1450 • C under a pressure of 60 MPa. The effect of ZrO 2 stabilizers and the source of WC powder on the densification, phase constitution, microstructure and mechanical properties of the ZrO 2 -WC composites were investigated and analyzed. The experimental results revealed that the amount and type of ZrO 2 stabilizers played a primary role on the phase constitution and mechanical properties of the composites in comparison to the morphology and size of the WC powder. The 2 mol% Y 2 O 3 -stabilized composites exhibited much better mechanical properties than that of 1.75 mol% Y 2 O 3 -stabilized or 1 mol% Y 2 O 3 + 6 or 8 mol% CeO 2 co-stabilized composites. A Vickers hardness of 16.2 GPa, fracture toughness of 6.9 MPa m 1/2 , and flexural strength of 1982 MPa were obtained for the composites PECS from a mixture of nanometer sized WC and 2 mol% Y 2 O 3 -stabilized ZrO 2 powder.