Optimization of processing conditions and characterization investigations of ceramic injection molded and sintered ZrO2/WC composites

In this investigation, 3 mol% Y2O3 stabilized ZrO2-based composites reinforced with 10 vol.%, 20 vol.% and 40 vol.% WC (named as 3Y-TZP/10WC, 3Y-TZP/20WC and 3Y-TZP/40WC) were fabricated by using injection molding and sintering. Mechanical properties of these composites varied due to WC addition and dwelling time. Density, strength and toughness decreased with shorter dwelling time and increasing WC content however a significant enhancement in fracture toughness was obtained by 3Y-TZP/20WC composite which had 9.2 MPa m1/2 toughness. Severe unlubricated wear tests which were performed under 55 N normal load and 45 km sliding distance showed that 3Y-TZP/20WC composite had the lowest wear rate and wear volume values which are 2 × 10−8 mm3/(N m−1) and 0.05 mm3, respectively.

Research highlights
► Significant enhancement in fracture toughness was obtained by 20 vol.% WC dispersed 3 mol% yttria stabilized zirconia composite (3Y-TZP/20WC) which had 9.2 MPa m1/2 toughness. Severe unlubricated wear tests which were performed under 55 N normal load and 45 km sliding distance showed that 3YTZP/20WC composite had the lowest wear rate and wear volume values which are 2 × 10−8 mm3/(N m−1) and 0.05 mm3, respectively. Results indicated that pressureless sintering following to ceramic injection molding is a promising production route to manufacture wear resistant and tough WC refractory carbide dispersed zirconia matrix composites. Significant advantages of this technique would be bulk production availability, part complexity and lower production costs.