Korean Journal of Materials Research ISSN:1225-0562(Print) 2287-7258(Online) 한국재료학회지

ZrO₂ is a candidate material for hip and knee joint replacements because of its excellent combination of biocompatibility, corrosion resistance and low density. However, the drawback of pure ZrO₂ is a low fracture toughness at room temperature. One of the most obvious tactics to cope with this problem is to fabricate a nanostructured composite material. Nanomaterials can be produced with improved mechanical properties(hardness and fracture toughness). The high-frequency induction heated sintering method takes advantage of simultaneously applying induced current and mechanical pressure during sintering. As a result, nanostructured materials can be achieved within very short time. In this study, W and ZrO₂ nanopowders are mechanochemically synthesized from WO₃ and Zr powders according to the reaction(WO₃ + 3/2 Zr→W+ 3/2 ZrO₂). The milled powders are then sintered using high-frequency induction heating within two minutes under the uniaxial pressure of 80MPa. The average fracture toughness and hardness of the nanostructured W-3/2 ZrO₂ composite sintered at 1300°C are 540 kg/mm² and 5 MPa·m^1/2, respectively. The fracture toughness of the composite is higher than that of monolithic ZrO₂. The phase and microstructure of the composite is also investigated by XRD and FE-SEM.