Spark plasma sintered Al2O3-YSZ-TiO2 composites: Processing, characterization and in vivo evaluation

Al2O3 and Al2O3-YSZ composites containing 3 and 5 wt.% TiO2 were prepared by spark plasma sintering at temperatures of 1350-1400 degrees C for 300 s under a pressure of 40 MPa. The grain growth of alumina was suppressed by the addition of YSZ. Al2O3-YSZ composites showed higher hardness than monolithic Al2O3. There was not a considerable difference in hardness values for Al2O3-YSZ composites containing 10 and 20 vol.% YSZ and the addition of TiO2 decreased the hardness of the composites. The fracture toughness of Al2O3 increased from 2.8 MPa.m(1/2) to 4.3 MPa.m(1/2) with the addition of 10 vol.% YSZ, further addition resulted in higher fracture toughness values. The fracture toughness values were increased with TiO2 addition and the highest value of fracture toughness, 53 MPa.m(1/2), was achieved with the addition of 20 vol.% YSZ and 5 wt.% TiO2. Preliminary in vivo tests demonstrated the biocompatibility and osseointegration of the composites after 6 week postimplantation in femur of Wistar rats. (C) 2014 Elsevier B.V. All rights reserved.