Development of electrically conductive zirconia Part1: The optimal process parameters and mechanical properties

Abstract The Taguchi method was applied to analyze the optimum process parameters of a 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) containing 30 wt% titanium nitride (TiN) (3Y-TZP/TiN). Four process parameters—(1) sintering type, (2) crushing time of TiN powder, (3) the first-step sintering duration, and (4) the second-step sintering temperature were chosen as the controlling factors. Fracture toughness, flexural strength, hardness, relative density, and electric resistance were examined using an L 9 orthogonal array. The results indicated that the fracture toughness was mainly affected by the duration of the first sintering step. The highest fracture toughness (9.275 MPa m 1/2 ) was achieved at 97.3 vol% of the tetragonal phase in 3Y-TZP/TiN. In addition, 3Y-TZP/TiN possessing a high fracture toughness of 8.59 MPa m 1/2 and a flexural strength of 680.77 MPa was fabricated using the optimum process parameters, 8 h crushing time of TiN powder, and the two-step sintering process. The electric resistance for 3Y-TZP/TiN was 3.26×10 −3  Ω cm.