Electrical and mechanical properties of ZrO2(2 mol% Y2O3)MoSi2 composites and their laminated materials

Well-densified composites with the compositions ZrO2(2Y)MoSi2 = 6040 and 8020 mol% have been fabricated by hot isostatic pressing for 2 h at 1400 °C and 196 MPa. Electric resistivities (ϱ) of the two composites are very different; the former and latter composites correspond to metallic and insulating materials, respectively. The properties are strongly dependent on the textures. Laminated materials with the compositions ZrO2(2Y)MoSi2 = (6040)/(8020)/(6040) mol% have been prepared by the same technique. Overall electric resistivities in directions perpendicular and parallel to the interfaces have been determined to be ϱ⊥ ≈ 1 × 1011 Ω · cm and ϱ∥≈ 1 × 10−4 Ω · cm, respectively. Residual stress as much as ≈150 MPa is induced in the interfaces. The fracture toughness (KIc) is greatly affected by the residual stress.