Electrical properties and microstructural evolution of ZrO2–Al2O3–TiN nanocomposites prepared by spark plasma sintering

Abstract Electroconductive ZrO 2 –Al 2 O 3 –25 vol% TiN ceramic nanocomposites were prepared by spark plasma sintering at 1200 °C for 3 min. The electrical resistivity of the composites decreased from 4.5 × 10 −4 Ω m to 3 × 10 −5 Ω m as the Al 2 O 3 content in the ZrO 2 –Al 2 O 3 matrix increased from 0 to 100 vol%. SEM images graphically presented the microstructural evolution of the composites and a geometrical percolation model was applied to investigate the relationship between the electrical property and the microstructure. The results indicated that the addition of Al 2 O 3 to ZrO 2 –TiN improved the electrical conductivity of the material by tailoring the structure from “nano–nano” type for ZrO 2 –TiN to “micro–nano” type for ZrO 2 –Al 2 O 3 –TiN.