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

Electroconductive ZrO2-Al2O3-25 vol% TiN ceramic nanocomposites were prepared by spark plasma sintering at 1200 degrees C for 3 min. The electrical resistivity of the composites decreased from 4.5 x 10(-4) Omega m to 3 x 10(-5) Omega m as the Al2O3 content in the ZrO2-Al2O3 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 Al2O3 to ZrO2-TiN improved the electrical conductivity of the material by tailoring the structure from nano-nano type for ZrO2-TiN to micro-nano type for ZrO2-Al2O3-TiN. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.