A Novel Approach For Preparing Electrically Conductive SiAlON-TiN Composites by Spark Plasma Sintering

An effective approach for preparing electrically conductive SiAlON-TiN composites was developed. Granules of a designed composition of alpha-beta SiAlON was obtained by spray drying and coated with varying amounts of TiO(2) powder homogenously by mechanical mixing. Fully dense composites were obtained by spark plasma sintering (SPS) under a pressure of 50 MPa at 1650 degrees C for 5min. According to the SEM analysis, unique microstructures containing continuously segregated in-situ formed TiN phase in 3-D were achieved. Additionally, XRD studies revealed that all TiO(2) was successfully converted to TiN. The resistivity of the alpha-beta SiAlON (1x10(11) Omega.m) was drastically reduced with the addition of only 5 vol. % TiO(2) (2x10(-4) Omega.m).