Title of article :
Densification and Mechanical Properties of Electroconductive Si3N4 -Based Composites Prepared by Spark Plasma Sintering
Author/Authors :
AHMAD, NORHAYATI Universiti Teknologi Malaysia - Faculty of Mechanical Engineering - Department of Materials Engineering, Malaysia , SUEYOSHI, HIDEKAZU Kagoshima University - Graduate School of Science and Engineering - Department of Nano-structure and Advanced Materials, Japan
Abstract :
conventional powder processing (SPS1) and in-situ reaction sintering (SPS2). Rapid densification of SPS was achieved for sample SPS1 and SPS2 within a few minutes at low temperature. Sample SPS1 sintered at 1550°C showed rapid transformation of α to β Si3N4 while for sample SPS2 sintered at 1350°C, a significant degree of α to β Si3N4 transformation was achieved. Homogeneous distribution of equiaxed TiN grains in matrix Si3N4 resulting in high hardness (21.7 GPa) and bending strength (621 MPa) for sample SPS1 sintered at 1550oC. Elongated TiN grains as the reinforcement of Si3N4 matrix composites was found to increase the toughness (8.39 MPa m1/2) of sample SPS2 sintered at 1350°C. The composites prepared by SPS2 sintered at 1250-1350°C had low electrical resistivity and could be machined by electrical discharge machining (EDM).
Keywords :
Densification , mechanical properties , silicon nitride , titanium nitride composites , spark plasma sintering
