Characterization of sintered TiC-SiC composites

摘要

TiC-SiC composites were fabricated using TiC and SiC powders as starting materials at the range of 1650-2000 DEG C in Ar atmosphere by two-step method. In the first step, the ingots with intragranular SiC or TiC particle were prepared by arc-melting technique, subsequently, crushed and ground into TiC and SiC composite powders. In the second step, TiC-SiC composites were sintered using these as-prepared composite powders by SPS method. It was concluded that these TiC-SiC composites prepared by two-step method showed more excellent properties than that prepared by arc-melting technique. The hardness of the fabricated TiC-SiC composites was 25-27 GPa at the load of 0.98-9.8 N, which was obviously greater than that of arc-melting composites. The thermal conductivity of the TiC-SiC composites was 18-48 W K~(-1) m~(-1) at the range of 298-1273 K and slightly decreased with increasing temperature. The electrical conductivity of the composites was (2-5) X 10~5 S m~(-1)at the range of 298-1273 K and slightly decreased with increasing temperature.