A Comparative Study on SiC-B4C-Si Cermet Prepared by Pressureless Sintering and Spark Plasma Sintering Methods

Silicon carbide (SiC)–boron carbide (B 4 C) based cermets were doped with 5, 10, and 20 wt pct Silicon (Si) and their sinterability and properties were investigated for conventional sintering at 2223 K (1950 °C) and spark plasma sintering (SPS) at 1623 K (1350 °C). An average particle size of ~3 µ m was obtained after 10 hours of milling. There is an enhancement of Vickers microhardness in the 10 wt pct Si sample from 18.10 in conventional sintering to 27.80 GPa for SPS. The relative density, microhardness, and indentation fracture toughness of the composition SiC 60 (B 4 C) 30 Si 10 fabricated by SPS are 98 pct, 27.80 GPa, and 3.8 MPa m 1/2 , respectively. The novelty of the present study is to tailor the wettability and ductility of the cermet by addition of Si into the SiC-B 4 C matrix. Better densification with improved properties is achieved for cermets consolidated by SPS at lower temperatures than conventional sintering.