Wet Processing and Low‐Temperature Pressureless Sintering of SiC Using a Novel Al 3 BC 3 Sintering Additive

Highly concentrated slurry preparation and low‐temperature pressureless sintering of SiC using a novel Al 3 BC 3 additive were investigated. Al+B 4 C+C powder mixture, which is a conventional sintering additive system of SiC, could not be dispersed in ethyl alcohol above 10 vol%. In contrast, Al 3 BC 3 slurry (average particle size: 0.5 μm) could be prepared up to 50 vol% solid loading and SiC slurry containing 10 wt% Al 3 BC 3 was successfully fabricated up to 45 vol%. The relative density of SiC was 97.9% after pressureless sintering at 1850°C. Young's modulus and hardness of a sintered SiC were 411 and 22.5 GPa, respectively. The present report proposes a method for the low‐temperature pressureless sintering of SiC specimens having complex shape and fair mechanical properties by the application of a ternary compound (Al 3 BC 3 ) as a novel‐sintering additive.