Microstructures and properties of in situ lamellar Al4SiC4 bonded SiC bricks: The effect of induction heating

Abstract SiC is extensively used in high-temperature industrial furnaces because of its excellent slag resistance. However, it suffers from poor sinterability due to strong covalent bond and low self-diffussion coefficient, which does harm to mechanical properties of SiC based materials. In this work, induction heating and addition of Al-Si alloy were used to improve the mechanical performance of phenolic resin bonded SiC bricks. The results showed that the addition of the Al-Si alloy to the phenolic resin bonded SiC bricks resulted in the formation of an in situ Al4SiC4 binder phase after heat treatment at 1700 °C for 2 h, which significantly improved the mechanical properties of the bricks. Furthermore, compared with ordinary heating, SiC bricks had more excellent properties after induction heating. Because the induced electric field can promote the wetting of the SiC aggregates by the Al-Si-C drops during induction heating, which caused the in situ Al4SiC4 binder phase besieged the SiC aggregates. Good mechanical properties were obtained owing to the generation of the new binder phase.