Preparation and application of ZrB2-SiCw composite powder for corrosion resistance improvement in Al2O3–ZrO2–C slide plate materials

ZrB 2 -SiCw (w-whisker) composite powders were synthesized by a microwave-assisted carbo/borothermal reduction method under argon atmosphere using zircon , boric acid, and activated carbon as starting materials. The optimized ZrB 2 -SiCw composite powder was obtained by adjusting heating temperature and amounts of boric acid and activated carbon. Further, the effect of the optimized ZrB 2 -SiCw composite powder addition on corrosion resistance of the Al 2 O 3 –ZrO 2 –C slide plate material against O 2 and Ca-treated steel was investigated. The results showed that the relative content of ZrB 2 -SiCw increased with increasing temperature. The excess of boric acid favored the formation of the ZrB 2 -SiCw, and the optimum amount of boric acid was overdosed to 30–45 wt%. The corrosion resistance and thermo-mechanical properties of Al 2 O 3 –ZrO 2 –C slide plate material could be improved effectively with 6 wt% ZrB 2 -SiCw composite powder addition, which was attributed to the excellent oxidation and corrosion resistance of ZrB 2 -SiCw composite powder. In addition, ZrB 2 -SiCw could confer excellent thermal shock resistance and reduce the generation of cracks, ultimately preventing corrosive media from infiltrating into slide plates, further increasing corrosion resistance of the plates.