Enhanced performance of Al2O3-SiC-C castables via in-situ formation of multi-reinforced phases by introducing surface treated composite metal powders

摘要

Al2O3-SiC-C (ASC) castables were prepared with bauxite and silicon carbide as major raw materials and introducing large amount of surface treated composite metal powders (STCMPs) as antioxidant. Their compre-hensive properties were greatly improved attributed to the in situ formation of multi-reinforced phases including carbide silicon whiskers and mullite fibers in the matrix. Compared with the corresponding samples without STCMPs, the high temperature modulus of rupture of those with 6 wt% STCMPs calcined in air increased by 47.3% and with 8 wt% STCMPs calcined in reducing atmosphere increased by 220%. The retained CMOR ratio of the sample with 6 wt% STCMPs calcined in reducing atmosphere was high up to 50% after 5 cycles thermal shocks. Moreover, the oxidation index and slag erosion index of samples with 6 wt% STCMPs were decreased by 45% and 74%. This work provides a new perspective for the preparation of ASC castables with excellent high -temperature performance.

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