Abstract

Coke dry quenching（CDQ）is an advanced technology because of the advantages of saving energy and environmentally friendly, but the damage of CDQ furnace ramp pillar seriously affected the safe operation and production efficiency in the CDQ. Therefore, the development of a durable refractory for CDQ furnace ramp pillar is of great significance. The CDQ furnace ramp pillar need withstand great bending stress and thermal stress, but the strength and thermal shock resistance of current mullite-silicon carbide material is poor. In this paper, the toughening effect of the in-situ generated AlN whiskers on mullite-SiC materials were studied and examined. The results show adding the metal aluminum powder into the mullite-SiC materials, the strength and thermal shock resistance of materials increase obviously, especially at the amount of 6wt%. The hexagonal AlN phase formed in materials added with metal aluminium after nitriding at 850℃, and the in-situ AlN whiskers with a length of 2mm~10mm, a diameter of 5nm~100nm generated after nitriding at 1000℃. A network structure of AlN whiskers formed in the matrix material, improved the tougheness through whiskers pull out and whiskers federation. The flexural strength of the sample at 1000℃ was improved from 9.6MPa to 39.6MPa. Reducing the particle size of metal aluminium powder can promote the generating of AlN whiskers.