Influence of additive on high temperature performance of glaze

Using SiO2 - Al2O3 - B2O3 - K2O - Na2O system glaze as base material, adding silicon powder or alumina powder with grain size 15 mu m by the mass percent of 10%, 20%, 30%, respectively, melting properties of glaze were investigated. Slilica solution as binder, the anti-oxidation coating were prepared. Oxidation resistance was determined by coating to the surface of the Al2O3-C specimens. The results show that additives can raise flow temperature prominently, but has little influence on softening point and semi-sphere point; Glazing temperature ranges are obtained with different additive contents; Glazing temperature rises with addition of silicon; Glazing temperature range widens with silicon adding; Glazing temperature ranges were not strictly corresponding with softening temperature point and flow temperature point; But differences were not tremendous; glazing temperature ranges can be estimated from softening temperature point and flow temperature point. Alumina has not prominent influence on glazing temperature, but glaze forms smoothly with alumina, and oxidation resistance was good.