Effect analysis of metakaolin on high-temperature strength of zircon non-stick coating for dressing of casting mould

Non-stick coating based on complex filler (zircon and metakaolin) is studied. The mechanism for increasing of the strength of this coating is implemented at the expense of metakaolin, since during the synthesis of mullite, reinforcing frame is formed in the form of filamentous crystals, which gives the coating increased strength at high temperatures. The effect on the of mullite synthesis the main temperature-kinetic factors is established by the method of complete three-factor experiment. Regression equation is obtained, which allow to identify the dependence of the coating high-temperature strength on the established factors (temperature, metacaolin content, heat time). The necessary and sufficient concentration of metakaolin (18...22 %) is confirmed, which ensures the formation of the mullite phase in the temperature range of 1000...1500 °C, which to increase in the cohesive and adhesive strength of the coating during the interaction of the melt and the mould.