Wettability of ZrO2-CaO and ZrO2-Y2O3 substrates with molten iron of low oxygen content

The Wettability of ZrO2-CaO and ZrO2-Y2O3 substrates with the molten iron of low oxygen content was examined at 1873 K by the use of the sessile drop method. The effect of substrate composition on wettability was made clear, that was, the contact angle was decreased once and increased afterwards with increasing CaO content on using the ZrO2-CaO substrates and low contact angles of about 115 deg were obtained for the ZrO2-Y2O3 substrates. Only minor amount of iron transferred from the molten iron into substrate particles and the grains of substrate grew at the rate of 2 mu m/h or less. Neither the transfer of iron nor the grain growth influenced the contact angle. From the work of adhesion it was presumed that the inter-molecular force was predominant at the molten iron-zirconia interface and the chemical interaction also would contribute to the interfacial bonding.