Corrosion of Al-Li alloy melt on oxide refractories

Abstract

Purpose When smelting Al-Li alloy, the material inevitably comes into contact with various oxide-refractories. These refractories are subjected to varying degrees of melt-corrosion at high temperatures. The purpose of this study is to find stable oxide refractories at casting temperature. Design/methodology/approach Four materials were selected for evaluation, and their corrosion by the Al-Li alloy at casting temperature and different holding times was measured. Subsequently, scanning electron microscopy and energy-dispersive spectroscopy were used to study the interfaces. Stable refractory materials were selected by comparing the thicknesses of the reaction layers. Findings The thickness of the Al-Li/ZrO2 reaction layer varies linearly with the square root of the holding duration. Therefore, the growth of the reaction layer is controlled by diffusion. The reaction layer of Al-Li/Al2O3 is thinner, and its growth is also controlled by diffusion. However, there were no obvious reaction layers between the Al-Li alloy and MgO or Y2O3. By comparing these reaction-layer thicknesses, the order of stability was found to be ZrO2 < Al2O3 < MgO and Y2O3. Originality/value These results provide a scientific basis for the optimal selection of refractory materials for Al-Li alloy smelting.