Abstract: The addition of Ti O₂during the electroslag remelting (ESR) of Ti-containing superalloys can restrain the loss of Ti elements.The physical properties of the slag system are related to the smooth operation of smelting and the excellent quality of products.A five-membered slag system composed of Ca F₂-Al₂O₃-Ca O-MgO, and different contents of Ti O₂was designed for ESR of superalloys.The effects of Ti O₂content on the melting point, viscosity, density, optical alkalinity, electrical conductivity, and other physical parameters of the slag were studied.Resultsshow that the melting temperature range of the slag is 1264-1296℃.In addition, the melting point of the slag decreases gradually with the increase in Ti O₂content and the formation of a low-melting-point phase.The addition of Ti O₂can decrease the viscosity of the slag, and this viscosity in the high-temperature region (1350-1550℃) only slightly changes, thereby improving the surface-forming quality of the ESR ingot.The electrical conductivity, optical basicity, and density of the slag system decrease with the increasing Ti O₂content from 0%to 9%of the mass fraction.The density and optical alkalinity show no considerable changes, and the five groups of slag are in line with the ESR on the density and optical alkalinity requirements.