Comparative Investigation of the Undercooling Capacity and Single-Crystal Castability of Some Ni-Based Superalloys

The undercooling capacity of a superalloy is an essential physical property to determine its single-crystal (SC) castability, because stray grains (SGs) will be formed if the geometrical established at platform extremities exceeds applied alloy. In present work, both eight Ni-based superalloys and their SC castability were experimentally investigated. liquidus temperature, critical temperature for grain nucleation, hence capacities investigated alloys evaluated based on evolution during heating cooling processes. current experimental study revealed significant difference in superalloys. production blade castings, tendency form SG defects was found highly related alloy’s capacity. having low around 10 K very prone formation SGs. comparison, with moderate from 20 30 could easily cast into blades without SGs, exhibiting best castability. Other factors influencing also analyzed. As result, criterion geometry-related proposed, which influence alloy capacity, casting geometry, solidification condition are involved.