Development of Directional Solidification for High-Temperature and Intermetallic Alloy Castings (Review)

The improvement of the technology of casting turbine blade castings with a directional and single-crystal structure, casting equipment, and the methods to improve the quality of castings are reviewed. The technology of directional solidification is shown to ensure the production of turbine blades from new nickel superalloys with high performance properties, which meet the requirements imposed on the parts of modern gas turbine engines. The requirements for the structure of turbine blades made of carbon-free alloys, unlike carbon-containing single-crystal alloys, and for acceptable deviations from a specified crystallographic orientation (CGO) of the blades are considered. The trends in the appearance of characteristic defects in the single-crystal structure of the blades are studied. The evolution of domestic and foreign melting and casting equipment for directional solidification is presented, and the conditions for the formation of a single-crystal fine structure of high-temperature alloys in the thin sections of blades with a new penetrating cooling method are discussed.