Research Progress on Preparation of Highly Homogeneous Cast Billets of Hard-to-deform Superalloys by Electron Beam Coating Solidification Technology
Deformed superalloys are widely used in the rotating components of the hot sections of aerospace engines and gas turbines,due to their excellent high-temperature strength,creep resistance service life,and good microstructural stability.In recent years,as the two major types of machines have evolved towards larger sizes,higher thrust-to-weight ratios,and greater bypass ratios,the performance requirements for materials used in hot section components have increased significantly.To meet these demands,the wrought superalloys have primarily developed along the trends of higher alloying,increased volume fraction of γ'phase,and higher carbon content.This has led to challenges during the preparation of these materials,including severe segregation,coarse microstructures,and difficulties in billet forming,which result in inferior mechanical properties and severely hinder the development of difficult-to-deform superalloys.To solve these issues,a novel preparation technology that is electron beam coating solidification technology is introduced.This technology not only enhances the purity and homogeneity of the alloy but also improves its thermoplasticity.In this paper,the practical applications of this technology will be introduced,aiming to offer new insights for the development of hard-to-deform superalloys.