Energy-Assisted additive manufacturing for weldable and non-weldable Ni-based superalloys: a review

Abstract

Additive manufacturing (AM) of Ni-based superalloys has garnered significant attention for fabricating complex, high-performance components in aerospace, gas turbines, and other demanding applications, owing to its ability to achieve intricate geometries with excellent high-temperature strength and corrosion resistance. However, the process and material characteristics of AM for Ni-based superalloys introduce challenges that hinder industrial adoption. Recent studies have demonstrated that supplying additional energy beyond the heat required to melt the feedstock can address these challenges. This review systematically examines the effects of mechanical and thermal energy on AM deposits of Ni-based superalloys. Given the distinct material characteristics of weldable and non-weldable Ni-based superalloys, mechanical and thermal energy influence these classes of superalloys differently during AM. Therefore, various methods for applying mechanical and thermal energy, either individually or simultaneously, are comprehensively analyzed, along with their effects on weldable and non-weldable Ni-based superalloys. The effects of the energy applied through each method on weldable and non-weldable alloys are systematically summarised in terms of the internal defects, microstructures, and mechanical properties.