| Abstract Scope |
PWA1480 is a Ni SX superalloy with exceptionally high-temperature strength, creep resistance, and microstructural stability. However, Additive Manufacturing (AM) of PWA1480 is challenging due to its high γ′ phase content (~65 vol%), which increases susceptibility to solidification cracking and results in elevated interdendritic porosity. In this study, process development of state-of-the-art Selective Laser Epitaxy (SLE) process tailored for epitaxial deposition of PWA 1480 onto SX substrates is reported. The process incorporates substrate induction heating and a high-purity, controlled argon atmosphere to mitigate thermal gradients and oxidation, promoting defect-free deposition. Comprehensive analyses were conducted to assess porosity, chemical composition, crystallographic orientation, and microstructural features. Our results demonstrate fully dense, high-quality single-crystal grains exceeding 500μm in size, with crack-free and porosity-free substrate-deposit interfaces. The influence of key process parameters on microstructure and crystallographic alignment was investigated. This work provides critical insights for advancing the AM of next-generation turbine components with this alloy. |