Rapid L-PBF printing of IN718 coupled with HIP-quench: A novel approach to manufacture and heat treatment of a nickel-based alloy

Abstract

There has been a growing interest in additive manufacturing in recent years, with researchers actively working on improving component quality through adjustments to printing parameters, lead time, and productivity. Rapid L-PBF printing has emerged as an attractive approach to expedite component manufacturing. However, employing a rapid building strategy may lead to additional internal flaws, which can be addressed during a Hot Isostatic Pressing (HIP) cycle. In this study, Inconel 718 was L-PBF printed using two distinct strategies: one involving the creation of a dense 1 mm shell with loosely packed powders in the core and the other utilizing different sets of printing parameters for the shell and core, respectively. These strategies resulted in a 60% and 45% printing time reduction, respectively, compared with the time requirement for printing same-size cubic samples with optimized parameters. Additionally, full densification and porosity elimination were achieved through a HIP-quench approach, obviating the need for further heat treatment. The study presents the final microstructures and retained flaws, along with assessing the degree of recrystallization via EBSD analysis and evaluating mechanical properties using hardness measurements and compression tests.