Rapid L-PBF Printing of IN718 Coupled with HIP-Quench: A Faster Approach to Combine Manufacturing and Heat Treatment in a Nickel-Based Alloy

Abstract

Additive manufacturing has been attracting more and more interest in recent years. Researchers are constantly involved in enhancing component quality by tailoring the printing parameters, increasing the lead time and decreasing overall productivity. Rapid L-PBF printing is becoming an appealing strategy to make the components manufacturing faster. However, a rapid building strategy will likely cause a higher density of internal flaws that will be healed during the Hot Isostatic Pressing (HIP) cycle. In this work, Inconel 718 was L-PBF printed with two different strategies: The first consisted in creating a dense 1mm shell leaving loosened powders in the core; the latter used two sets of printing parameters for the 1mm shell and the core, respectively. The two strategies lead to 60 and 45% time reduction, respectively. Secondly, full densification and porosity elimination were achieved using a HIP-quench approach, which combines a fast-cooling step at the end of the HIP cycle, eliminating the need for a further annealing treatment. This work shows the results presenting the final microstructures and the retained flaw. Finally, the microstructural degree of recrystallization was also assessed via EBSD analysis.