Optimizing surface quality of additively manufactured Inconel 718 with cryogenic polishing

Abstract This project investigates the effect of cryogenic polishing on the surface quality of additively manufactured Inconel 718, focusing on its application in the aerospace industry. The research aims to optimize the finishing process through the use of abrasive brushes combined with cryogenic cooling, reducing tool wear and enhancing efficiency. A series of experiments were conducted using a radial abrasive brush with ceramic materials on Inconel 718 plates, processed on a horizontal multitasking machine. Cryogenic assistance was provided via a BeCold® refrigeration system using a jet stream to maintain temperatures ≤ 20 °C, while dry brushing, was also tested for comparison reaching approximate temperatures of 60 °C. Results show that both processes significantly reduce surface roughness, with dry brushing achieving a maximum reduction of 74% and cryogenic polishing achieving up to 77%. Additionally, cryogenic conditions demonstrated better control of thermal expansion, maintaining dimensional tolerances (± 0.02 mm), crucial for high-precision applications in the aerospace sector. These findings highlight the potential of cryogenic polishing to improve surface finish and dimensional accuracy in the manufacturing of Inconel 718 components.