Metal additive manufacturing (AM) can revolutionize the production of metal components by reducing steps, scrap, lead time, and/or costs. This allows for optimized part design and improved properties such as shape and weight. Despite its advantages, AM also presents challenges such as strong surface textures, defects, and residual stresses that compromise mechanical strength and performance. Defects, including significant surface roughness and near-surface pores, hinder widespread adoption and require post-processing to remove defects. Due to the complexity of AM components, conventional methods such as grinding reach their limits. REM specializes in surface finishing solutions with advanced surface finishing technology, addressing these challenges and unlocking the full potential of additive manufacturing across industries.
NASA-AFRL-NCDMM
In a successful SBIR Phase I and II collaboration with NASA, REM developed a prototype machining cell and an optimized surface finishing (OFT) technique for AM components (specifically for rocket engine components) with maximum dimensions of ~30 x 30 x 24 inches. The developed technology is capable of significantly improving the as-built surface roughness of components by uniformly removing surface material and near-surface defects. Furthermore, the uniform material removal enables the use of OFT to reduce the wall thickness of AM components, thus overcoming the limitation of minimum wall thicknesses in printing technologies.
Following a successful demonstration of the developed technologies and processes, NASA expressed a need to process significantly larger DED-LB/p/metal rocket engine components. AFRL expressed a similar need related to newer PBF-LB machines with larger build volumes, capable of printing significantly larger components. By incorporating AFRL funding into a NASA Phase IIE project, REM was able to successfully meet the requirements of both programs.
As part of this program, REM developed an OFT and a tool that meets these scaling challenges while retaining all the proven features and benefits of the previously demonstrated technology. This scaled-up technology is capable of processing components up to approximately 60 inches in diameter and approximately 72 feet in length/height.
As a culmination of this program, REM successfully completed the machining of demonstration components for both NASA and AFRL, meeting or exceeding all targets for material removal, material removal uniformity, and surface roughness reduction.
The developed technology enables the printing of thicker walls, which can then be reduced to the final target dimensions using OFT, resulting in improved material properties and a better surface finish. Thus, REM’s OFT is helping to realize the many manufacturing and component benefits of AM for large-scale applications.
REM presented these results at the America Makes 2024 Spring Technology Review & Exchange (TRX), and aspects of this work were featured in Elementum 3D’s recent April 2024 Momentum Newsletter issue.
REM thanks NASA Marshall Space Flight Center (Paul Gradl), AFRL / National Center for Defense Manufacturing and Machining (NCDMM, Litsa Rubino), Elementum3D and RPMI for their time, effort and contribution to this success.
About REM Surface Engineering
REM Surface Engineering, inventor of the ISF® Process, the Rapid ISF® Process, the Extreme ISF® Process, and the REM® Process, is a global leader in surface engineering solutions. REM isotropic superfinishing technologies are value-added and performance-enhancing improvements over conventional machining operations such as grinding and lapping. Founded in 1965 by Robert Michaud in Southington, CT, REM Surface Engineering is a family-owned company that has been serving our partners and customers for over 55 years. REM Surface Engineering operates four locations in Brenham, Texas; Southington, Connecticut; Merrillville, Indiana; St. Neots, United Kingdom; and Krefeld, Germany, offering products and services worldwide.