Session Details

Session 12: Advances in Surface Finishing

Abstract Number:

103

New approaches may be required for surface finishing of additively ‎manufactured metal parts. New ‎methods to achieve this surface ‎finishing will be presented.‎

Topics:

Advances in Research
Advances in Surface Finishing Technology

Metal additive manufacturing (AM) is being pursued as ‎manufacturing technique in order to shorten development cycles ‎and reduce cost through rapid iteration and agile design. Metal AM ‎allows for designs that were not previously possible, optimizing the ‎balance between mechanical strength and weight. However, rough ‎as-built surfaces do not meet engineering specifications, with ‎roughness measurements between Sa = 5 – 60 mm. Furthermore, ‎depending on the build angle the surface roughness varies widely ‎within a single part. These rough surfaces result in different surface ‎morphology and chemistry compared to other manufacturing ‎methods which has a direct impact on the susceptibility to localized ‎corrosion and mechanical performance. This variation is also ‎amplified depending on the machine used to build the material. We ‎have extensively characterized the surface roughness, and corrosion ‎response of AM 316L stainless steel (SS) that has been built on ‎different machines which result in significantly different surface ‎properties.‎

Our team is also developing environmentally friendly surface ‎finishing techniques to reduce the surface roughness to meet ‎specifications, increase corrosion performance, and drastically ‎reduce the part-to-part variations. We have used optical methods to ‎measure the surface roughness of as-built AM 316L SS, A20x (AM ‎aluminum alloy), and Ti6-4. Aqueous and atmospheric corrosion ‎measurements have been performed on 316L SS. Finally, EDS/SEM ‎measurements reveal there is significant chemical segregation on the ‎surface of the as-built material; however, surface treatment methods ‎being developed by the group have been shown to remove this layer. ‎Post-processing surface treatments result in a more homogeneous ‎surface and improve the performance of the material. ‎

UNDERSTANDING METAL ADDITIVE MANUFACTURED SURFACES

Daniel Hooks

Scientist

Los Alamos National Laboratory