Reducing surface roughness of metallic freeform-fabricated parts using non-tactile finishing methods

Metallic parts created using current freeform fabrication processes have an unacceptably high surface finish (Ra » 1:0 mm) for many functional applications. This paper addresses the use of non-tactile laser polishing for surface finishing of commercial selective laser sintered iron±copper parts. A laser polishing window of energy density for roughness reduction up to a 37% of the original Ra value ranged between ~250 and 580 J cm-2. Several surface melting regimes are identified and analysed. The impact of oxidation on surface finish is discussed.