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 (R-a much greater than 1.0 mum) 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 LIP to a 37% of the original R-a value ranged between similar to250 and 580 J cm(-2). Several surface melting regimes are identified and analysed. The impact of oxidation on surface finish is discussed.