Enhancing surface finish of additively manufactured titanium and cobalt chrome elements using laser based finishing

Gora, Wojciech S. and Tian, Yingtao and Cabo, Aldara Pan and Ardron, Marcus and Maier, Robert R. J. and Prangnell, Philip and Weston, Nicholas J. and Hand, Duncan P. (2016) Enhancing surface finish of additively manufactured titanium and cobalt chrome elements using laser based finishing. Physics Procedia, 83. pp. 258-263. ISSN 1875-3892

Abstract

Additive manufacturing (AM) offers the possibility of creating a complex free form object as a single element, which is not possible using traditional mechanical machining. Unfortunately the typically rough surface finish of additively manufactured parts is unsuitable for many applications. As a result AM parts must be post-processed; typically mechanically machined and/or and polished using either chemical or mechanical techniques (both of which have their limitations). Laser based polishing is based on remelting of a very thin surface layer and it offers potential as a highly repeatable, higher speed process capable of selective area polishing, and without any waste problems (no abrasives or liquids). In this paper an in-depth investigation of CW laser polishing of titanium and cobalt chrome AM elements is presented. The impact of different scanning strategies, laser parameters and initial surface condition on the achieved surface finish is evaluated.