LASER MACROPOLISHING OF ADDITIVELY MANUFACTURED PARTS OF MARAGING STEEL WITH RESPECT TO SURFACE PROPERTIES

This article is focused on the laser macro polishing of additively manufactured (AM) parts. The material that is being processed is maraging steel (MS1). The main part of the study is to find suitable parameters to significantly reduce the surface roughness of 3 surfaces with completely different topologies. The investigated parameters are scanning speed, defocussed laser and laser power. However, other material properties are also tested. Fatigue life, tensile and hardness testing were carried out for 3 different sets of laser macro polishing parameters. It was found that surface roughness reduction of Ra by over 90 % is possible. Interestingly, tensile testing of parameters 1 and 2 showed more brittle-like behaviour in comparison to parameter 3. This was further supported by hardness testing, which showed increased hardness in the centre of the samples.