Modelling and optimization of laser polishing of additive laser manufacturing surfaces

Purpose - Direct metal deposition (DMD) with laser is an additive manufacturing process enabling rapid manufacturing of complex metallic and thin parts. However, the final quality of DMD-manufactured surfaces is a real issue that would require a polishing operation. Polishing processes are usually based on abrasive or chemical techniques. These conventional processes are composed by many drawbacks such as accessibility of complex shapes, environmental impacts, high time consumption and cost, health risks for operators, etc. [...] This paper aims to solve these problems and improve surface quality by investigating the laser polishing (LP) process. Design/methodology/approach - Based on melting material by laser, the LP process enables the smoothing of initial topography. However, the DMD process and the LP processes are based on laser technology. In this context, the laser DMD process is used directly on the same machine for the polishing operation. Currently, few studies focus on LP of additive laser manufacturing surfaces, and it tends to limit the industrial use of additive manufacturing technology. The proposed study describes an experimental analysis of LP surfaces obtained by DMD process. Findings - The investigation results in the improvement of a complete final surface quality, according to LP parameters. For mastering LP processes, operating parameters are modelled. Originality/value - This experimental study introduces the LP of thin and complex DMD parts, to develop LP applications. The final objective is to create a LP methodology for optimizing the final topography and productivity time according to parts' characteristics.