Since its creation, Additive Manufacturing (AM) has experienced a tremendous growth particularly over the last decade due to the industrial paradigm shift intended for improving conventional manufacturing procedures. This work is focused on an emerging AM process known as Wire-Arc Additive Manufacturing (WAAM) to assess its potential for further applications involving metallic costumer-oriented parts. Contrary to most AM processes, WAAM allows deposition of material layer-by-layer to be accomplished under high deposition rates, low production times and near 100% material efficiency using accessible equipment. The work stems from evaluating the economic viability in the production of parts by WAAM as an alternative for conventional processes such as those used in traditional subtractive approaches. For that purpose, a process-based cost model (PBCM) was developed for estimating production costs using a strong technological approach. The PBCM was tested with the production of a case study part by WAAM and its environmental impact was further assessed through life cycle assessment (LCA). Results show that WAAM can be economically and environmentally viable within specific industrial contexts. Moreover, further developments and optimizations of process variables and equipment will allow this technology to mature into tackling novel production challenges in a time and cost-effective manner.
26 July 2017 in Journal of the Brazilian Society of Mechanical Sciences and Engineering
Additive manufacturing technologies are becoming more popular, as they allow the fabrication of specific parts with complex geometries not achievable by conventional manufacturing. In metal additive manufacturing, one of the most widely used technologies is laser powder bed fusion. This work focuses on the influence of different processing parameters on the density of AISI 316L stainless parts obtained through this technology. The article presents a review of published works on the deposition of AISI 316L stainless steel using laser powder bed fusion to define an optimal range of parameters to produce parts with densities above 99%, complemented by density measurements for new sets of laser powder bed fusion processing parameters within the defined optimal range. The investigation provides a further insight on the effect of operating parameters such as vector size and gas atmosphere (Nitrogen and Argon) on the part density. The density measurements were performed using two techniques: micrograph analysis and Archimedes method. Results reveal that an increase in vector size has a negative influence on part density. With the Archimedes method, a maximum relative density of 99.87% was achieved using Nitrogen atmosphere, showing that it is possible to produce near fully dense parts by laser powder bed fusion without post-processing by laser re-melting.