An investigation into the effect of a recycling regime upon ELI Ti6Al4V (Grade 23) powder used within the selective laser melting (SLM) process

Ryan Harkin

Abstract

 Selective laser melting (SLM) provides the opportunity to design and manufacture components with high levels of geometric complexity, via the layer on layer build approach associated. A major advantage related to this additive manu­facturing (AM) process, is the ability to recycle and reuse any exposed, unused powder during manufacturing. Improving the cost-effectiveness of the process. However, research sug­gests that throughout a recycle regime the powder character­istics can change. As a result, impacting upon the mechanical properties of the as-built components produced. This study will track ELI Ti6Al4V (Grade 23) powder across 8 recycles, analyzing the powder after each recycle phase. Providing a comprehensive analysis of the powder characteristics during recycling, to determine any indication of powder variation. Characterization will include chemical composition, sizing, bulk morphology and density analysis. Results show that there is a significant increase of Oxygen content (wt%). In addition, narrowing of the particle size distribution (PSD) is evident.