Enhanced Productivity in Electron Beam-Based PowderBed Fusion : A Study of Thick Layers in Ti-6Al-4V for Implant Manufacturing

Sammanfattning

This thesis investigates the influence of increased layer thickness on the Electron Beam PowderBed Fusion processing of Ti-6Al-4V, with a focus on build productivity and the resulting material characteristics. Experimental builds were conducted on the Freemelt ONE system using several different layer thickness settings. For each build, the total process time was recorded and the resulting specimens were characterised in terms of surface quality, porosity, microstructure, and hardness. The results show that increasing layer thickness directly reduces the number of layers required and therefore shortens overall build time. This demonstrates a clear productivity gain, although the extent of this improvement depends on the specific geometry and process conditions. All manufactured specimens successfully completed the build without defects that would require interruption or part abandonment. Microstructural analysis revealed the expected α+β lamellar morphology characteristic of EB-PBF Ti-6Al-4V. Although grain sizes were not quantified, visual comparison indicates subtle differences between the layer-thickness conditions, particularly in lamella coarseness. Porosity measurements showed low overall pore content. Hardness testing produced values within the typical range for EB-PBF Ti-6Al-4V, with minor differences observed between samples. Overall, the study confirms that increased layer thickness can be used to enhance process productivity while maintaining material quality within acceptable limits. The findings provide practical insight into the balance between manufacturing efficiency and material performance and highlight the relevance of parameter optimisation for EB-PBF processing of Ti-6Al-4V.