Manufacturing of Ti–6Al–4V Micro-Implantable Parts Using Hybrid Selective Laser Melting and Micro-Electrical Discharge Machining

Selective laser melting (SLM) is one of the additive manufacturing techniques in which a 3D product is built layer-by-layer. A hybrid micro fabrication technology combines both the design freedom of SLM and the high surface quality of Micro-Electrical Discharge Machining (μ-EDM). The aim was to manufacture high-quality micro implantable components with the highest density and the best surface quality. Statistical experimental design using analysis of variance technique was used to determine the significance of SLM process parameters on the amount of porosity and internal defects. Microstructure analysis using image processing was used to calculate the parts porosity. After SLM optimization, the samples were further processed using m-EDM to improve their surface quality. The effect on porosity formation is more considerable. Similarly, the influence of the hatching spacing is more significant at higher scan speeds. High density can be achieved using slow laser speed and small hatch spacing. This can consequently result in a material re-melting which eliminates powder/metal splashing and porosity formation.