Effect of the hatching strategies on mechanical properties and microstructure of SEBM manufactured Ti-6Al-4V specimens

Powder Bed Additive Manufacturing is a relatively novel 3D-printing method of fabrication metallic components predominantly working with pre-alloyed powders. Laser or electron beam melt the powder in each layer according to the cross-section of the printed model. The combination of freedom of design and high mechanical properties of resulting material make PB-AM popular for different industrial applications including biomedical implants and aerospace part production. Titanium alloys and especially Ti-6Al-4V are among the most popular materials for additive manufacturing. It is mainly due to its high strength to weight ratio, biocompatibility, and high fatigue and corrosion resistance. Selective electron beam melting is already well-known effective additive manufacturing technology for wide range of applications. The high mechanical properties are provided due to vacuum environment of the process and specific temperature conditions. The final microstructure and required properties could be controlled by the adjustment of internal process parameters such as beam power (BP), beam scan rate (BR), hatching distance (HD) — distance between beam traces, and layer thickness (LT). In the current research the hatching strategy for SEBM manufacturing of Ti-6Al-4V was optimized and its influence on the mechanical properties and microstructure of the resulting components was analyzed. It was found that optimized HD with additional proper placement of components on the start platform can help to shorten the lead time without compromising the mechanical properties.