Additive Layer Manufacturing: Comparison of Ti-6Al-4V Components Fabricated by Laser Beam and Tungsten Inert Gas Welding

Additive Layer Manufacturing (ALM) technologies gain increasing interest for manufacturing and repair in the aerospace industry due to their potential to reduce costs and the ecological impact. Laser or electron beam systems based on selective sintering of powder beds are already commercially applied, but are rather limited in the component size. Systems manufacturing the components layer by layer by melting a wire allow the fabrication of much larger components as typically necessary in the aerospace. In the present paper two different wire based systems will be compared: in one system the Ti-6Al-4V wire is melted by a laser beam, in the other by a tungsten inert gas welding torch (arc beam). The different fabrication set-ups and the obtained component morphologies and microstructures will be described. Mechanical properties such as strength, ductility, stiffness, hardness and high cycle fatigue will be presented at different load-directions and post heat treatments. Material fabricated by laser beam typically shows higher static tensile and fatigue strength while fabricated by arc beam shows higher ductility. Both materials show higher strength and lower ductility parallel than perpendicular to the deposition plain. Ageing at 600°C for 4h is suitable to increase strength and annealing at 843°C for 2 h is suitable to increase ductility of both materials.