Recycling of titanium alloy powders and swarf through continuous extrusion (Conformtm ) into affordable wire for additive manufacturing

Abstract

Over the last 20 years, there has been growing research and development investment to exploit the benefits of wire deposition additive manufacturing (AM) for the production of near-net shape components in aircraft and space applications. The wire feedstock for these processes is a significant part of the overall process costs, especially for high-value materials such as alloyed titanium. Powders for powder-based AM have tight specifications regarding size and morphology, resulting in a significant amount of waste during the powder production. In the aerospace sector, up to 95% of forged billet can be machined away, and with increasing aircraft orders, stockpiles of such machining swarf are increasing. In this study, the continuous extrusion process—Conform™ —was employed to consolidate waste titanium alloy feedstocks in the forms of gas atomised powder and machining swarf into wire. Samples of wire were further cold-drawn down to 40% reduction, using conventional wiredrawing equipment. As close to 100% of the waste powder can be converted to wire by using the Conform™ process. This technology offers an attractive addition to the circular economy for manufacturers and, with further development, could be an important addition as industries move toward more sustainable supply chains.