Machining of titanium alloys using WC cutting tools: conventional vs. 3D printed Ti-6AI-4V

The advancement of material science ed to the introduction of 3D printing metals. One of these metals, titanium, is a material with the best weight to strength ration of any metal. As it is expensive to manufacture, 3D printing aims to create intricate components that would normally be uneconomically viable. 3D printing does not yet produce parts with a good quality surface finish, hence requiring machining to get the desired finish. With little information on how to machine the 3D printed material, the thesis sets out to investigate whether the machining parameters typically used for commercial grade are suitable for 3D printed titanium. The project involves lathe machining both commercial grade and SLM 3D printed Ti-6AI-4V and using different cutting tools at different machining parameters to find trends and the most optimal cutting procedure. Electron microscopes (SEM) and compositional analysis (EDS) is used to analyse the specimens to confirm if any diffusion or premature wearing of the carbide occurred. As 3D printed titanium is a much harder material than commercial grade, the coating failed and large built up edges formed on the cutting tools. No diffusion was found on the uncoated cutting tools; the coating on the cutting tool, titanium is the same as the machined metal' it is inconclusive whether diffusion occurred. 3D printing requires decades of innovation before it is at a standard where processing is no longer required. Until then machining will remain as a post processing method. Effective machining will introduce the widespread use of 3D printed specimens and minimise the downsides of such manufacturing methods.