Characterisation of Ti6Al4V (ELI) Powder Used by the South African Collaborative Program in Additive

Abstract

The South African Additive Manufacturing Strategy recommends research and development towards “Qualified AM parts for medical and aerospace” as one of the national priorities. In response to this, the national Collaborative Program in Additive Manufacturing includes a sub-programme on “Qualification of Additive Manufacturing of Ti6Al4V for Medical Implants and Aerospace Parts”. This sub-programme entails comprehensive systematic research aimed at establishing a database of material and process data needed for qualification of the AM powders, AM processes and post-process treatments used for medical and aerospace applications. The paper describes the approach taken to characterise the Ti6Al4V (ELI) powder in the as received state and after exposure during repeated AM build cycles, by determining the physical and chemical properties of powder used in two selective laser melting (SLM) machines and a laser engineered net shaping (LENS) machine. Properties of the powder that were determined include the particle size, particle size distribution, morphology, oxygen and nitrogen gas content, and elemental composition. Characterisation techniques employed are Scanning Electron Microscopy, Laser Diffraction, Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), and Inert Gas Fusion. The results of the analyses on as-received powder and powder after exposure to numerous build cycles in the different AM machines are presented and discussed.