Factors influencing powder-properties of TiAl6V4 along the L-PBF process chain

Abstract

In the laser-based powder bed fusion process (L-PBF), the used powder is exposed to a multitude of mechanical and atmospheric parameters along the entire process chain, beginning with the production of the powder, over transportation, storage and processing and ending with the recycling of the material. The chemical composition and shape of individual powder particles, for example, as well as the characteristic properties of the entire powdered material change depending on the duration and intensity of the effects of, among other things, the atmosphere, temperature, humidity and external forces. Once the influencing variables and their effects are known, the changes in the powder can be counteracted in a targeted manner. In this way, it is possible to restore or maintain the powder properties relevant to the L-PBF process, making the overall process more robust and reliable. This paper discusses the results of investigations on significant influencing factors that cause a change in the powder material during L-PBF, representing the cost-intensive titanium alloy Ti-6Al-4V. The results can be used to derive powder handling and management recommendations that can ensure powder quality throughout the service life.