Characterisation of flow behaviour of metal powders for 3D printing application

A reliable quantification of bulk flow behaviour of particles is of paramount importance in powder processing. A good example is the use of appropriate metal powders and consistency of particles flow in high value additive manufacturing process which leads to significant effects on the quality of the final products. For this process, the interest is to investigate a “reliable” flow behaviour of loosely compacted powders. To achieve this aim, it is important to follow a method to measure the powder flowability at very low stresses (10-100 Pa) and applicable to the conditions of aforementioned process, as common techniques can reliably provide powder flow characteristics only for the consolidation stresses of above 1KPa. Ball indentation technique provides a measure of hardness which can be related to flow resistance and flowability for loosely compacted powders. However, the challenge of this technique is to attain a reliable indentation process and measurement. To overcome of this limitation in-situ x-ray microtomography would be a non-destructive and quick technique which is reveal internal properties of samples during consolidationindentation and provide accurate data of whole process.