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Metal powder characterisation
Metal powder characterisation for Additive Manufacturing: Beyond state-of-the-art standards The control of powder feedstock characteristics is essential in metal Additive Manufacturing in order to guarantee the quality of built parts and reduce production costs. However, powder behaviour is influenced by a large number of particle properties, along with environmental conditions which can modify these properties. In the following article, Granutools’ Dr Aurélien Neveu reviews some of the current standards applicable to powder feedstock characterisation, and highlights how to make such procedures more robust, repeatable and meaningful for end-users with regards to real AM powders and process conditions.
Much important work in defining standardised procedures for metal AM has been carried out over the last decade. In particular, recent technical specifications for powder feedstock characterisation have been published in ISO/ASTM 52907. The document provides technical recommendations on performing characterisation tests ranging from microscopic to macroscopic particle properties. The current state of the art in standards relies on well-established methods allowing manufacturers to independently evaluate either the intrinsic properties of the particles (e.g., particle size distribution (PSD), morphology, chemical composition) or the macroscopic manifestation of these properties (e.g., flowability, packing dynamics). Despite the fact that the information gathered from these methods relies on the same underlying mechanisms, the results obtained are strongly dependent on the measurement configuration and conditions. Moreover, the large number of methods described in ISO/ASTM 52907 prevents the standard from providing
Vol. 7 No. 3 © 2021 Inovar Communications Ltd
comprehensive and universally applicable procedures to Additive Manufacturing end-users. This situation highlights a need to identify the relevant parameters to be used in metal powder characterisation for Additive Manufacturing. More specifically, the link between powder properties
and their relation to the powder’s performance in the AM process is still lacking. Therefore, improvements to the current standards are required based on state-of-the-art characterisation methods and their recent outcomes. In the following article, we shed light on the importance of some key param-
Fig. 1 Granutools offers a range of instruments for powder testing and characterisation
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