Most metal powders for additive manufacturing (AM) are produced by either gas or plasma atomisation methods. Plasma atomisation processes are more expensive but produce particles of highly regular morphology, particles with a smoothness and sphericity that typically surpass levels achievable with gas atomisation.
This raises the question – do I need a plasma atomised powder? Will superior morphology deliver tangible benefit that justifies paying a premium or can a suitable gas atomised powder be equally fit for purpose?
When it comes to powder manufacture, gas atomised powders can exhibit considerable variability with respect to morphology, depending on the process specifics and the degree of optimisation. Therefore, manufacturers also need to quantify the value of superior particle morphology, to understand what is attainable in terms of product differentiation. With appropriate optimisation, how effectively can gas atomised products compete with plasma atomised alternatives?
Differences in morphology are easy to see and quantify, using techniques such as scanning electron microscopy and image analysis, but the results don’t directly elucidate in-process performance. Measuring bulk powder properties such as powder flowability brings complementary insight, helping to quantify the impact of morphology in a process relevant way, as these example studies demonstrate.
This article reviews a study carried out by Markusson (Lulea University of Technology, Lulea, Sweden), in collaboration with GKN Aerospace Engine Systems (Trollhattan, Sweden), who made a detailed physical assessment of five commercial Inconel® 718 powders; print trials were also carried out. A primary aim was to determine whether one of four options might be a suitable alternative to a powder already in use by GKN for laser melt deposition (LMD) applications.
Click here to read the full article in 3Dprint.com.