Purdue researchers study powders for in-space Additive Manufacturing
Researchers from Purdue University, West Lafayette, Indiana, USA, have published research in Advanced Manufacturing focused on the characterisation of powders for Additive Manufacturing in space.
As the cost of space travel has decreased, there has been a rising interest in space-based manufacturing which would enable long-term exploration and habitation. High launch costs necessitate the use of extraterrestrial resources like lunar regolith and recycled space debris for in-space Additive Manufacturing. Metal debris in Earth’s orbit presents a valuable feedstock, while lunar regolith, composed of fine particles, may be suitable for powder-based manufacturing techniques.
While its attributes make powder-based AM an attractive manufacturing opportunity, powder behaviour in microgravity, vacuum conditions, and extreme temperature variations present significant challenges. Unlike standardised AM powders, lunar regolith has a varied size distribution and irregular particle shapes, affecting flowability and the suitability to Additive Manufacturing.
In ‘Powder characterization for in-space additive manufacturing’, the researchers tested various powder characterisation techniques to determine their viability for space applications, emphasising the need for modifications to account for non-Earth environments. The study also reviewed real-time monitoring technologies essential for ensuring build quality in in-space Additive Manufacturing and outlined recent advancements in computational modelling for predicting powder behaviour in space.
By refining powder production, characterisation, and process adaptation, the Purdue team believes that in-space AM can minimise reliance on Earth-based supply chains, enabling the construction of tools, habitats, and infrastructure directly in space.
The study
The researchers concluded that powder-based Additive Manufacturing techniques, including Powder Bed Fusion (PBF), Binder Jetting (BJT) and Directed Energy Deposition (DED), were the most compatible with the use of lunar regolith. These processes eliminate the need for the regolith to be suspended in liquids or embedded in a filament or sheet matrix.
However, producing powders in space introduces unique challenges, including microgravity-induced particle dispersion, limited heat dissipation, and the need for autonomous operation. Among the available methods, electrolysis was stated to be the most viable due to its adaptability to low-pressure environments and reliance on solar power, while chemical reduction offers a feasible alternative when local metal oxides and reducing agents are available. In contrast, atomisation and mechanical crushing face significant limitations due to their dependence on gravity-assisted processes and convective cooling.
Further complicating in-space powder production, the behaviour of powders under microgravity, extreme temperatures, and varying pressures remains poorly understood. These environmental factors significantly influence powder flow dynamics, which are integral to ensuring reliable performance in space-based AM systems. Addressing these challenges required the researchers to make use of specialised containment, monitoring, and material handling systems tailored for space conditions, such as electrostatic or magnetic particle control, real-time process automation, and radiative heat dissipation.
To address the technical barriers for in-space AM, this review focused on identifying key techniques for powder characterisation for use in microgravity conditions. A comprehensive review of existing characterisation techniques was presented for powder characteristics, including particle size distribution, shape, density, flowability, and chemical composition. These characterisations provide a detailed understanding of powder behaviour and offer insight into particle–particle interactions in space.
Additionally, state-of-the-art micro-scale modelling of powder flow was also reviewed to improve process reliability for in-space manufacturing. By simulating powder behaviour in microgravity, extreme temperatures, and varying pressures, these models provide greater predictive capabilities for AM performance. Such simulations reduce the need for expensive experimental setups, allowing for more efficient development and validation of space-based AM processes.
The full paper is available here.
