In a significant stride for additive manufacturing, researchers have introduced a novel binder system that could revolutionize the production of magnesium alloy components, with potential ripples across industries, including energy. The study, led by Hyeonseok Kim from the School of Mechanical and Materials Engineering at University College Dublin, presents a plasticiser-free thermoplastic polyurethane (TPU) binder that achieves an unprecedented 70 vol% powder loading in screw-based material extrusion (SBME). This breakthrough could pave the way for more efficient and cost-effective manufacturing processes.
Traditionally, material extrusion of magnesium alloys has relied on multi-component binder systems, often incorporating plasticisers. However, these can lead to phase separation and instability during extrusion. Kim and his team’s TPU binder, with its single-backbone structure, eliminates these issues, enabling stable extrusion at high powder fractions. “Unlike conventional systems, our TPU binder doesn’t require plasticisers,” Kim explains. “This not only simplifies the process but also opens up possibilities for bypassing solvent debinding, saving time, cost, and energy.”
The implications for the energy sector are substantial. Magnesium alloys are lightweight and strong, making them ideal for components in electric vehicles, renewable energy systems, and other green technologies. The ability to produce these components more efficiently and sustainably could accelerate the transition to cleaner energy solutions.
The study, published in *Materials & Design* (translated as *Materials & Design*), also revealed a unique viscosity-reduction mechanism in TPU. As powder particles disrupt polymer chain entanglements, the flow improves at high loadings. This, combined with TPU’s cohesive melting profile, ensures uniform extrusion and prevents nozzle clogging, a common issue with traditional binders like polypropylene-polyethylene copolymer (PPcoPE).
However, the journey towards perfecting this process is not without challenges. Preliminary sintering studies showed no densification for both binders, likely due to carbonate and oxide surface layers on the magnesium alloy. This suggests a need for further research into magnesium alloy compositions to enhance sinterability.
The potential of TPU as a binder in additive manufacturing is immense. As Kim puts it, “Our findings highlight TPU’s potential for record-high powder loadings in next-generation powder-based additive manufacturing.” This research could shape future developments in the field, driving innovation and efficiency in manufacturing processes across various industries.
In the quest for sustainable and efficient manufacturing, this breakthrough offers a promising path forward. As the energy sector continues to evolve, advancements like these will be crucial in meeting the demands of a greener future.