The project – completed as part of the NCC’s Core Research programme, and supported by Rolls-Royce, Reaction Engines, MBDA and 3M – has demonstrated that a novel oxide-based ceramic material from 3M can be used in automated deposition.
The material is called tow-preg: a combination of carbon, filament and plastic resin binder.
While conventional nickel-based superalloys have a maximum continuous temperature of approximately 800°C, oxide-based CMCs can operate at 1000°C, with the higher operating temperature potentially improving the efficiency of aerospace engines and reducing fuel consumption and the subsequent CO₂ emissions.
However, the widespread use of CMCs is currently limited to high value applications, such as heat shields and turbine vanes. Being able to process a more affordable version of the material using AFP technology will reduce the final cost of making CMC parts, making them a more appealing proposition for industries who require components that can withstand high temperatures. Furthermore, using an automated process will offer excellent control over material deposition and could prove a vital innovation to improve material consistency.
The project team adapted existing AFP technology, typically used to process organic matrix composites, like carbon fibre reinforced epoxy materials, to process 3M’s material. They also investigated how process parameters such as speed, heat and compaction force influence the material deposition and quality. Identifying the optimal deposition parameters reduces the material variability, removing one of the largest challenges for CMCs to be used more widely. This could also lower the cost of CMCs and create less waste.
Dr. Dave King, engineering capability lead for advanced materials at the NCC, said: “By manufacturing 3D trial parts, we have demonstrated compatibility of CMC Towpregs with existing AFP equipment. In the next year we hope to use our optimised manufacturing parameters to create even more complex geometries, starting with curved surfaces, to closer represent industrial parts. With 3M’s support, we are also investigating wider material formats to reduce the number of inter tape joints in the material to increase its performance. These factors are critical for their deployment in industry.”
A video is available via https://www.youtube.com/watch?v=boLlYmGvMS4&t=2s
