The UK has taken a significant step towards reducing its reliance on overseas suppliers for ceramic matrix composites (CMC) – advanced materials expected to play a key role in future defence systems, hypersonic flight (speeds exceeding Mach 5) and nuclear power.
CMCs contain ceramic fibres embedded within a ceramic matrix, overcoming the inherent brittleness traditionally associated with the materials. Lightweight and as strong as metal, they retain their strength and shape under extreme heat and mechanical load, making them well-suited to spacecraft, advanced propulsion systems and other high-temperature environments.
The modern composites are predominantly manufactured in China, Japan and the US, and are often subject to export controls. That dependency creates a vulnerability in the defence supply chain and limits the UK’s ability to develop and deploy systems independently, according to the National Composites Centre (NCC).
“With hypersonic weapons now demonstrated by multiple adversaries, the UK can’t afford to remain reliant on overseas supply chains. We must accelerate investment in advanced materials if we’re serious about sovereign capability,” says Dr David King, NCC’s principal defence engineer.
Bath company Cross Manufacturing has now established the UK’s first pilot-scale manufacturing facility for oxide-based CMCs, bringing a key stage of production onshore. The programme was supported by the Defence Science and Technology Laboratory (DSTL) and delivered through a consortium including the Ministry of Defence, the University of Oxford, the NCC, the UK Atomic Energy Authority and defence firms QinetiQ and MBDA.
The programme demonstrates how defence investment in science and technology can accelerate industrial capability, says DSTL chief executive Dr Paul Hollinshead: “By moving rapidly from laboratory research to an industrially relevant pilot production line, the programme has accelerated the UK’s ability to convert scientific excellence into deployable capability.”
Cross Manufacturing specialises in high-temperature sealing and retaining rings made from metallic alloys, which approach their structural stability limit at about 850°C. As demand for advanced thermal protection has increased across aerospace, defence and energy, that limitation has become more acute – driving the need for materials capable of operating at 1,000°C and beyond, while maintaining mechanical integrity and sealing performance.
The pilot line is the culmination of Cross Manufacturing’s decade-long effort to move ceramic matrix composites from the laboratory to pilot-scale production, laying the foundation for future industrial scale-up.
While CMC research capability exists within the UK, it has historically been fragmented across academia and specialist centres, with no integrated route to production. That fragmentation has long been a barrier to scaling advanced materials beyond demonstration, says Dr Talha Pirzada, research and technology manager at Cross Manufacturing.
“There’s no shortage of research or industrial capability in isolation,” he tells Professional Engineering. “The challenge is aligning them. Industry is focused on delivering a product; academia is focused on understanding the fundamentals. Bringing those together is what allows you to move up the technology readiness curve.”
The pilot line has already produced a range of demonstrator components, validating the process across multiple geometries and use cases. While the current focus is on oxide-based CMCs, the underlying process can be applied to other ceramic composites at earlier stages of maturity.
“The same production methods are replicable across different types of CMC, like silicon carbide, which is suitable for nuclear applications,” Pirzada says. “Oxide CMCs are at TRL 5 (validated at pilot-scale), while silicon carbide CMCs are at TRL 3 (proof-of-concept stage), with further development required.”
Ultra-high temperature CMCs, which hold the potential to operate at temperatures exceeding 2,500°C, remain at TRL 1. But Pirzada believes the programme has demonstrated one pathway to accelerate CMC development through technology readiness levels.
If true, it would reduce lead times, improve access to critical materials and enable closer collaboration between designers and manufacturers. Unlike monolithic ceramic materials, which are simpler to incorporate into designs with but offer limited scope for optimisation, ceramic matrix composites allow greater design flexibility but also increased complexity. Many design engineers remain unfamiliar with them. Pirzada says work is now underway to define the material property requirements needed to support broader adoption across sectors.
The longer-term challenge will be scaling production to meet demand while maintaining consistency. “For us, the focus is on process control and repeatability,” Pirzada says. “If you can’t manufacture consistently, you can’t qualify parts for critical applications.”
Extracted from IMechE website, read more here