Two propellers immediately catch visitors’ attention on the reception desk of the Polar Technology stand. The first is manufactured entirely from carbon composite. The second is exactly the same propeller, but completely coated with a thin metallic layer. “They are here to show the before and after,” explains George Brown, Marketing Manager at Polar Technology, whom we met at the show. “We start with a composite propeller and add a metallic protection to combine the lightweight properties of composites with the metal’s resistance to erosion.” More than a simple demonstration piece, the comparison illustrates the principle behind the technology the company has developed to protect the most exposed areas of aerospace structures.
For manufacturers of aircraft, helicopters, drones and eVTOLs, leading edges are among the most heavily stressed areas of any structure. Constant exposure to rain, sand, ice, insects and airborne particles gradually erodes composite surfaces, reducing aerodynamic performance and increasing maintenance requirements. It is this challenge that the two British partners are seeking to address.
A solution designed for aerospace composite structures
Polar Technology, a UK specialist in surface engineering, electroplating and protective solutions for aerospace components, has joined forces with Ultima Forma, a British company specialising in high-precision electroforming, to develop a new generation of leading-edge protection for composite structures.
Officially unveiled at Farnborough following the completion of the LEEF (Leading-Edge Electro-Forms) project, the solution is based on an electroforming process that deposits an ultra-thin layer of nickel or nickel-cobalt alloy precisely matched to the geometry of the component. Ultima Forma manufactures the metallic protection with a high level of precision, while Polar Technology integrates it onto composite parts through bonding or co-moulding. According to the partners, this approach provides a perfectly fitted protective layer while keeping additional weight to a minimum.
Tests carried out during the project demonstrated particularly high levels of performance. According to the companies, protected composite structures offer erosion resistance up to 88 times greater than unprotected composites. They also report a 64% lower wear rate than comparable titanium protection systems, while allowing the thickness of the metallic layer to be tailored locally to meet the requirements of each application.
The technology has not been developed in isolation. The project has benefited from the involvement of several aerospace companies, including Short Brothers, the Northern Ireland-based aerostructures manufacturer owned by Boeing, and Vertical Aerospace, the British developer of electric vertical take-off and landing (eVTOL) aircraft.
Target applications include propellers, rotor blades, wings, engine air intakes and other aerodynamic components exposed to severe erosion. The objective is to extend the service life of composite structures, reduce maintenance interventions and preserve aerodynamic performance throughout the operational life of the aircraft. The partners also highlight the technology’s ability to accommodate complex geometries and integrate into existing manufacturing processes, making it easier to adopt in future aerospace programmes.
A technology with applications beyond aerospace
Although aerospace represents the initial commercial market, both companies see far broader opportunities for the process. Electroforming allows metal to be deposited only where it delivers functional value, with thickness tailored according to local mechanical loads or environmental conditions. This capability opens up potential applications in defence, energy, transportation, industrial equipment and hydrogen technologies, where components must combine low weight, mechanical strength and protection against highly aggressive operating environments.
The partners believe this approach makes it possible to retain the intrinsic advantages of composites while benefiting from the performance of metals only where they are needed, all within a process compatible with large-scale industrial production.
The LEEF project was co-funded by Innovate UK, the UK’s innovation agency, as part of its strategy to strengthen the competitiveness of the national aerospace supply chain.
This support enabled the partners to progress from process optimisation through erosion and corrosion testing to industrialisation. The technology is now presented as market-ready for aerospace programmes, while further developments are under way to adapt it to other industrial sectors where composite materials operate under particularly demanding conditions.
Beyond the demonstration at Farnborough, the two propellers displayed on the stand ultimately capture the project’s ambition: to preserve the qualities that have made composites so successful, lightweight performance, stiffness and design freedom, while adding the durability of metal only where it is truly required to withstand harsh operating environments. This hybrid approach could help support the next generation of aircraft, drones and eVTOLs.
Photos: Ultima Forma/ Polar Technology
