Scientific
publications 
and theses

The development of an automated technology to metallize polymer based composite for lightning strike protection is the aim of the CO3 project (EU Grant agreement: ID831979). In this study, thermal and electrical conductivities of composites were achieved by the cold spray deposition of Cu or Al coatings.

Several strategies were tested:

l) a protective polymer film co-cured at the substrate surface before cold spraying,

ll) cold spraying a mix of metal and polymer powders,

lll) surface preparation of the substrate by Supercritical Nitrogen Deposition, prior to cold spray. Material characterizations and real part demonstrators will be presented.

Fusion assembly is a highly promising technique for joining thermoplastic composite to thermoset composites,
enabling the use of both the most affordable composite material and process for each substructure. However,
some major challenges need to be addressed such as functionalizing the thermoset composite surface through co-
curing with an appropriate thermoplastic interlayer or realizing a fast and robust welding process that meets all
quality and mechanical requirements. In this paper, we investigated the potential of polyetheretherketone (PEEK)
and its amorphous (PEEK A) and semicristalline (PEEK SC) states as interlayer materials, co-cured onto thermoset
composites. A surface preparation involving the atmospheric plasma process demonstrated that both PEEK state
materials can be used as interlayer with favorable adhesion properties. The influence of the plasma treatment on
surface properties and morphology was also experimentally characterized.

Cold spray : winning strategies for the metallization of thermoset and thermoplastic composites for the aeronautical industry.

Unlike their metal counterparts, composite structures do not readily conduct away the electrical currents generated by lightning strikes. Cost reduction and expected production in aeronautics require automated manufacturing process. The development of an automated technology to metallize polymer based composite for lightning strike protection is the aim of the CO3 project. In this study, thermal and electrical conductivities of the composites are achieved by the cold spray deposition of the metallic (Cu or Al) coating. The critical points to be addressed were substrate erosion during cold spray, lack of polymer-metal adhesion as well as poor deposition efficiency.

Cold Spray of metallic coatings on polymer based composites for the lightning strike protection of airplane structures

Unlike their metal counterparts, composite structures do not readily conduct away the electrical currents generated by lightning strikes. Cost reduction and expected production growth of the next middle range airplanes require automated manufacturing process of polymer components. The development of an automated technology to metallize polymer based composite for lightning strike protection is the aim of the CO3 project (EU Grant agreement: ID831979). In this study, thermal and electrical conductivities of composites were achieved by cold spray deposition of Cu or Al coatings. Critical points to be addressed were substrate erosion during cold spray, lack of polymer-metal adhesion and poor deposition efficiency. Several strategies were tested: i) a thin polymer film was cocured at the substrate surface before cold spraying, to enable implantation of metallic particles in the film, helping coating build-up and protecting the fibers of the composite. ii) Cold spraying a mix of metal and polymer powders to improve coating adhesion and prevent fiber damage. iii) Supercritical Nitrogen Deposition technology, prior to cold spray, to mechanically anchor metallic particles into the polymer. Subsequent cold spraying of purely metallic coatings was more efficient and showed better adhesion. All coatings were tested in terms of adhesion strength and electrical conductivity.

Cold Spray metallization of thermoset ant thermoplastic composites for ligthning strike protection.