Development of low pressure cold sprayed copper coatings on carbon fiber reinforced polymer (CFRP)

A new method which allows the development of Low Pressure Cold Sprayed copper coatings on PEEK (PolyEther-Ether-Ketone) based composites reinforced by carbon fibers is investigated. Due to the solid state and high velocities of impacting particles, cold spraying involves a high erosion on composite materials, leading to an absence of coatings and sometimes damaged carbon fibers. As a result, few dozen micrometers of pure PEEK matrix have been added on the surface of the composite to act as an interfacial layer between composite and coating. Optimization of the LPCS parameters has been carried out, using a careful choice of powder size distribution in order to avoid substrate damage, erosion and coating delamination. Dense copper coatings exceeding 100 mu m thick have been obtained. SEM observations have been carried out to evaluate the microstructure of coatings, and the minimal required matrix thickness regarding the size distribution of the powder.