The invention claimed is:
1. A process for cold spraying a substrate, comprising:
feeding metallic coating particles to a convergent-divergent nozzle device, the metallic coating particles being fed without a plastic encapsulation;
supplying a dispersion, comprising a liquid suspension agent and plastic particles dispersed in the liquid suspension agent, to the nozzle device while the metallic coating particles are being fed to the nozzle device, the plastic particles being smaller than the metallic coating particles;
accelerating the metallic coating particles with the nozzle device in a cold gas jet, while allowing the plastic particles to accumulate on the coating particles, thereby forming plastic encapsulated coating particles before the metallic coating particles contact the substrate; and
depositing the encapsulated coating particles on the substrate to from a layer having a metallic first microstructure phase and a second microstructure phase made of a plastic.
2. The process as claimed in claim 1 , wherein the metallic coating particles and the dispersion of plastic particles are fed to a stagnation chamber at an upstream end of the nozzle device.
3. The process as claimed in claim 1 , wherein
the plastic is a thermoplastic fluoropolymer.
4. The process as claimed in claim 1 , wherein
the plastic particles are formed from at least one plastic selected from the group consisting of polytetrafluoroethylene (PTFE), perfluoroalkoxy (PFA), fluorinated ethylene propylene (FEP), ethylene-tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE) and polyvinylidene fluoride (PVDF).
5. The process as claimed in claim 1 , wherein
the metallic coating particles have a mean particle diameter of at least 5 μm and at most 10 μm, measured without plastic encapsulation.
6. The process as claimed in claim 1 , wherein
the metallic coating particles have a mean particle diameter of at least 7 μm and at most 8 μm, measured without plastic encapsulation.