Polymers and carbon fibre reinforced polymer (CFRP) composites are used to replacemetallic components in wide range of applications. In most of the applications, the surfaceof the polymers and CFRP composites that interacts require good wear resistance.Coating the surface by chromium nitride known to possess good wear resistance byPulsed DC Reactive Magnetron Sputtering technique is one of the methods suitable forpolymers having low temperature resistance. Adhesion is a challenging part while coatingthe polymers and polymer based composites as polymers are innately hydrophobic havinglow surface energy. Plasma pretreatment of polymer surfaces helps to improve theadhesion. In the present study, the following polymer based substrates were used: vinylester matrix CFRP composites, vinyl ester-thermosetting polymer and thermoplasticpolymers such as polyamide PA), polycarbonate (PC) and polymethyl methacrylate(PMMA). The effect of ion cleaning on adhesion by pull off adhesion tester was analysedwith argon ions for CFRP, and with argon and argon/nitrogen mixture for the polymers.The film stoichiometry is generally found to influence the properties of the coating. Toknow the effect, chromium nitride was deposited at different nitrogen partial pressure onCFRP and polymer substrates. Other than the nitrogen partial pressure, the substratematerial was also found to affect the structure, mechanical properties and wearperformance of the coatings. Depending on the polymer substrate material, therelationship between wear resistance and plastic deformation resistance of the coatingvaried. The wear performance of coatings on CFRP was not well due to the presence ofcarbon fibres near the surface that made the surface rough and inhomogeneous.Asymmetric pulsed DC used for the unbalanced magnetron sputtering technique for thepresent study is known to produce high levels of energetic ion bombardment due to thefluctuations in plasma potential, which occur during the pulse cycle. The bombardmentof the substrate by these ions may have a significant impact on the growing film. The ionfluxes and energies, which impinge on the substrate during the deposition of chromiumwere analyzed using energy resolved mass spectrometry at different pulse frequencies. Itwas found that there was a remarkable increase in ion flux at higher pulse frequencies.The variation of the ion flux with pulse frequency was explained by a simple model. Thebehavior of the ion fluxes on the magnetron centre line and in off-axis position wascompared and was found that on the centre line there was an additional mid energy ionflux, which was not present in the offset position. This change arises from the ion flowdirected along the magnetic field lines from the racetrack region to the substrate or probe position because of the unbalanced magnetron configuration. Chromium nitride wascoated on silicon and glass substrates at different pulse frequencies to know the effect ofion bombardment at off-axis position of the substrate on coating characteristics such asstructure, morphology and mechanical properties. From distortion in structure to changein morphology, roughness, stress and mechanical properties, the ion energy bombardmentwas found to have a significant impact on the coating.
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