Investigation of the corrosion-wear failure mechanism of multilayer Cr/GLC coatings under hydrostatic pressure-tribocorrosion alternation

Graphite-like carbon (GLC) coating is a candidate protection coating for corrosion-wear resistance of materials surface in deep-sea environments. The mechanics-electrochemistry coupling failure mechanism and the corrosion-wear interaction failure of coatings have been an urgent problem that needs to be solved. In this paper, the corrosion-wear failure behaviour of multilayer Cr/GLC coating during static corrosion-tribocorrosion alternating cycles at 0.1 MPa and 15 MPa was investigated by electrochemical impedance spectroscopy (EIS), polarization curves and scanning electron microscope (SEM). The results show that the corrosion-wear morphology of multilayer Cr/GLC coating under high pressure and tribocorrosion coupling is more severe than that at atmospheric pressure, and the coating's corrosion resistance and wear resistance significantly decreased. High hydrostatic pressure amplifies the corrosive effect in the corrosion-wear interaction, accelerating purely mechanical wear and corrosion-accelerated wear processes of coatings. The action mechanism of complex mechanics and complex electrochemistry on the corrosion-wear failure of multilayer Cr/GLC coating is discussed.