Wear and corrosion resistance of titanium carbo-nitride coated Al-7075 produced through PVD

Titanium carbo-nitride coatings were deposited using plasma-assisted physical vapour deposition technique on Al-7075 aluminium alloy plates. Studies were conducted to understand the bonding between the coating and substrate, and to examine the wear- and corrosion-resistant properties under heat treatments. The nature of bonding was characterized using scanning electron microscope. The pin-on-disc wear test, according to G99 ASTM standard, displayed the frictional force, coefficient of friction and wear for the samples. Simultaneously, the corrosion tests, according to G5-14 ASTM standard, performed for a period of 48 h, using electrochemical impedance and potentiodynamic polarization tests displayed the Nyquist and Tafel plots for analysis. The wear and corrosion rates of samples heat-treated at $$500^\circ \hbox {C}$$ for 1 h were found to be $$0.066\hbox {e-}6\,\hbox {g\,s}^{{-1}}$$ and $$2.962\hbox {e}2\,\hbox {g mm}^-2\,\hbox {s}^{{-1}}$$ , respectively. While that of samples heat-treated at $$500^\circ \hbox {C}$$ for 12 h were found to be $$0.366\hbox {e-}6\,\hbox {g s}^{{-1}}$$ and $$4.177\hbox {e}2\,\hbox {g mm}^-2\,\hbox {s}^{{-1}}$$ . Both the wear and the corrosion performance investigations were in good agreement with each other. Thus, the tribo-corrosive deterioration of titanium carbo-nitride coated Al-7075 had escalated with an increase in durations of the heat treatment.