Pulsed electrodeposition of Co–W amorphous and crystalline coatings

Replacement of hard chromium plating has been of particular interest to many industrial applications, including automotive, aircraft, and machinery parts that require high hardness and wear/corrosion resistance. Co–W alloy coatings, owing to their eco-friendly processing and high hardness/wear resistance, are promising for electrolytic chromium replacement. In the present study, pulsed electrodeposition of amorphous and crystalline Co–W coating is reported. Systematic investigations on the effect of pulse duty cycle and pulse frequency on development of surface microstructure, phases, composition, surface roughness, and micro-hardness are presented. Furthermore, detailed analysis of micro-/nano-mechanical (using ball-on-disc wear tester and nanoindentor) and corrosion (using potentiodynamic polarization method) behavior of optimized Co–W coatings is presented.