Effect of Duty Cycle on Microstructure, Tungsten Content and Wear Resistance of Tungsten-Cobalt Films Prepared by Electrodeposition

Abstract

By studying effect of different duty cycles on tungsten-cobalt film to improve its performances, tungsten-cobalt films were prepared on the surface of PCrNi3MoVA steel by electrodeposition under different duty cycles. The results show that grain size increases with increasing duty cycle but tungsten content, microhardness, film-based bond strength and TC₍₁₀₀₎ increase first and then decrease with increasing duty cycle. When the duty cycle is 30%, tungsten-cobalt films with highest tungsten content (43.37%), grain size (12.3 nm) and largest TC₍₁₀₀₎ (0.845) have highest microhardness (7.1 GPa) and strongest film-base bond (24 N), which results in lowest friction coefficient (0.31) and smallest wear rate (2 × 10⁻⁵ mm³N⁻¹m⁻¹) that is only 28.57% for the tungsten-cobalt film prepared under 100% duty cycle.