Relationship between tribological properties of hard chromium coatings and performances of chromium plating electrolyte

Abstract

Hard chromium coatings are commonly used for applications requiring low friction coefficient and wear resistance. The aim of this work is to study the influence of electroplating conditions (electrolyte temperature and cathodic current density) on the efficiencies of both cathodic and anodic reactions and the tribological properties of chromium electrodeposits. First, the mass balance allows the evolution of the electrolyte composition to be followed, especially the decrease in CrVI species, due to their reductions to chromium metal and trivalent chromium. Experimental results highlight the significant effects of the current density and the electrolyte temperature on the cathodic efficiencies. The strong link between plating electrolyte temperature and coating properties (roughness and tribological characteristics) is then shown.