A review of the tribological behavior of electrodeposited cobalt (Co) based composite coatings

Abstract

In recent years, composite coating is widely used for reduction of friction, and wear and to protect the surface of metal of various industrial components from corrosion. Cobalt-based coatings are getting considerable attention because of their advantages for suitable electrical and magnetic properties. Moreover, cobalt (Co)-based composite coatings are relatively inexpensive compared with other composite coating such as nickel-based composite, epoxy/alumina composite and copper-based composite. Furthermore, various cobalt-based composite electrodeposition processes are eco-friendly compared with hard chrome toxic coating. Reinforcing micro/nanoparticles into the matrix of metallic reduce the coefficient of friction and wear loss in the contact area of the metal surface. The incorporation of these particles into pure Co film results in the pyramidal morphology structure changing to needle-shaped. Several factors such as types of coating materials, substrate, bath composition, deposition method, current density, electrolyte pH, concentration, and size of particles strongly affect the wear, friction coefficient, corrosion, and microhardness of these coatings. The main purpose of this review is to provide a summary and introduce gaps in recent tribo-mechanical research (including corrosion resistance) about cobalt base composite coatings as well as coating conditions for different methods such as current density, temperature, and agitation.

Keywords

• Tribology
• Composite
• Coating
• Tribological electro deposition
• Hardness
• Cobalt