Preparation and self-lubricity investigation of CNTs/Ni composite coatings under severe conditions

Abstract

Carbon nanotubes (CNTs) demonstrate the potential to improve the tribological properties of nanocomposite coatings. Herein, CNTs/Ni composite coatings were quickly fabricated by the direct current (DC) electrodeposition. The adhesion strength was estimated by the scratch test incorporation with an acoustic emissive signal. Much attention was paid on the self-lubricity of the CNTs/Ni composite coating under severe conditions. Results indicated that presence of CNTs enhanced the adhesion strength of the pure Ni coating. Notably, CNTs contributed towards 54.5 % of friction reduction in comparison to the pure Ni coating at dry friction. The improvement of tribological properties was attributed to that under high contact stress the embedded CNTs were crushed to tiny lubricating particles and produced protective film on rubbing surfaces.