Experimental Research on Hard and Crack-Free Electrodeposited Chromium Coatings

Abstract

In order to eliminate cracks in the chromium coating, a novel method named flexible extrusion assisted chromium electroplating was proposed. The bright and crack-free chromium coatings were electrodeposited by using the perturbation and extrusion of hard and insulating particles. The prepared deposits were characterized by scanning electron microscope (SEM) and three-dimensional topography. The testing results showed that the surface was very smooth and there was no micro cracks in the coating. Micro hardness of the electrodeposited layer was also tested. It was confirmed that the chromium coating electrodeposited with rotating cathode in hard particles had high micro hardness as to 850HV and the micro hardness could be controlled by the process parameters. The rule of the micro hardness was concluded by analyzing current density and rotating speed. In addition the results of salt spray test and electrochemical polarization curve showed that the coating deposited by new method had higher corrosion resistance than that by traditional method.

Morphology and Properties of Solid Chrome Plating, Obtained by the Galvano-Mechanical Method

“…The image clearly shows both the good adhesion of the coating with the metal base and the uniformity of the thickness of the coating. At the same time, cracks characteristic of solid chromium coatings (from the surface to the base metal) are observed [18][19][20].…”

Effect of Abrasive Tools in Galvanomechanical Treatment on the Roughness of the Deposited Chromium Layer

“…The bright and crack-free chromium coatings were electrodeposited by using the perturbation and extrusion of hard and insulating particles in the paper Li, X.L., Liu, X.H., Tian, H.B., Yuan, W.J., Experimental research on hard and crack-free electrodeposited chromium coatings [20].…”