Influence of CH₃SO₃H and AlCl₃ in direct and pulse current electrodeposition of trivalent chromium

Abstract

Comparison of direct and pulse current electrodeposition of the trivalent chromium from urea formic acid as a complexing agent was studied in detail. The influences of CH₃SO₃H and AlCl₃ on the properties of the deposit were also studied. The presence of CH₃SO₃H exhibits higher current efficiency and better corrosion resistance because of its higher hydrogen overpotential. The pulse current electrodeposition leads to growth of β-Cr. The corrosion studies were conducted by potentiodynamic polarisation and electrochemical impedance spectroscopy. The morphology of the deposits was characterised by scanning electron microscopy (SEM) and X-ray diffraction.

Keywords:

• ON TIME
• OFF TIME
• COATINGS
• CHROMIUM
• PULSE ELECTRODEPOSITION