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Keywords
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Cr electrodeposition, trivalent chromium, deposition condition, current efficiency, corrosion, wear
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Abstract
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The effects of bath composition and deposition condition on trivalent chromium electrodeposition
were investigated. Corrosion and tribological behavior of the Cr film was also studied and the results
were compared to the substrate. According to the results, there was an optimum amount for each one
of the bath Cr2(SO4)3.6H2O(chromium sulfate) concentration, pH and current density at which the
highest current efficiency was obtained. However, the current efficiency was continuously decreased
by raising the bath temperature and deposition time. According to hardness evaluations, enhancing
temperature, pH and Cr2(SO4)3.6H2Oconcentration of the bath decreased microhardness of the Cr
films. XRDand SEM results revealed that all the Cr electrodeposits had an amorphous structure and
nodular morphology. Polarization and impedance results showed that the 316 L stainless steel
substrate was more corrosion resistant than the optimum Cr coating. Corrosion potential of the
substrate was nobler and its corrosion current density was half of the Cr film. However, the wear loss
and friction coefficient of the substrate were about 3 and 1.5 times higher than the Cr coating,
respectively.
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