Optimization of Electrochemical Variables of Pulse-Reverse Electroplating in Trivalent Chromium Bath to Enhance the Corrosion Resistance of Chromium Film

The present paper focused on the use of the salt of rare earth cerium as corrosion inhibitor of Zinc by using cathodic electrolytic passivation method. The corrosion resistance and the microphology of the cerium passivation film were studied by the methods of electrochemical method, scanning electron microscopy (SEM). From the results, it was shown that good corrosion resistance of cerium-based trivalent chromium conversion coating was obtained when the compositions were as follows: Ce (SO4)2, 6g/L; Cr2(SO4)3, 18.9g/L and NaNO3; current density, 2A/dm2; temperature, 40 oC; time, 60s. SEM revealed that the cerium trivalent chromium conversion coatings formed uniform cerium hydroxide and chrimuim hydroxide deposition on the surface of Zinc.

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Microstructure and flow accelerated corrosion resistance of Cr coatings electrodeposited in a trivalent chromium bath

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2021.127527 ◽

2021 ◽

pp. 127527

Author(s):

Ying Wang ◽

Yanhong Liu ◽

Guangbin Li ◽

Mingmin Zheng ◽

Yusha Li ◽

...

Keyword(s):

Corrosion Resistance ◽

Trivalent Chromium ◽

Accelerated Corrosion ◽

Flow Accelerated Corrosion

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Corrosion Resistance of Pulse-Electroplated Ni-W Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.185.15 ◽

2012 ◽

Vol 185 ◽

pp. 15-17 ◽

Cited By ~ 3

Author(s):

Kung Hsu Hou ◽

Yun Feng Chang ◽

Ming Der Ger

Keyword(s):

Corrosion Resistance ◽

Pulse Current ◽

Design Method ◽

Transfer Rates ◽

Electrochemical Tests ◽

Duty Cycles ◽

Lower Health ◽

Reverse Pulse ◽

Pulse Reverse ◽

Nickel Tungsten

Nickel-tungsten (Ni-W) plating process exhibited fewer environmental hazards and lower health hazards than conventional chromium bath processes did, because they had the potential to be substituted for certain future applications. This study attempted to develop Ni-W alloy coatings with different weight percentages of tungsten to produce by using nickel-tungsten citrate electrolyte baths that are deposited by pulse current power source techniques. The composition of the ratio of tungsten/nickel was controlled by the change from ion mass transfer rates for the interface between cathodes and electrolytes that were caused by adjustment by charging the over potential or rest that was regulated by the on-off time during pulse and reverse-pulse current. In this study, the corrosion resistance and the composition of the coatings related to the operating parameters were also discussed through the analyses of the experimental design method. Results were found that Ni-W alloy compositions governed through regulation of pulse and pulse-reverse parameters. The frequencies of electric current, Ton and Toff with pulse duty cycles had great impact on chemical composition and surface morphology for the deposits. Results of the electrochemical tests indicated the pulse plated Ni-W metal alloy coatings in which the corrosion resistance was superior to that of the alloy deposited by the direct current technique.

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Corrosion Resistance of Cr-P-C Alloy Plating Film Produced Using a Trivalent Chromium Bath.

Journal of The Surface Finishing Society of Japan ◽

10.4139/sfj.50.1153 ◽

1999 ◽

Vol 50 (12) ◽

pp. 1153-1157 ◽

Cited By ~ 1

Author(s):

Takuo NAKADE ◽

Tsutomu MORIKAWA ◽

Yukihiro SATO ◽

Masayuki YOKOI

Keyword(s):

Corrosion Resistance ◽

Trivalent Chromium ◽

Alloy Plating

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