M. Elsharif et al., ENVIRONMENTALLY ACCEPTABLE PROCESS FOR ELECTRODEPOSITION OF HARD CHROMIUM FROM CHROMIUM(III) ELECTROLYTE, Transactions of the Institute of Metal Finishing, 73, 1995, pp. 19-25
Citations number
16
Categorie Soggetti
Metallurgy & Metallurigical Engineering","Materials Science, Coatings & Films
In engineering applications the hexavalent chromium plating process pr
ovides excellent wear and corrosion resistant coatings (50-100 mu m).
However, this process is based on the highly toxic and environmentally
unacceptable chromium (VI) electrolytes. Persistent attempts over man
y years, have been made to deposit a thick coating of high quality chr
omium from environmentally more acceptable chromium (III) electrolytes
to replace the chromium (VI) process. The most successful studies hav
e shown that it is possible to produce thick coatings of chromium (III
) electrolytes bur due to the very slow rate metal deposition Sailing
to about 1 mu m/hr, the process is unsuitable as a commercially viable
hard chromium system. The present project has developed a laboratory
scale high speed electrodeposition process based on chromium (III) ele
ctrolyte. This paper reports on an investigation in to the enhanced pl
ating rate (300 mu m/hr) using high flow rates and high current densit
y system. Excellent quality deposits were obtained using this process.
The quality, structure and properties of the deposits have been exami
ned and related to the prevailing electrohydrometallurgical condition
thereby providing quantitative and qualitative data on which to base t
he engineering design of an advanced environmentally acceptable platin
g system.