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Structure and Porosity of Electrodeposited Platinum: Evaluation of Four Plating Methods.
Lynch-MJ; Walters-RP; Flinn-DR
MISSING :18 pages
The Bureau of Mines evaluated the feasibility of substituting platinum-coated metals for bulk platinum shapes as a means for conserving platinum. Platinum coatings were prepared using four different methods of electrodeposition, then tested and evaluated. In order for platinum coatings to be useful in process environments, they must be thick, adherent, stress-free, and pore-free. The Bureau evaluated direct-current, current reversal, cathode shielding, and pulsed-current plating techniques for producing a pore-free platinum electrodeposit from a molten cyanide bath. Aqueous corrosion tests of fe-10cr substrates coated with approximately 25 um of platinum showed that pulse plating yielded the most corrosion-resistant and, hence, the most pore-free coatings. The morphology of coating cross sections was in all cases columnar. The average grain size of pulse-plated deposits was independent of thickness, while all other plating techniques produced grains that increased in size as the coatings became thicker. It is believed that the constant grain size in the pulse- plated deposits resulted from better mass transport during the electrodeposition.
IH; Report of Investigations
Page last reviewed: May 5, 2020Content source: National Institute for Occupational Safety and Health Education and Information Division