Session Details

Session 2: Metal Finishing: Past, Present, and Future

Abstract Number:


Understanding the benefits achieved by using synthetically ‎manufactured copper & silver salts for ‎the cyanide free ‎electroplating of busbars.‎


General Surface Finishing

Usage of copper is very much common to the manufacturers of busbars because of their ‎conductive ‎and mechanical properties. To reduce the cost user’s in this subcontinent have ‎shifted to feasible, ‎substitute aluminum as base material. Bot copper & aluminum with time ‎gets oxidized. Oxidized ‎layer on metal base is not as conductive as the bare metal. As metal ‎oxidizes it will slowly become ‎less conductive and eventually begin to weaken, flake and fall ‎apart.‎

Electroplating of busbars helps to keep cleaner contact surface by preventing corrosion. The ‎‎traditional electroplating processes used in this application are as under:‎
• Copper plating
• Silver plating
• Tin plating

Copper & Silver are plated extensively plated using established cyanide containing baths. ‎But, ‎increased personal safety and health consciousness coupled recent ROHS, OSHA, EPA ‎directives have ‎led to more interest towards the usage of cyanide free electrolytes. Cyanide ‎free chemistries for both ‎copper & silver plating are reported by researchers since years, but ‎these processes could not ‎eventually got commercially accepted due to lower tolerance ‎towards metallic impurities, poor ‎colour stability (turning into blackish yellow tint on storage ‎of the plated silver deposit) & also, ‎inadequate deposit adhesion. Processes are developed ‎& commercialized to produce finer grained ‎copper & silver deposits utilizing cyanide free ‎chemistries. Tolerance towards impurities of such ‎silver plating proposition is found to be ‎improved significantly. In addition silver deposit from this ‎chemistry is brighter in ‎appearance. Main differentiators for these processes are the copper & silver ‎complexes ‎which are synthetically manufactured utilizing copper & silver salts for respective systems. ‎‎Analytical findings e.g. coating morphology, deposit hardness, internal stress, adhesion tests, ‎etc. of ‎such innovative propositions for both cyanide free alkaline copper & silver-plating ‎processes are ‎presented in this paper.‎


Ashok Nalawade

General Manager of R&D

Grauer & Weil India, Ltd.‎

Subrata Chakraborty

Vice-President of R&D

Grauer & Weil India, Ltd.‎