Design Considerations

SELECTING COPPER PLATING

FOR DIE CASTINGS

  • NO OTHER PRACTICAL METHOD PREVENTS ATTACK ON BASIS METAL
  • GOOD COVERAGE
  • GOOD CORROSION RESISTANCE

FOR STEEL PARTS

  • READILY BUFFED
  • GOOD COVERAGE
  • PRE-PLATE FOR ACID COPPER

Zinc base die castings are plated with copper prior to plating with nickel and chromium for two major reasons: (1) copper metal is relatively inert to the acid nickel and chromium plating baths, and (2) copper plates in the recesses more readily than nickel or chromium. Better coverage in the recessed areas of the parts improves the corrosion resistance of plated zinc base die castings.

Most of the reasons for selecting copper for plating steel parts are self-explanatory. Copper is soft and is readily buffed. Although copper from acid plating baths has poor adhesion, plating of a copper “strike” from a cyanide bath solves the problems of adhesion and good coverage.

Types of Cyanide Copper Plating Baths