Heat Treat Services
For your Heat Treat requirements, ProPlate® has facilities for heat treating both small and large parts.
Copper is the second most common metal plated, behind nickel. It provides a soft, red, ductile, solderable surface. Copper is an excellent electrical conductor. However, it is not often used as a final plate because it tarnishes easily.
MIL-C-14550, ASTM-B734, AMS 2418
Copper is able to fill sharp corners and surface imperfections allowing smooth and uniform coverage of the base metal. The throwing and leveling properties of copper insure that pinholes and subsequent blistering of finish metals will be avoided.
Because copper has excellent leveling properties and very high throwing efficiency, it makes an excellent undercoat for most other metals. In addition, because copper is ductile, it polishes easily to a high shine so that it supports a bright, shiny finishing metal above it.
Generally copper is applied as an underplate in thickness between 100 and 200 micro inches.
Anti-diffusion & Multi-Layer Plating
Metallic copper diffuses very rapidly through metallic gold. However, copper will not diffuse through nickel or palladium. For this reason, a layer of nickel or palladium should always be considered between copper and gold. Copper which has diffused through gold will appear on the outer surface of the gold electrodeposit and will quickly begin to form a partial oxide layer on the surface of the electrodeposited part.
Nickel is generally suggested as the anti-diffusion layer owing to its lower material cost. However, nickel is a magnetic metal whereas palladium is not. So in applications where non-magnetic performance is required, palladium would be the antiduffusion layer of choice. It could also be considered in a non-magnetic, non-oxidizing application as a replacement to gold.
Copper makes an excellent undercoat on aluminum, which is a base metal that most other electrodeposited metals will not attach to. Also, copper is also about the only metal that can be electroplated onto zinc die casts.