Hyperion Electroforming, Inc., specializes in the manufacture of coldshields, but other small parts can be made using some or all of the same processes. Parts that are less than approximately 4.5 inch (115 mm) diameter by 6 inch (150 mm) height are considered "small" in this context.
Our capabilities include copper plating or electroforming from conventional copper sulfate bath, and nickel plating or electroforming from conventional nickel sulfamate or Watts nickel baths.
Gold plating is available per the current version of ASTM B 488, Type 2, or MIL-G-45204, Type I; both of these specifications designate minimum gold purity of 99.7%. Note, however, that MIL-G-45204 is obsolete, so the preferred specification is the latest version of ASTM B 488.
Coldshields are usually made with a copper-nickel-gold laminate, but other combinations are also easily produced. For example, for some applications it may be desirable to combine the thermal properties of copper with the corrosion resistance of nickel by making an electroform that is mostly copper with a thin deposit of nickel on the interior and the exterior surfaces. Similarly, when nickel is selected for its wear resistant properties, a thin layer of copper can be included to provide a visual indicator of having reached the part's wear limit.
Because electrodeposition starts at zero thickness, any deposit thickness is possible; however, in practice the thickness of copper or nickel deposits is usually limited to not more than approximately 1/8 inch (3 mm). Without incurring the cost of secondary machining or grinding operations, deposit thickness is typically controlled to within ±10% of the nominal thickness.
Since gold is much more expensive than either copper or nickel it is usually used only for thin deposits; both ASTM B 488 and MIL-G-45204 limit consideration to nominal deposit thickness of 200 µinch (5 µm) or less. Gold is available in thicker deposits, however.