Case studies

A manufacturer of water-carrying precision components made of brass uses its parts with deionised (DI) water. It is precisely this purity that attacks brass: dezincification threatens – with loss of strength and tightness, up to leaks. In addition, the surfaces to be protected lay deep inside pipe and angle geometries that are hard to reach by electroplating.

SURPRO developed a tin-nickel coating for this, using an electrolyte that deposits well even at low current densities, combined with process control tailored to the internal contours. Cross-sections prove it: the protective layer evenly reaches the internal water-carrying areas as well.

For a manufacturer of cryogenic rocket engines, we gold-plated the inside of the Venturi throat – the narrowest point of the nozzle. Cryogenic propellants combined with ambient humidity can cause icing there and disturb the propellant flow; the gold layer counteracts this. The challenge was not the gold itself, but the deep, highly constricted geometry where standard processes fail due to shadowing and uneven layer distribution.

SURPRO therefore designed the plating rack, current distribution and electrolyte flow specifically for the Venturi geometry. A sectioned reference part confirms uniform gold deposition all the way into the throat – a validated process for demanding aerospace applications.

A manufacturer of electromechanical components for signal and power transmission needed highly conductive, wear-resistant contact surfaces – yet only a small part of each component is electrically active. Full-surface hard gold plating would have consumed unnecessary gold and significantly increased production costs.

SURPRO therefore combines two processes: the non-functional areas are masked by pad printing with a specially developed, plating-resistant lacquer system, after which only the exposed contact surfaces are hard gold plated. The result: 80% less precious metal, lower component costs and unchanged electrical performance – reproducible in serial production.