Military connectors are getting a ‘green’ make-over with an eco-friendly, cadmium-free black plating. Acal Bfi tells buyers what to watch out for
Having eliminated lead from virtually all electronic components, the directive on the Restriction of Hazardous Substances (RoHS) is now focussing attention on cadmium. Unlike lead, however, where defence, aeronautical and other critical equipment was exempt, the Ministry of Defence is set to phase out cadmium plating on military connectors. It will be replaced with a new, and more environmentally-friendly, black zinc nickel plating.
The supply chain is already gearing up to provide the new cadmium-free black connectors. For Amphenol and Acal BFi this will be a UK-based process, with plating carried out by Amphenol in Whitstable, and assembly by Acal BFi, in its Amphenol-approved facility in Wokingham.
Acal BFI’s interconnect product manager, Farzana Riaz, explained: “Amphenol has designed and installed a new processing line at its UK plating facility. In preparation for the launch of the cadmium-free connectors, Acal BFi is putting in inventory and preparing to assemble and ship samples of Amphenol black zinc nickel-plated connectors from January 2013. Both companies will be working closely with customers’ buyers and engineers to ensure that the transition to the new finish will be as smooth as possible.”
Plan for transition
For buyers, this means looking at the plating on standard military connectors, such as the Mil-DTL-38999 and Mil-C-26482, to ensure they have a plan for the change-over.
In some ways, the transition from traditional olive-green cadmium to black zinc will be easier for buyers than the move from lead-inclusive to lead-free. For Amphenol, the type of coating will be specified using a different identifier within the part number. At goods-in, all it will take is a simple visual inspection to confirm whether the connector is olive-green or black.
The main driver for the change is the reduced environmental impact, but black zinc nickel-plated connectors are also capable of providing rugged performance in harsh environmental conditions. This is crucial because, typically, connectors such as Mil-C-26482, Mil-DTL-38999 and Amphenol’s Rhino 38999 series, are used in military as well as other harsh applications including next-generation electric and mass transit vehicles, or vehicles used in difficult environments, as well as in communication, power generation and metering equipment.
The conductive, non-reflective finish of the new black zinc nickel plating allows connectors to operate between -65 and 175°C, in accordance with Mil-DTL-38999, and the finish is approved to withstand 500 hours of exposure to salt spray.
Further tests by Amphenol have demonstrated that black zinc nickel has a high level of compatibility with other plating materials and there are no significant galvanic reactions with cadmium, zinc cobalt or electro-less nickel-plated parts. While not recommended, this means black zinc nickel-plated connectors could still be mated with legacy connectors during the transition period.
Get specialist advice
Making the change will need the combined efforts of buyers and engineers. Acal BFi is working with the design and chemical analysis teams at Amphenol to provide customers with specialist advice on selecting the most appropriate plating finish for each application. For critical applications, Acal BFi can arrange tests in Amphenol’s UK test facility, using analytical technology such as x-ray fluorescence and an atomic absorption spectrophotometer.
Commercial advice will also ensure that the correct part number is specified for cadmium and black zinc nickel-plated connectors, as well as providing fast prototyping and volume assembly of connectors from Acal BFi’s UK manufacturing facility.
The change from conventional olive-green connectors to the new black finish promises to be less complex than the change to lead-free, however buyers and engineers could still find that advice and fast prototyping, from specialists such as Amphenol and Acal BFi, could help them to go green by changing to black connectors.