An Alternative to Electroplating
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New nickel-chromium-plating process does not use hexavalent or trivalent chromium By Dean JobbNickel Magazine, March 2007 -- Two California inventors are promoting an inexpensive and environmentally friendly process for chrome-plating automotive wheels, marine hardware, faucets and other items that require a decorative and durable finish. The process uses vacuum metallization technology and a nickel-rich chromium alloy. “This is going to revolutionize the way wheels are chrome-plated,” predicts Gary Goodrich, president of California-based Goodrich Technology Corp. and co-developer of the patented composition and process. The Chrysler division of Daimler Chrysler has approved the finish – marketed under the trade name PermaStar – for its vehicles. General Motors, Toyota, Honda and other carmakers are already either taking a look or already testing the product for themselves. Goodrich and co-inventor Patrick Colahan set out to find an alternative to traditional electroplating. “We are two guys who saw a need years ago for a chrome alternative,” says Colahan, who brought his experience in production engineering to the search. Goodrich was in the business of remanufacturing aluminum wheels and wanted to find a better way to refinish rims. The process works like this: two layers of primer are applied to a substrate at high temperature, producing what Colahan calls “a glass-like finish” without the usual mechanical polishing. The primed wheel or other object is then placed in a vacuum metallization chamber containing a small amount of argon gas. A base coat of 80% nickel and 20% chromium is vaporized and applied to the object to a thickness of 1,000 angstroms. “It’s put down atomically, one atom at a time,” says Goodrich. The same process is used to apply an additional 500-Angstrom thick layer of pure chromium. The final step is to add a protective acrylic topcoat. Colahan and Goodrich experimented with other metals, including other nickel alloys and titanium, but 80-20 nickel-chromium – the first alloy they tried – proved to work best for the base layer. Colahan says the chromium addition helps to vaporize the nickel. There also appears to be benefits for the natural environment with the new process. Each wheel uses less nickel and chrome and weighs less than a conventionally plated wheel. Thus there are material savings when the wheel is made, and less nickel and chromium lost when the wheel is eventually recycled. “You get a highly reflective chrome look that can hold up to corrosion,” Goodrich says. The coating adheres to various substrates – steel, magnesium, bronze, brass, aluminum and plastic – and can be used any place where corrosion is a factor. The coating has been successfully tested on porthole rings, vents and other deck fittings of a U.S. Coast Guard cutter. The PermaStar coating boasts two important advantages: the application process does not use hexavalent or trivalent chromium or other hazardous compounds, and claims to have significant cost savings (Colahan projects that a production line capable of turning out 100 wheels per hour could apply the coating for US$8.75 per wheel, compared with at least $45 for conventional plating). Goodrich Technology patented its application process in 2002 and obtained a patent for its coating
compositions in December 2006. A California manufacturer has been licensed to use the process, and the
company is negotiating with other potential licencees in the Dean Jobb is a Halifax, N.S.-based freelance writer. Photos: Goodrich Technology Corp.
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