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Zinc alloy coatings have been used commercially since the early 1980's. Its origin is credited to both the Japanese and Europeans, where improved corrosion protection was observed over steed components. The coatings gained acceptance among American automotive companies in response to two industry-wide directives. The first was the mandate to restrict the level of cadmium on vehicles, beginning with the 1995 model year. The other was the challenge to extend the service life of vehicles to ten years, or in effect, to develop the “ten-year” car. Alternative finishes were sought as potential replacements for cadmium. Although a single surface finish has not been identified to have all of the functional characteristics of cadmium, zinc alloy coatings have many of the desirable properties. Among them are corrosion resistance and lubricity. Also, an added benefit is the extended corrosion protection that qualifies the zinc alloy coatings for the ten-year vehicle.

The Clean Air Act of 1990 stipulated tougher industry-wide standards for environmental pollution control from mobile sources. One way the U.S. automobile manufacturers may achieve compliance with the more stringent federal standards is to produce cars which utilize cleaner burning methanol blend fuels. However, the major shortcoming of the methanol blend powered vehicle is the accelerated corrosion of metallic components in direct contact with the fuel. Consequently, a laboratory test program was developed to screen suitable materials for the corrosive fuel environment. The metals selected for this test series were based on corrosion data from the National Association of Corrosion Engineers (NACE). They include stainless steel 304, 1010 steel and 356 aluminum. Established protective coatings and surface treatments, namely, electroless nickel, DACROMETB and conventional anodizing were also included in the test series.