Abstract

The Replacement of Electroplating

Author(s): Sara Brown

With growing concern about the hazardous wastes generated by traditional metal finishing operations, there is a major push in the United States to replace "dirty" electroplating methods (particularly chrome and cadmium) with "clean" technology. While many corporations and military organisations continue to use less polluting electroplates, others are abandoning bath technologies entirely in favour of current high performance dry coating processes like as Physical Vapour Deposition (PVD), Chemical Vapour Deposition (CVD), and thermal spraying. Various dry alternatives to electrolytic hard chrome, such as PVD, plasma nitriding, high velocity oxyfuel (HVOF), laser CVD, and laser cladding, have been investigated for use in both original equipment manufacture and rebuilding worn components with funding from the US Defense Department's Advanced Research Projects Agency. In this work, hard chrome replacement is utilized to demonstrate the criteria for electrolytic coating replacement in general. Hard chrome replacements are being studied to verify that they not only function at least as well as the chrome they replace, but also fit with how the coated components are manufactured, utilized, and maintained. They must be dependable and cost-effective, and they must meet the demands of the end user over the coated component's full life cycle. HVOF, PVD, and duplex plasma-nitride PVD coatings show significant potential as replacements in a wide range of applications, including bearing surfaces, hydraulics, and ornamental finishes. Performance statistics along with cost evaluations demonstrate that these alternatives can be cost-effective chrome replacements.