Hard Chrome Replacement

Chrome plating (electroplated hard chrome or EHC), has provided a surface treatment for the reduction of wear, and in some cases corrosion, for more than 70 years. However, there is an environmental issue with the hard chrome plating process. Chrome itself is essentially inert, and is in fact safely used in everyday items such as stainless steel cutlery. But, the hard chrome plating process uses a chromic acid solution, which enters the air in the form of a fine mist. This mist contains chromium ions in the hexavalent state, which has long been known to be carcinogenic. As a result, under the authority of the Clean Air Act, the EPA has recently promulgated new and more stringent rules to limit hexavalent chrome releases to the environment. These rules have increased the cost and complexity of hard chrome plating.

Luckily, over the past ten years HVOF (high velocity oxygen fuel) coating technology has developed the point where it is typically superior to chrome. According to the Hard Chrome Alternatives Team (HCAT), in general it is found that the performance of HVOF coatings is far superior to chrome in wear, fatigue, and impact resistance, and is at least equal in corrosion resistance. Furthermore, the HVOF deposition process is faster than chrome (typically an hour or two versus 24 hours) and HVOF does not cause hydrogen embrittlement (which also eliminates embrittlement relief heat treatments). The consequent reduction of in-shop time makes many landing gear components significantly cheaper to coat by HVOF than by chrome plating. Even where HVOF is a more expensive process, its improved performance lowers the expected overhaul frequency, reducing the lifetime cost of ownership. On the basis of overall cost and performance, therefore, it makes sense to replace hard chrome with HVOF coatings.

BASF Catalysts HVOF coatings can replace hard chrome plate in demanding applications such as aerospace landing gear, actuators and jet engine bearing applications. BASF Catalysts’s unique off-angle spray capability allows HVOF coatings to be applied to inside diameters up to 2.5 times the diameter size.

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