Validation of Functional Trivalent Chromium Plating Process

Problem/Impact: All DoD maintenance facilities are under pressure to reduce or eliminate the use of hexavalent chromium. Traditional chromium plating releases a mist of highly corrosive droplets that poses a risk to process operators. Hexavalent chromium has been implicated in long-term health effects, including cancer. It is also coming under an increasingly restrictive regulatory regime.

The urgency of this issue was underscored by a recent memorandum from the Under Secretary ofDefense, referring to the need to minimize or eliminate the use of hexavalent chromium as an “extraordinary situation”, requiring DoD to “go beyond established hazardous materials management processes” and to “more aggressively mitigate the unique risks to DoD operations now posed by” hexavalent chromium. Currently, solutions to the problem involve alternative technologies such as high velocity oxy-fuel, HVOF spray coating are either impractical/impossible for certain plating geometries (inside diameters) or extremely expensive to implement at DoD depot facilities.

In Phase I, an alternative electroplating process was developed that uses a safer trivalent chromium solution (in place of hexavalent chromium) in the plating bath without requiring a major upgrade to the plating facility. The unique process, introduced by Faraday Technology, not only avoids hexavalent chrome but also was shown to produce comparable or even better wear-resistant coatings. Further testing and verification is needed to validate the new trivalent chrome plating process.

Solution/Approach: Validate the unique trivalent chrome process developed in Phase I can in fact meet or exceed DoD and industry test standards compared to hexavalent chromium process.

Benefit: If the coating produced by the Faraday process performs comparably to the coating produced by the traditional hexavalent chromium process, the goal of minimizing worker exposure to hexavalent chromium will have been significantly advanced. In addition, if the coating is actually superior, in that it significantly extends the service life of parts in the field, the benefits could be substantial. For example, if the tri-chrome plating extends the time between stripping and re-plating by 20% due to longer wear, there will be corresponding benefits in readiness and cost savings.

Implementation: In the Phase II project, a prototype plating process will be set up and optimized in a lab environment that closely matches plating parameters used in a typical chrome plating facility. Test specimens will be plated and compared to hexavalent chromium-plated test specimens using a series of standardized tests per DoD and aircraft industry specifications. Additionally, a special test will be run to measure the potential presence of the more toxic hexavalent chromium in the trivalent chromium bath (if any) after a reasonable period of processing time.

NCMS Project Manager: Bill Chenevert (734)995-7989