Waterjet Stripping of Chrome Plate

ABSTRACT: Chrome plating is used extensively for aerospace and industrial applications because it is wear resistant, corrosion resistant, has a good surface finish and has good adhesion. Aircraft use chrome plating on landing gear components because of these characteristics. However these coatings eventually wear and have to be stripped and replaced. Stripping the chrome coating requires the use of acid baths, which generate waste through air borne contaminants, spills, drag-out, and bath fluid disposal after chemical activity is reduced. Overhaul facilities are faced with increasing costs to comply with regulations concerning these hazardous waste streams. Ormond's proposed solution is to replace these chemical baths with waterjet cavitation stripping which can economically strip hard chrome using only water that can be recycled in a closed loop system. The equipment required is readily available at Repair and Overhaul centers which allows for rapid adoption of the technology at low cost to the government. The process differs from the high pressure waterjet stripping used to remove thermal barrier coatings only in that it uses Ormond's cavitating nozzles to effect rapid coating removal without damage to the substrate. The process will also be applied to HVOF and other candidate chrome replacement coatings. BENEFIT: Waterjet cavitation stripping of hard chrome will reduce the hazardous waste from chemical stripping processes and eliminate the risk of hydrogen embrittlement and the need for post baking. This will say time and money for the repair and over haul facilities. Because Ormond's solution can use existing high pressure waterjet pumps and robots, the technology can be readily and inexpensively adopted by the government. This project will also address the stripping of candidate chrome replacement coatings such as HVOF WC-Co-Cr and nano cobalt phosphate.