Replacement of chromium electroplating using advanced material technologies on gas turbine engine components

Navy and Army Depots, and Air Force Air Logistics Centers (ALCs) generally use electrolytic hard chrome (EHC) plating in gas turbine engine maintenanc e operations to rebuild worn or corroded Darts, restore dimensional toleran ce, and replace worn or damaged chrome previously applied. This process inv olves the use of hexavalent chromium (hex-chrome), a known carcinogen. Hex- chrome is listed on the U.S. EPA's list of 17 "toxic enemies" and its 33/50 program targeted for hazardous material reduction, OSHA is considering dec rease of the personal exposure limit for hex-chrome from the current 0.1 mg /m(3) to 0.005 mg/m(3), Complying with these new regulations will significa ntly increase the compliance burden and operational cost of EHC plating. Th is paper, from the 2000 AESF Aerospace/Airline Plating and Metal Finishing Forum, outlines a joint project by the ALCs and OEMs (including GE Aircraft Engines) to demonstrate and approve thermal spray and HVOF coatings of gas turbine engines, The project, budgeted for more than $3M over three years, is starting in fiscal year 2000, It is anticipated that this project will demonstrate not only reduced pollution but also reduced weapon system cradl e-to-grave costs by lowering the cost of operation and maintenance, Expecte d benefits include: (1) Processing time will be significantly shorter for t hermal spray and HVOF coatings than EHC; (2) reductions in hex-chrome emiss ions; and (3) thermal spray and HVOF coatings are expected to reduce the fr equency of component repair and defer the need to fabricate replacement par ts for older engines,