DIAMOND-COATED COMPOSITES FOR ABRASION RESISTANCE

COMPOSITE MATERIALS ARE ATTRACTIVE FOR USE IN AIRCRAFT AND SPACECRAFT OWING TO PROPERTIES OF HIGH SPECIFIC STRENGTH. A PROBLEM CONFRONTING THE APPLICATION OF COMPOSITE MATERIALS FOR ROTORCRAFT IS THAT UNIMPROVED LANDING AREAS, AS WELL AS LOW ALTITUDE MISSIONS, RESULT IN SEVERE ABRASION OF THE COMPOSITES, PARTICULARLY ON COMPOSITE BLADES. OTHER SOURCES OF ABRASION ON BLADES, AS WELL AS AIRFRAME STRUCTURES, ARE THE EXHAUST FROM ROCKETS AND MISSILES FIRED FROM THE AIRCRAFT. RECENT EXPERIENCE IN OPERATION OF HELICOPTERS IN THE SAUDI ARABIAN DESERT HAS SHOWN THAT OPERATION IN A DESERT ENVIRONMENT RADICALLY SHORTENS THE LIFETIME OF ROTORCRAFT LEADING EDGES WHICH ARE COMPOSED OF COMPOSITES, TO THE DEGREE THAT KEY ARMY ATTACK HELICOPTERS WERE REPORTED TO HAVE BEEN RESTRICTED FROM TRAINING MISSIONS IN THE SAUDI DESERT. TO CIRCUMVENT THIS PROBLEM, HIGH INTEGRITY COATINGS ARE NEEDED FOR HIGH PERFORMANCE COMPOSITE COMPONENTS TO IMPROVE THE LIFE OF ROTORCRAFT BLADES AND OTHER KEY STRUCTURES AGAINST ABRASIONS. IN SUCH CASES THE COATING REPRESENTS AN ENABLING TECHNOLOGYH WHICH PERMITS THE OPERATION OF A MULTIMILLION DOLLAR FLIGHT VEHICLE. IT IS PROPOSED TO EXPLOIT RECENT TECHNOLOGY DEVELOPED FOR DIAMOND THIN FILM DEPOSITION ON CARBON/CARBON COMPOSITES AND OTHER MATERIALS FOR THIS PURPOSE.