HIGH TEMPERATURE, ABRADABLE COATINGS FOR TURBINE ENGINE COMPRESSORS

THE COMPRESSION SYSTEMS OF CURRENT AND FUTURE GAS TURBINE ENGINES REQUIRE EXTREMELY TIGHT CLEARANCES IN THE HIGH PRESSURE COMPRESSOR IN ORDER TO OBTAIN AND MAINTAIN HIGH PERFORMANCE AND EFFICIENCY. MANY OF THE CURRENT COMPRESSORS USE THERMAL SPRAY COATINGS DEPOSITED ONTO THE COMPRESSOR SHROUDS WHICH ARE DESIGNED TO BE EASILY ABRADED BY THE TURBINE BLADE TIPS, THUS ACHIEVING TIGHT CLEARANCES. UNFORTUNATELY THE CURRENT STATE OF THE ART OF THESE COATINGS CANNOT WITHSAND THE INCREASING HIGH TEMPERATURE ENVIRONMENTS OF NEXT GENERATION HIGH PERFORMANCE TURBINE ENGINE SYSTEMS. THERMAL SPRAY TECHNOLOGIES ALONG WITH THE SUBCONTRACTOR, ALLIED-SIGNAL AEROSPACE GARRETT ENGINE DIVISION, PROPOSE TO DEVELOP AND EVALUATE NEW PLASMA SPRAY COATINGS DESIGNED TO BE ABRADABLE TO TEMPERATURES UP TO 1200F. THESE COATINGS WILL BE DEPOSITED ONTO SHROUDS IN THE TURBINE ENGINE COMPRESSOR SECTION. THE COATINGS ABRADABILITY WILL BE EVALUATED BY THIN TITANIUM AIRFOILS AT ROOM TEMPERATURE AND 700F. THE COATINGS ABILITY FOR THERMAL STABILITY/SURVIVABILITY (TEMPERATURES UP TO 1200F), COMPATIBILITY WITH COMMONLY FOUND ENGINE FLUIDS, ADHESION TO THE SUBSTRATE, AND THE ABILITY TO MACHINE A SMOOTH SURFACE FINISH TO MINIMIZE TURBULENT FLOW IN THE COMPRESSOR WILL ALSO BE DETERMINED. ALL COATINGS WILL BE DEPOSITED BY THERMAL SPRAY TECHNOLOGIES USING NOVEL PLASMA SPRAY TECHNIQUES DEVELOPED BY THERMAL SPRAY TECHNOLOGIES. ABRADABILITY TESTS WILL BE RUN BY ALLIED-SIGNAL AEROSPACE COMPANY.