DEVELOPMENT OF HOT CORROSION RESISTANT ALLOYS USING ION BEAMPROCESSING

A FEASIBILITY STUDY WILL BE CARRIED OUT FOR DEVELOPING APPROPRIATE ION IMPLANTATION AND ION BEAM MIXING PROCEDURES TO SELECTIVELY IMPLANT IN ALLOY THE NEAR-SURFACE REGIONS OF INDUSTRIAL GAS TURBINE BLADE ALLOYS IN 939 AND IN 597 (NICKEL BASE SUPERALLOYS) FOR IMPROVED HOT CORROSION RESISTANCE. IONS TO BE IMPLANTED/USED IN ION-BEAM MIXING ARE YTTRIUM, CERIUM AND PLATINUM WHO HAVE BENEFICIAL EFFECTSON THE HOT CORROSION RESISTANCE OF THE ABOVE ALLOYS. A DEPOSITED LAYER OF THE APPROPRIATE ION ON THE SUBSTRATE WILLBE USED FOR THE ION-BEAM MIXING. ION BEAM PROCESSING WILL BE DONE USING THE ACCELERATOR FACILITY AT UES WITH ION ENERGY UP TO A FEW MEV AND DOSEAGE UP TO ABOUT 10(16) ATOMS PER CM (2). THE ION CONCENTRATION PROFILE IN THE NEAR SURFACE REGIONS WILL BE EVALUATED BY THE MASS (SPECIES) SPECIFIC THE RUTHERFORD BACKSCATTERING METHOD. CRUCIBLE TESTS WILL BE CONDUCTED IN AN ELEVATED TEMPERATURE IN THE PRESENCE OF NA(2)SO(4) TO ASSESS THE EFFECTIVENESS OF THE SURFACE MODIFICATIONS IN HOT CORROSION ENVIRONMENT AND TO ARRIVE AT THE POTENTIAL ION IMPLANTATION ION BEAM MIXING PROCESSES FOR EXTENSIVE STUDY IN PHASE II AND FOR COMMERCIALEXPLOITATION IN PHASE III. MICROSTRUCTURAL CHARACTERIZATIONOF THE SUBSTRATE AND ION-IMPLANTED ALLOYS WILL BE CARRIED OUT USING OPTICAL AND ELECTRON MICROSCOPY.