ELEVATED TEMPERATURE ALUMINUM IRON X ALLOYS

THE EVER INCREASING DEMAND TO INCORPORATE LIGHTER WEIGHT, LOWER COST ALLOYS FOR AEROSPACE APPLICATIONS HAS LED TO THE DEVELOPMENT OF A SERIES OF ALUMINUM-LITHIUM-X (AL-LI-X) AND ALUMINUM-IRON-X (AL-FE-X) ALLOYS. AL-LI-X ALLOYS PROVIDE SIGNIFICANT WEIGHT AND LIFE-CYCLE COST REDUCTIONS IN AIRCRAFT STRUCTURES BY VIRTUE OF THEIR HIGH STRENGTH IN CONJUNCTION WITH LOW DENSITY AND HIGHER MODULUS AS COMPARED WITH PRESENT COMMERCIAL HIGH STRENGTH 2XXX AND 7XXX SERIES ALUMINUM ALLOYS OR OTHER ALTERNATIVES SUCH AS TITANIUM ALLOYS OR ADVANCED COMPOSITES. AL-FE-X IS ANOTHER CLASS OF CURRENT ALLOY SYSTEM INTENDED FOR ELEVATED TEMPERATURE APPLICATIONS, AND SHOWS GREAT POTENTIAL TO ECONOMICALLY REPLACE TITANIUM ALLOYS. THESE ALLOYS HAVE SHOWN PROMISE TO OPERATE AT OR NEAR CAPACITY WITH RESPECT TO STRESS AND TEMPERATURE, BUT HAVE YET TO BE TESTED FOR THEIR CORROSIVE RESISTANCE BEHAVIOR. DETAILED INFORMATION ON THE CORROSION BEHAVIOR SUCH AS CREVICE CORROSION, GALVANIC CORROSION, EXFOLIATION, OF THESE ALLOYS IS LACKING. THEREFORE, IT IS PROPOSED TO CONDUCT AN INVESTIGATION ON AT LEAST SOME OF THEMOST PERTINENT CORROSION PROBLEMS EXPECTED IN APPLICATION.