In austere environments, erosion and corrosion seriously degrade the performance of airfoils in fan and compressor sections of gas turbine engines. To prevent damage to titanium airfoils, a powder metallurgy approach will be taken that produces a hard, erosion resistant leading edge. The leading edge should be strongly bonded to the blade body, have similar resonant characteristics (elastic modulus driven) as well as sufficiently similar to the chemistry of the blade body so as not to set up galvanic corrosion cells. The body of the blade will be fabricated using conventional powder to maintain the overall toughness of the blade in the event of large body ballistic impact. The approach that will be taken will be that of cryo-milling titanium alloy powder similar to that used in conventional blades, and using powder metallurgy techniques, such as HIP and CIP/HIP to assure that the hard, strong cryo-milled powder becomes an integral part of the leading edge of the blade. After milled and unmilled powders are placed so that the cryomilled powder will become the leading edge, consolidation will be followed by forging to obtain the proper airfoil shape.
Benefit: The commercial potential for an award and the subsequent successful completion of this program are enormous. The erosion problems encountered by military aircraft gas turbine engines are the same as those encountered by commercial gas turbine powered aircraft. Civilian blade manufacture will adapt the scheme used for improving military hardware, as this has historically been the route taken for aircraft engine innovation. The current civilian fleet of 3,000 gas turbine powered aircraft is expected to grow by several thousand over the next five years, according to estimates at this years Paris Air Show. Potential Market: With only two engines per aircraft, but 50 blades per engine plus spares, and retrofit of currently operating fan and first stage compressor blade sets, tens of thousands of erosion resistant blades per year, as developed under the proposed program, will be a conservative estimate of the potential market.
Keywords: High Strength, High Strength, lightweight alloys, Functionally Graded, ultrafine grain, magnesium alloys, manufacturing scalability
