FIBER-REINFORCED Al-Li COMPRESSOR AIRFOIL AND METHOD OF FABRICATING

摘要

A metal matrix composite lightweight compressor airfoil. The airfoil comprises a braided fabric embedded in a lightweight aluminum-lithium alloy. The airfoils are fabricated by forming a plurality of fiber tows by twisting filaments or fibers. The tows are then braided into a fabric. The fabric may be impregnated with an optional fugitive polymer that temporarily occupies interstices of the fabric to facilitate handling of the pre-formed braided fabric, but which is subsequently removed. The airfoil may then be formed as a MMC by one of two separate methods. In the first method, aluminum-lithium alloy is pressure augmented casting into a die that includes a preform of fabric impregnated with fugitive polymer. In a second method, a preform is formed using a tool and mandrel by impregnating fabric with aluminum-lithium alloy. Then aluminum-lithium alloy is pressure augmented cast into a die that includes the alloy-impregnated preform.