Development of metal-matrix composite blading for gas-turbine engines.

Abstract

Metal-matrix composite materials are of interest for aircraft gas-turbine engine compressor blading because they offer significant weight savings, resulting in increased aircraft payload and range. Design of these lightweight blades requires development of analytical techniques to determine the stresses and behavior of these anisotropic structures for both steady-state and vibratory loadings. An initial survey of composite material systems indicated that the most promising system for study was boron filament in an aluminum matrix. Tensile specimens of this material with 30 to 40 vol. % boron demonstrated specific strengths which exceeded that of conventional titanium by better than 50%. A simulated boronaluminum airfoil was produced containing unidirectional boron filaments which constituted 36 vol. % of the material. Testing indicated that the composite material airfoil had li times the torsional stiffness and better than twice the bending stiffness of a similar all-aluminum airfoil.