Mechanical Behaviors of Aluminum Alloys Reinforced with B and SiC Filaments, and Application of B-Al to High-Speed Rotor Cylinder

Abstract

B- and SiC- reinforced-aluminum alloys were consolidated under the diffusion bonding condition without using the vacuum bagging process. Metal cylinders reinforced with the filaments in the hoop direction were consolidated under a high bonding pressure introduced by the difference in thermal expansion between the inner and the outer dies heated to the consolidating temperature, while reinforced metal plates were consolidated with a hot press.B- and SiC- aluminum alloys were shown to have high strength and high tensile modulus not only in the direction of reinforcing filaments but also in the direction perpendicular to reinforcement. The strengths of B- and SiC- aluminum alloys were about 85 and 75% of the values calculated by the rule of mixtures, respectively, while the tensile moduli coincided rather well with the predicted values for both materials. The ratio of the fatigue strength to the tensile strength for B- and SiC- aluminum alloys was large in contrast with the small ratio for an aluminum alloy reinforced with SUS 304 filament.The hoop strength and the tensile modulus of B- and SiC- aluminum alloy cylinders coincided relatively well with those of the corresponding reinforced plate specimens.A high speed rotor made out of a B- aluminum alloy cylinder with a diameter of 200mm and a length of 300mm was shown to have a stable properties and endured the circumferential speed of 675m/S (64200rpm).