Abstract
Cylindrical aluminum alloy matrix composites (MMC) containing alumina fibers were fabricated by applying a centrifugal force to fibrous preforms at room temperature before infiltration. Fiber segregation towards the outer periphery disappeared after infiltration, since boiling of carbon-tetrachloride as a mixture with the fibers relieved fiber segregation at the drying stage between the centrifuge and infiltration processes. However, the fibers tended to be aligned with a tangential direction of cylindrial fibrous preform by a centrifugal force. The MMC with high fiber volume fraction (Vf) showed only a poor alignment of fiber due to the dense fiber packing, while the one with low-Vf also showed a poor alignment due to long fiber length. Consequently, the MMC with Vf of nearly 20% showed the highest strengthening efficiency in bending tests. The bending strength increased with increasing Vf, and showed about a 200MPa rise compared to those of the MMC with the planar-randomly oriented fibers and the same Vf.
