Fiber Orientation Control and Evaluation of Characteristics of Short Fiber Reinforced Metal Matrix Composite Fabricated by Low-pressure Infiltration Process

摘要

The microstructure control technique for short fiber reinforced MMC fabricated by LPI process was developed. The SiC short fiber was used as reinforcement and the Al-4mass%Cu alloy and Al-7mass%Si alloy as matrix. To control the volume fraction and the orientation of the fibers, the mixture consisting of Al particles (10 μm and 150 μm in diameter) and SiC short fibers was prepared as a preform. The preform and matrix were placed in silica tube container and then the alloy melt was forced to infiltrate into the preform by pressing with Ar gas. When only Al particles of 10μm in diameter were used in the preform, most of the fibers tend to orientate perpendicularly to the infiltration direction. On the other hand, when Al particles of both 10 μm and 150 μm in diameter were used, the fibers oriented randomly. It was suggested that large Al particles in the preform contributed to control the distribution of the three-dimensional orientation of fibers.