PM法による炭素繊維/金属基複合材料の創製とその熱伝導·熱膨張特性

摘要

Carbon fiber/metal matrix composites were fabricated by powder metallurgy process, spark plasma sintering followed by rotary swaging, to achieve high heat conduction and low thermal expansion. Pitch-based carbon short-fiber was mixed with the powder of aluminum or copper. A volume fraction of the fiber was 40 percent. Orientation angles of the fiber to the compacting direction were measured in the longitudinal sections of the composites. Hermans' orientation parameter was adopted to evaluate the fiber orientation. The swaging process caused the parameter to change markedly from -0.9 to 0.9 in both of Al and Cu matrix composites. These values mean that the fiber is dispersed perpendicularly to the compacting direction in the sintered objects and dispersed in parallel to that one in the objects with swaging process. Thermal conductivity of the composites increases with increasing Hermans' orientation parameter. The thermal conductivity of Al and Cu composites was 210 and 420 W centre dot m~(-1) centre dot K~(-1) at room temperature, respectively. Coefficients of thermal expansion of both Al and Cu matrix composites decreased approximately 25 percent as compared with those of monolithic Al and Cu metals.