| In this paper, optimum sintering condition of SiC_w/Al alloy composites by cold press-sintering method have been investigated in relation with density and hardness of the composites through a process variables such as pressure, sintering time, sintering temperature and sizing. A large amount of SiC whisker was observed to be surrounded grain boundary when Al poweder was coarsened. Green density of the composites was decreased with an increase of the volume fraction of SiC whiskers upto 15% and increased as compacting pressure increases 500㎫ to 700㎫. After sintering, both density and hardness of sintered composites was decreased with increasing SiC whisker volume fraction. It was found that the volume of increases with the volume fraction of SiC whiskers, whereas the volume of aluminum alloy matrix decrease. The relative density of the composites approved to increase with the repressure, sintering time and temperature. In particular, the hardness was significantly decreased in the temperature range of 100∼250℃ and steadily decreased above 250℃. The hardness of the composites with 15% SiC whisker was eight times greater than that of aluminum alloy matrix at 450℃. |
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