| 摘要 |
PURPOSE:To obtain the titled inexpensive composite material containing large amounts of graphite and excellent in collapsing strength, wear resistance, and tip stability, by adding a graphite powder to short fibers, as a matrix, prepared by cutting steel long fibers made by a wire shaving method into pieces and then by subjecting the resulting mixture to compacting and sintering. CONSTITUTION:The short fibers, e.g., of 20-30mum diameter are prepared from a low-Mn steel containing, e.g., 0.1-0.15% C, 0.05-0.10% Si, and 0.9-1.3% Mn by a wire shaving method. Then these long fibers are cut into pieces by means of a cutter mill, etc., until the prescribed aspect ratio is reached, so that desired short fibers are prepared. Subsequently, the graphite powder is added to the above short fibers as a matrix material, which is mixed by means of a ball mill, etc. Then, a green compact prepared by filling a metal mold with the above mixture and applying compaction is heated and sintered in a reducing atmosphere at a required temp. for a required length of time, so that desired metallic short fiber - graphite composite material can be obtained. Moreover, strength can be improved to a greater extent in this composite material by further application of heat treatment.
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