| 摘要 |
PURPOSE:To provide a titled composite material which has an excellent water leaking characteristic and sliding wear characteristic and does not attack the mating material by exerting an external pressure to a cast iron fiber molding specified in size and length and a matrix consisting of Al (alloy) and casting the matrix thereby forming the intermetallic compd. with the matrix on the surface of the cast iron fibers. CONSTITUTION:A 4-cycle engine piston is manufactured by using a direct extrusion- pressurizing method. More specifically, an annular molding 1 is manufactured of the cast iron fibers 1a, 1b... having <=100mum diameter and <=10m length and is inserted below a master mold 3 of a molding device 2. The intermetallic compd. is then formed to a suitable mat. from the Al alloy such as AC8A as the matrix 10 and the above- mentioned molding 1 by the direct extrusion-pressurizing method and is then solidified to cast the piston. More specifically, the fiber molding 13 consisting essentially of the cast iron fibers is composited with the head part of the piston 11 shown in the figure and thereafter grooves 14, 15 for piston rings are worked. As a result, the attacking characteristic of the piston and the piston rings is made soft by the lubricity of graphite and the hard layer is formed on the surface of the piston by the formation of FeCl3, etc. by which the sliding friction characteristic is improved.
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