| 摘要 |
A piston is manufactured by incorporating a reinforcement which is formed at least in part by a fibre material and which is so non-uniform as to provide differing characteristics in the cast piston in predetermined differing regions of the piston. For example, the volumetric density of the fibres may be different in one region of the reinforcement as compared with another region in order to produce a more resistant region in the cast piston. Additionally or alternatively, the reinforcement may hold finely divided materials which combine with the piston material during casting to give improved properties. Examples of this are the incorporation of particles of silicon, silicon carbide or silicon nitride to improve wear and/or the incorporation of molybdenum disulphide and tungsten disulphide or graphite to improve lubrication. |
