In a crankcase of a reciprocating piston engine is cast into the cylinder liner from a hypereutectic aluminum / silicon - alloy

摘要

A cylinder liner sealed into a reciprocating piston engine and comprises a strongly supereutectic aluminium/silicon alloy of a specified composition which is free of melt-independent particles of hard material and which is composed in such a way that fine silicon primary crystals and intermetallic phases automatically form from the melt as hard particles. By means of spray compaction, a blank is allowed to grow from finely sprayed melt droplets, with a fine distribution of the hard particles being produced by the setting of small melt droplets. The blank can then be formed by cold extrusion to give a shape approximating the cylinder lining. After subsequent premachining, the face is fine machined, subsequently honed in at least one stage and then the hard particles lying at the face are exposed, forming plateau areas of the particles which project above the remaining surface of the base microstructure of the alloy. The mechanical exposure of the primary crystals or particles is carried out in the manner of a honing process using felt strips which are cylindrically shaped on the outside and a slurry of SiC particles in honing oil.