| 摘要 |
A method of making an engine block with coated cylinder bore walls by: (a) casting the engine block of metal primarily with a low cost aluminum alloy such as 319 grade, (b), removing contaminants from the cast cylinder bore walls to provide at least one annular cleansed fresh metal surface, (c) depositing a plasma sprayed coating onto the surface with a powder mixture containing solid lubricant particles that provide a dry coefficient of friction of .3 or less, (d) shaping such coating to be concentric about the true axis of said cylinder bore walls, and (e) honing the coating to final finish smoothness. Exposing fresh metal (removal of any metal oxide) can be carried out by grit (shot) blasting, electric discharge erosion, mechanical machining of serrations, or by plasma etching. Concentric shaping may be carried out either by rough machining the cylinder bore walls followed by deposition of the thinnest coating that requires only finish honing, or by deposition of a thicker coating followed by rough honing of the coating to concentricity.
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