| 摘要 |
<p>A cast aluminum piston for internal combustion engines having mechanically compacted inner boss bore faces, the structure of the aluminum material disposed below these inner faces having a grain pattern orientated in the circumferential direction of the boss bore over a radial depth of at least 0.1 mm and preferably 0.2 mm. This grain pattern is achieved by rolling at a temperature of at least 350 degrees C. up to 400 degrees C. with simultaneous expansion of the bore diameter by about 0.2 to 0.5 mm.</p> |
