| 摘要 |
PROBLEM TO BE SOLVED: To obtain a hypereutectic Al-Si alloy casting having excellent wear resistance even without cutting off the casting surface by crystallizing the primary crystal of Si even the surface layer part. SOLUTION: After pouring molten the hypereutectic Al-Si containing 13.5-25 wt.% Si into a mold such as a metallic mold, a graphite mold, a gypsum mold, the molten metal in contact with the inner surface of the mold at the temp. range between the primary crystal of Si crystallize-starting temp. and the eutectic temp., is cooled at average cooling rate of <=100 deg.C/sec. The average cooling rate of <=100 deg.C/sec is achieved by holding the mold temp. at >=300 deg.C, succeedingly pouring the molten metal into a specified portion in the inner surface of the mold, incorporating a heating mechanism or heat-insulating material into a specified position and applying satin-like finishing onto the inner surface of the mold.
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