METHOD FOR REFINING PRIMARY SILICON OF HYPEREUTECTIC AL-SI ALLOY

摘要

A method for refining the primary silicon of a hypereutectic Al-Si alloy adopts the TiB₂ particle phase to refine the primary silicon of the hypereutectic Al-Si alloy during the general casting of the hypereutectic Al-Si alloy. According to the method, the TiB₂ particle phase is adopted to refine the primary silicon of the hypereutectic Al-Si alloy during the casting of the hypereutectic Al-Si alloy, and the primary silicon can be refined to a size below 50 micrometers under the general casting condition. With high stability of the TiB₂ particle in the molten Al alloy, the refining effect is lasting, and the modifying and refining effects on the eutectic silicon in the alloy by the element of Sr or Na can not be affected; and the eutectic silicon and the primary silicon of the hypereutectic Al-Si alloy can be refined at the same time, so that the performance of the alloy is greatly improved.