Refinement of primary silicon in hyper-eutectic Al-Si alloy

Abstract

Effects of phosphor and other elements added to the hyper-eutectic Al-Si alloys, containing 20% of silicon on the microstructure of alloys are studied.The results of the experiments are summarized as follows:(1) Excellent refining effect of primary silicon were obtained by the addition of As as well as P, when each content is not less than 0.03%.(2) With the addition of P and As, on the cooling curves appearing the remarkable difference in comparison with other element.(3) Electromicroscopic examination of the refined silicon with the addition of P and As revealed a ting crystal shapes.The result of the experiments supported the hetrogeneous nucleation theory, commonly believed to be the mechanism of phosphorous refinements.