Abstract: The effect of superheating on the solidification in Al-Si 16% o alloy is investigated. It is showed that the amount and size of the primary silicon phase increased greatly after superheating of high temperature (＞900℃). The latent heat and initial temperature of primary solidification also increased obviously after high temperature superheating (＞900℃) by DSC analysis. By the way of X-ray diffractemeter, it is found that the atomic coordination number of Al-Si16% alloy is higher than pure Al at high temperature (> 900℃) and less than pure Al at low temperature (<900℃). The peaks implied solid Si phase appeared on diffraction intensity cure of liquid Al-Si16% alloy after superheating of high temperature while they were absent in the case of low temperature superheating.

Key words: Al-Si16 %, Solidification, Superheating temperature