Abstract:Using high temperature X-ray diffraction analysis, the liquid structures of Al-13%Si alloy at 625~1 250℃on heating and those at 675℃after overheating of various temperatures were presented. It is shown that the atomic density and coordination number of the melt increased slightly at first, then decreased greatly at 775~875℃. The liquid structure of the melt at 675℃and the morphology of the solidified alloy had no obvious change after overheating at various temperatures. These results indicate that structural transformation happens in liquid Al-13%Si and it is reversible.

Key words: Al-13%Si alloy　structural transformation　X-ray diffraction analysis