An experimental schematic for examining effects of modification on surface tension of ZL102 Al-Si alloy is designed to establish a mathematical model by the regression orthogonal method

and the surface tension of ZL102 Al-Si alloy melt is measured in the front of the furnace by self-developed rapidly measuring surface tension apparatus. The results show that the influencing orders on surface tension of the ZL102 Al-Si alloy are modifier addition

then modification time

then modification temperature

then interactive phase and secondary phase can be ignored. The calculated results are well in agreement with measured ones.