Refinement and thermal analysis of hypereutectic Al-25%Si alloy

来源期刊：中国有色金属学报(英文版)2001年第3期

论文作者：张忠华 边秀房 王艳 刘相法

文章页码：374 - 377

Key words：hypereutectic Al-Si alloys; refinement; differential scanning calorimeter; enthalpy

Abstract: Refinement and thermal analysis of hypereutectic Al-25%Si alloy were investigated with scanning electron microscope (SEM) and differential scanning calorimeter (DSC). The results show that the average size of primary silicon in Al-25%Si alloy without and with phosphorus addition are 250 μm and 30μm, respectively. But the primary and eutectic growth temperature is raised by about 17.3℃ and 4 ℃ respectively due to phosphorus addition. The primary nucleation temperatures are 745.0 ℃ and 762.0℃ for untreated and treated samples and in addition, the enthalpy changes of primary and eutectic transformation are -261.0 J/g and -397.3 J/g without phosphorus addition, -294.2 J/g and -386.1 J/g with phosphorus addition, respectively. Otherwise the mechanisms of refinement and thermal transformation of Al-25%Si alloy in solidifying process are also discussed.