【摘要】 研究了A112.5%Si合金液存在较大过热度的情况下,电脉冲处理对其凝固组织中初晶相和共晶相的影响。研究发现,经电脉冲处理后的共晶AlSi合金凝固组织中出现了过共晶组织中才应出现的初晶硅,αAl枝晶长度变短;差示扫描量热法(DSC)曲线发生变化,电脉冲处理后有明显的初晶硅析出拐点,并且过冷度减小。理论分析表明,电脉冲处理促进了铝硅合金液中Si相的形核与长大,对AlSi熔体的液态结构产生了影响,从而使其凝固过程和凝固组织发生变化。更多还原

【Abstract】 The effect of electric pulse treatment on primary and eutectic phase in superheated liquid Al-12.5%Si alloy was studied. It is found that the primary silicon which should be observed in hypereutectic Al-Si alloy, appears in the solidification structure of Al-12.5% Si alloy treated by electric pulse and the size of dendrite α-Al decreases. Evident inflection point of DSC cooling curve of 612.8℃ indicates primary silicon appearing in the electric pulse treated Al-12.5% Si alloy. Besides, the super-cooling temperature decreases. Theoretical analysis shows that the electric pulse treatment promotes the nucleation and growth of silicon phase in liquid Al-Si alloy therefore the treatment affects the structure of liquid metal to modify the solidification structure.更多还原