【摘要】 采用传统铸造法制备了不同Yb含量（15%、21%及29%）的Al-Yb二元共晶合金，通过金相显微镜（OM）、扫描电子显微镜（SEM）、拉伸力学性能测试和显微硬度检测等手段，研究了不同脉冲电流参数对合金共晶组织的影响，分析了合金组织及性能变化的原因。结果表明：Al-15Yb、Al-21Yb和Al-29Yb的组织，分别为典型亚共晶、完全共晶和过共晶组织，Al-15Yb的共晶区存在极细共晶层片结构，层片间距为100～200nm。经过脉冲电流处理后，Al-21Yb的共晶组织层片结构转变为短棒状和圆点状，材料发生软化，抗拉强度由铸态的167MPa降到脉冲电流处理后的143MPa，伸长率由铸态的4%最高增加到7%。在实际应用中，脉冲电流处理可作为一种高效的手段，用于提升共晶合金的塑性变形能力。更多还原

【Abstract】 Al-Yb binary eutectic alloys with varying Yb contents(15%, 21%, and 29%) were prepared using the conventional casting method. The influence of different pulse current parameters on the eutectic structure of these alloys were investigated through metallographic microscopy(OM), scanning electron microscopy(SEM), tensile mechanical properties testing, and microhardness testing. The reasons for the changes in the microstructure and properties of the alloy were thoroughly analyzed. The results indicate that the microstructures of Al-15Yb, Al-21Yb, and Al-29Yb are characteristic of hypoeutectic, complete eutectic, and hypereutectic compositions, respectively. The eutectic region of Al-15Yb exhibits a finely lamellar structure with an interlamellar spacing of 100～200nm. Following pulsed current treatment, the lamellar structure of Al-21Yb transforms into short rods and rounded particles, resulting in material softening. The tensile strength decreases from 167MPa in the as-cast state to 143MPa after pulse current treatment, while the elongation increases from 4% to 7%, matching the as-cast level. In practical applications, pulsed current processing proves to be an effective method to enhance the plastic deformation capacity of eutectic alloys.更多还原