【摘要】 通过金相显微镜(OM)、场发射扫描电镜(SEM)和万能试验机研究了不同频率下的脉冲磁场时效处理对A356合金微观组织和力学性能的影响。结果表明，与0 Hz时效处理相比，合金经过不同频率的脉冲磁场处理后微观组织得到改善，力学性能明显提升。当脉冲磁场频率为60 Hz时，合金的抗拉强度和屈服强度分别达到358 MPa和278 MPa,在满足工厂技术要求的前提下，工艺耗时比工厂T6热处理工艺缩短570 min。分析表明，不同频率的脉冲磁场时效处理合金具有不同的吉布斯自由能和扩散速率，改变合金晶粒、共晶Si和Si颗粒的尺寸和形貌，从而对合金的综合性能产生影响。更多还原

【Abstract】 Effects of pulse magnetic field aging with different frequencies on microstructure and mechanical properties of A356 alloy were investigated by using metallographic microscope(OM), field emission scanning electron microscope(SEM), transmission electron microscope(TEM) and universal testing machine. The results show that compared with 0 Hz aging treatment, the microstructure and mechanical properties of the alloy are improved by pulse magnetic field aging with different frequencies. When the pulse magnetic field frequency is 60 Hz, the tensile strength and yield strength of the alloy reach 358 MPa and 278 MPa, respectively, where the required aging treatment time is 570 min shorter than that of the factory T6 heat treatment process under the premise of meeting the technical requirements of the factory. It is found that after pulse magnetic field aging with different frequencies, the alloy owns different Gibbs free energy and diffusion rate, the size and morphology of the grains, eutectic Si and Si particles are changed, thus the comprehensive properties of the alloy are affected.更多还原