(南昌航空大学 轻合金加工科学与技术国防重点学科实验室，南昌 330063)
摘 要: 通过测试与分析不同脉冲超声功率、施振时间、脉冲超声频率下ZL205A合金微观组织及Cu元素含量，系统研究脉冲超声工艺对ZL205A合金微观组织及偏析的影响。结果表明：脉冲超声工艺对ZL205A合金微观组织及偏析影响的显著。随着的脉冲超声功率、施振时间、脉冲超声频率增大，ZL205A合金的组织越来越细小且圆整，随后ZL205A合金的组织又逐渐粗大且不规则。最佳脉冲超声工艺为脉冲超声功率1200 W、施振时间120 s、脉冲超声频率1.67 Hz。脉冲超声工艺改变Cu元素在a (Al)中的分布曲线，在一定范围内提高Cu元素的有效分配系数ke，对脉冲超声功率与施振时间影响较大，改变Cu元素在凝固过程中溶质再分配行为，改善ZL205A合金微观偏析。
关键字: 脉冲超声；ZL205A合金；微观组织；微观偏析
（National Defence Key Disciplines Laboratory of Light Alloy Processing Science and Technology, Nanchang Hangkong University, Nanchang 330063, China）
Abstract:The effect of pulsed ultrasonic process on the microstructure and microsegregation of ZL205A alloy was studied systemically through testing and analyzing the microstructure and Cu element content under different pulsed ultrasonic powers, applying vibration time and pulsed ultrasonic frequency. The results indicate that the pulse ultrasonic process has significant effects on the microstructure and microsegregation of ZL205A alloy. With the increase of pulsed ultrasonic power, applying vibration time and pulsed ultrasonic frequency, the microstructures of ZL205A alloy become more and more fine and round, however, with further increasing, the microstructure turns rough and irregular. The optimal pulse ultrasonic process is pulsed ultrasonic power of 1200 W, applying vibration time of 120 s and pulsed ultrasonic frequency of 1.67 Hz. Meanwhile, the pulsed ultrasonic process has changed the distribution curve of Cu element in a(Al), and the effective distribution coefficient ke of Cu element is improved within a certain range, especially, the effects of the pulsed ultrasonic power and applying vibration time are significant, which change the behavior of Cu element solute redistribution in the process of solidification and improve the microsegregation of ZL205A alloy.
Key words: pulsed ultrasound; ZL205A alloy; microstructure; microsegregation
