间断直流磁场对Al-5Mg-3Zn-1Cu合金凝固组织和性能的影响
Effect of Intermittent Direct Current Magnetic Field on Solidification Microstructure and Properties of Al-5Mg-3Zn-lCu Alloy
曾麟添 1周全 1陈乐平 1刘武平 1刘厚清1
作者信息
- 1. 南昌航空大学航空制造工程学院,南昌 330063
- 折叠
摘要
对Al-5Mg-3Zn-1Cu合金的凝固过程施加不同直流电压(0～300 V)和放电频率(0～20 Hz)以及占空比为30％的间断直流磁场,研究了间断直流磁场对其凝固组织及力学性能的影响.结果表明:间断直流磁场有效细化了合金的凝固组织,初生α-Al相由无磁场时的粗大枝晶变为细小的蔷薇状晶粒,第二相由粗大而连续的网格状结构变为细小而断续分布结构.随着直流电压的增加,合金的晶粒尺寸、第二相体积分数和长度均减小,抗压强度和断裂应变均先升后降;随着放电频率的增加,晶粒尺寸、第二相体积分数和长度均先减小后增大,抗压强度和断裂应变均先升后降.施加间断直流磁场后,合金的拉伸性能提高,断口中的准解理面减少,撕裂棱增多.当直流电压为200 V、放电频率为5 Hz时,合金的抗压强度和断裂应变最大,与无磁场时相比分别提高了31.6％和43％,抗拉强度和断后伸长率则分别提高了 79.71％和83.3％.
Abstract
The solidification of Al-5Mg-3Zn-1Cu alloy was treated by intermittent direct current magnetic field under 30％duty cycle and different direct current voltages(0-300 V)and discharge frequencies(0-20 Hz).The effect of intermittent direct current magnetic field on solidification microstructure and mechanical properties of the alloy was studied.The results show that applying intermittent direct current magnetic field effectively refined the solidification structure of the alloy.The primary α-Al phase changed from coarse dendrites without magnetic field to fine rose-like grains,and the second phase changed from coarse and continuous grid structure to fine and discontinuous distribution structure.With the increase of direct current voltage,the grain size,the second phase volume fraction and length of the alloy decreased,and the compressive strength and fracture strain increased first and then decreased.With the increase of discharge frequency,the grain size,the second phase volume fraction and length decreased first and then increased,and the compressive strength and fracture strain increased first and then decreased.After applying intermittent direct current magnetic field,the tensile properties of the alloy were improved,the quasi-cleavage surface decreased in number,and the tearing edge increased in number.When the direct voltage was 200 V,and the discharge frequency was 5 Hz,the compressive sthength and fracture strain were the largest,which increased by 31.6％and 43％compared with those without magnetic field,and the tensile strength and percentage elongation after fracture increased by 79.7％and 83.3％,respectively.
关键词
Al-5Mg-3Zn-1Cu合金/间断直流磁场/凝固组织/力学性能Key words
Al-5Mg-3Zn-1Cu alloy/intermittent direct current magnetic field/solidification microstructure/mechanical property引用本文复制引用
出版年
2024
NETL
NSTL
万方数据