摘要
目的在不同振幅的超声振动辅助情况下,研究6061铝合金材料拉伸性能和微观组织的变化。方法在不同超声振幅条件下进行了不同拉伸速率的超声辅助拉伸试验。通过显微硬度计对拉伸试件的硬度进行测量。采用扫描电子显微镜观察分析断口形貌。采用金相显微镜观察超声振动作用下材料微观组织的变化。结果随着超声振动的施加,拉伸试件的显微硬度显著提升,显微硬度的增幅与超声振幅和振动施加时长成正比,试件断口中的韧窝尺寸和韧窝数量显著提高,大尺寸晶粒数量显著下降,细小晶粒持续增加。拉伸过程中的流动应力显著下降,屈服强度从285.01 MPa下降至264.51 MPa,抗拉强度由355.71 MPa下降至336.09 MPa,伸长率变化较小。结论在拉伸过程中超声振动起到硬化作用,硬化作用效果的主要影响因素是超声振动的振幅大小和超声作用时长。产生超声硬化效果是因为在超声的作用下,材料的小尺寸晶粒数量显著提升,从而产生的细晶强化效应导致力学性能增强。
The work aims to study the changes in tensile properties and microstructure of 6061 aluminium alloy materials under ultrasonic vibration assisted conditions with different amplitudes.Ultrasonic-assisted tensile tests were carried out under different ultrasonic amplitude conditions and different tensile rates respectively.The hardness of the tensile specimens was measured by the microhardness tester.The scanning electron microscope was used to observe and analyze the fracture mor-phology.The metallographic microscope was used to observe the changes in the microstructure of the material under the effect of ultrasonic vibration.The microhardness of the tensile specimens increased significantly with the application of ultrasonic vibration,and the increase in the microhardness was proportional to the ultrasonic amplitude and the duration of vibration applica-tion.The size of the ligamentous nests and the number of ligamentous nests in the fracture of the specimens increased signifi-cantly.The number of large-sized grains decreased significantly and the number of fine grains increased continuously.There was a significant decrease in the flow stress during stretching,with the yield strength decreasing from 285.01 MPa to 264.51 MPa,the tensile strength decreasing from 355.71 MPa to 336.09 MPa,and the change in elongation being small.The ultrasonic vibra-tion has a hardening effect in the auxiliary tensile process,and the main factors affecting the hardening effect are the amplitude size of ultrasonic vibration and the duration ultrasonic action.The reason for the ultrasonic hardening effect is that the number of small-sized grains of the material is significantly increased by ultrasound,which results in the strengthening effect of fine grains leading to the enhancement of the mechanical properties.
作者
吕源
潘熙祥
易聪
杨坪川
林芯仪
李鑫
王岩
王一凡
LYU Yuan;PAN Xixiang;YI Cong;YANG Pingchuan;LIN Xinyi;LI Xin;WANG Yan;WANG Yifan(School of Mechanical Engineering,Xi'an University of Science and Technology,Xi'an 710054,China;Chengdu Aircraft Industrial(Group)Corporation Ltd.,Chengdu 610092,China)
出处
《精密成形工程》
北大核心
2025年第6期143-149,共7页
Journal of Netshape Forming Engineering
基金
国家自然科学基金(52005399)。
关键词
6061铝合金
拉伸性能
超声振动
显微组织
声软化效应
6061 aluminum alloy
tensile properties
ultrasonic vibration
microstructure
acoustic softening effect
