Wang Chunju, Zhang Weiwei, Cheng Lidong, Zhu Changqiong, Wang Xinwei, Han Haibo, He Haidong, Hua Risheng
School of Mechanical and Electrical Engineering, Robotics and Microsystems Center, Soochow University, Suzhou 215131, China.
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Materials (Basel). 2020 Jan 31;13(3):637. doi: 10.3390/ma13030637.
Ultrasonic vibration (UV) is widely used in the forming, joining, machining process, etc. for the acoustic softening effect. For parts with small dimensions, UV with limited output energy is very suitable for the microforming process and has been gaininf more and more attention. In this investigation, UV-assisted uniaxial tensile experiments were carried out utilizing GB 5052 thin sheets of different thicknesses and grain sizes, respectively. The coupling effects of UV and the specimen dimension on the properties of the material were analyzed from the viewpoint of acoustic energy in activating dislocations. A reduction of flow stress was found for the existing acoustic softening effects of UV. Additionally, the residual effects of UV were demonstrated when UV was turned off. The uniform deformation ability of thin sheet could be improved by increasing the hardening exponent with UV. The experimental results indicate that UV is very helpful in improving the forming limit in microsheet forming, e.g., microbulging and deep drawing processes.
超声振动（UV）因其声学软化效应而广泛应用于成型、连接、加工等过程。对于尺寸较小的零件，输出能量有限的超声振动非常适合微成型工艺，并且越来越受到关注。在本研究中，分别利用不同厚度和晶粒尺寸的GB 5052薄板进行了超声振动辅助单轴拉伸试验。从激活位错的声能角度分析了超声振动与试样尺寸对材料性能的耦合效应。由于超声振动存在声学软化效应，发现流动应力降低。此外，当超声振动关闭时，还证明了其残余效应。通过超声振动提高硬化指数可以改善薄板的均匀变形能力。实验结果表明，超声振动在提高微薄板成型（如微胀形和拉深工艺）的成型极限方面非常有帮助。
