Applying ultrasonic vibration during single-point and two-point incremental sheet forming
Applying ultrasonic vibration during single-point and two-point incremental sheet forming
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DOI：
10.1016/j.promfg.2019.06.137
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Randy Cheng;N. Wiley;M. Short;Xun Liu;A. Taub
中科院分区：
文献类型：
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作者：
Randy Cheng;N. Wiley;M. Short;Xun Liu;A. Taub
在基本的拉伸和压缩试验以及相关的工业过程中，已经对各种材料进行了超声辅助变形的研究。在材料塑性变形过程中应用UA时，通常会观察到流动应力的降低。研究了超声能量对单点渐进成形和两点渐进成形的影响。对半球型ISF工具进行了纵向超声振动，振动频率为20 kHz。UA-SPIF选择了一系列圆锥形状，UA-TPIF选择了45°圆锥形背模。一般来说，在所研究的条件下，振动幅度与成形力的减小之间存在正相关关系。与UA-SPIF相比，UA-TPIF的减力效果更为显著。假设UA-SPIF允许整个薄板的薄膜振动，从而降低了输入到局部塑性变形区的有效超声能量。此外，UA-TPIF在施加超声波振荡的区域显示出局部的薄板厚度减小。
Ultrasonic assisted (UA) deformation has been studied on a variety of materials in both fundamental tensile and compression tests as well as in relevant industrial processes. Reductions in flow stress are a common observation when applying UA during material plastic deformation. The objective of this work is to study the effects of ultrasonic energy on single-point (SPIF) and two-point (TPIF) incremental forming. A longitudinal ultrasonic vibration is applied to a hemispherical ISF tool at 20kHz oscillating frequency. A series of conical shapes were selected for UA-SPIF and a 45° conical shape backing die is selected for UA-TPIF. Generally, a positive correlation between oscillation amplitude and reduction in forming forces is observed in the investigated conditions. The force reduction in UA-TPIF is much more significant compared with UA-SPIF. It is hypothesized that UA-SPIF allows membrane vibration of the entire sheet, which lowers the effective ultrasonic energy input into the local plastic deformation region. In addition, UA-TPIF shows a local sheet thickness reduction in regions where ultrasonic oscillation is applied.