Ultrasonic vibration has been widely studied because of its excellent utility and performance in the plastic forming of metals. The mechanism and effects of ultrasonic vibration on material flow and deformation have therefore become a focus for current research. The mechanisms of ultrasonic vibration as it acts on materials include the volume effect and the surface effect. Double Cup Extrusion (DCE) testing is an ideal method for studying the surface effect but there have been few studies and some conclusions from those studies have been contradictory. For the present study, a new ultrasonic vibration-assisted DCE device was specifically designed and used for the experiment. In the tests, friction factors were calibrated and analyzed using the finite element method (FEM). The results show that ultrasonic vibration can effectively improve interface friction conditions in DCE. By changing ultrasonic loadings, an explanation was found for the ‘illusion’ that ultrasonic vibration increased interface friction, as had previously been reported. It was also shown that ultrasonic vibration exhibits a significant size effect, which can efficiently offset the negative size effect of friction in the micro-forming process. Further, it was found that the ultrasonic effect is influenced by the wall thickness of the formed part—the smaller the wall thickness, the more significant the effect of ultrasonic vibration.

超声波振动因其在金属塑性成形中的优异实用性和性能而被广泛研究。超声波振动对材料流动和变形的机理和影响因此成为当前研究的热点。超声波振动作用于材料的机理包括体积效应和表面效应。双杯挤压 (DCE) 测试是研究表面效应的理想方法，但研究很少，而且这些研究的一些结论相互矛盾。在本研究中，专门设计并使用了一种新的超声波振动辅助 DCE 装置进行实验。在测试中，使用有限元方法 (FEM) 校准和分析摩擦系数。结果表明，超声振动能有效改善DCE界面摩擦条件。通过改变超声波载荷，发现了对超声波振动增加界面摩擦的“错觉”的解释，正如之前报道的那样。还表明超声波振动具有显着的尺寸效应，可以有效抵消微成形过程中摩擦的负面尺寸效应。进一步发现，超声效应受成型件壁厚的影响——壁厚越小，超声振动的影响越显着。还表明超声波振动具有显着的尺寸效应，可以有效抵消微成形过程中摩擦的负面尺寸效应。进一步发现，超声效应受成型件壁厚的影响——壁厚越小，超声振动的影响越显着。还表明超声波振动具有显着的尺寸效应，可以有效抵消微成形过程中摩擦的负面尺寸效应。进一步发现，超声效应受成型件壁厚的影响——壁厚越小，超声振动的影响越显着。