超声振动辅助微镦粗仿真及试验研究

Simulation and experiment study on ultrasonic vibration assisted micro upsetting

摘要:

为改善材料塑性,降低微镦粗成形力,延长模具寿命,提高微镦粗成形质量,开展了超声振动辅助微镦粗研究. 对紫铜超声振动辅助微墩粗进行建模仿真,研究超声参数对微墩粗成形力、试件变形的作用规律；搭建超声振动辅助微成形平台并进行试验,获取不同超声功率下紫铜微镦粗成形力曲线和成形件表面形貌、尺寸等参数. 仿真结果表明:超声振动使微镦粗成形力降低,试件变形增大,且成形力降低量、试件变形增大量与超声振幅成正线性关系,与超声频率成非线性正相关. 试验结果表明:超声功率越大,微镦粗成形力降低值越大；超声功率小于1.5 kW,超声功率越大,成形件表面越平整；超声功率大于1.5 kW,超声功率越大,成形件表面越粗糙；超声功率小于1.8 kW,超声功率越大,成形件鼓形越小,成形越均匀；超声功率达到1.8 kW后,成形件变形集中在两端,微镦粗成形严重不均匀. 仿真和试验研究表明,超声振动可以降低微镦粗成形力,加速材料塑性变形,提高微镦粗成形效率,改善成形件表面形貌,减小微镦粗鼓形并提高微镦粗均匀性.

Abstract:

To reduce the micro upsetting force, extend the life of the mold and improve the plasticity and the forming quality of material, the ultrasonic vibration assisted micro upsetting was studied. Modeling and simulation of ultrasonic vibration assisted micro upsetting on copper was carried out to study the effect of ultrasonic parameters on forming force and deformation, and the results showed that the ultrasonic vibration could reduce the micro upsetting force and increase the deformation, the force reduction and deformation increase had a positive linear relationship with the ultrasonic amplitude and a non-linear positive correlation with the ultrasonic frequency. Ultrasonic vibration assisted micro forming platform was built up and the micro upsetting force curves, the surface topography and size of the specimen under different ultrasonic powers were obtained. Experimental results showed that the micro upsetting force reduction increased with the increasing of ultrasonic power. The surface topography was improved with the increasing of ultrasonic power when the power was lower than 1.50 kW. But the surface topography was worse with the increasing of ultrasonic power when the power was higher than 1.50 kW. Simulation and experiment study showed that the ultrasonic vibration could effectively reduce the micro upsetting force, increase plastic deformation, reduce the drum shape and improve the surface topography and forming uniformity.