超声辅助镦挤塑性成形过程材料变形模式研究

发布时间：2018-08-24 15:13

【摘要】：从材料塑性变形的角度,结合试验和应力波理论,研究超声效应对于材料变形的影响规律,提出超声辅助镦挤过程中的材料变形模式。基于镦挤试验,研究材料铝的小孔填充能力和径向变形规律,试验结果表明超声辅助振动可以大幅提高小孔的填充能力和接触区域的径向变形量。利用扫描电镜测试手段,研究了镦挤成形工件的表面形貌,发现超声辅助塑性成形零件表面生成了高硬度的氧化铝膜。归纳总结超声辅助塑性变形过程中的变形模式,基于材料变形等效的原则,结合应力波理论和冲击动力学方法,认为超声辅助镦挤过程中的变形模式与材料塑性模量下降、接触区域摩擦因子下降和超声振动的间歇冲击有关。
[Abstract]:From the point of view of plastic deformation of materials, combined with test and stress wave theory, the influence of ultrasonic effect on material deformation is studied, and the deformation mode of materials during ultrasonic assisted upsetting and extrusion is put forward. Based on upsetting test, the pore filling capacity and radial deformation of aluminum were studied. The experimental results show that ultrasonic assisted vibration can greatly improve the filling capacity of small holes and the radial deformation of contact region. The surface morphology of the workpiece formed by upsetting extrusion was studied by means of scanning electron microscope (SEM). It was found that a high hardness alumina film was formed on the surface of the workpiece formed by ultrasonic assisted plastic forming. Based on the principle of equivalent deformation of materials, combined with the theory of stress wave and impact dynamics, it is concluded that the deformation mode and plastic modulus of materials decrease in the process of ultrasonic assisted upsetting extrusion. The decrease of friction factor in the contact region is related to the intermittent impact of ultrasonic vibration.
【作者单位】：杭州电子科技大学机械工程学院;浙江大学机械工程学院;宁波双林汽车部件股份有限公司;
【基金】：国家自然科学基金(51475130) 中国博士后基金(2013M541769) 浙江省自然科学基金(LY14E050025)资助项目
【分类号】：TG306

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