设计了材料局部超声波与压力载荷耦合的压痕实验装置,以7050铝合金和哈氏C-276镍基合金为实验材料进行挤压实验,研究超声振动挤压对材料单点流变行为的影响规律及传能机理。研究表明,超声能对材料单点受载的塑性变形具有降载、提效双重效应;经分析论证,在局部流变的界面上叠加超声场时,变形区金属以脉冲方式产生滑移流变;同时滑移脉冲激励滑移体内部粒子的谐振响应,产生高能的短波声子,传播到变形区高密度位错晶界,导致这些区域粒子能量的跃迁,并最终转化为材料的塑性变形能。
Experimental indentation test equipment with coupling of ultrasonic and pressure loading on partial material was designed.The extrusion experiment of 7050 aluminum alloy,and Hastelloy C-276 nickel-based alloy were carried out to study the effecting rule of ultrasonic vibration pressing on the material single point rheological behavior and the mechanism of energy transmission.The results show that,ultrasonic energy can reduce the load and promote the efficiency for the plastic deformation process of material in single point loading.It shows that when ultrasonic field is added to the partial rheological interface,the metal in the deformation zone slides in pulse mode.Meanwhile,encouraged by the sliding pulse,the grains inside the sliding material perform a resonance response,and high energy short-wave phonon are generated.It spread to the high density dislocation crystal boundary in the deformation zone,leading the energy jump of those grains,and finally this energy translating into plastic deformation energy of the metal.