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超声振动会明显降低材料塑性变形过程中的流动应力,但是超声振动引起这一现象的原因还有待深入研究。在介观尺度下基于二维离散位错动力学,根据纯钛的塑性变形特点,对位错的运动进行了合理的简化,建立了纯钛TA1的离散二维位错动力学模型,对超声辅助微镦粗进行了模拟研究。同时,利用所建模型研究了介观尺度下超声振动对于位错密度的影响,结果表明,在介观尺度下该二维位错动力学模型可较为客观地描述超声振动对材料塑性变形的影响;在介观尺度下超声振动会降低材料在塑性变形过程中的位错密度。
Ultrasonic vibration will obviously reduce the flow stress in the process of plastic deformation, but the cause of this phenomenon due to ultrasonic vibration remains to be further studied. Based on the two-dimensional discrete dislocation dynamics at mesoscopic scale, the dislocation motion is reasonably simplified according to the plastic deformation characteristics of pure titanium. A discrete two-dimensional dislocation kinetics model of pure titanium TA1 is established. Aided micro upsetting simulation study. The effect of ultrasonic vibration on the dislocation density at mesoscopic scale was also studied by using the proposed model. The results show that this two-dimensional dislocation dynamics model can objectively describe the influence of ultrasonic vibration on plastic deformation under mesoscopic scale Ultrasonic vibration at mesoscopic scale will reduce the dislocation density of the material during plastic deformation.