超声振动辅助摩擦堆焊热-流耦合数值模拟

传统摩擦堆焊能量输入形式单一,随着堆焊材料强度的提高,堆焊过程中需要施加更大的轴向压力和转矩,极大限制其推广应用.为了解决上述问题,提出一种在耗材棒前方的基板上施加超声振动的超声振动辅助摩擦堆焊新工艺.以Ti-6Al-4V为研究对象,基于超声宏观软化效应建立了一个三维热-流耦合数值模型,定量分析了不同振幅下的超声振动对摩擦堆焊过程中温度场和材料流动行为的影响.计算结果表明,超声振动的预热效应并不明显,随着振幅的增加,超声振动能够显著提高熔合区塑性材料流动速度,降低材料黏度,扩大塑性材料流动区域.

Numerical Simulation of Thermal-Fluid Coupling in Ultrasonic Vibration Assisted Friction Surfacing

Traditional friction surfacing has a single energy input form. As the strength of the welded material increases, the larger axial pressure and torque need to be applied during the surfacing process, which greatly limit its application. In order to solve the above problem, a new ultrasonic vibration assisted friction surfacing technology with ultrasonic vibration applied to the substrate in front of the consumable rod was presented. Taking Ti-6Al-4V as the research object, a three-dimensional numerical model of thermal-fluid coupling was established based on the ultrasonic softening effect. The effects of ultrasonic vibration with different amplitudes on the temperature field and material flow behavior were quantitatively analyzed. The calculation results show that the preheating effect of ultrasonic vibration is not obvious. With the increase of amplitude, ultrasonic vibration can significantly increase the flow velocity of plastic material in the fusion zone, decrease the material’s viscosity and expand the flow region of plastic material.