Laser welding method for ultrasonic vibration along with welding

Abstract

The invention relates to a laser welding method for ultrasonic vibration along with welding, and belongs to the field of welding. According to the method, preheating is applied in the welding process,and ultrasonic vibration is applied to the front side of a weld joint at a certain distance behind a molten pool; a corresponding relation exists between the preheating temperature T and the distanced from the top end of an ultrasonic head to the welding position, wherein the relation expression is as follows: T is equal to 30d-40, the unit T is DEG C, and the unit d is mm; and the position, thepower and the force of ultrasonic application are adjusted according to the mechanical property of materials under the preheating temperature. According to the laser welding method, the welding residual stress can be effectively reduced, pores and cracks are reduced, and thus the fatigue performance of the weld joint is improved, and the welding deformation is reduced. By adopting the method, thetemperature gradient in the cooling process can be effectively reduced, and the residual stress is reduced; and the plasticity of the ultrasonic application area can be improved, and the ultrasonic effect is better. The ultrasonic impact can effectively reduce residual stress, refine crystal grains and reduce pores and cracks, and thus the fatigue performance of the weld joint is improved; and the metal plastic extension of the weld joint can effectively reduce the welding deformation.

Description

technical field [0001] The invention belongs to the field of welding and relates to a laser welding method accompanied by welding ultrasonic vibration. Background technique [0002] Welding is a heating and cooling process with localized heating and cooling. When heated, the metal around the weld expands, producing compressive plastic deformation under the restraint of the fixture. When cooling, this part of the metal shrinks to produce tensile plastic deformation, elastic deformation and tensile stress. The stress that still exists after cooling to room temperature is the residual stress. When the clamp is released after welding, the residual stress is redistributed, the tensile stress near the weld is reduced, and the compressive stress is generated in the area away from the weld. Under the action of stress, the workpiece produces deflection deformation. It can be seen that the main cause of welding deformation is welding residual stress. Residual stress will not only ...

AI Technical Summary

Problems solved by technology

The impact frequency is 2Hz, the frequency is low, and the uniformity of the weld is affected

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