Dual ultrasonic-assisted laser-CMT composite welding system and welding method

Abstract

The invention relates to a dual ultrasonic-assisted laser-CMT composite welding system and a welding method. The system is composed of a workbench, an ultrasonic mechanical vibration mechanism and a laser-CMT composite welding part; the workpiece clamping and welding speed is completed by a PLC control system, the ultrasonic vibration mechanism comprises an upper ultrasonic mechanism and a lower ultrasonic mechanism, and the upper ultrasonic mechanism is provided with an adjustable angle waist hole, so that the application of ultrasonic at different angles is facilitated; the laser-CMT composite welding part realizes welding of low thermal input and low welding deformation; and an aluminum-based composite material is clamped to the workbench through pre-welding cleaning such as grinding and cleaning, and a self-made flux-cored wire is selected by a welding wire. By adjusting the ultrasonic position and angle (distance d1, d2, and theta), the dual ultrasonic-assisted laser-CMT compositewelding system meets the welding of low stress and low thermal input of the aluminum-based composite material, the fluidity of a molten pool is improved, the tensile strength of a welded joint reaches 70% or above of base metal, the number of pores in the joint is obviously reduced, the number of brittle intermetallic compounds Al4C3 in weld metal is reduced, the brittle intermetallic compounds Al4C3 are distributed in a dispersed mode, and a product TIC plays a role of a reinforcement phase.

Description

technical field [0001] The invention relates to the welding field of aluminum-based composite materials, in particular to a dual-ultrasonic-assisted laser-CMT composite welding system and a welding method. Background technique [0002] Aluminum matrix composites have the advantages of low density, high specific strength / specific stiffness, high shear strength, low thermal expansion coefficient, high temperature resistance, wear resistance and wear resistance, etc., and have many applications in ships, aerospace and other fields, but The fusion welding of aluminum matrix composites is difficult. When the aluminum alloy matrix is ​​heated above the melting point, the reinforcing phase such as silicon carbide is still solid, which easily leads to high viscosity of the molten pool, poor fluidity, and poor weld formation. The number of welded joint defects increases, the joint strength is low, the reinforcement phase is easy to burn, and brittle intermetallic compounds, pores and...

AI Technical Summary

Problems solved by technology

[0006] (1) The heat input of fusion welding is large, the loss of reinforcement phase is large, and it is difficult to obtain high-quality welded joints

[0007] (2) The fluidity of the molten pool of aluminum-based composite materials is poor, and the wettability between the reinforced phase particles with a high melting point and the Al collective is poor. The molten pool is prone to stickiness and inclusions, which affect the quality of the weld.

[0008] (3) A large amount of Al4C3 intermetallic compounds are formed in the weld metal, which increases the brittleness of the weld and reduces the performance of the joint

[0009] (4) There is a significant difference in physical properties between the reinforcing phase and the matrix. Under the fast cooling rate of fusion welding, it is easy to form voids and pore defects, reducing the performance of the joint

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