Method for improving strength of laser stitch welding joint of copper and steel dissimilar metal

A technology for dissimilar metals and welding joints is applied in the field of improving the strength of copper-steel dissimilar metal laser stitched welding joints, which can solve the problems of low efficiency, reduce joint strength, and increase welding, so as to achieve wide application prospects, improve metallurgical reaction, and tensile strength. improved effect

Pending Publication Date: 2020-05-15
WENZHOU UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Among them, soldering iron soldering is prone to defects such as excess tin slag and virtual soldering; resistance spot welding is prone to produce obvious solder spots, and the capacitor charging and discharging time is long during welding, and the efficiency is low, and there are many limitations in application, while copper and steel There are large differences in melting point, linear expansion coefficient, thermal conductivity, mechanical properties, etc., and poor metallurgical compatibility. During fusion welding, eutectics with low melting points will be produced, which greatly reduces the strength of the joint, which increases the difficulty of welding between copper and steel dissimilar metals. , not conducive to the direct welding of copper and steel

Method used

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  • Method for improving strength of laser stitch welding joint of copper and steel dissimilar metal
  • Method for improving strength of laser stitch welding joint of copper and steel dissimilar metal
  • Method for improving strength of laser stitch welding joint of copper and steel dissimilar metal

Examples

Experimental program
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Effect test

Embodiment 1

[0029] T2 red copper and 304L stainless steel plates with a thickness of 1mm are used.

[0030] Polish the surface of the workpiece to be processed (T2 copper plate, thickness 1mm) with sandpaper to remove surface metal oxides; clean the surface of the processed workpiece with absolute ethanol to remove surface grease and other stains. Through the above treatment, a relatively clean workpiece surface is obtained.

[0031] Use the picosecond green laser with a wavelength of 515nm after frequency doubling to etch a parallel groove texture on one end of the stainless steel surface along the laser processing direction; the texture process parameters are as follows: the laser power is 40% of the peak power, the laser frequency is 400kHz, The pulse width is 10 ps, ​​the scanning speed is 0.5 m / s, the defocus amount is 0, and the scanning times are 70 times; the depth of the formed micro-grooves is 34.865 μm, and the surface roughness is 4.367 μm.

[0032] The stainless steel plate w...

Embodiment 2

[0035] T2 red copper and 304L stainless steel plates with a thickness of 1mm are used.

[0036] Polish the surface of the workpiece to be processed (T2 copper plate, thickness 1mm) with sandpaper to remove surface metal oxides; clean the surface of the processed workpiece with absolute ethanol to remove surface grease and other stains. Through the above treatment, a relatively clean workpiece surface is obtained.

[0037] Use the picosecond green laser with a wavelength of 515nm after frequency doubling to etch a parallel groove texture on one end of the stainless steel surface along the laser processing direction; the texture process parameters are as follows: the laser power is 40% of the peak power, the laser frequency is 400kHz, The pulse width is 10 ps, ​​the scanning speed is 1 m / s, the defocus amount is 0, and the scanning times are 90 times; the depth of the formed micro-grooves is 23.206 μm, and the surface roughness is 3.591 μm.

[0038] The stainless steel plate wit...

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Abstract

The invention relates to a method for improving the strength of a laser stitch welding joint of copper and steel dissimilar metal. The method comprises the steps: firstly, the metal surface at the welding lap-joint position is pretreated; then parallel groove textures are machined and constructed on the metal surface of the welding lap-joint position through a picosecond pulse laser to form shape-controllable, uniform and flat texture surfaces; and finally, laser stitch welding is conducted on the copper and steel dissimilar metal through a pulse green light disc laser to improve the welding strength. A laser texture machining technology and a laser welding technology are combined effectively to improve the bonding strength of the copper and steel dissimilar metal; shape-controllable, uniform and flat parallel microtextures are etched on the metal surface efficiently and quickly, other various microtextures with complex shapes can also be etched, and the machining efficiency is high; welding wires do not need to be additionally used, and thus the production cost is greatly lowered; and through texturing treatment on the welding surface, a metallurgical reaction in a welding pool isimproved, the diffusion effect of Fe on the steel side into the molten pool is enhanced, and the bonding strength of copper and steel metal welding is improved.

Description

technical field [0001] The invention relates to a method for improving the strength of laser lap welding joints of copper and steel dissimilar metals, belonging to the technical field of laser processing. Background technique [0002] Electronic control technology is an important symbol to measure the development level of new energy vehicles, and relays are the core components of the electronic control system. In order to meet the functional requirements of new energy vehicles for high voltage, high current and long life, new challenges are posed to the performance of contacts in relays. The copper-steel contact material not only has the excellent electrical conductivity and corrosion resistance of copper, but also takes into account the high strength and high toughness of steel, so as to increase the service life of the contacts in the process of closing and breaking. [0003] Traditional contact welding uses soldering iron tin welding and resistance spot welding. Among t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B23K26/21B23K26/60B23K26/352B23K103/22
CPCB23K26/21B23K26/352B23K26/60B23K2103/22
Inventor 冯爱新尚大智周远航张健干贤德潘晓铭韩磊王术新唐杰
Owner WENZHOU UNIVERSITY
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