Six kinds of aluminum alloy welding methods

1. TIG welding technology

Nowadays, TIG welding technology has been widely used. Through TIG welding thin plate welding technology, aluminum alloy materials can be perfectly matched, which provides more possibilities for welding technology of aluminum alloy materials.

T1G welding has the advantages of wide application, stable welding process, good welding quality, suitable for thin plate thick welding, and easy automation of welding process. , but the 71G welding ground has problems such as poor wind resistance, insufficient stability in the welding process, and low production efficiency due to porosity.

TIG welding is mainly used for welding thin and medium-thick engineering material workpieces. The application of TIG welding in the jointing of aluminum alloy car bodies of EMUs is mainly the manual welding of aluminum alloy port plates. The protective gas is usually pure gas. , and its welding quality is high, which can well meet the assembly accuracy requirements of the EMU car body.

2. High energy density welding

The high energy density is mainly used in the development of new equipment, the intelligence of equipment and the flexibility of processing, the improvement and diagnosis of beam quality, and the welding of new materials. Laser welding, electron beam welding, plasma welding, etc. all belong to high energy density welding.

2.1 Laser welding

Laser has been widely used in many fields, especially in the field of aluminum alloy welding. When laser welding aluminum and its alloys, especially during heat treatment, the possibility of defects must be considered.

Compared with traditional welding technology, laser welding has significant advantages, such as small deformation, small heat-affected range, high production efficiency, light joint damage, low heat input, etc.

Compared with the traditional method, the depth-to-width ratio of laser welding is larger, the heat-affected zone becomes narrower, the welding speed is fast, the welding deformation is very small, and the energy density is also very high.

However, in order to obtain a good forming effect and a high-quality seam, suitable welding parameters are particularly important. After an orthogonal experiment on the pulse laser welding parameters of the 5052 aluminum alloy sheet, the results show that the defocus amount is -2.5mmn Under the welding parameters of welding speed 270 mm/min and pulse frequency 18 Hz, high-quality welds with good surface shape and certain penetration depth can be obtained.

2.2 Electron beam welding

Electron beam welding refers to the use of heat energy generated by converging high-power-density electron beams in a high-vacuum environment to bombard the joint of the workpiece for thick welding. It is a welding method for heating and melting gold to form thick seams. The welding process is in It is carried out under vacuum because the influence of air on the shape of the weld can be avoided in a vacuum.

Temperature measurement during electron beam welding is a difficult task. Although electron beam welding has high heating power density, large welding bee depth ratio, and strong adaptability, it also has certain restrictions. The equipment is more complicated and difficult to operate.

The size and shape of the workpiece to be welded are also limited, and the electronic beam welding workpiece is required to be demagnetized before welding to prevent magnetic offset from affecting the welding effect.

2.3 Plasma arc welding

Plasma arc welding is a new and efficient welding method, which has the characteristics of high productivity, high welding efficiency, low cost, good weld quality, fast welding speed, and small stress deformation.

Rectangular wave AC welding power supply is often used for plasma arc welding of aluminum and aluminum alloys, and argon is often used as a shielding gas. For pure aluminum and anti-rust aluminum, plasma arc welding is used, and the welding effect is good. In the process of micro-beam plasma welding, there are three areas with obvious differences in arc light radiation. The light radiation and size changes in the three arc areas are mainly due to the instantaneous changes of pulse current values at low frequencies.

3. Resistance spot welding

Compared with manual tying, electric yang joints have the advantages of high production efficiency, labor saving, and cost reduction. However, due to the high welding current, defects and unstable joint quality often occur in welds.

The experimental results show that the embossing-resistance point composite connection can realize the effective connection of the 5052 aluminum alloy joint, and the morphology of the joint can be detected by ultrasonic C-scanning.

There are many factors affecting the nugget size and shear force of the resistance spot welding joint. The nugget diameter and resistance of the joint increase with the increase of welding current and welding time. And the mesh will decrease with the increase of the electrode force.

Compared with pure aluminum, the plastic deformation temperature range of aluminum alloy is narrow, the linear expansion rate is large, and the elongation rate is small. Therefore, it is necessary to precisely control the welding parameters to avoid strong lines and shrinkage cavities. Electric positive point thickness is also related to other thick connection methods. The welded joints of austenitic stainless steel and aluminum alloy dissimilar materials have the characteristics of welding and brazing.

4. Friction stir welding

The effect of friction stir welding is affected by its welding parameters. During the welding process of friction stir welding, the pollution to the environment is very small, and it is mainly used for non-ferrous metals with low melting temperature, such as aluminum, copper and other alloy materials. The material selection of the stirring head will affect the welding effect.

Aluminum alloy materials are easy to produce pores when welding, which requires a new welding technology to repair the weld defects of aluminum alloy materials, and friction plug repair welding is such a welding technology, friction stir welding also has high application value and Study Gaoyi, it is an innovative welding technology researched and developed on the basis of friction stir welding.

5. MIG welding technology

In the welding process of MIG welding, the arc is stable and the oxidation is weak. It is suitable for welding non-ferrous metals such as aluminum, copper, and iron. Compared with submerged arc welding and manual arc welding, MIG welding technology has low welding cost and high weld crack resistance. Small deformation after welding, high production efficiency, easy operation and other advantages.

For traditional MIG welding, the arc stability of aluminum alloy welding is poor, and defects such as burn-through and molten pool collapse are prone to occur, which makes the welding efficiency low. Waveform parameters are used to obtain well-formed welds, which make up for some defects in the traditional MIG welding technology. However, the overall performance of dual-pulse MIG welding equipment still needs to be improved.

6. CMT welding technology

As an additive manufacturing method, CMT welding has been widely used in the automotive industry, defense sector and power generation. M welding technology has the advantages of small heat input, more stable arc, small welding deformation, and uniform weld seam. The input is low, and the thick plate is not easy to penetrate, resulting in relatively low efficiency.

CMT welding is superior to MIG welding to a certain extent. The CMT welding method can obtain aluminum alloy welded joints that are better than pulse welding. CMT welding technology is suitable for thin plate welding, especially the welding of aluminum materials.