Aluminum alloy welding method
1, tungsten argon arc welding
Tungsten argon arc welding is mainly used for aluminum alloys, which is a good welding method. However, tungsten argon arc welding equipment is complicated and is not suitable for operation under open air conditions.
2, resistance spot welding, seam welding
This welding method can be used to weld aluminum alloy sheets with a thickness of 5 mm or less. However, the equipment used in welding is complicated, the welding current is large, and the productivity is high, and it is particularly suitable for the mass production of parts and components.
3, pulse argon arc welding
Pulsed argon arc welding can improve the stability during welding and can adjust parameters to control arc power and weld formation. The weldment has small deformation and small heat-affected zone and is especially suitable for welding on thin plates, all-position welding and the like, as well as welding of forging aluminum, hard aluminum and super-hard aluminum with high heat sensitivity .
4, friction stir welding
Friction stir welding is first and foremost widely used in the field of light metal structures such as aluminum alloys and magnesium alloys. The biggest feature of this method is that the welding temperature is lower than the melting point of the material, and cracks, pores, etc. caused by welding can be avoided. defect.
Welding wire selection
1. Selection of welding wire
For the 6005A, 6082, and 5083 base metals, the selected wire grade is 5087/ AlMg4.5MnZr. The 5087 did not only have good crack resistance, excellent anti-porosity performance, but also good strength properties. For the selection of wire specifications, the wire of large diameter is preferred. The same welding filling amount is the same weight as the welding wire, the surface area of the small size welding wire of the large size welding wire is much smaller. Therefore, the surface contamination of the small specification welding wire is small, that is, the oxidation area is small, and the welding quality is easier to meet the requirements... In addition, the wire feeding process of large diameter wire is easier to handle. For the base material with a thickness of 8 mm or less, a 1.2 mm diameter welding wire is generally used, and for a base material having a thickness of 8 mm or more, a 1.6 mm diameter welding wire is used. The automatic welder uses a 1.6mm diameter wire.
2. Selection of protective gas
Ar100% is characterized by a stable arc and easy arc ignition. For base metals with a thickness of 8mm or less, Ar100% is generally used for welding. For base metal with a thickness of 8 mm and above and welds with high porosity, Ar70%+He30% is used for welding. The characteristics of helium are 9 times the thermal conductivity of argon, the welding speed is faster, the porosity is reduced, and the penetration is increased. When the thick plate is welded, the penetration depth of Ar100% and Ar70% + He30%. The gas flow rate selection is not as large as possible, and the flow rate is too large to cause turbulence, resulting in insufficient protection of the molten pool, and the reaction of the air with the deposited metal changes the weld structure, degrades performance, and the tendency to produce welded pores increases.