What welding machine need to use when welding aluminum plate
Spot welding of aluminum alloy
The application of aluminum alloys is very extensive, divided into two major categories of cold work hardening and heat treatment strengthening. Spot welding of aluminum alloys has poor weldability, especially heat-treated aluminum alloys. The reasons and the technical measures to be taken are as follows:
(1) Higher electrical conductivity and thermal conductivity must use higher current and shorter time to achieve sufficient heat to form the nugget; it can also reduce surface overheating, avoid electrode adhesion, and electrode copper ions to pure aluminum The coating layer diffuses and reduces the corrosion resistance of the joint.
(2) The plastic temperature range is narrow and the coefficient of linear expansion must be greater than the electrode pressure. The follow-up of the electrode is good enough to avoid the cracks caused by excessive tensile stress when the nugget solidifies. For aluminum alloys with large crack tendency, such as LF6, LY12, and LC4, the method of increasing the forging pressure must also be adopted so that the nugget has enough plastic deformation during solidification to reduce the tensile stress so as to avoid cracks. When the bent electrode cannot withstand a large setting pressure, it is also possible to use a slow cooling pulse after the welding pulse to avoid cracks. For large thickness aluminum alloys, two methods can be used together.
(3) The oxide film on the surface is easy to be cleaned before welding. Otherwise, spatter and nugget formation may be easily caused. (In tearing inspection, the shape of the nugget is irregular, and the bosses and holes are not circular), so that the strength of the solder joints reduce. Uneven cleaning will cause the solder joint strength to be unstable.
Based on the above reasons, spot welding aluminum alloy should use the following features of the welder:
1) Can provide high current in a short time
2) The current waveform is preferably characterized by ramping up and down
3) Accurate control of process parameters, independent of grid voltage fluctuations
4) Can provide valence and saddle electrode pressure
5) The inertia and friction of the machine head are small, and the electrodes follow well.
In recent years, the market has emerged a domestic intelligent DC spot welder capable of real-time display of welding current, electrode pressure and electrode thermal expansion curve, and capable of on-line evaluation of welding quality---servo cylinder pressure, medium frequency inverter with quality monitoring system Spot welding machine, the welding machine in the welding process visualization, intelligent, and real-time monitoring of solder joint quality has reached the international advanced level, suitable for welding of important aluminum alloy components.
The application of aluminum alloys is very extensive, divided into two major categories of cold work hardening and heat treatment strengthening. Spot welding of aluminum alloys has poor weldability, especially heat-treated aluminum alloys. The reasons and the technical measures to be taken are as follows:
(1) Higher electrical conductivity and thermal conductivity must use higher current and shorter time to achieve sufficient heat to form the nugget; it can also reduce surface overheating, avoid electrode adhesion, and electrode copper ions to pure aluminum The coating layer diffuses and reduces the corrosion resistance of the joint.
(2) The plastic temperature range is narrow and the coefficient of linear expansion must be greater than the electrode pressure. The follow-up of the electrode is good enough to avoid the cracks caused by excessive tensile stress when the nugget solidifies. For aluminum alloys with large crack tendency, such as LF6, LY12, and LC4, the method of increasing the forging pressure must also be adopted so that the nugget has enough plastic deformation during solidification to reduce the tensile stress so as to avoid cracks. When the bent electrode cannot withstand a large setting pressure, it is also possible to use a slow cooling pulse after the welding pulse to avoid cracks. For large thickness aluminum alloys, two methods can be used together.
(3) The oxide film on the surface is easy to be cleaned before welding. Otherwise, spatter and nugget formation may be easily caused. (In tearing inspection, the shape of the nugget is irregular, and the bosses and holes are not circular), so that the strength of the solder joints reduce. Uneven cleaning will cause the solder joint strength to be unstable.
Based on the above reasons, spot welding aluminum alloy should use the following features of the welder:
1) Can provide high current in a short time
2) The current waveform is preferably characterized by ramping up and down
3) Accurate control of process parameters, independent of grid voltage fluctuations
4) Can provide valence and saddle electrode pressure
5) The inertia and friction of the machine head are small, and the electrodes follow well.
In recent years, the market has emerged a domestic intelligent DC spot welder capable of real-time display of welding current, electrode pressure and electrode thermal expansion curve, and capable of on-line evaluation of welding quality---servo cylinder pressure, medium frequency inverter with quality monitoring system Spot welding machine, the welding machine in the welding process visualization, intelligent, and real-time monitoring of solder joint quality has reached the international advanced level, suitable for welding of important aluminum alloy components.
CNC Milling, CNC Milling Parts,CNC Precision machining,CNC machining,CNC machining Parts
Chongqing Henghui Precision Mold Co., Ltd , https://www.citool.com