Almost all kinds of welding methods can be used in welding aluminum and aluminum alloys, gas welding and electrode arc welding methods, and its equipment is simple and easy to operate. Gas welding can be used for restore welding of aluminum sheets and castings that do not claim high welding quality. Electrode arc welding can be used for restore welding of aluminum alloy castings.
The method of inert gas shielded welding is actually a widely used method of welding aluminum and aluminum profiles. So how is the aluminum profile welded successfully?
1. Cleaning before welding: When welding aluminum and aluminum alloys, it is necessary to strictly remove the oxide film and oil stains on the welding port of the workpiece and the surface of the welding wire before welding;
①Chemical cleaning has high efficiency and stable quality, and is suitable for cleaning welding wires and workpieces that are small in size and produced in batches.
②Mechanical cleaning: When the workpiece size is relatively large, the production cycle is relatively long, and the multi-layer welding or chemical cleaning is stained again, we can use mechanical cleaning.
2. Backing plate: The strength of aluminum alloy will be very low at high temperature, and the fluidity of liquid aluminum is good, and the weld metal is prone to collapse during welding. In order to ensure penetration without collapse, a backing plate is often used to hold the molten pool and nearby metal during welding. The backing plate can be made of graphite plate, stainless steel plate, carbon steel plate, copper plate or copper rod. An arc-shaped groove is opened on the surface of the backing plate to ensure that the reverse side of the weld is formed.
3. Preheating before welding: thin and small aluminum parts generally do not need preheating. When the thickness is 10 mm to 15 mm, preheating before welding can be performed. According to different types of aluminum profiles, its preheating temperature It is also different. We can use oxygen-acetylene flame, electric furnace or blowtorch to heat it. Preheating can decrease the deformation of the weldment and decrease flaw such as pores.