Aluminum alloy is widely used in various welded structure products because of its light weight, high strength, good corrosion resistance, non-magnetic, good formability and good low temperature performance, etc. The weight of the structure can be reduced by more than 50% by using aluminum alloy instead of steel plate. Therefore, aluminum and aluminum alloys are widely used in the fields of aviation, aerospace and electrical engineering, and are also increasingly used in the petrochemical industry.
Aluminum and aluminum alloys have strong thermal conductivity and large heat capacity, large coefficient of linear expansion, low melting point and low strength at high temperature, etc. It is difficult to weld, and to maintain the quality of welding not only requires the correct welding method, but also pay attention to some protective measures
Aluminum welding is toxic, at high temperatures, the metal iron and aluminum will be partially oxidized, and iron oxide is not much harm to the human body, while aluminum oxide can cause Alzheimer's disease, that is, Alzheimer's disease. So iron welding is mainly gas and flux toxicity, while aluminum welding also more aluminum oxide toxicity.
Tools and materials: the required special aluminum wire feeding tools: non-metallic liner tube, U-groove drive roller, inlet and outlet guide, contact head Method of operation 1. Load wire to the welder with one hand holding the wire shaft without releasing, unpacking the cellophane, on the other hand holding the other end of the wire loose (into the drive roller before releasing) PS: to hold the loose end, or the whole bundle of wire will be loose 2.
2. adjust the tightness of the wire brake first adjust the tightness to the lowest gear, then load the wire and let it roll through the drive wheel. ps: the tightness is only so that the wire does not come loose, not too tight and not too loose. If the wire roller moves and the other parts do not move, it is not tight enough; 3. Set the drive roller looseness by first placing the wire head at a slight angle 1 inch from the surface of the insulating material; after that set the roller looseness to almost minimum; press the gun switch to see if the wire is sliding when it touches the surface of the insulating material; adjust the looseness from that point until the wire stops sliding. Be careful not to be too tight, too tight the wire will break. Next, also do a good job of safety measures, bring welding gloves to avoid burns.
Special tips and precautions: Make sure the power supply is well connected; Do a good job of cleaning and use degreasing solvents to remove all grease; Make sure the surface of the workpiece is dry before welding; Do not weld near combustible materials; Use a clean stainless steel wire brush to remove the surface oxides of aluminum; When welding, the welding torch cable should be straight.
Aluminum welding methods are divided into roughly three categories, according to the welding method.
One category is non-melting electrode argon arc welding, the second category is melting electrode argon arc welding, the third category is low-temperature brazing.
First, the non-melting electrode tig welding welding method using the skills AC tig welding, secondary inverter output, this time you need to master the adjustment of the machine, and the choice of materials used, and for aluminum alloy tig welding power size to match the thickness of the aluminum plate is also critical.
Second, the method of molten pole tig welding and the use of skills need to choose a stable pulse power supply, wire feeder wire to be good, with graphite conduit and aluminum welding special conductive nozzle and conduit, try to use 1.2 specifications of the coil wire, and high hardness, such as 5356 aluminum welding wire.
Third, the method of low-temperature brazing and the use of skills Need to deal with the surface oxide film, the cleaner the better, choose a low melting point brazing material welding such as the temperature is relatively low WEWELDING53 low-temperature aluminum welding rod or 303 low-temperature aluminum welding rod welding.
|toxicity||vs stainless steel|
|vs steel||vs brass gear|