For aluminum welding, operators are required to ensure that the basic material clean and remove any impurities and alumina hydrocarbon cutting oils and solvents. Alumina on the surface of the material melts at 3700 K, while the base material, including aluminum, at 1,200 F. Therefore, leaving a puncture on the surface oxide base material melted filler inhibits the item. In order to remove oxides of aluminum, used in stainless steel brush or wire solvents and etching solutions. When using a brush stainless steel brush, only in one direction. Be careful not to brush roughly as follows: washing raw material may further oxides to implant the workpiece. Even with the cleaning brush aluminum just does not work with aluminum brush, which has been used on steel or stainless steel. Make sure that when using a chemical etching solutions, please remove it from the work before welding. To minimize the risk of hydrocarbons from oils or cutting solvents entering the weld, remove them from the degreaser. Verify that the degreaser does not contain hydrocarbons. Preheating: Preheating of the workpiece can weld aluminum to avoid cracks. Preheating temperature should not be used more than 230 F-temperature indicator to prevent overheating of. In addition to placing tack welds at the beginning and end of the section is welded to the heating assistance will be. Welders should be heated thick piece of aluminum during welding is a thin piece of cold running, if any, try to run and run-off-on cards. Tech push: aluminum, led to the gun from the weld puddle instead moves to a better cleaning of welds reducing pollution, improving and protective cover gas. Speed: aluminum welding must be carried out quickly and hot. In contrast to the steel, said high thermal conductivity of aluminum with hot current and voltage settings and higher welding speed. If the speed is too slow, the dangers of excessive Burnthrough welders, especially on thin sheet aluminum-Gage. Shielding gas: argon, due to the excellent cleaning action and penetration profile, is most commonly used shielding gas when welding aluminum. Welding 5xxx series aluminum alloys, shielding gas mixture of argon in conjunction with helium – helium, 75 percent of the maximum – will be minimized the formation of magnesium oxide. Welding: Select a rod for welding of aluminum, which is similar to the melting temperature of the base material. More operator can narrow the melting of metal, it will be easier for the welding of the alloy. For Wire, 3/64- and 1 / 16 – inches in diameter. The larger the diameter of the pipe, the easier it is fed. In order to weld thin-gage material, and 0 035 inch diameter wire with pulse welding process at a low wire feed – in conjunction 100-300 inch / min – works well. The convex shape of weld seams in aluminum welding, crater cracking causes most failures. cracking is due to the high coefficient of thermal expansion of aluminum and a significant contraction joints appear cool. The risk of rupture is concave on the largest craters as the surface contracts crater and tears as cools. Therefore, the collection of welding form a crater or a convex shape of the hill. As the weld cools, convex shape of the crater will compensate for shrinkage forces. The choice of energy source: When selecting a power source for GMAW of aluminum, the first method of transfer or pulsed spray arc. are constant current (CC) and constant voltage (CV) for spray welding used. Spray-arc has a small stream of molten metal and spray it on the bow of electrode wire to the base material. The thick aluminum welding, which requires electricity to more than 350 cc gives the best results. transfer Pulse is usually carried out with the supply inverter. Newer supply procedures and built-in pulse-type filler wire and the diameter is based. During pulsed GMAW, a drop of sweat additional transfers from the electrode to each item in the current pulse. This process produces positive droplets and transfer of results will be in a few spots and faster speeds, and not as a spray transfer welding. With pulsed GMAW process on aluminum for improved heat control, ease of welding outside position and allows the operator to thin-gage materials at low rates of feed and movement of welding wire. Wire feed : the preferred method for feeding soft aluminum wire over long distances is a push-pull method, a closed wire-feed cabinet to protect the cable from the workers’ environment. Fixed torque of the engine with a variable speed wire feed housing supports push and guide wire through the gun at a constant strength and speed. The high torque motor in the gun passes through the conduit and a wire feed speed and arc length consistent. the issue in some shops, welders of the same wire feed equipment for the steel wire and aluminum. In this case, the use of plastic or Teflon-liner will help to ensure a smooth, according to administration of aluminum wire. For the pipes, using a chisel type of incoming and outgoing wire, plastic pipes in the vicinity to support the drive roller to prevent the wire from tangling. When welding, keep the gun cable as straight as possible to minimize the resistance wire feeds. Checks the accuracy of alignment between the drive rolls and guide tubes to prevent the shaving of aluminum. Use drive rolls designed for aluminum. to provide set-roll-up drive voltage wire feeds. Excessive tension will deform the wire and cause severe and erratic feeding; Too little tension results in uneven feeding. Both diseases can lead to unstable arc and weld porosity. Welding guns: Use a separate layer of a gun for aluminum welding. In order to prevent chaffing of wire, try both ends of the liner back to the elimination of existing between the linear and the gas diffuser arms. Go vessels often lead to minimize the potential for abrasion of aluminum wire feeding problems of nitrogen. Use the contact tip of the 0th used 015 cm greater than the diameter of filler – like tip is heated, it will expand in an oval shape and may go beyond the wire feeder. In general, when welding current exceeds 200, the heat gun on the water and minimize the creation of wire feeding problems.


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