Tin and a soldering iron can be used to solder aluminum. The secret is to remove the aluminum oxide layer using a specific flux. Use a high-power soldering iron since aluminum heats up rather quickly.
Aluminum will quickly oxidize in the air to generate a dense oxide coating on the surface because of its extremely active chemical characteristics. Apply flux first to the aluminum welding area before dipping the hot soldering iron in tin and setting it on the welding area to preheat. Flux thins and thickens as the temperature rises, so add additional flux and tin to coat the tip of the soldering iron with solder. Rub the tip of the soldering iron both before and after welding.The recommended range for the friction distance is between 3 and 5 mm. The aluminum oxide deposit on the component's surface is scraped at this point by the soldering iron's tip. It is unable to produce a new oxide film at the welding site due to the molten tin covering and isolation from the air, and the tin can touch the aluminum sections with the oxide layer that has recently been removed in time.When the molten tin transforms from a spherical to a flat shape, it has successfully connected with the aluminum components. Stop rubbing at this point, remove the leftover flux while it's still hot, and then weld using the pre-tinned wire tip or other parts. It is really practical. Fusion welding and pressure welding are two methods for joining aluminum. Brazing is not possible because aluminum has a low enough melting point (660 degrees Celsius).
First, drop a few drops of dilute hydrochloric acid at the welding place of the aluminum components to remove the oxide film on the surface. After a while, add a few drops of a concentrated copper sulfate solution. When the welding place is all covered with copper, wash off the excess sulfuric acid with water. Copper solution and hydrochloric acid solution, and then soldering with a 45-75W soldering iron, the effect is good.
A piece of aluminum is heated and melted in a crucible, and then 2 to 5 times of tin is added to melt it for later use, and then it is very convenient to weld according to the conventional method.
On the cleaned aluminum surface, apply a layer of mercuric nitrate solution, use a 100w soldering iron tip to eat more tin, and use the soldering iron tip to rub the soldering surface while applying the mercuric nitrate solution. This can be firmly welded on. But note: Mercury is poisonous, so it should be welded in a ventilated place, and do not use highly toxic mercuric chloride.
Welding aluminum parts by soil method, prepare white powder for sawing glass fiber board in advance, put it on the surface of the welding place, rub it on the welding surface with a 75w soldering iron until a layer of tin is attached to the aluminum surface, and then use a cloth to remove the white powder and After the rosin mixture is removed, the general method can be used for welding. After practice, this method is simple and the welding effect is satisfactory. It is also possible to mix rosin and iron filings, then polish the surface of the aluminum parts with sandpaper, put the rosin and iron powder on the smooth surface of the welding place, and repeatedly rub with a soldering iron to make the aluminum surface eat a layer of tin, and then follow the general method. Smooth welding.
The surface of the welding part of the aluminum parts is polished brightly, and then drop a few drops of sewing machine oil, the amount of oil should be sufficient, then use a sharp knife to scrape back and forth at the welding place several times, and then dip the soldering iron into the solder and rosin and rub back and forth at the welding place, the tin is very fast It will be firmly attached to the aluminum parts, and this method is also relatively simple and practical.
The surface of tin-soldered aluminum appears to be firm, but in fact the mechanical strength is very low, and a slightly larger tear will peel off. The key is that the complex formed on the bonding surface is physical infiltration. Due to the blocking of a part of the oxide layer, the affinity of tin and aluminum It is also not good, the welding surface is not fully bonded, and the strength is very low.
