Introduce the production content, control and heating of copper-aluminum brazing
Everyone may not have a special understanding of what copper-aluminum brazing is, and even many friends have never heard of copper-aluminum brazing. Kehua introduces the production content, control and heating of copper-aluminum brazing to friends in need. For details, please read below. Aluminum brazing Production process Pre-treatment Copper-aluminum brazing is to weld copper and aluminum materials through brazing technology, which is one of the main methods of copper-aluminum welding. The specific operation steps of copper-aluminum brazing are as follows: 1. Welding of copper tube and aluminum tube: 2. Welding of copper bar and aluminum bar (or copper wire and aluminum wire): 1) Joint design: The unilateral gap of the joint should be controlled at 0.08~0.2 mm, the length of the weld is generally not more than 30mm. 2) Surface treatment: Use lye or metal cleaning solution to clean the oil and other contaminants from the joint welding, and then use a scraper (or coarse sandpaper, or copper brush, or wire brush) to scrape off the insulation layer on the surface of the joint welding . Note: It cannot be polished, because the solder is welded by capillary action, and it is not conducive to welding after polishing. For control and heating, the air-assisted combustion torch with uniform heating is preferred (the welding tip is equipped with a rotating device, and the flame is evenly sprayed, and Songfeng is available for sale), and the reducing flame (natural gas, petroleum liquefied gas) is preferred. The flame should be soft and can completely Cover the welding area. When heating, the flame should be moved up and down and left and right with the connection area as the center, so that the connection area is heated evenly (when different metals are connected, more metals with good thermal conductivity should be heated. For example, when copper and aluminum are welded, they should be Heat more copper parts to ensure that the temperature of the connected parts is consistent). While heating, the flux-cored welding wire can touch the workpiece in the connection area (the welding wire is melted by the temperature of the workpiece, and the welding effect is better). When it is found that the welding wire can be melted, it should be immediately Feed the welding wire and stop heating to avoid over-burning and damage to the base metal. Feed the welding wire until the molten solder fills the weld (because the molten solder penetrates into the weld by capillary action, so when you see it visually When the welding seam is full of solder, the feeding of the welding wire can be stopped to avoid unnecessary waste). After welding, remove the welding torch to allow it to cool naturally. Note: When welding, avoid the flame aiming at a certain point for a long time and the welding temperature is not suitable When the temperature exceeds 550°C, avoid burning the base metal. Safety warning: Wear protective clothing, protective gloves and protective glasses (or protective face shield) for brazing work, and beware of liquid flux splashing on the skin and causing burns. It needs further treatment. Although the flux residue is visible, it is non-corrosive, does not absorb moisture and is firmly attached. If necessary, it is recommended to use physical methods to remove it, such as using a metal brush to remove after soaking (if there is small burr, it can be polished with fine sandpaper. Drop). Aluminum brazing After Kehua introduced the production content, control and heating of copper-aluminum brazing to friends in need, I believe that everyone has a certain understanding of it. If you have any other questions, please feel free to contribute.