Soldering metals

There are many technological methods for obtaining permanent connections between parts. One of these methods is soldering. It is a technological process in which parts are heated and joined using another molten material called solder. To achieve this, the solder has a melting point significantly lower than the metal being joined. Soldering This process is performed using flux. It protects the surface being joined from atmospheric influences and promotes better solder flow.

Soldering metals This is a highly effective joining method. It is widely used for soldering pipes. For a strong connection, it is crucial to select the correct size for the parts being joined. The gap between them is 0.03–2 mm. Soldering can be:

1. Low-temperature soldering. This involves heating the solder to 450 degrees Celsius, primarily electrically;
2. High-temperature. The solder is heated above 450 degrees Celsius with a torch.

The following solders are used for soldering:

• copper-silver;
• tin-lead;
• gallium;
• copper-zinc;
• bismuth and others

Each of them has its own melting point and is more suitable for a certain metal.

Soldering metals classified into the following types:

1. Capillary soldering. The essence of soldering is to create capillary attraction due to the small joint gap. It can be vertical or horizontal;
2. Diffusion. Occurs through the diffusion of the base metal and solder. Subdivided into atomic diffusion and reaction diffusion;
3. Contact-reactive. The joining process can involve the formation of a eutectic, as well as the formation of a solid solution;
4. Reactive flux soldering. During heating, the flux reacts with the metal, forming a solder. This type of soldering can be done with or without solder.
5. Soldering and welding. This can be done with or without reflow.

Metal soldering technology

Metal soldering technology proceeds in the following order:

1. First, the surfaces of the parts to be joined are thoroughly cleaned. The chamfer is removed;
2. A thin layer of flux is applied. The type of flux used depends on the properties of the metal being soldered. To ensure better flux distribution over the surface, the parts being joined should be rotated. Alternatively, the surface is tinned;
3. The workpiece is then heated with a torch within a certain radius of the joint. For better soldering, the joint is heated to a temperature significantly higher than the melting point of the solder;
4. Solder is applied to the heated joint, melting quickly and filling the gap between the parts being joined. Some types of soldering involve tinning the cleaned surface and then joining and heating;
5. After soldering, allow the parts to cool naturally. Otherwise, the quality of the connection may suffer.

Metal soldering technology A solderless method is used to join titanium and copper. Contact melting is used. Since copper melts at 1083 degrees Celsius, and titanium at 1725 degrees Celsius, when tightly joined and heated to 900 degrees Celsius, the existing gap is filled with melt at the point of contact. This is a process of metal diffusion.

Soldering is used in connecting heat exchanger pipes, in refrigeration units, systems that transfer various liquids and gases, etc.