When you need to fasten securely togetherdifferent solid compounds, then often soldering is chosen for this. This process is widespread in many areas of industry. We have to solder and home craftsmen.
Эта операция выручает не только тогда, когда The TV or computer has failed, and to restore it is necessary to replace the burnt-out chip or chip. With this process, restore refrigeration equipment, industrial systems. Soldering helps if it is necessary to obtain a tight joint. In addition, some materials simply can not be combined in another way.
Solder alloys and flux types are selected independing on the materials you have to work with. For example, when operating with aluminum products, a different flux is needed, different from what is suitable for copper or silver. Below we consider the main characteristics of each of them and choose the best option for work.
Various alloys are used as it.metals. There are also compounds based on pure metal. In order to create quality compounds with the help of a solder, these materials must be distinguished by certain qualities.
First of all, any kind of solder should haveexcellent wettability. Without this feature, the parts to be soldered simply cannot be reliably in contact with each other. What is wettability? This is such an interesting phenomenon, when the strength of bonds between particles of a solid substance and a liquid is higher than that of molecules of a liquid. If there is wettability, then the liquid will spread over the surface and into all cavities. So, if solder for soldering does not wet, for example, copper, then it cannot be used with this metal. For soldering it does not use lead in its pure form. Its wetting characteristics are very low and one cannot count on a high quality compound.
Whatever the type of solder, the temperature at which it begins to melt must necessarily be lower than the melting of soldered materials. It should also be higher than the working temperatures of the parts.
Говоря о температуре плавления, подразумевают две points. This is the value at which the low-melting components start the melting process, and the minimum where the alloy turns into a liquid. The difference between these two temperatures is called the crystallization range. If the place of soldering is within the limits of this difference, then even small mechanical loads on the part can completely destroy the structure of the solder. In such a connection will be marked by high fragility and resistance. Remember the main thing: you should not in any way affect the connection until the solder for soldering has not completely crystallized.
Какой бы ни был тип и вид сплава, с каким бы It is not used as a material; it should not contain heavy metals or any other toxic substances above the established norm. The composition of the solder corresponds to the material details. Otherwise, you will not be able to get a reliable connection. Excessive brittleness will be observed.
Any solder, regardless of the type anddestination must be thermostable. Also solder for soldering should have electrical stability. The coefficients of thermal expansion and thermal conductivity should be considered. They should not differ significantly from the values that apply to brazed products.
All existing alloys for this operationdivided into soft, or low-melting, where the melting point is up to 450 degrees Celsius, and solid. Here it significantly exceeds the above value.
One of the most popular and commonconsidered to be tin-lead alloys with different content of components. In order to give the material the necessary characteristics, various additional ingredients can be added to the solder for soldering. For example, bismuth and cadmium are used to lower the melting point. Adding antimony can increase the strength of the solder joint.
Lead and tin alloys have a lowmelting point and low strength. They should not be used for parts, the operation of which implies a serious load. Also, these solders are not recommended if the working temperatures of the parts are above 100 ° C. If you have to solder the loaded parts with soft solders, you should try to increase the contact area of the two products.
Среди самых популярных мягких материалов можно to allocate POS-18, POS-30, POS-40, POS-61, POS-90. The numbers here are not just. This is the percentage of tin in the alloy. In industry, it is often used in the manufacture of electronics, instrument making. In everyday life, they can combine a variety of details: schemes for televisions, microwaves, electric kettles and other small appliances.
ПОС-90 предназначен для работы с деталями, which will then be processed by electroplating technology. POS-61 can be used to repair high-precision equipment. Also, the alloy is ideal for connecting parts of high responsibility from a variety of materials. POS-61 perfectly proved itself as a solder for brazing copper and brass. Solder is suitable when you need to achieve strong connections with a high degree of electrical conductivity.
POS-40 is widely used for operations withirresponsible and inaccurate details. At the same time the working zone can heat up to high temperatures. POS-30 is suitable for brazing copper or brass, steel alloys and iron.
Among the refractory alloys, only two groups are distinguished and widely used. These are mainly copper or silver alloys.
The first group can be attributed to solders made of copper andzinc. They are well suited for those compounds that will be affected only by static loads. The fragility of these alloys does not allow them to be used in the nodes that will experience shock or any vibration.
Copper solders or zinc-based compoundsPMC-36 and PMC-54 can be attributed. The first is the ideal solder for brazing brass and any other copper connections. The second is suitable for work on copper parts, bronze or steel.
If you need to connect twosteel parts, then you can use pure copper, brass brands L-62, L-62, L-68. These brass-based solders make it possible to create stronger and more flexible compounds. Copper alloys do not have such characteristics.
Silver alloys are considered the highest quality.The composition may also contain zinc and copper. PSR-70 - solder for copper soldering, for work with brass or silver parts. This element is suitable if the connection must conduct electricity. PSP-65 is used in the manufacture of jewelry, fittings, water pipes. PSR-45 is required to connect those parts that operate under vibration and shock loads.
There are also other, less popular solders.Often they are used for rare metals or for working in special conditions. For example, nickel-based compounds are designed for products that operate at elevated temperatures. They also solder stainless alloys. Gold-based solders are used to work with vacuum tubes. There are corresponding solders for magnesium.
Soldering materials and formulations are shipped inthe most different forms. So, it can be a wire, thin foil, tablets, powder. In addition, solder is available in the form of pasta or granules. The shape depends on how the solder will be delivered to the work area.
Соединение алюминиевых деталей пайкой применяется in industry and in everyday life. For example, the frames of modern bicycles are made of aluminum alloys - in the process of extreme driving, they often break. The question is: what kind of solder to choose?
Aluminum brazing is considered very difficult.process. But in fact, this is so if the process uses materials for stainless steel or brass, steel, copper. The reason for this is the oxide film. That it does not give the necessary level of wettability, and the base metal does not dissolve.
Чтобы работа осуществилась на должном уровне, Solder for aluminum soldering should contain silicon, aluminum, as well as copper, zinc and silver. Today it is possible to find formulations for sale, where all these components are in different ratios.
When choosing a reliable solder, it is important to consider the following. The maximum resistance to corrosion and high strength will have the compound that was made with solder, which contains a lot of zinc.
Also for aluminum, you can apply compounds onbased on tin and lead. But it is important to qualitatively prepare the work surface, brush it with a stainless steel brush and use active fluxes. But experts do not recommend the use of such an element.
Any solder for soldering aluminum high temperature. The most optimal, which allow you to get a reliable connection - aluminum-silicon and aluminum-copper-silicon.
As noted above, you can work with it.most formulations. It is possible to use both low-temperature low-melting and hard solders. Still used compounds based on tin with lead, tin, silver, copper with silver and zinc.
If you need to repair the motherboardcomputer or repair the TV in the country, fit any fusible elements. If it is necessary to solder the fittings on the pipes or repair the plumbing or a refrigerator, then only solid braze solder will fit. This is how you can get a quality result.
If you need to connect stainless steel parts,then professionals recommend using tin and lead rods. Also suitable are materials with cadmium. Fusible zinc-based alloys can be used. However, they should not be used together with carbon or low alloy steels. The best solder for soldering stainless steel is a composition based on pure tin. In addition, only tin is allowed if the soldering point is in contact with food.
If the work will be carried out in dry orkiln atmosphere, then you should apply silver with manganese, chromium-nickel solders or pure copper (or even better brass). When it is necessary to solder in corrosive conditions, silver tinols with a small part of nickel are used.
Connect between two such parts is not difficult.Affordable and efficient solder for soldering steel - POS-41. There is also a POS-60 and others, you can apply even pure tin. But zinc compounds are poorly suited. Especially when it comes to carbon or low-alloy materials.
During the operation, flux plays no less a role than solder. It is a chemical solvent and oxide scavenger. It also protects metals from oxidation and increases wetting.
To work with lead and tin based itemsHydrochloric acid, zinc chloride can be used as a flux. Also suitable is ammonia chloride. These are active fluxes. Rosin, vaseline, olive oil and many other substances can be classified as inactive.
For example, hydrochloric acid solutions canuse with soft solders. Zinc chloride is used with brass, copper, steel. The ammonia sleeps perfectly dilutes and dissolves fatty substances. For aluminum, use the composition of tung oil, rosin, calcined zinc chloride. You can also apply concentrated phosphoric acid.
So, we found out what solders exist, and which one is better to use in different cases.
