Solder - a metal or alloy used in soldering to fill the gap between the joined parts in order to obtain a monolithic connection. Used alloys of tin, lead, cadmium, Copper, nickel, etc. Solders can be divided into two groups - soft and hard. To include soft solders with melting points up to 300 ° C, to a solid - above 300 ° C. In addition, solder vary widely in the mechanical strength. Soft solders have a tensile strength of 16-100 MPa, and solid - 100-500 MPa.
Soft solders are tin-lead alloys (POS) with the tin of 10 (POS-10) to 90% (POS-90), the rest lead. Conductivity of these solders is 9-15% pure Copper. A large number of tin-lead solder contains a small percentage of antimony.
|Composition and characteristics of soft solders|
|Grade||Composition, %||Melting point, °С||Tensile strength||Application|
|POS-18||Tin – 18Antimony –2,0÷2,5Lead – rest||277||2,8÷3,0||Soldering parts of copper, galvanized iron and steel|
|POS-30||Tin – 30Antimony – 1,5÷2,0Lead – rest||256||4,0÷5,0||Soldering parts of copper, iron and steel and tin|
|POS-40||Tin – 40 Antimony – 1,2÷2,0Lead –rest||235||3,5÷4,5||Soldering critical parts of steel and brass. Tinning and soldering equipment wires and cable lugs|
|POS-61||Tin – 61 Antimony – 0,8 Lead -rest||190||4,7÷5,5||Soldering current carrying copper and brass parts, and thin and outlet ends of winding wires|
|POSК-50||Tin – 50 cadmium – 18 Lead – 32||145||5,5÷6,0||Mounting parts and soldering of copper wire|
|AVIA-1||Tin – 55 Zink – 25 cadmium – 20||200||7,5||Soldering electrical components made of aluminum and aluminum alloys|
When selecting the type of solder to consider its characteristics and apply depending on destination soldered parts. When soldering the parts that prevent overheating, use solder having a low melting point.
The most widely used grade finds solder POS-40. It is used in soldering connecting wires, resistors, capacitors. POS-30 solder is used for soldering shielding coatings, Brass plates and other details. Along with primeieniem standard grades is used and POS-61 solder (60% tin and 40% lead).
Soft solders are made in the form of bars, billets, wire (diameter 3 mm) and tubes filled with flux. The technology of solder is easy and quite feasible in the workshop: the lead is melted in metal cup and a small part adds tin content of which is determined depending on the type of solder. Alloy remove carbon deposits from the surface of the molten solder and poured vderevyannye or steel molds. Adding bismuth, cadmium, and other additives necessary.
Soldering of different parts that do not allow heat significantly, used fusible alloys, which are obtained by adding to the lead-tin bismuth and cadmium or one of these metals.
|Composition and characteristics of low-melting solders|
When using bismuth and cadmium solders should be aware that they have a very fragile and create less strong junction than lead-tin.
Solder - a metal or alloy used in soldering to fill joined parts in order to obtain a monolithic connection. Used alloys of tin, lead, cadmium, Copper, nickel and other solder alloys can be divided into two groups - soft and hard. Solder melting point 300 ° C, to solid - above 300 °C. In addition, solders differ by mechanical strength.
|Composition and characteristics of hard solders|
Depending on zinc content, solder changes color. These solders used for soldering Bronze, Brass, steel and other metals having high melting point. Solder the PMC-42 is used in soldering Brass with 60 - 68% Copper. Solder the PMC-52 is used in soldering Copper and Bronze. Copper Zink solders made by melting copper and zinc in electric furnaces, in a graphite crucible. As the melting Copper crucible added zinc, after the melting of zinc added about 0.05% phosphorus copper. The melting point of the solder must be less than the melting point of solder the metal. In addition to these copper-zinc solders, finding use silver solder.
|Composition and characteristics of silver solders|
Silver solders have great strength, welded joints and easily handled. Solders SEP-10 SEP-12 are used for soldering Brass containing not less than 58% of Copper, solder SEP-25 SEP-45 - Soldering Copper, Bronze and Brass, solder SEP-70 with the highest grade silver - Soldering waveguides volume loops, etc. Besides the standard silver solders are used, and others.
|Composition and characteristics of non-standard silver solders|
The first one used for brazing Copper, steel, nickel, and the second one, with high conductivity - for soldering wires, and the third can be used for brazing Copper, but not suitable for ferrous metals, and the fourth has a special low-melting solder is universal soldering Copper and its alloys , nickel, and steel.
In some cases, as the solder used commercially pure Copper melting stemperaturoy 1083 ° C.
Soldering of Aluminum causes great difficulties due to its ability to easily oxidized in air. Recently, aluminum solder with ultrasonic soldering.
|Composition and characteristics aluminum brazing|
|-||-||-||69,8-64,5||5,2-6,5||25-29||Brazing, melting point 525°С|
As flux use rosin and stearin. Brazing material is applied with a special flux. Ingredients: lithium chloride (25-30%), potassium fluoride (8-12%), zinc chloride (8-15%), potassium chloride (59-43%). Melting temperature to 460 °C.