The low melting point and good wetting ability have determined its use as the main component of many bar solder lead free. Magnesium, titanium, nickel, copper, as well as noble metals: gold and silver are good as alloying elements for solders.
Bar solder lead free with bismuth
As solders, not pure bismuth is good, but alloys based on it, into which alloying elements are introduced: lead, tin, cadmium, etc. (Table 11.1). A typical bismuth solder is the well-known Wood's alloy. Bismuth-rich brazing alloys are characterized by an increase in volume upon transition from a liquid to a solid state, as well as upon cooling after solidification.
This ensures that there are no leaks, so they are good in the manufacture of containers for liquids. Solders with bismuth do not wet steels well; they are good for brazing copper.
Indium bar solder lead free
These solders, in addition to indium, can contain tin, lead, and silver. These are including in bar solder lead free. Due to the high wetting ability of indium in relation to metals and non-metallic materials, solders are good for soldering semiconductors, glass, and plastics. So in the electronics industry, a solder with 5% silver is good. Solder containing 45% Sn, 26% Pb, rest.
The liquids temperature of tin and alloys based on it is in the range of 145-250 ° С. These are fusible solders. The properties of tin solders are determined by tin polymorphism. At a temperature of 13.2 ° C, white tin with a density of 7.28 g / cm3, which has a tetragonal crystal lattice, is converted into gray tin with a density of 5.82 g / cm3 with a cubic lattice.
This transformation occurs with the release of heat, a large change in volume, which causes destruction and the formation of a gray powder (tin plague). This transformation occurs with the release of heat, a large change in volume, which causes destruction and the formation of a gray powder. These are also known as bar solder lead free.
Tin-lead bar solder lead free
In tin-lead solders, tin plague was not observed. The recrystallization temperature of these solders is close to 20 ° C. This means that the solders do not rivet, that is, under load, the phenomenon of creep is possible, therefore they are good for joints that do not experience mechanical stress, for example, for soldering electronic equipment. The properties of the solders are given in table. 11.2.
These are fusible solders with a liquidus temperature of 276 ... 380 ° C. Pure lead is suitable for soldering many metals: copper, iron, nickel, cobalt and their alloys. However, lead is prone to creep at room temperatures (Gy = -33 ° C). Alloying lead solder with antimony, silver, zinc, cadmium allows not only to prevent creep, but also to increase the strength of the solder as compare to bar solder lead free.
Low melting bar solder lead free
Low-melting solders based on lead and cadmium provides increased corrosion resistance for brazed joints of aluminum alloys. For soldering glass to metal, lead solder alloyed with antimony and zinc (5% Sb, 3% Zn) is good. Subsequently, the temperature coefficients of linear expansion of the solder and glass are close in values.
Cadmium solders are fusible (liquidus temperature 285-38СГС). The main alloying components of cadmium solders are silver and zinc. The tensile strength of these brazing alloys is higher than that of brazing alloys based on lead and tin or bar solder lead free.
K1, KZ, PSrZKd solders provide heat resistance of copper brazed joints up to 250 ° С, PSr8KTsN solder - up to 300 ° С. Solder Cd - 5% Ag is good for soldering scomposites with an aluminum matrix. Solder Cd - 25% Sn, which has low resistance, is good when soldering printed circuit boards.
The melting point of zinc (419 ° C) is higher than that of other low-melting metals. Zinc has low ductility and strength, poor ability to spread and flow into the gap due to the high melting point.
Zinc solders are alloyed with aluminum, cadmium, and copper to lower the melting point and increase strength and ductility. The maximum strength of Zn - Sn solders is achieved with a 20-30% tin content.
Solder Zn - 7% Cu has a very high ductility, it is rolled into foil with a thickness of 100 microns. Zinc solders are good for brazing aluminum alloys, providing corrosion resistance and a sufficiently high strength of the brazed joints. Furthermore, zinc solders with cadmium are good for brazing galvanized iron as compared to bar solder lead free.
Medium and high melting bar solder lead free
These solders are good in cases where the product during operation can be heated to temperatures exceeding the soldering temperatures of low-melting alloys, in addition, the strength of these solders is much higher than that of low-melting alloys.
Aluminum solders are classified as medium-melting. The most widely good is silumin, an alloy of the Al - Si system of eutectic composition, containing 11.7% silicon with a melting point of 577 ° C and alloys based on it. These solders have good fluidity and corrosion resistance. Aluminum solders can be alloyed with magnesium, zinc, copper, manganese, etc.
PET soldering acid
The optimum temperature of the soldering process with its use is 150 - 320 degrees. In addition, it is good for bar solder lead free.
There are two types:
It is good for oxidized parts consisting of ferrous or non-ferrous metal. Moreover, active soldering grease is not good in radio engineering. Neutral soldering grease does not contain active components; therefore it can be good for soldering radio components.
Types of soldering with bar solder led free
Among the most widespread welding techniques, there is also the bar solder lead free. This method does not require the use of shielding gas. And it is easy to carry out indifferently both in the workshop and on the outdoor construction site.
Welding takes place also in this case thanks to the generation of an electric arc. Furthermore, this comes to strike between the edges of the base metal and the electrode.
The latter consists of a metal rod, coated with antioxidant materials. Moreover, the action of the oxidizing elements ensures a more effective welding. Similarly, it protects the welding bath from oxidation and prevents the formation of slag.