Bismuth solder

Wismut-bleierz, n. schapbachite. -blende, /. bismuth blende, eulytite. -blUte, /. bismuth Ocher, bismite, -bromid, n. bismuth bromide, -butter, /. (Old Chem.) butter of bismuth (bismuth trichloride), -chlorid, n. bismuth chloride, bismuth trichloride, wismuten, v.t. solder with bismuth or bismuth solder. 

Marshall, J., Calderon, X, and Sees, X, Microstructural and Mechanical Characterization of 43 3 14 Tin-Lead-Bismuth, Soldering and Surface Mount Technology, No. 9, October 1991, pp. 25-27. 

Vianco, P.T. Rejent, J.A. Tin-Silver-Bismuth Solders for Electronics Assembly, U.S. Patent 5439639,... 

Melton, C.M. Beckenbaugh, W. Miller, D. Tin Bismuth Solder Paste, and Method Using Paste to Form Connection Having Improved High Temperature Properties. US Pat. No. 5,389,160, Feb.l4, 1995. 

Solders are alloys that have melting temperatures below 300°C, formed from elements such as tin, lead, antimony, bismuth, and cadmium. Tin—lead solders are commonly used for electronic appHcations, showing traces of other elements that can tailor the solder properties for specific appHcations. 

Solders. In spite of the wide use and development of solders for millennia, as of the mid-1990s most principal solders are lead- or tin-based alloys to which a small amount of silver, zinc, antimony, bismuth, and indium or a combination thereof are added. The principal criterion for choosing a certain solder is its melting characteristics, ie, soHdus and Hquidus temperatures and the temperature spread or pasty range between them. Other criteria are mechanical properties such as strength and creep resistance, physical properties such as electrical and thermal conductivity, and corrosion resistance. 

In former times, tin was used widely as a constituent of metal alloys, of which bronze, solder, and pewter are common examples. Bronze is an alloy of copper containing approximately 20% tin and smaller amounts of zinc. Pewter is another Cu-Sn alloy that contains tin as the major component ( 85%), with roughly equal portions of copper, bismuth, and antimony. Solder consists of 67% lead and 33% tin. 

The low-melting-point (157 °C), silver metal is mainly used in alloys to decrease the melting point. Combined with tin, lead, and bismuth to produce soldering metal for wide temperature ranges. The element is highly valuable in the electronics age as its unique properties are ideal for solar cells, optoelectronics, and microwave equipment. The arsenide is used in lasers and is also suitable for transistors. ITO (indium tin oxide) is a transparent semiconductor with wide application in displays, touchscreens, etc. In the household, indium as an additive prevents the tarnishing of silverware. Some electronic wristwatches contain indium batteries. 

Uses. Low melting solders, low melting alloys and metallurgical additives. Bismuth is a metal with some unusual properties like Ge and Ga its volume increases in solidification. It is the most diamagnetic metal, its alloys show large thermoelectric effect with the exception of Be has the lowest absorption cross-section for thermal neutrons. 

The RoHS Directive was a major catalyst for research and adoption of lead-free solutions in electronic equipment. Alternatives to lead in soldering range from tin (Sn), silver (Ag) and copper (Cu) to bismuth (Bi) and zinc (Zn). These heavy metals do not have the same toxicity and bioaccumulation potential of lead (Pb). ... 

Alloys.—Lead entars into the construction of several alloys, many of whioh have been already referred to—see Aktimoky, Bismuth, et cetera, ante —add pewter, or solder, so largely employed by the plumber, is a combination of this metal and tin, in the proportion of two parts of lead to one of tin sometimes, however, the proportion is varied, according to tho requirements of the plumber. 

Pewter is an alloy of 80 per cent, of lead with 20 per cent, of tin plumbers solder consists of two parts of lead to one of tin Britannia metal is made of equal parts of brass, tin, antimony, and bismuth. 

PMS liquids are corrosion-inert substances. Under normal conditions and heated to 100-150 °C they do not cause corrosion and for a long period of time do not change in airflow when in contact with aluminum and magnesium alloys, bronzes, carbon and doped steels, as well as titanium alloys. PMS liquids do not change their properties under 100 °C in air for 200 hours in contact with the above-listed alloys as well as with beryllium, bismuth, cadmium, Invar alloy, brass, copper, mel-chior, solder, lead, silver. The stability of the properties of PMS liquids in these conditions is usually accompanied by the absence of metal and alloy corrosion, although the colour of the metal surface may slightly change. 

The classical electronics solder alloy (Sn + 37 wt% Pb) contains the inhalation-toxic element lead and is being replaced in electronics for health reasons. A Pb-free solder is Sn-3.5wt% Ag indium and bismuth alloys are other eutectic-forming alloying additives to Sn. The classical brazing alloy is at the Cu-Ag eutectic (Ag-F 28.1 w% Cu) and is well suited for mechanically strong contacts with Cu and its alloys. 

In a substitutional alloy some of the host metal atoms are replaced by other metal atoms of similar size. For example, in brass about one-third of the atoms in the host copper metal are replaced by zinc atoms, as shown in Fig. 16.25(a). Sterling silver (93% silver and 7% copper), pewter (85% tin, 7% copper, 6% bismuth, and 2% antimony), and plumber s solder (67% lead and 33% tin) are other examples of substitutional alloys. 

The primary use of bismuth metal is in making alloys. Many bismuth alloys have low melting points. The metal itself melts at 520°F (271°C), but some bismuth alloys melt at temperatures as low as 160°F (70°C). This temperature is below the boiling point of water. These alloys are used in fire sprinkler systems, fuel tank safety plugs, solders, and other applications. 

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