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77-545: Met-Mex Peñoles is a large metallurgical and chemical company located in Torreón, Coahuila Mexico . This industrial site processes the majority of the zinc and lead mineral ores mined in Mexico and some other countries. The facility produces the following metals: silver , gold , zinc, lead, cadmium and bismuth ; as well as the following chemicals: sulfuric acid , oleum , and antimony trioxide . This metallurgical complex

154-507: A burial site located in the western industrial zone of Varna , approximately 4 km from the city centre, internationally considered one of the key archaeological sites in world prehistory. The oldest gold treasure in the world, dating from 4,600 BC to 4,200 BC, was discovered at the site. The gold piece dating from 4,500 BC, found in 2019 in Durankulak , near Varna is another important example. Other signs of early metals are found from

231-646: A catalytic tip to heat a bit, without flame, are used for portable applications. Hot-air guns and pencils allow rework of component packages (such as surface mount devices) which cannot easily be performed with electric irons and guns. For non-electronic applications, soldering torches use a flame rather than a soldering tip to heat solder. Soldering torches are often powered by butane and are available in sizes ranging from very small butane/oxygen units suitable for very fine but high-temperature jewelry work, to full-size oxy-fuel torches suitable for much larger work such as copper piping. Common multipurpose propane torches,

308-830: A complex circuit board in one operation, vastly reducing production cost of electronic devices. Musical instruments, especially brass and woodwind instruments, use a combination of soldering and brazing in their assembly. Brass bodies are often soldered together, while keywork and braces are most often brazed. The solderability of a substrate is a measure of the ease with which a soldered joint can be made to that material. Some metals are easier to solder than others. Copper, zinc, brass, silver and gold are easy. Iron, mild steel and nickel are next in difficulty. Because of their thin, strong oxide films, stainless steel and some aluminium alloys are even more difficult to solder. Titanium , magnesium , cast irons , some high-carbon steels , ceramics , and graphite can be soldered but it involves

385-410: A ductile to brittle transition and lose their toughness, becoming more brittle and prone to cracking. Metals under continual cyclic loading can suffer from metal fatigue . Metals under constant stress at elevated temperatures can creep . Cold-working processes, in which the product's shape is altered by rolling, fabrication or other processes, while the product is cold, can increase the strength of

462-400: A flame or carbon arc torch to achieve the melting of the filler. Soft solder filler metals are typically alloys (often containing lead ) that have liquidus temperatures below 350 °C (662 °F). In this soldering process, heat is applied to the parts to be joined, causing the solder to melt and to bond to the workpieces in a surface alloying process called wetting . In stranded wire,

539-430: A heated iron whereas the other methods typically require a higher temperature torch or a furnace to melt the filler metal. Different equipment is usually required since a soldering iron cannot achieve high enough temperatures for hard soldering or brazing. Brazing filler metal is stronger than silver solder, which is stronger than lead-based soft solder. Brazing solders are formulated primarily for strength, silver solder

616-422: A joint. A good solder joint produces an electrically conductive, water- and gas-tight join. Each type of solder offers advantages and disadvantages. Soft solder is so called because of the soft lead that is its primary ingredient. Soft soldering uses the lowest temperatures (and so thermally stresses components the least) but does not make a strong joint and is unsuitable for mechanical load-bearing applications. It

693-577: A large thermal mass to store enough heat for soldering large areas before needing re-heating in the fire; the larger the head, the longer the working time. The copper surface of the tool must be constantly cleaned and re-tinned during use. Historically, soldering coppers were standard tools used in auto bodywork, although body solder has been mostly superseded by spot welding for mechanical connection, and non-metallic fillers for contouring. During WW2 and for some time afterwards SOE forces used small pyrotechnic self-soldering joints to make connections for

770-404: A lesser extent steel and zinc. This mechanical soldering is similar to a low temperature brazing operation, in that the mechanical characteristics of the joint are reasonably good and it can be used for structural repairs of those materials. The American Welding Society defines brazing as using filler metals with melting points over 450 °C (842 °F) — or, by the traditional definition in

847-413: A liquid bath. Metallurgists study the microscopic and macroscopic structure of metals using metallography , a technique invented by Henry Clifton Sorby . In metallography, an alloy of interest is ground flat and polished to a mirror finish. The sample can then be etched to reveal the microstructure and macrostructure of the metal. The sample is then examined in an optical or electron microscope , and

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924-401: A major concern. Cast irons, including ductile iron , are also part of the iron-carbon system. Iron-Manganese-Chromium alloys (Hadfield-type steels) are also used in non-magnetic applications such as directional drilling. Other engineering metals include aluminium , chromium , copper , magnesium , nickel , titanium , zinc , and silicon . These metals are most often used as alloys with

1001-428: A metal chassis, while large irons have tips too cumbersome for working on printed circuit boards (PCBs) and similar fine work. A 25-watt iron will not provide enough heat for large electrical connectors, joining copper roof flashing, or large stained-glass lead came. On the other hand, a 100-watt iron may provide too much heat for PCBs. Temperature-controlled irons have a reserve of power and can maintain temperature over

1078-839: A process similar to joining carbides: they are first plated with a suitable metallic element that induces interfacial bonding. Soldering filler materials are available in many different alloys for differing applications. In electronics assembly, the eutectic alloy with 63% tin and 37% lead (or 60/40, which is almost identical in melting point) has been the alloy of choice. Other alloys are used for plumbing, mechanical assembly, and other applications. Some examples of soft-solder are tin-lead for general purposes, tin-zinc for joining aluminium , lead-silver for strength at higher than room temperature, cadmium-silver for strength at high temperatures, zinc-aluminium for aluminium and corrosion resistance, and tin-silver and tin-bismuth for electronics. A eutectic formulation has advantages when applied to soldering:

1155-409: A pump in a bath of liquid solder produces an elevated "wave" of solder which the part is quickly passed through. Wave soldering uses surface tension to keep solder from bridging the insulating gaps between the copper lines of flux-coated printed wiring boards / printed circuit boards . The electric soldering iron is widely used for hand-soldering, consisting of a heating element in contact with

1232-480: A similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist. The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy . Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mineral processing ,

1309-615: A smelted copper axe dating from 5,500 BC, belonging to the Vinča culture . The Balkans and adjacent Carpathian region were the location of major Chalcolithic cultures including Vinča , Varna , Karanovo , Gumelnița and Hamangia , which are often grouped together under the name of ' Old Europe '. With the Carpatho-Balkan region described as the 'earliest metallurgical province in Eurasia', its scale and technical quality of metal production in

1386-563: A superior metal could be made, an alloy called bronze . This represented a major technological shift known as the Bronze Age . The extraction of iron from its ore into a workable metal is much more difficult than for copper or tin. The process appears to have been invented by the Hittites in about 1200 BC, beginning the Iron Age . The secret of extracting and working iron was a key factor in

1463-407: A torch or other high temperature source and darkened goggles to protect the eyes from the bright light produced by the white-hot work. It is often used to repair cast-iron objects, wrought-iron furniture, etc. Soldering operations can be performed with hand tools, one joint at a time, or en masse on a production line. Hand soldering is typically performed with a soldering iron , soldering gun , or

1540-418: A torch, or occasionally a hot-air pencil. Sheetmetal work was traditionally done with "soldering coppers" directly heated by a flame, with sufficient stored heat in the mass of the soldering copper to complete a joint; gas torches (e.g. butane or propane) or electrically heated soldering irons are more convenient. All soldered joints require the same elements of cleaning of the metal parts to be joined, fitting up

1617-433: A very mild 'no-clean' flux might be perfectly acceptable for production equipment, but not give adequate performance for more variable hand-soldering operations. Different types of soldering tools are made for specific applications. The required heat can be generated from burning fuel or from an electrically operated heating element or by passing an electric current through the item to be soldered. Another method for soldering

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1694-436: A wide range of work. A soldering gun heats a small cross-section copper tip very quickly by conducting a large AC current through it using a large cross-section one-turn transformer; the copper tip then conducts the heat to the part like other soldering irons. A soldering gun will be larger and heavier than a heating-element soldering iron of the same power rating because of the built-in transformer. Gas-powered irons using

1771-401: Is a chemical surface-treatment technique. It involves bonding a thin layer of another metal such as gold , silver , chromium or zinc to the surface of the product. This is done by selecting the coating material electrolyte solution, which is the material that is going to coat the workpiece (gold, silver, zinc). There needs to be two electrodes of different materials: one the same material as

1848-420: Is also unsuitable for high-temperature applications as it loses strength, and eventually melts. Silver soldering, as used by jewelers, machinists and in some plumbing applications, requires the use of a torch or other high-temperature source, and is much stronger than soft soldering. Brazing provides the strongest of the non-welded joints but also requires the hottest temperatures to melt the filler metal, requiring

1925-443: Is an industrial coating process that consists of a heat source (flame or other) and a coating material that can be in a powder or wire form, which is melted then sprayed on the surface of the material being treated at a high velocity. The spray treating process is known by many different names such as HVOF (High Velocity Oxygen Fuel), plasma spray, flame spray, arc spray and metalizing. Electroless deposition (ED) or electroless plating

2002-708: Is collected and processed to extract valuable metals. Ore bodies often contain more than one valuable metal. Tailings of a previous process may be used as a feed in another process to extract a secondary product from the original ore. Additionally, a concentrate may contain more than one valuable metal. That concentrate would then be processed to separate the valuable metals into individual constituents. Much effort has been placed on understanding iron –carbon alloy system, which includes steels and cast irons . Plain carbon steels (those that contain essentially only carbon as an alloying element) are used in low-cost, high-strength applications, where neither weight nor corrosion are

2079-455: Is defined as the autocatalytic process through which metals and metal alloys are deposited onto nonconductive surfaces. These nonconductive surfaces include plastics, ceramics, and glass etc., which can then become decorative, anti-corrosive, and conductive depending on their final functions. Electroless deposition is a chemical processes that create metal coatings on various materials by autocatalytic chemical reduction of metal cations in

2156-644: Is found in the Balkans and Carpathian Mountains , as evidenced by findings of objects made by metal casting and smelting dated to around 6000-5000 BC. Certain metals, such as tin, lead, and copper can be recovered from their ores by simply heating the rocks in a fire or blast furnace in a process known as smelting. The first evidence of copper smelting, dating from the 6th millennium BC, has been found at archaeological sites in Majdanpek , Jarmovac and Pločnik , in present-day Serbia . The site of Pločnik has produced

2233-481: Is somewhat absorbed by the surrounding metal, resulting in a joint that is actually stronger than the metal being joined. The metal being joined must be perfectly flush, as silver solder cannot normally be used as a filler and will not fill gaps. Another difference between brazing and soldering is how the solder is applied. In brazing, one generally uses rods that are touched to the joint while being heated. With silver soldering, small pieces of solder wire are placed onto

2310-503: Is the largest producer of silver in the world, the largest producer of zinc in Latin America , and the most important producer of gold and lead in Mexico. Peñoles Group is not only Met-Mex. It includes a variety of business units like mines, metallurgical, chemical and administrative companies. Metallurgy Metallurgy is a domain of materials science and engineering that studies

2387-530: Is the more common one in the United Kingdom . The / ˈ m ɛ t əl ɜːr dʒ i / pronunciation is the more common one in the United States US and is the first-listed variant in various American dictionaries, including Merriam-Webster Collegiate and American Heritage . The earliest metal employed by humans appears to be gold , which can be found " native ". Small amounts of natural gold, dating to

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2464-409: Is to facilitate the soldering process. One of the obstacles to a successful solder joint is an impurity at the site of the joint; for example, dirt, oil or oxidation . The impurities can be removed by mechanical cleaning or by chemical means, but the elevated temperatures required to melt the filler metal (the solder) encourages the work piece (and the solder) to re-oxidize. This effect is accelerated as

2541-426: Is to place solder and flux at the locations of joints in the object to be soldered, then heat the entire object in an oven to melt the solder; toaster ovens and hand-held infrared lights have been used by hobbyists to replicate production soldering processes on a much smaller scale. A third method of soldering is to use a solder pot where the part (with flux) is dipped in a small heated iron cup of liquid solder, or

2618-421: Is used by jewelers to protect the precious metal and by machinists and refrigeration technicians for its tensile strength but lower melting temperature than brazing, and the primary benefit of soft solder is the low temperature used (to prevent heat damage to electronic components and insulation). Since the joint is produced using a metal with a lower melting temperature than the workpiece, the joint will weaken as

2695-450: Is usually described as easy, medium, or hard in reference to its melting temperature, not the strength of the joint. Extra-easy solder contains 56% silver and has a melting point of 618 °C (1,145 °F). Extra-hard solder has 80% silver and melts at 740 °C (1,370 °F). If multiple joints are needed, then the jeweler will start with hard or extra-hard solder and switch to lower-temperature solders for later joints. Silver solder

2772-558: The electronics industry for the manufacture and repair of printed circuit boards (PCBs) and other electronic components. It is also used in plumbing and metalwork , as well as in the manufacture of jewelry and other decorative items. The solder used in the process can vary in composition, with different alloys used for different applications. Common solder alloys include tin-lead, tin-silver, and tin-copper, among others. Lead-free solder has also become more widely used in recent years due to health and environmental concerns associated with

2849-490: The extraction of metals , thermodynamics , electrochemistry , and chemical degradation ( corrosion ). In contrast, physical metallurgy focuses on the mechanical properties of metals, the physical properties of metals, and the physical performance of metals. Topics studied in physical metallurgy include crystallography , material characterization , mechanical metallurgy, phase transformations , and failure mechanisms . Historically, metallurgy has predominately focused on

2926-404: The liquidus and solidus temperatures are the same, so there is no plastic phase, and it has the lowest possible melting point. Having the lowest possible melting point minimizes heat stress on electronic components during soldering. And, having no plastic phase allows for quicker wetting as the solder heats up, and quicker setup as the solder cools. A non-eutectic formulation must remain still as

3003-499: The "iron" (a larger mass of metal, usually copper) which is in contact with the working tip made of copper. Usually, soldering irons can be fitted with a variety of tips, ranging from blunt, to very fine, to chisel heads for hot-cutting plastics rather than soldering. Plain copper tips are subject to errosion/dissolution in hot solder, and may be plated with pure iron to prevent that. The simplest irons do not have temperature regulation. Small irons rapidly cool when used to solder to, say,

3080-518: The 6th–5th millennia BC totally overshadowed that of any other contemporary production centre. The earliest documented use of lead (possibly native or smelted) in the Near East dates from the 6th millennium BC, is from the late Neolithic settlements of Yarim Tepe and Arpachiyah in Iraq . The artifacts suggest that lead smelting may have predated copper smelting. Metallurgy of lead has also been found in

3157-642: The Balkans during the same period. Copper smelting is documented at sites in Anatolia and at the site of Tal-i Iblis in southeastern Iran from c. 5000 BC. Copper smelting is first documented in the Delta region of northern Egypt in c. 4000 BC, associated with the Maadi culture . This represents the earliest evidence for smelting in Africa. The Varna Necropolis , Bulgaria , is

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3234-690: The United States, above 800 °F (427 °C). Aluminium soldering alloys generally have melting temperatures around 730 °F (388 °C). This soldering / brazing operation can use a propane torch heat source. These materials are often advertised as "aluminium welding", but the process does not involve melting the base metal, and therefore is not properly a weld. United States Military Standard or MIL-SPEC specification MIL-R-4208 defines one standard for these zinc-based brazing/soldering alloys. A number of products meet this specification. or very similar performance standards. The purpose of flux

3311-441: The ambient temperature approaches the melting point of the filler metal. For that reason, the higher temperature processes produce joints which are effective at higher temperatures. Brazed connections can be as strong or nearly as strong as the parts they connect, even at elevated temperatures. "Hard soldering" or "silver soldering" is used to join precious and semi-precious metals such as gold, silver, brass, and copper. The solder

3388-402: The amount of phases present as well as the degree of strain to which a sample has been subjected. Current advanced characterization techniques, which are used frequently in this field are: Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Electron Backscattered Diffraction (EBSD) and Atom-Probe Tomography (APT). Soldering Soldering is commonly used in

3465-466: The choice of method depends on the application and the materials being joined. Soldering is an important skill for many industries and hobbies, and it requires a combination of technical knowledge and practical experience to achieve good results. There is evidence that soldering was employed as early as 5,000 years ago in Mesopotamia. Soldering and brazing are thought to have originated very early in

3542-416: The coating material and one that is receiving the coating material. Two electrodes are electrically charged and the coating material is stuck to the work piece. It is used to reduce corrosion as well as to improve the product's aesthetic appearance. It is also used to make inexpensive metals look like the more expensive ones (gold, silver). Shot peening is a cold working process used to finish metal parts. In

3619-534: The filler metal for each type of soldering can be adjusted to modify the melting temperature of the filler. Soldering differs from gluing significantly in that the filler metals directly bond with the surfaces of the workpieces at the junction to form a bond that is both electrically conductive and gas- and liquid-tight. Soft soldering is characterized by having a melting point of the filler metal below approximately 400 °C (752 °F), whereas silver soldering and brazing use higher temperatures, typically requiring

3696-467: The higher temperature silver soldering process. Small mechanical parts are often soldered or brazed as well. Soldering is also used to join lead came and copper foil in stained glass work. Electronic soldering connects electrical wiring to devices, and electronic components to printed circuit boards . Electronic connections may be hand-soldered with a soldering iron. Automated methods such as wave soldering or use of ovens can make many joints on

3773-619: The highly developed and complex processes of mining metal ores, metal extraction, and metallurgy of the time. Agricola has been described as the "father of metallurgy". Extractive metallurgy is the practice of removing valuable metals from an ore and refining the extracted raw metals into a purer form. In order to convert a metal oxide or sulphide to a purer metal, the ore must be reduced physically, chemically , or electrolytically . Extractive metallurgists are interested in three primary streams: feed, concentrate (metal oxide/sulphide) and tailings (waste). After mining, large pieces of

3850-731: The history of metal-working, probably before 4000 BC. Sumerian swords from c.  3000 BC were assembled using hard soldering. Soldering was historically used to make jewelry, cookware and cooking tools, assembling stained glass , as well as other uses. Soldering is used in plumbing, electronics, and metalwork from flashing to jewelry and musical instruments. Soldering provides reasonably permanent but reversible connections between copper pipes in plumbing systems as well as joints in sheet metal objects such as food cans, roof flashing , rain gutters and automobile radiators . Jewelry components, machine tools and some refrigeration and plumbing components are often assembled and repaired by

3927-402: The image contrast provides details on the composition, mechanical properties, and processing history. Crystallography , often using diffraction of x-rays or electrons , is another valuable tool available to the modern metallurgist. Crystallography allows identification of unknown materials and reveals the crystal structure of the sample. Quantitative crystallography can be used to calculate

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4004-501: The joining of metals (including welding , brazing , and soldering ). Emerging areas for metallurgists include nanotechnology , superconductors , composites , biomedical materials , electronic materials (semiconductors) and surface engineering . Metallurgy derives from the Ancient Greek μεταλλουργός , metallourgós , "worker in metal", from μέταλλον , métallon , "mine, metal" + ἔργον , érgon , "work" The word

4081-505: The joint, heating the parts, applying flux, applying the filler, removing heat and holding the assembly still until the filler metal has completely solidified. Depending on the nature of flux material used and the application, cleaning of the joint may be required after it has cooled. Each solder alloy has characteristics that work best for certain applications, notably strength and conductivity, and each type of solder and alloy has different melting temperatures. The term silver solder denotes

4158-467: The joint. These fluxes cannot be used in electronics because their residues are conductive leading to unintended electrical connections, and because they will eventually dissolve small diameter wires. Citric acid is an excellent water-soluble acid-type flux for copper and electronics but must be washed off afterwards. Fluxes for soft solder are currently available in three basic formulations: Flux performance must be carefully evaluated for best results;

4235-555: The late Paleolithic period, 40,000 BC, have been found in Spanish caves. Silver , copper , tin and meteoric iron can also be found in native form, allowing a limited amount of metalworking in early cultures. Early cold metallurgy, using native copper not melted from mineral has been documented at sites in Anatolia and at the site of Tell Maghzaliyah in Iraq , dating from the 7th/6th millennia BC. The earliest archaeological support of smelting (hot metallurgy) in Eurasia

4312-646: The lead into the groundwater. Unfortunately, common lead-free solders are not eutectic formulations, melting at around 220 °C (428 °F), making it more difficult to create reliable joints with them. Other common solders include low-temperature formulations (often containing bismuth ), which are often used to join previously soldered assemblies without unsoldering earlier connections, and high-temperature formulations (usually containing silver ) which are used for high-temperature operation or for first assembly of items which must not become unsoldered during subsequent operations. Alloying silver with other metals changes

4389-506: The melting point, adhesion and wetting characteristics, and tensile strength. Of all the brazing alloys, silver solders have the greatest strength and the broadest applications. Specialty alloys are available with properties such as higher strength, the ability to solder aluminum, better electrical conductivity, and higher corrosion resistance. There are three forms of soldering, each requiring progressively higher temperatures and producing an increasingly stronger joint strength: The alloy of

4466-511: The metal prior to heating. A flux, often made of boric acid and denatured alcohol, is used to keep the metal and solder clean and to prevent the solder from moving before it melts. When silver solder melts, it tends to flow towards the area of greatest heat. Jewelers can somewhat control the direction the solder moves by leading it with a torch; it will even sometimes run straight up along a seam. A number of solder materials, primarily zinc alloys, are used for soldering aluminium and alloys and to

4543-553: The noted exception of silicon, which is not a metal. Other forms include: In production engineering , metallurgy is concerned with the production of metallic components for use in consumer or engineering products. This involves production of alloys, shaping, heat treatment and surface treatment of product. The task of the metallurgist is to achieve balance between material properties, such as cost, weight , strength , toughness , hardness , corrosion , fatigue resistance and performance in temperature extremes. To achieve this goal,

4620-507: The operating environment must be carefully considered. Determining the hardness of the metal using the Rockwell, Vickers, and Brinell hardness scales is a commonly used practice that helps better understand the metal's elasticity and plasticity for different applications and production processes. In a saltwater environment, most ferrous metals and some non-ferrous alloys corrode quickly. Metals exposed to cold or cryogenic conditions may undergo

4697-482: The ore feed are broken through crushing or grinding in order to obtain particles small enough, where each particle is either mostly valuable or mostly waste. Concentrating the particles of value in a form supporting separation enables the desired metal to be removed from waste products. Mining may not be necessary, if the ore body and physical environment are conducive to leaching . Leaching dissolves minerals in an ore body and results in an enriched solution. The solution

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4774-447: The physical and chemical behavior of metallic elements , their inter-metallic compounds , and their mixtures, which are known as alloys . Metallurgy encompasses both the science and the technology of metals, including the production of metals and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking . Metalworking relies on metallurgy in

4851-402: The piece being treated. The compression stress in the surface of the material strengthens the part and makes it more resistant to fatigue failure, stress failures, corrosion failure, and cracking. Thermal spraying techniques are another popular finishing option, and often have better high temperature properties than electroplated coatings. Thermal spraying, also known as a spray welding process,

4928-445: The process of shot peening, small round shot is blasted against the surface of the part to be finished. This process is used to prolong the product life of the part, prevent stress corrosion failures, and also prevent fatigue. The shot leaves small dimples on the surface like a peen hammer does, which cause compression stress under the dimple. As the shot media strikes the material over and over, it forms many overlapping dimples throughout

5005-666: The product by a process called work hardening . Work hardening creates microscopic defects in the metal, which resist further changes of shape. Metals can be heat-treated to alter the properties of strength, ductility, toughness, hardness and resistance to corrosion. Common heat treatment processes include annealing, precipitation strengthening , quenching, and tempering: Often, mechanical and thermal treatments are combined in what are known as thermo-mechanical treatments for better properties and more efficient processing of materials. These processes are common to high-alloy special steels, superalloys and titanium alloys. Electroplating

5082-1008: The production of metals. Metal production begins with the processing of ores to extract the metal, and includes the mixture of metals to make alloys . Metal alloys are often a blend of at least two different metallic elements. However, non-metallic elements are often added to alloys in order to achieve properties suitable for an application. The study of metal production is subdivided into ferrous metallurgy (also known as black metallurgy ) and non-ferrous metallurgy , also known as colored metallurgy. Ferrous metallurgy involves processes and alloys based on iron , while non-ferrous metallurgy involves processes and alloys based on other metals. The production of ferrous metals accounts for 95% of world metal production. Modern metallurgists work in both emerging and traditional areas as part of an interdisciplinary team alongside material scientists and other engineers. Some traditional areas include mineral processing, metal production, heat treatment, failure analysis , and

5159-402: The remote detonation of demolition and sabotage explosives. These consisted of a small copper tube partially filled with solder and a slow-burning pyrotechnic composition wrapped around the tube. The wires to be joined would be inserted into the tube and a small blob of ignition compound allowed the device to be struck like a match to ignite the pyrotechnic and heat the tube for long enough to melt

5236-546: The same kind used for heat-stripping paint and thawing pipes, can be used for soldering pipes and other fairly large objects either with or without a soldering tip attachment; pipes are generally soldered with a torch by directly applying the open flame. A soldering copper is a tool with a large copper head and a long handle which is heated with a small direct flame and used to apply heat to sheet metal such as tin plated steel for soldering. Typical soldering coppers have heads weighing between one and four pounds. The head provides

5313-471: The solder is drawn up into the wire between the strands by capillary action in a process called 'wicking'. Capillary action also takes place when the workpieces are very close together or touching. The joint's tensile strength is dependent on the filler metal used; in electrical soldering little tensile strength comes from the added solder which is why it is advised that wires be twisted or folded together before soldering to provide some mechanical strength for

5390-599: The soldering process, reducing the surface tension of the molten solder and causing it to flow and wet the workpieces more easily. For many years, the most common type of flux used in electronics (soft soldering) was rosin -based, using the rosin from selected pine trees . It was nearly ideal in that it was non-corrosive and non-conductive at normal temperatures but became mildly reactive (corrosive) at elevated soldering temperatures. Plumbing and automotive applications, among others, typically use an acid-based ( hydrochloric acid ) flux which provides rather aggressive cleaning of

5467-408: The soldering temperatures increase and can completely prevent the solder from joining to the workpiece. One of the earliest forms of flux was charcoal , which acts as a reducing agent and helps prevent oxidation during the soldering process. Some fluxes go beyond the simple prevention of oxidation and also provide some form of chemical cleaning (corrosion). Many fluxes also act as a wetting agent in

5544-771: The success of the Philistines . Historical developments in ferrous metallurgy can be found in a wide variety of past cultures and civilizations. This includes the ancient and medieval kingdoms and empires of the Middle East and Near East , ancient Iran , ancient Egypt , ancient Nubia , and Anatolia in present-day Turkey , Ancient Nok , Carthage , the Celts , Greeks and Romans of ancient Europe , medieval Europe, ancient and medieval China , ancient and medieval India , ancient and medieval Japan , amongst others. A 16th century book by Georg Agricola , De re metallica , describes

5621-760: The temperature drops through the liquidus and solidus temperatures. Any movement during the plastic phase may result in cracks, resulting in an unreliable joint. Common solder formulations based on tin and lead are listed below. The fraction represent percentage of tin first, then lead, totaling 100%: For environmental reasons and the introduction of regulations such as the European RoHS ( Restriction of Hazardous Substances Directive ), lead-free solders are becoming more widely used. They are also suggested anywhere young children may come into contact with (since young children are likely to place things into their mouths), or for outdoor use where rain and other precipitation may wash

5698-552: The third millennium BC in Palmela , Portugal, Los Millares , Spain, and Stonehenge , United Kingdom. The precise beginnings, however, have not be clearly ascertained and new discoveries are both continuous and ongoing. In approximately 1900 BC, ancient iron smelting sites existed in Tamil Nadu . In the Near East , about 3,500 BC, it was discovered that by combining copper and tin,

5775-467: The type of solder that is used. Some soft solders are "silver-bearing" alloys used to solder silver-plated items. Lead-based solders should not be used on precious metals because the lead dissolves the metal and disfigures it. The distinction between soldering and brazing is based on the melting temperature of the filler alloy. A temperature of 450 °C is usually used as a practical demarcation between soldering and brazing. Soft soldering can be done with

5852-498: The use of lead . In addition to the type of solder used, the temperature and method of heating also play a crucial role in the soldering process. Different types of solder require different temperatures to melt, and heating must be carefully controlled to avoid damaging the materials being joined or creating weak joints. There are several methods of heating used in soldering, including soldering irons, torches, and hot air guns . Each method has its own advantages and disadvantages, and

5929-434: Was originally an alchemist 's term for the extraction of metals from minerals, the ending -urgy signifying a process, especially manufacturing: it was discussed in this sense in the 1797 Encyclopædia Britannica . In the late 19th century, metallurgy's definition was extended to the more general scientific study of metals, alloys, and related processes. In English , the / m ɛ ˈ t æ l ər dʒ i / pronunciation

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