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64-512: The facility was originally built by GM as the "Oldsmobile Differential Plant and Foundry" in 1919. The foundry was repurposed as the "Reatta Craft Centre" in 1984 when GM chose it as the manufacturing site of the Buick Reatta , which began production in 1988 after a stamping plant, body shop, and assembly area were constructed. After the end of production of the Reatta, the plant was renamed

128-445: A hollow cavity of the desired shape, and then allowing it to cool and solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting is most often used for making complex shapes that would be difficult or uneconomical to make by other methods. Melting is performed in a furnace . Virgin material, external scrap, internal scrap, and alloying elements are used to charge

192-500: A material. Heat treatment techniques include annealing , case-hardening , precipitation strengthening , tempering , and quenching . Although the term "heat treatment" applies only to processes where the heating and cooling are done for the specific purpose of altering properties intentionally, heating and cooling often occur incidentally during other manufacturing processes such as hot forming or welding. After degating and heat treating, sand or other molding media may remain adhered to

256-430: A mold yields leftover metal — including heads, risers, and sprue (sometimes collectively called sprue) — that can exceed 50% of the metal required to pour a full mold. Since this metal must be remelted as salvage, the yield of a particular gating configuration becomes an important economic consideration when designing various gating schemes, to minimize the cost of excess sprue, and thus overall melting costs. Heat treating

320-464: A rate of tens of nanometers per minute. The addition of hydrogen to the plasma augments the removal efficiency by chemical mechanisms. Mechanical agitation is another possibility for disrupting the oxide layer. Ultrasound can be used for assisting tinning and soldering; an ultrasonic transducer can be mounted on the soldering iron, in a solder bath, or in the wave for wave soldering . The oxide disruption and removal involves cavitation effects between

384-424: A single piece or solid pattern. More complex designs are made in two parts, called split patterns. A split pattern has a top or upper section, called a cope, and a bottom or lower section called a drag. Both solid and split patterns can have cores inserted to complete the final part shape. Cores are used to create hollow areas in the mold that would otherwise be impossible to achieve. Where the cope and drag separates

448-426: A steel foundry will use an EAF or induction furnace. Bronze or brass foundries use crucible furnaces or induction furnaces. Most aluminium foundries use either electric resistance or gas heated crucible furnaces or reverberatory furnaces. Degassing is a process that may be required to reduce the amount of hydrogen present in a batch of molten metal. Gases can form in metal castings in one of two ways: Hydrogen

512-499: Is a factory that produces metal castings . Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron . However, other metals, such as bronze , brass , steel , magnesium , and zinc , are also used to produce castings in foundries. In this process, parts of desired shapes and sizes can be formed. Foundries are one of

576-401: Is a common contaminant for most cast metals. It forms as a result of material reactions or from water vapor or machine lubricants. If the hydrogen concentration in the melt is too high, the resulting casting will be porous; the hydrogen will exit the molten solution, leaving minuscule air pockets, as the metal cools and solidifies. Porosity often seriously deteriorates the mechanical properties of

640-416: Is a group of industrial and metalworking processes used to alter the physical, and sometimes chemical, properties of a material. The most common application is metallurgical. Heat treatments are also used in the manufacture of many other materials, such as glass. Heat treatment involves the use of heating or chilling, normally to extreme temperatures, to achieve a desired result such as hardening or softening of

704-463: Is called the parting line . When making a pattern it is best to taper the edges so that the pattern can be removed without breaking the mold. This is called draft . The opposite of draft is an undercut where there is part of the pattern under the mold material, making it impossible to remove the pattern without damaging the mold. The pattern is made of wax, wood, plastic, or metal. The molds are constructed by several different processes dependent upon

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768-567: Is common to paint castings to prevent corrosion and improve visual appeal. Some foundries assemble castings into complete machines or sub-assemblies. Other foundries weld multiple castings or wrought metals together to form a finished product. More and more, finishing processes are being performed by robotic machines, which eliminate the need for a human to physically grind or break parting lines, gating material, or feeders. Machines can reduce risk of injury to workers and lower costs for consumables — while also increasing productivity. They also limit

832-546: Is dependent on the alloy system quantities produced. For ferrous materials EAFs, cupolas, and induction furnaces are commonly used. Reverberatory and crucible furnaces are common for producing aluminium, bronze, and brass castings. Furnace design is a complex process, and the design can be optimized based on multiple factors. Furnaces in foundries can be any size, ranging from small ones used to melt precious metals to furnaces weighing several tons, designed to melt hundreds of pounds of scrap at one time. They are designed according to

896-490: Is happening inside the mold or die during the casting process. Flux (metallurgy) In metallurgy , a flux is a chemical reducing agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time. They are used in both extractive metallurgy and metal joining . Some of the earliest known fluxes were sodium carbonate , potash , charcoal , coke , borax , lime , lead sulfide and certain minerals containing phosphorus . Iron ore

960-436: Is known as diffusion soldering. Fluxless brazing of copper alloys can be done with self-fluxing filler metals. Such metals contain an element capable of reaction with oxygen, usually phosphorus . A good example is the family of copper-phosphorus alloys. Fluxes have several important properties: The composition of fluxes is tailored for the required properties - the base metals and their surface preparation (which determine

1024-426: Is much more reactive than molecular hydrogen. In contact with surface oxides it forms hydroxides, water, or hydrogenated complexes, which are volatile at soldering temperatures. A practical dissociation method is an electrical discharge. Argon-hydrogen gas compositions with hydrogen concentration below the low flammable limit can be used, eliminating the safety issues. The operation has to be performed at low pressure, as

1088-414: Is not known which component of the fumes causes the problem. While molten solder has low tendency to adhere to organic materials, molten fluxes, especially of the resin/rosin type, adhere well to fingers. A mass of hot sticky flux can transfer more heat to skin and cause more serious burns than a comparable particle of non-adhering molten metal, which can be quickly shaken off. In this regard, molten flux

1152-401: Is similar to molten hot glue . In some cases the presence of flux is undesirable; flux traces interfere with e.g. precision optics or MEMS assemblies. Flux residues also tend to outgas in vacuum and space applications, and traces of water, ions and organic compounds may adversely affect long-term reliability of non-hermetic packages. Trapped flux residues are also the cause of most voids in

1216-934: Is soluble in molten rosin. Some activators may also contain metal ions, capable of exchange reaction with the underlying metal; such fluxes aid soldering by chemically depositing a thin layer of easier solderable metal on the exposed base metal. An example is the group of fluxes containing zinc , tin or cadmium compounds, usually chlorides, sometimes fluorides or fluoroborates. Common high-activity activators are mineral acids , often together with halides, amines, water or alcohols: Inorganic acids are highly corrosive to metals even at room temperature, which causes issues during storage, handling and applications. As soldering involves high temperatures, compounds that decompose or react, with acids as products, are frequently used: The terms resin flux and rosin flux are ambiguous and somewhat interchangeable, with different vendors using different assignments. Generally, fluxes are labeled as rosin if

1280-541: Is then removed from its mold. Where the mold is sand based, this can be done by shaking or tumbling. This frees the casting from the sand, which is still attached to the metal runners and gates — which are the channels through which the molten metal traveled to reach the component itself. Degating is the removal of the heads, runners, gates, and risers from the casting. Runners, gates, and risers may be removed using cutting torches , bandsaws , or ceramic cutoff blades. For some metal types, and with some gating system designs,

1344-422: Is typically dual: dissolving the oxides already present on the metal surface to facilitate wetting by molten metal, and acting as an oxygen barrier by coating the hot surface, preventing oxidation. For example, tin-lead solder attaches very well to copper metal, but poorly to its oxides, which form quickly at soldering temperatures. By preventing the formation of metal oxides, flux enables the solder to adhere to

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1408-549: The "Lansing Craft Centre". Over its existence, the Lansing Craft Center manufactured GM's low-volume vehicles including the EV1 , Cadillac Eldorado , convertible Chevrolet Cavalier and Pontiac Sunfire and Chevrolet SSR . In November 2005, General Motors announced that it would close the Lansing Craft Center in mid-2006, and the final SSR, a unique black-on-silver model, was assembled on March 17, 2006. The plant

1472-678: The Sn-Sb 5 requires as little as 10 °C, but the Sn-Pb 37 alloy requires 77 °C above its melting point to dissolve its surface oxide. The self-dissolved oxide degrades the solder's properties and increases its viscosity in molten state, however, so this approach is not optimal. Solder preforms are preferred to be with high volume-to-surface ratio, as that limits the amount of oxide being formed. Pastes have to contain smooth spherical particles, preforms are ideally made of round wire. Problems with preforms can be also sidestepped by depositing

1536-415: The activator generally increases with temperature, up to a certain value where activity ceases, either due to thermal decomposition or excessive volatilization. However the oxidation rate of the metals also increases with temperature. At high temperatures, copper oxide reacts with hydrogen chloride to water-soluble and mechanically weak copper chloride, and with rosin to salts of copper and abietic acid which

1600-655: The activators is primarily disruption and removal of the oxide layer on the metal surface (and also the molten solder), to facilitate direct contact between the molten solder and metal. The reaction product is usually soluble or at least dispersible in the molten vehicle. The activators are usually either acids, or compounds that release acids at elevated temperature. The general reaction of oxide removal is: Salts are ionic in nature and can cause problems from metallic leaching or dendrite growth, with possible product failure. In some cases, particularly in high- reliability applications, flux residues must be removed. The activity of

1664-572: The amount of material being removed. These steps are done prior to any final machining. After grinding, any surfaces that require tight dimensional control are machined. Many castings are machined in CNC milling centers. The reason for this is that these processes have better dimensional capability and repeatability than many casting processes. However, it is not uncommon today for castings to be used without machining. A few foundries provide other services before shipping cast products to their customers. It

1728-436: The casting surface. Numerous materials may be used to clean cast surfaces, including steel, iron, other metal alloys, aluminium oxides, glass beads, walnut shells, baking powder, and many others. The blasting media is selected to develop the color and reflectance of the cast surface. Terms used to describe this process include cleaning, bead blasting, and sand blasting . Shot peening may be used to further work-harden and finish

1792-423: The casting. To remove any mold remnants, the surface is cleaned using a blasting process. This means a granular media will be propelled against the surface of the casting to mechanically knock away the adhering sand. The media may be blown with compressed air, or may be hurled using a shot wheel. The cleaning media strikes the casting surface at high velocity to dislodge the mold remnants (for example, sand, slag) from

1856-553: The clean metal surface, rather than forming beads, as it would on an oxidized surface. In soldering metals, flux serves a threefold purpose: it removes any oxidized metal from the surfaces to be soldered, seals out air thus preventing further oxidation, and improves the wetting characteristics of the liquid solder. Some fluxes are corrosive , so the parts have to be cleaned with a damp sponge or other absorbent material after soldering to prevent damage. Several types of flux are used in electronics. A number of standards exist to define

1920-463: The composition and thickness of surface oxides), the solder (which determines the wetting properties and the soldering temperature), the corrosion resistance and ease of removal, and others. Fluxes for soft soldering are typically of organic nature, though inorganic fluxes, usually based on halogenides or acids, are also used in non-electronics applications. Fluxes for brazing operate at significantly higher temperatures and are therefore mostly inorganic;

1984-491: The entire casting manufacturing route. Casting process simulation was initially developed at universities starting from the early ' 70s , mainly in Europe and in the U.S. , and is regarded as the most important innovation in casting technology over the last 50 years. Since the late ' 80s , commercial programs (such as PoligonSoft, AutoCAST and Magma) are available which make it possible for foundries to gain new insight into what

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2048-433: The facility. The process includes melting the charge, refining the melt, adjusting the melt chemistry and tapping into a transport vessel. Refining is done to remove harmful gases and elements from the molten metal to avoid casting defects. Material is added during the melting process to bring the final chemistry within a specific range specified by industry and/or internal standards. Certain fluxes may be used to separate

2112-787: The flow of slag in smelting, is the origin of the word flux in metallurgy. The flux most commonly used in iron and steel furnaces is limestone , which is charged in the proper proportions with the iron and fuel . Fluxes have several serious drawbacks: In special cases the drawbacks are sufficiently serious to warrant using fluxless techniques. Acid flux types (not used in electronics) may contain hydrochloric acid , zinc chloride or ammonium chloride , which are harmful to humans. Therefore, flux should be handled with gloves and goggles, and used with adequate ventilation. Prolonged exposure to rosin fumes released during soldering can cause occupational asthma (formerly called colophony disease in this context) in sensitive individuals, although it

2176-416: The fluxes for use at lower temperatures. At higher temperatures even relatively mild chemicals have sufficient oxide-disrupting activity, but the metal oxidation rates become fairly high; the barrier function of the vehicle therefore becomes more important than the fluxing activity. High molecular weight hydrocarbons are often used for this application; a diluent with a lower molecular weight, boiling off during

2240-401: The furnace must be designed for temperatures over 1,600 °C (2,910 °F). The fuel used to reach these high temperatures can be electricity (as employed in electric arc furnaces ) or coke . The majority of foundries specialize in a particular metal and have furnaces dedicated to these metals. For example, an iron foundry (for cast iron) may use a cupola , induction furnace, or EAF, while

2304-505: The furnace. Virgin material refers to commercially pure forms of the primary metal used to form a particular alloy . Alloying elements are either pure forms of an alloying element, like electrolytic nickel , or alloys of limited composition, such as ferroalloys or master alloys. External scrap is material from other forming processes such as punching , forging , or machining . Internal scrap consists of gates , risers , defective castings, and other extraneous metal oddments produced within

2368-453: The joint. Thicker gold coatings are usually limited to use with indium-based solders and solders with high gold content. Removal of the oxides from the solder preform is also troublesome. Fortunately some alloys are able to dissolve the surface oxides in their bulk when superheated by several degrees above their melting point; the Sn-Cu 1 and Sn-Ag 4 require superheating by 18–19 °C,

2432-422: The joints. Flux-less techniques are therefore desirable there. For successful soldering and brazing, the oxide layer has to be removed from both the surfaces of the materials and the surface of the filler metal preform; the exposed surfaces also have to be protected against oxidation during heating. Flux-coated preforms can also be used to eliminate flux residue entirely from the soldering process. Protection of

2496-403: The largest contributors to the manufacturing recycling movement, melting and recasting millions of tons of scrap metal every year to create new durable goods. Moreover, many foundries use sand in their molding process. These foundries often use, recondition, and reuse sand, which is another form of recycling. In metalworking , casting involves pouring liquid metal into a mold , which contains

2560-411: The metal at the elevated temperatures has to be avoided. This means that fluxes need to be more aggressive and to provide a physical barrier. Traditionally borax was used as a flux for brazing, but there are now many different fluxes available, often using active chemicals such as fluorides as well as wetting agents. Many of these chemicals are toxic and due care should be taken during their use. In

2624-498: The metal from slag and/or dross and degassers are used to remove dissolved gas from metals that readily dissolve in gasses. During the tap, final chemistry adjustments are made. Several specialised furnaces are used to heat the metal. Furnaces are refractory-lined vessels that contain the material to be melted and provide the energy to melt it. Modern furnace types include electric arc furnaces (EAF), induction furnaces , cupolas , reverberatory , and crucible furnaces. Furnace choice

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2688-430: The metal. An efficient way of removing hydrogen from the melt is to bubble a dry, insoluble gas through the melt by purging or agitation. When the bubbles go up in the melt, they catch the dissolved hydrogen and bring it to the surface. Chlorine, nitrogen, helium and argon are often used to degas non-ferrous metals. Carbon monoxide is typically used for iron and steel. There are various types of equipment that can measure

2752-413: The metals to be joined. In some applications molten flux also serves as a heat-transfer medium, facilitating heating of the joint by the soldering tool. In high-temperature metal joining processes ( welding , brazing and soldering ), fluxes are nearly inert at room temperature, but become strongly reducing at elevated temperatures, preventing oxidation of the base and filler materials. The role of flux

2816-487: The molten solder and the base metal surface. A common application of ultrasound fluxing is in tinning of passive parts (active parts do not cope well with the mechanical stresses involved); even aluminium can be tinned this way. The parts can then be soldered or brazed conventionally. Mechanical rubbing of a heated surface with molten solder can be used for coating the surface. Both surfaces to be joined can be prepared this way, then placed together and reheated. This technique

2880-483: The organic compounds tend to be of supplementary nature, e.g. to make the flux sticky at low temperature so it can be easily applied. The surface of the tin-based solder is coated predominantly with tin oxides; even in alloys the surface layer tends to become relatively enriched by tin. Fluxes for indium and zinc based solders have different compositions than fluxes for ordinary tin-lead and tin-based solders, due to different soldering temperatures and different chemistry of

2944-464: The oxides involved. Organic fluxes are unsuitable for flame soldering and flame brazing, as they tend to char and impair solder flow. Some metals are classified as "unsolderable" in air, and have to be either coated with another metal before soldering or special fluxes or protective atmospheres have to be used. Such metals are beryllium , chromium , magnesium , titanium , and some aluminium alloys . Fluxes for high-temperature soldering differ from

3008-489: The potential for human error and increase repeatability in the quality of grinding. Casting processes simulation uses numerical methods to calculate cast component quality considering mold filling, solidification and cooling, and provides a quantitative prediction of casting mechanical properties, thermal stresses and distortion. Simulation accurately describes a cast component's quality up-front before production starts. The casting rigging can be designed with respect to

3072-461: The preheat phase, is usually used to aid application. Common fluxes are ammonium chloride or resin acids (contained in rosin ) for soldering copper and tin ; hydrochloric acid and zinc chloride for soldering galvanized iron (and other zinc surfaces); and borax for brazing , braze-welding ferrous metals, and forge welding . Organic fluxes typically consist of four major components: Inorganic fluxes contain components playing

3136-400: The presence of hydrogen. Alternatively, the presence of hydrogen can be measured by determining the density of a metal sample. In cases where porosity still remains present after the degassing process, porosity sealing can be accomplished through a process called metal impregnating . In the casting process, a pattern is made in the shape of the desired part. Simple designs can be made in

3200-469: The process of smelting , inorganic chlorides, fluorides (see fluorite ), limestone and other materials are designated as "fluxes" when added to the contents of a smelting furnace or a cupola for the purpose of purging the metal of chemical impurities such as phosphorus, and of rendering slag more liquid at the smelting temperature. Slag is a liquid mixture of ash , flux, and other impurities. This reduction of slag viscosity with temperature, increasing

3264-493: The reaction speed is too slow for practical applications.) Very low partial pressures of oxygen and water vapor have to be achieved for the reaction to proceed. Other reactive atmospheres are also in use. Vapors of formic acid and acetic acid are the most commonly used. Carbon monoxide and halogen gases (for example carbon tetrafluoride , sulfur hexafluoride , or dichlorodifluoromethane ) require fairly high temperatures for several minutes to be effective. Atomic hydrogen

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3328-413: The required component properties. This has benefits beyond a reduction in pre-production sampling, as the precise layout of the complete casting system also leads to energy , material, and tooling savings. The software supports the user in component design, the determination of melting practice and casting methoding through to pattern and mold making, heat treatment , and finishing. This saves costs along

3392-512: The same role as in organic fluxes. They are more often used in brazing and other high-temperature applications, where organic fluxes have insufficient thermal stability. The chemicals used often simultaneously act as both vehicles and activators; typical examples are borax , borates , fluoroborates , fluorides and chlorides . Halogenides are active at lower temperatures than borates, and are therefore used for brazing of aluminium and magnesium alloys; they are however highly corrosive. The role of

3456-449: The solder alloy directly on the surfaces of the parts or substrates, by chemical or electrochemical means for example. A protective atmosphere with chemically reducing properties can be beneficial in some cases. Molecular hydrogen can be used to reduce surface oxides of tin and indium at temperatures above 430 and 470 °C; for zinc the temperature is above 500 °C, where zinc is already becoming volatilized. (At lower temperatures

3520-444: The sprue, runners, and gates can be removed by breaking them away from the casting with a sledge hammer or specially designed knockout machinery. Risers must usually be removed using a cutting method (see above) but some newer methods of riser removal use knockoff machinery with special designs incorporated into the riser neck geometry that allow the riser to break off at the right place. The gating system required to produce castings in

3584-542: The stability of atomic hydrogen at atmospheric pressure is insufficient. Such hydrogen plasma can be used for fluxless reflow soldering. Active atmospheres are relatively common in furnace brazing; due to the high process temperatures the reactions are reasonably fast. The active ingredients are usually carbon monoxide (possibly in the form of combusted fuel gas) and hydrogen. Thermal dissociation of ammonia yields an inexpensive mixture of hydrogen and nitrogen. Bombardment with atomic particle beams can remove surface layers at

3648-408: The surface. The final step in the process of casting usually involves grinding, sanding, or machining the component in order to achieve the desired dimensional accuracies, physical shape, and surface finish. Removing the remaining gate material, called a gate stub, is usually done using a grinder or sander . These processes are used because their material removal rates are slow enough to control

3712-523: The surfaces against further oxidation is relatively simple, by using vacuum or inert atmosphere. Removal of the native oxide layer is more troublesome; physical or chemical cleaning methods have to be employed and the surfaces can be protected by e.g. gold plating. The gold layer has to be sufficiently thick and non-porous to provide protection for reasonable storage time. Thick gold metallization also limits choice of soldering alloys, as tin-based solders dissolve gold and form brittle intermetallics , embrittling

3776-482: The type of foundry, metal to be poured, quantity of parts to be produced, size of the casting, and complexity of the casting. These mold processes include: In a foundry, molten metal is poured into molds . Pouring can be accomplished with gravity, or it may be assisted with a vacuum or pressurized gas. Many modern foundries use robots or automatic pouring machines to pour molten metal. Traditionally, molds were poured by hand using ladles . The solidified metal component

3840-414: The type of metals that are to be melted. Furnaces must also be designed based on the fuel being used to produce the desired temperature. For low temperature melting point alloys, such as zinc or tin, melting furnaces may reach around 500 °C (932 °F). Electricity, propane, or natural gas are usually used to achieve these temperatures. For high melting point alloys such as steel or nickel-based alloys,

3904-483: The various flux types. The principal standard is J-STD-004. Various tests, including the ROSE test , may be used after soldering to check for the presence of ionic or other contaminants that could cause short circuits or other problems. Brazing (sometimes known as silver soldering or hard soldering ) requires a higher temperature than soft soldering (> 450 °C). As well as removing existing oxides, rapid oxidation of

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3968-573: Was also used as a flux in the smelting of copper. These agents served various functions, the simplest being a reducing agent, which prevented oxides from forming on the surface of the molten metal, while others absorbed impurities into slag , which could be scraped off molten metal. Fluxes are also used in foundries for removing impurities from molten nonferrous metals such as aluminium , or for adding desirable trace elements such as titanium . As reducing agents, fluxes facilitate soldering , brazing , and welding by removing oxidation from

4032-618: Was demolished from 2008 to 2009. At the time of its closure, the plant size was 985,000 square feet (91,500 m) and the facility employed 400, many of whom were transferred to the new Lansing Grand River Assembly , as well as some operations transferred to the nearby Lansing Delta Township Assembly . The facility was demolished in 2008 along with the Lansing Metal Center . 42°44′33.81″N 84°35′6.41″W  /  42.7427250°N 84.5851139°W  / 42.7427250; -84.5851139 Foundry A foundry

4096-426: Was formerly used to repair small damages on aluminium aircraft skins. A very thin layer of zinc can be used for joining aluminium parts. The parts have to be perfectly machined, or pressed together, due to the small volume of filler metal. At high temperature applied for long time, the zinc diffuses away from the joint. The resulting joint does not present a mechanical weakness and is corrosion-resistant. The technique

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