A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal in a mold, and removing the mold material or casting after the metal has solidified as it cools. The most common metals processed are aluminum and cast iron. However, other metals, such as bronze, steel, magnesium, copper, tin, and zinc, are also used to produce castings in foundries.

Process

Melting

Melting is performed in a furnace. Virgin material, external scrap, internal scrap, and alloying elements are used to charge 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 the gates, risers, or defective castings.

The process includes melting the charge, refining the melt, adjusting the melt chemistry and tapping into a transport vessel. Refining is done to remove deleterious 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. During the tap, final chemistry adjustments are made.

Furnace

Several specialised furnaces are used to melt 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 is dependent on the alloy system and quantities produced. For ferrous materials, EAFs, cupolas, and induction furnaces are commonly used. Reverberatory and crucible furnaces are common for producing aluminum 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 mere ounces to hundreds of tons, and they are designed according to the type of metals that are to be melted. Also, furnaces must be designed around 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 327° Celsius. Electricity, propane, or natural gas are usually used for these temperatures. For high melting point alloys such as steel or nickel based alloys, the furnace must be designed for temperatures over 1600° Celsius. The fuel used to reach these high temperatures can be electricity 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 a steel foundry will use an EAF or induction furnace. Bronze or brass foundries use crucible furnaces or induction furnaces. Most aluminum foundries use either an electric resistance or gas heated crucible furnaces or reverberatory furnaces.

Degassing

In the case of aluminium alloys, a degassing step is usually necessary to reduce the amount of hydrogen in the liquid metal. If the hydrogen concentration in the melt is too high, the resulting casting will contain gas porosity that will deteriorate its mechanical properties.

An efficient way of removing hydrogen from the melt is to bubble argon or nitrogen. To do that, several different types of equipment are used by foundries. When the bubbles go up in the melt, they catch the dissolved hydrogen and bring it to the top surface. There are various equipment which measure the amount of hydrogen present in it. Alternatively, the density of the aluminum sample is calculated to check amount of hydrogen dissolved in it.

Mould making

In the casting process a pattern is made in the shape of the desired part. This pattern is made out of wax, wood, plastic or metal. Simple designs can be made in 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. Where the cope and drag separates is called the parting line. thumb|A diagram of an undercut in a mould.thumb|left|A diagram of draft on a pattern.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 sand making it impossible to remove the pattern without damaging the mould. The molds are constructed by several different processes dependent upon 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:

Sand casting — Green or resin bonded sand mold.

Lost-foam casting — Polystyrene pattern with a mixture of ceramic and sand mold.

Investment casting — Wax or similar sacrificial pattern with a ceramic mold.

Ceramic mold casting — Plaster mold.

V-process casting — Vacuum is used in conjunction with thermoformed plastic to form sand molds. No moisture, clay or resin is needed for sand to retain shape.

Die casting — Metal mold.

Billet (ingot) casting — Simple mold for producing ingots of metal normally for use in other foundries.

Pouring

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 for pouring molten metal. Traditionally, molds were poured by hand using ladles.

Shakeout

The solidified metal component 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

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, 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 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 melting costs.

Surface cleaning

After degating, sand or other molding media may adhere to the casting. To remove this 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 media strikes the casting surface at high velocity to dislodge the molding media (for example, sand, slag) from the casting surface. Numerous materials may be used as media, including steel, iron, other metal alloys, aluminum oxides, glass beads, walnut shells, baking powder among 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 the surface.

Finishing

The final step in the process 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 sanding. These processes are used because their material removal rates are slow enough to control the amount of material. 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 many components to be used without machining.

A few foundries provide other services before shipping components to their customers. Painting components to prevent corrosion and improve visual appeal is common. Some foundries will assemble their castings into complete machines or sub-assemblies. Other foundries weld multiple castings or wrought metals together to form a finished product.

More and more the process of finishing a casting is being achieved using robotic machines which eliminate the need for a human to physically grind or break parting lines, gating material or feeders. The introduction of these machines has reduced injury to workers, costs of consumables whilst also reducing the time necessary to finish a casting. It also eliminates the problem of human error so as to increase repeatability in the quality of grinding. With a change of tooling these machines can finish a wide variety of materials including iron, bronze and aluminium.

See also

Coremaking

Foundry sand testing

Gimson and Company

May Brothers and Company

Smelting

Hydrogen gas porosity

Inclusions in aluminium castings

References

. .

External links

The Institute of Indian Foundrymen

American Foundry Society

World Foundry Organization

Photographic documentation of the founding process

Category:Metalworking

de:Giesserei fa:ریخته گری fr:Fonderie it:Fonderia lb:Géisserei nl:Gieterij pl:Odlewnia simple:Foundry sr:Livenje sv:Hytta

Alexander Vasilyevich Mosolov (;  – 11 July 1973) was a significant Russian composer of the early Soviet era, known best for his early futurist piano sonatas, orchestral episodes, and vocal music.

Mosolov studied at the Moscow Conservatory and achieved his greatest fame in the Soviet Union and around the world for his 1926 composition, ''Iron Foundry''. Later conflicts with Soviet authorities led to his expulsion from the Composers' Union in 1936 and imprisonment in the Gulag in 1937. Following an early release, which had been argued for by his Conservatory teachers, Mosolov turned his attention to setting Turkmen and Kyrgyz folk tunes for orchestra. His later music conformed to the Soviet aesthetic to a much greater degree, but he never regained the success of his early career.

Mosolov's works include five piano sonatas, four string quartets, twelve orchestral suites, eight symphonies, and a substantial number of choral and voice pieces.

Biography

Mosolov was born to an upper-middle class family in Kiev, in the Russian Empire. His mother, Nina Alexandrovna, was a professional singer at the Bolshoi Theater and a graduate of the Kiev school of music, and she gave Mosolov his first musical lessons. The family moved to Moscow in 1904. Mosolov's father, Vasiliy Alexandrovich, died a year later when Mosolov was five years old. After his father's death, Mosolov's mother married a successful painter and teacher, Mikhail Leblan. Young Mosolov was greatly impacted by the cosmopolitan lifestyle into which he was raised; both German and French were spoken in the home and the family took trips to Berlin, Paris, and London.

Mosolov attended high school until 1916, and in 1917 worked in the office of the People's Commissioner for State Control. Through this, he personally delivered mail to Vladimir Lenin three times, which had a profound impact on the young Mosolov. At the start of the Bolshevik Revolution, Mosolov volunteered in the Red Army's First Cavalry Regiment and fought on the Polish and Ukrainian fronts. He received the Order of the Red Banner on two occasions. He suffered from post-traumatic stress disorder due to the war and was medically discharged in July 1921. Mosolov entered the Moscow Conservatory, where he studied under Reinhold Glière until 1925; in that year he began composition studies under Nikolai Myaskovsky. He also studied piano under Grigoriy Prokofiev and Konstantin Igmunov. He graduated from the Conservatory in 1925 after presenting his graduation piece, the cantata ''Sphynx'', based on the Oscar Wilde poem of the same name. That same year, he was granted membership in the Association for Contemporary Music (ACM).

left|thumb|200px|Mosolov in 1927Despite forays into composition, Mosolov's primary emphasis at this time was with performance, as he was an accomplished pianist. After the performance of his First String Quartet at the Frankfurt Festival of the International Society for Contemporary Music (ISCM) on June 30, 1927 was met with critical acclaim, Mosolov shifted his focus to composition. He was appointed secretary of the Russian section of the ISCM in 1927 and 1928. In 1928 and 1929, Mosolov was commissioned by the Bolshoi Theater to compose a futurist imagination of what Moscow would be like in 2117 for a speculative ballet called ''The Four Moscows''. Leonid Polovinkin, Anatoly Alexandrov, and Dmitri Shostakovich were also involved, each to compose Moscow in 1568, 1818, and 1918 respectively, but nothing ever came of the project.

After the onset of socialist realism as the official aesthetic of the Soviet Union in 1932, Mosolov traveled to Central Asia, where he researched and collected samples of Turkmen, Tajik, Armenian, and Kyrgyz songs. Mosolov became the first composer to create a symphonic suite on a Turkmen folk song. His settings of folk songs were met with criticism from Soviet arbiters. Rather than simply set the melodies in an orchestral setting, Mosolov used dense textures and polytonality that disregarded the style of socialist realism. In 1932 and in desperation, he wrote a letter to Joseph Stalin pleading for Stalin's influence. In his letter, Mosolov wrote, "Since 1926, I am an object of permanent badgering. Now, this has become insufferable. I must compose, and my works must be performed! I must test my works against the masses; if I come to grief, I'll know where I must go." He went further to ask for Stalin to "influence the proletarian musicians and their myrmidons, who have badgered me during the whole last year, and to allow me to work in the USSR" or "authorize my departure abroad, where I, with my music, could be more useful for the USSR than here, where I am harassed and badgered, where I'm not allowed to display my forces, to test myself."

On February 4, 1936, Mosolov was expelled from the Composers' Union for treating waiters poorly and taking part in a drunken brawl in Press House, a local restaurant. After this, Mosolov traveled voluntarily to the Turkmen and Uzbek republics to collect folk songs as a form of rehabilitation. His attempts were unsuccessful, and he was arrested on November 4, 1937 for alleged counter-revolutionary activities under Article 58, Paragraph 10 of the Soviet criminal code and sentenced to eight years in the Gulag. He served in the prison from December 23, 1937 until August 25, 1938. Glière and Myaskovsky had sent a letter to Mikhail Kalinin, the chairman of the Central Executive Committee of the Russian Soviet Federative Socialist Republic, arguing for Mosolov's release citing his turn towards realism, his "outstanding creative ability," and the fact that neither teacher had seen in Mosolov any anti-Soviet disposition. On July 15, 1938, Mosolov's sentence was commuted to a five-year exile—he could not live in Moscow, Leningrad, or Kiev until 1942. His quick release, having only served eight months of his eight year sentence, was possible because he had been imprisoned not on political charges but on an overblown accusation of "hooliganism" brought by Mosolov's enemies in the Composers' Union.

When World War II broke out, Mosolov composed ''Signal'', an opera which dealt with the war. However, the compositions of Mosolov's later life were so uncharacteristic of his earlier style that one scholar noted that it was "impossible to discern the former avant-gardist in the works written from the late thirties onward". Mosolov lived in Moscow and continued to compose until his death in 1973.

Musical style

Mosolov's earliest music implies that Mosolov was influenced by German romanticism, but this influence waned as he began studying under Myaskovsky and Glière. In an early piece, "Four Songs," Op. 1, Mosolov explored the use of ostinato. Widespread use of ostinato became the defining signature of Mosolov's music: ''Iron Foundry'' is built of many ostinati working in tandem to create the sound of a factory, it is used in the Second and Fifth Piano Sonatas, etc.

Dissonance "in the extreme" and chromaticism are also Mosolov's signatures, though he stops short of the structured twelve-tone technique of Schoenberg. Instead of tone rows, Mosolov uses thickly-clustered, heavily chromatic chords to make his point. Folk music also saw use by Mosolov. As the first composer of a symphonic suite on a Turkmen folk song, Mosolov adopted the use of folk music before it was mandated under Socialist realism. His Second Piano Sonata incorporated Kyrgyz melodies, and his "Three Children's Scenes" utilized a city street song. However, instead of carefully setting the music for orchestra, Mosolov handled the music "like thematic grist for his compositional mill." This use of folk tunes continued after his Stalinist "rehabilitation." However, Mosolov's early works were marked by dense textures and polytonality that was lost after his expulsion and persecution.

Works

:''For a complete list, see List of compositions by Alexander Mosolov.

Among Mosolov's more notable pieces are his ''Four Newspaper Advertisements'' and ''Three Children's Scenes'', written in 1926. In ''Four Newspaper Advertisements'', Mosolov set four brief announcements in the newspaper ''Izvestiya'' to music. The topics of the four short pieces range from a lost dog to the announcement of a name change. In contrast, the text to ''Three Children's Scenes'' was written by Mosolov himself, and is much darker. The first, called "Mama, give me a needle, please!" is a short song in which the protagonist tortures a cat; the singer even mimics the screams of the cat, and the song ends with a sung shout of "A wicked creature!"

Mosolov's most famous composition, ''Iron Foundry'', was originally the final movement of a ballet suite titled, ''Steel''. The work premiered in Moscow on December 4, 1927, in a concert held by the ACM to commemorate the tenth anniversary of the Revolution. Its Western debut was at the ISCM festival in Liège on September 6, 1930, and it came to America two months later when the Cleveland Symphony Orchestra held a performance. Although it was originally praised as "a mighty hymn to machine work" and as a piece that glorified industrialization and "the worker", as the years passed the piece began to receive criticism from increasingly conservative Soviet authorities. Some critics argued that the workers, ironically enough, didn't enjoy such music, while others argued that the workers, "for whom machine oil is mother's milk," were roused and inspired by music of their time. One critic found in the music "no organized will to victory, in fact very little besides the petty-bourgeois anarchy", while conceding that it was "striving to find an individual idiom"; another called it a "grossly formalistic perversion of a contemporary topic". Today, only ''Iron Foundry'' remains from ''Steel'': the manuscripts were lost in 1929, the same year that Mosolov came under increased fire from Soviet authorities.

Notes

References

Sources

Leningrad Association of Contemporary Music, ''October and the New Music'' (1927). Quoted in Mosolov, Alexander. Alexander Mosolov to Joseph Stalin, May 1932. In ''Russkiy avangard i tvorchestvo Aleksandra Mosolova 1920–1930-kh godov'', by Igor Vorobev. St. Petersburg: Kompozitor, 2004.

External links

Chronology of Mosolov's life and compositions

Biography on the official website of Myaskovsky

Category:Russian composers Category:Soviet composers Category:Russian Futurist composers Category:20th-century classical composers Category:Russian classical pianists Category:Soviet classical pianists Category:Moscow Conservatory alumni Category:People from Kiev Category:1900 births Category:1973 deaths

de:Alexander Wassiljewitsch Mossolow es:Aleksandr Mosólov fr:Alexandre Mossolov it:Alexander Mosolov nl:Aleksandr Mosolov ja:アレクサンドル・モソロフ ru:Мосолов, Александр Васильевич uk:Мосолов Олександр Васильович zh:亚历山大·瓦西里耶维奇·莫索洛夫