Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Metallurgy shopping experience:

1. Compare - without doubt the biggest advantage that the Metallurgy offers shoppers today is the ability to compare thousands of Metallurgy at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.

2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about

3. Testimonials - don't know anybody that has bought a Metallurgy? Wrong! If the Metallurgy is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.

4. Questions - Got a question about Metallurgy then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....

5. Reputation - Never heard of the company selling Metallurgy? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Metallurgy and build up a picture of their reputation for sales, returns, customer service, delivery etc.

6. Returns - still worried that even after all of the above your Metallurgy wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.

7. Feedback - happy with your Metallurgy then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.

8. Security - check for the yellow padlock on the Metallurgy site before you buy, and the s after http:/ /i.e. https:// = a secure site

9. Contact - got a question about Metallurgy, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.

10. Payment - ready to pay for your Metallurgy, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.

Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic Chemical element, their intermetallics, and their compounds, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use. The term is nowadays distinguished from the craft of metalworking.

History s, from the Nong Shu, by Wang Zhen, 1313 AD, during the Chinese Yuan Dynasty.The earliest recorded metal employed by humans appears to be gold which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC.

Silver, copper, tin and meteoric iron can also be found native, allowing a limited amount of metalworking in early cultures. Egyptian weapons made from meteoric iron in about 3000 B.C. were highly prized as "Daggers from Heaven"W. Keller (1963) The Bible as History page 156 ISBN 0 340 00312 X. However, by learning to get copper and tin by heating rocks and combining copper and tin to make an alloy called bronze, the technology of metallurgy began about 3500 B.C. with the Bronze Age.

The extraction of iron from its ore into a workable metal is much more difficult. It appears to have been invented by the Hittites in about 1200 B.C., beginning the Iron Age. The secret of extracting and working iron was a key factor in the success of the PhilistinesW. Keller (1963) The Bible as History page 177 ISBN 0 340 00312 XB. W. Anderson (1975) The Living World of the Old Testament page 154 ISBN 0-582-48598-3

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 Egypt and Anatolia (Turkey), Carthage, the Greeks and ancient Romes of ancient Europe, medieval Europe, ancient and medieval China, ancient and medieval India, ancient and medieval Japan, etc. Of interest to note is that many applications, practices, and devices associated or involved in metallurgy were first established in ancient China long before Europeans mastered these crafts (such as the innovation of the blast furnace, cast iron, steel, hydraulic-powered trip hammers, etc.) R. F. Tylecote (1992) A History of Metallurgy ISBN 0-901462-88-8.

A 16th century book by Georg Agricola called De re metallica describes the highly developed and complex processes of metal extraction and metallurgy of the time. Agricola has been described as the "father of metallurgy"Karl Alfred von Zittel (1901) History of Geology and Palaeontology page 15

Extractive 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 sulfide to a purer metal, the ore must be redox either physically, chemistry, or electrolyte.

Extractive metallurgists are interested in three primary streams: feed, concentrate (valuable metal oxide/sulfide), and tailings (waste). After mining, large pieces of the ore feed are broken through crushing and/or grinding in order to obtain particles small enough where each particle is either mostly valuable or mostly waste. Concentrating the particles of a 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 In-situ leaching. Leaching dissolves minerals in an ore body and results in an enriched solution. The solution 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.

Important Common Alloy Systems Common engineering metals include aluminium, chromium, copper, iron, magnesium, nickel, titanium and zinc. These are most often used as alloys. Much effort has been placed on understanding the iron-carbon alloy system, which includes steels and cast irons. Plain carbon steels are used in low cost, high strength applications where weight and corrosion are not a problem. Cast irons, including ductile iron are also part of the iron-carbon system.

Stainless steel or galvanized steel are used where resistance to corrosion is important. Aluminium alloys and magnesium alloys are used for applications where strength and lightness are required.

Cupro-nickel alloys such as Monel are used in highly corrosive environments and for non-magnetic applications. Nickel-based superalloys like Inconel are used in high temperature applications such as turbochargers, pressure vessels, and heat exchangers. For extremely high temperatures, single crystal alloys are used to minimize creep.

Production engineering of metals In industrial engineering, metallurgy is concerned with the production of metallic components for use in consumer or engineering products. This involves the production of alloys, the shaping, the heat treatment and the surface treatment of the product. The task of the metallurgist is to achieve balance between material properties such as cost, weight, tensile strength, toughness, Hardness (materials science), corrosion and fatigue (material) resistance, and performance in temperature extremes. To achieve this goal, the operating environment must be carefully considered. In a saltwater environment, ferrous metals and some aluminium alloys corrode quickly. Metals exposed to cold or cryogenic conditions may endure 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 (physics) at elevated temperatures can creep (deformation).

Metal Working Processes Metals are shaped by processes such as casting, forging, Flow Forming, Rolling (metalworking), extrusion, sintering, metalworking, machining and Fabrication (metal). With casting, molten metal is poured into a shaped Molding (process). With forging, a red-hot Billet (manufacturing) is hammered into shape. With rolling, a billet is passed through successively narrower rollers to create a sheet. With extrusion, a hot and malleable metal is forced under pressure through a die, which shapes it before it cools. With sintering, a powder metallurgy is compressed into a die at high temperature. With machining, Lathe (tool), milling machines, and drills cut the cold metal to shape. With fabrication, sheets of metal are cut with guillotines or gas welding and bent into shape.

"Cold working" processes, where the product’s shape is altered by rolling, fabrication or other processes while the product is cold, can increase the strength of the product by a process called work hardening. Work hardening creates dislocation in the metal, which resist further changes of shape.

Various forms of casting exist in industry and academia. These include sand casting, investment casting (also called the “lost wax process”), die casting and Continuous Casting.

Joining Welding is a technique for joining metal components by melting the base material. A filler material of similar composition may also be melted into the joint.Brazing is a technique for joining metals at a temperature below their melting point. A filler with a melting point below that of the base metal is used, and is drawn into the joint by capillary action. Brazing results in a mechanical and metallurgical bond between work pieces.Soldering is a method of joining metals below their melting points using a filler metal.Soldering results in a mechanical joint and occurs at lower temperatures than brazing.

Heat Treatment Metals can be heat treatment by to alter the properties of toughness, hardness or resistance to corrosion. Common heat treatment processes include Annealing (metallurgy), precipitation strengthening, quenching, and tempering. The annealing process softens the metal by allowing recovery of cold work and grain growth. Quenching can be used to harden alloy steels, or in precipitation hardenable alloys, to trap dissolved solute atoms in solution. Tempering will cause the dissolved alloying elements to precipitate, or in the case of quenched steels, improve impact strength.

Surface Treatment Electroplating is a common 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. It is used to reduce corrosion as well as to improve the product's aesthetic appearance.{{Main|Thermal spray--> Thermal spraying techniques are another popular finishing option, and often have better high temperature properties than electroplated coatings.Case hardening is a process in which an alloying element, most commonly carbon or nitrogen, diffuses into the surface of a monolithic metal. The resulting interstitial solid solution is harder than the base material, which improves wear resistance without sacrificing toughness.

Electrical and electronic engineering Metallurgy is also applied to electrical and electronic materials where metals such as aluminium, copper, tin and gold are used in power lines, wires, printed circuit boards and integrated circuits.

Metallurgical techniques

Metallurgists study the microscopic and macroscopic properties using metallography. 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. A metallurgist can then examine the sample with an optical or electron microscope and learn a great deal about the sample's composition, mechanical properties, and processing history.

Crystallography, often using diffraction or x-rays or electrons, is another valuable tool available to the modern metallurgist. Crystallography allow the identification of unknown materials and reveals the crystal structure of the sample. Quantitative crystallography can be used to calculate the amount of phases present as well as the degree of strain to which a sample has been subjected.

The physical properties of metals can be quantified by mechanical testing. Typical tests include tensile Strength of materials, compressive strength, hardness, impact toughness, fatigue and creep life.

References

See also

Additional Information Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic Chemical element, their intermetallics, and their compounds, which are called alloys. It is also the technology of metals: the way in which science is applied to their practical use. The term is nowadays distinguished from the craft of metalworking.

History s, from the Nong Shu, by Wang Zhen, 1313 AD, during the Chinese Yuan Dynasty.The earliest recorded metal employed by humans appears to be gold which can be found free or "native". Small amounts of natural gold have been found in Spanish caves used during the late Paleolithic period, c. 40,000 BC.

Silver, copper, tin and meteoric iron can also be found native, allowing a limited amount of metalworking in early cultures. Egyptian weapons made from meteoric iron in about 3000 B.C. were highly prized as "Daggers from Heaven"W. Keller (1963) The Bible as History page 156 ISBN 0 340 00312 X. However, by learning to get copper and tin by heating rocks and combining copper and tin to make an alloy called bronze, the technology of metallurgy began about 3500 B.C. with the Bronze Age.

The extraction of iron from its ore into a workable metal is much more difficult. It appears to have been invented by the Hittites in about 1200 B.C., beginning the Iron Age. The secret of extracting and working iron was a key factor in the success of the PhilistinesW. Keller (1963) The Bible as History page 177 ISBN 0 340 00312 XB. W. Anderson (1975) The Living World of the Old Testament page 154 ISBN 0-582-48598-3

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 Egypt and Anatolia (Turkey), Carthage, the Greeks and ancient Romes of ancient Europe, medieval Europe, ancient and medieval China, ancient and medieval India, ancient and medieval Japan, etc. Of interest to note is that many applications, practices, and devices associated or involved in metallurgy were first established in ancient China long before Europeans mastered these crafts (such as the innovation of the blast furnace, cast iron, steel, hydraulic-powered trip hammers, etc.) R. F. Tylecote (1992) A History of Metallurgy ISBN 0-901462-88-8.

A 16th century book by Georg Agricola called De re metallica describes the highly developed and complex processes of metal extraction and metallurgy of the time. Agricola has been described as the "father of metallurgy"Karl Alfred von Zittel (1901) History of Geology and Palaeontology page 15

Extractive 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 sulfide to a purer metal, the ore must be redox either physically, chemistry, or electrolyte.

Extractive metallurgists are interested in three primary streams: feed, concentrate (valuable metal oxide/sulfide), and tailings (waste). After mining, large pieces of the ore feed are broken through crushing and/or grinding in order to obtain particles small enough where each particle is either mostly valuable or mostly waste. Concentrating the particles of a 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 In-situ leaching. Leaching dissolves minerals in an ore body and results in an enriched solution. The solution 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.

Important Common Alloy Systems Common engineering metals include aluminium, chromium, copper, iron, magnesium, nickel, titanium and zinc. These are most often used as alloys. Much effort has been placed on understanding the iron-carbon alloy system, which includes steels and cast irons. Plain carbon steels are used in low cost, high strength applications where weight and corrosion are not a problem. Cast irons, including ductile iron are also part of the iron-carbon system.

Stainless steel or galvanized steel are used where resistance to corrosion is important. Aluminium alloys and magnesium alloys are used for applications where strength and lightness are required.

Cupro-nickel alloys such as Monel are used in highly corrosive environments and for non-magnetic applications. Nickel-based superalloys like Inconel are used in high temperature applications such as turbochargers, pressure vessels, and heat exchangers. For extremely high temperatures, single crystal alloys are used to minimize creep.

Production engineering of metals In industrial engineering, metallurgy is concerned with the production of metallic components for use in consumer or engineering products. This involves the production of alloys, the shaping, the heat treatment and the surface treatment of the product. The task of the metallurgist is to achieve balance between material properties such as cost, weight, tensile strength, toughness, Hardness (materials science), corrosion and fatigue (material) resistance, and performance in temperature extremes. To achieve this goal, the operating environment must be carefully considered. In a saltwater environment, ferrous metals and some aluminium alloys corrode quickly. Metals exposed to cold or cryogenic conditions may endure 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 (physics) at elevated temperatures can creep (deformation).

Metal Working Processes Metals are shaped by processes such as casting, forging, Flow Forming, Rolling (metalworking), extrusion, sintering, metalworking, machining and Fabrication (metal). With casting, molten metal is poured into a shaped Molding (process). With forging, a red-hot Billet (manufacturing) is hammered into shape. With rolling, a billet is passed through successively narrower rollers to create a sheet. With extrusion, a hot and malleable metal is forced under pressure through a die, which shapes it before it cools. With sintering, a powder metallurgy is compressed into a die at high temperature. With machining, Lathe (tool), milling machines, and drills cut the cold metal to shape. With fabrication, sheets of metal are cut with guillotines or gas welding and bent into shape.

"Cold working" processes, where the product’s shape is altered by rolling, fabrication or other processes while the product is cold, can increase the strength of the product by a process called work hardening. Work hardening creates dislocation in the metal, which resist further changes of shape.

Various forms of casting exist in industry and academia. These include sand casting, investment casting (also called the “lost wax process”), die casting and Continuous Casting.

Joining Welding is a technique for joining metal components by melting the base material. A filler material of similar composition may also be melted into the joint.Brazing is a technique for joining metals at a temperature below their melting point. A filler with a melting point below that of the base metal is used, and is drawn into the joint by capillary action. Brazing results in a mechanical and metallurgical bond between work pieces.Soldering is a method of joining metals below their melting points using a filler metal.Soldering results in a mechanical joint and occurs at lower temperatures than brazing.

Heat Treatment Metals can be heat treatment by to alter the properties of toughness, hardness or resistance to corrosion. Common heat treatment processes include Annealing (metallurgy), precipitation strengthening, quenching, and tempering. The annealing process softens the metal by allowing recovery of cold work and grain growth. Quenching can be used to harden alloy steels, or in precipitation hardenable alloys, to trap dissolved solute atoms in solution. Tempering will cause the dissolved alloying elements to precipitate, or in the case of quenched steels, improve impact strength.

Surface Treatment Electroplating is a common 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. It is used to reduce corrosion as well as to improve the product's aesthetic appearance.{{Main|Thermal spray--> Thermal spraying techniques are another popular finishing option, and often have better high temperature properties than electroplated coatings.Case hardening is a process in which an alloying element, most commonly carbon or nitrogen, diffuses into the surface of a monolithic metal. The resulting interstitial solid solution is harder than the base material, which improves wear resistance without sacrificing toughness.

Electrical and electronic engineering Metallurgy is also applied to electrical and electronic materials where metals such as aluminium, copper, tin and gold are used in power lines, wires, printed circuit boards and integrated circuits.

Metallurgical techniques

Metallurgists study the microscopic and macroscopic properties using metallography. 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. A metallurgist can then examine the sample with an optical or electron microscope and learn a great deal about the sample's composition, mechanical properties, and processing history.

Crystallography, often using diffraction or x-rays or electrons, is another valuable tool available to the modern metallurgist. Crystallography allow the identification of unknown materials and reveals the crystal structure of the sample. Quantitative crystallography can be used to calculate the amount of phases present as well as the degree of strain to which a sample has been subjected.

The physical properties of metals can be quantified by mechanical testing. Typical tests include tensile Strength of materials, compressive strength, hardness, impact toughness, fatigue and creep life.

References

See also

Additional Information

Metallurgy
MEng Metallurgy – UCAS Code: J200. You can find more information about this course by following the `Quick Links´ on the right to its entry in the University´s online ...

Metallurgy - Wikipedia, the free encyclopedia
Metallurgy is a domain of materials science that studies the physical and chemical behavior of metallic elements, their intermetallic compounds, and their compounds, which are ...

Welcome to Metallurgy and Materials
Metallurgy and Materials, University of Birmingham ... Welcome to Metallurgy and Materials. Materials surround us - from bricks to body scanners - and our programmes in Metallurgy ...

BUBL LINK: Metallurgy
Titles: Descriptions: AMM: The World Metals Information Network; Archaeometallurgical Links; Archaeometallurgy in Archaeological Projects; Foundry Online; Historical Metallurgy ...

Ancient Metallurgy Research Group | AGES | University of Bradford
Archaeological Geographical & Enviromental Sciences ... Archaeometallurgy Research Laboratory. The Archaeometallurgy Research Laboratory was established in 1992 The ARL encourages ...

Metallurgy and Materials Case Studies - Teaching and Learning ...
Introduction. Welcome to the Metallurgy and Materials web-based resource of case study learning. This site gives details of case studies running in the following courses:

Department of Materials Science and Metallurgy
Department of Materials Science and Metallurgy.

TWI services - metallurgy
The range of available services is listed ... Information and advice from TWI and its partners are provided in good faith and based, where appropriate, on the best ...

The Historical Metallurgy Society
Forum for exchange of information and research in the subject. Annual conference. Publishes annual journal Historical Metallurgy (contents list of all volumes.)

History of Metallurgy and Materials at Birmingham
Metallurgy and Materials, University of Birmingham ... Metallurgical studies at Birmingham date back to 1881 when the first students were registered for an option in Chemistry in ...

 

Metallurgy



 
Copyright © 2008 Hintcenter.com - All rights reserved.
Home | Terms of Use | Privacy Policy
All Trademarks belong to their repective owners. Many aspects of this page are used under
commercial commons license from Yahoo!