Introduction
Metallurgy is the field of materials science and material engineering that studies the physical and chemical behaviour of metallic elements, their microstructure compounds and their mixtures, which are mostly known as alloy. Metallurgy can be refers as the technology of metals where science is applied to the production of metals, and the engineering of metal components for the uses of products for consumers and manufacturers.
Metals are widely use in industrial, economic growth and most importantly our daily life. Metals can be found in our car (steel), cell phones (gold, tin), computers (mercury, lithium), electrical wires (copper) and soda can (aluminium). But what is the prime factor that really determines the quality of metals? I would say TOUGHNESS.
Toughness is the ability of a metal to mutilate plastically and to absorb energy in the process before it breaks or fracture. Metals can be heat treated to alter the properties of strength, ductility, toughness, hardness or resistance to corrosion. This can be done by using heat treatment processes which include precipitation strengthening, quenching, annealing and tempering. Annealing and tempering are the most prominent methods for treating metals. A material may become more or less brittle, harder or softer, or stronger or weaker, depending on the treatment used.
Content
HEAT -TREATMENT
Heat treatment is a process using the controlled application of heat to change the physical and chemical properties of a material, and is commonly used in metals. However, materials such as glasses can also be heat treated despite metals only.
Annealing
Annealing and tempering are not the same types of heat treatment. Annealing can be defined as heating the steel to aus...
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...oves mach-inability and perfect grain size. Their main purpose is to make further processing operations easier or possible. Bainite, pearlite and ferrite formed through annealing.
In the other hand, the Hardening processes consist of quenching and tempering. They help in developing the appropriate bulk and surface properties. Martensite can be found in the structure of hardened or quenched steel. Martensite is a hard but brittle structure which needs tempering. After tempering, the toughness is increased and the brittleness is reduced, then it will have broad use throughout engineering field. Their principal use is to render the part fit for final use.
In summary, the rate of cooling from the austenite phase is the main determinant of final structure and properties.
To look it in a simple way, annealing is softening while tempering is hardening.
We use metals to construct all kinds of structures, from bridges to skyscrapers to elevators. The strength as well as durability of materials that are crafted out of metal make the materials ideal not only for construction but also for many other applications.
After quenching, the heated steel will cool down. Due to the different rate of cooling, the different types of microstructure will be formed. The formation of pearlite, bainite and martensite determine the physical properties such as hardness, strength and ductility.
The heat input rate is one of the most important variables in fusion welding, since it governs heating rates, cooling rates and weld pool size. In the welding of steel, this is important relationship since increased cooling rates increase the risk of hydrogen-induced cracking. The other metallurgical feature that is directly affected by the heat input rate is grain size in the heat affected zone (HAZ) and in the weld metal. In steel welding it is necessary to seek a heat input rate that gives the optimum combination of grain size and cooling rate [11]. Before the actual welding is done, all the earlier steps such as layout, plate edge preparation, fit up and alignment should be well planned with regard to achieving...
These globules act as a lubricant, decreasing the friction coefficient between the tools and the materials by creating discontinuities of chip fragmentation. Therefore, it reduces cutting force and then, the tool wear rate is minimized [13]. Different alloying elements help to improve the machinability are usually added to brass. The most common element used in this situation is lead, which improves the machinability with excellent chip breakage, low tool wear and high applicable cutting parameters. These aspects can be explained by two basic phenomena; in the first, the solubility of lead in brass is extremely low and lead segregates in the entire microstructure, particularly at the grain boundaries.
These include, high strength, low weight, high chemical resistance and high cut resistance. This material does not corrode or rust and is also unaffected when placed in or under water.
Pounding metal and fabricating metal in thin sheets and sections that humans need or want has a long history. The discovery of how to make and control fire made extracting metals form or more efficient instead of having to find almost pure nuggets of metal. In many civilizations copper was the metal they used but that was succeeded by bronze eventually it is made of copper and tin.
Since all metals have different densities and makeups I think that the heat capacity will greatly vary. The makeup of iron is very different than aluminum so the heat capacity will be quite different. Also, a lot of metals are not completely pure and that will also have some effect on the heat capacity.
A wide variety of coating alloys and wrought alloys can be prepared that give the metal greater strength, castability, or resistance to corrosion or high temperatures. Some new alloys can be used as armor plate for tanks, personnel carriers, and other military vehicles.
The Web. The Web. 28 Apr. 2014. The 'Standard' of the 'Standard'. Metal Melting 101 - How To.
If work-hardening is performed at elevated temps it is said to be hot-worked. In contrast cold-working is done right around room temperature. In both situations the work hardening increases the strength and hardness because of plastic deformation. This causes atoms in a crystal to become disordered, which means that the atoms have moved into a disordered structure. This then raises the strength and hardness by impairing the easy movement of dislocations. Cold working was done at first along with harness testing, once familiarized with all of this testing relationships between hardness, microstructure, and degree of work hardening of brass were
4.6. Final Concept Summary Concept Two: This concept utilizes rollers in the milling process to crack open the grain. Though rollers are more expensive that the other milling methods, they provide a larger contact surface area which proves to be most effective and most efficient in this process. Heat exchangers and steam jackets were selected to heat the water for the mashing process.
(a) Noncombustible steel
Metalloids can be applied in almost all aspects of life. From being used in gum and toys to technology and spacecraft, metalloids are very useful. For example, Silicon can be used in electrical insulators, fabric softeners, hair sprays, hand creams, furniture, polishes, paints, adhesives, and gum. While Arsenic is used for bronzing, the hardening of lead in shotgun shells, and as a dopant, because metalloids are semiconductive, Antimony could be used in making bells, tools, printing presses, batteries, alloys, bullets, and cable sheathing. Furthermore, Tellurium is used to build electronics and make metals easier to cut. Tellurium is also used in coloring glass, porcelain, enamel, and ceramics. Lastly, Germanium is used in fluorescent lamps, infrared spectroscopes, and infrared detectors. Together, metalloids have many applications that can be used to create and upgrade certain
Metals possess many unique fundamental properties that make them an ideal material for use in a diverse range of applications. Many common place things know today are made from metals; bridges, utensils, vehicles of all modes of transport, contain some form of metal or metallic compound. Properties such as high tensile strength, high fracture toughness, malleability and availability are just some of the many advantages associated with metals. Metals, accompanied by their many compounds and alloys, similar properties, high and low corrosion levels, and affects, whether negative or positive, are a grand force to be reckoned with.
This is the textbook for my materials science and engineering class. It contains information about the behaviors and properties of materials such as metals and polymers. This source will prove useful because in the field of tensegrity, the type of material used to make a structure is very important. In the field of engineering/tensegrity, this source is considered as a reference