Metal forming, also known as mechanical working on metal. Metal forming often also intended to produce a new form or enhance the properties of metals. The formation of the solid state can be divided into hot working in establishment without any deductions such as forgings, rolling, pressing and others.
And the establishment with such cutting machining operation is formed with a variety of machine tools such as lathes, milling, drilling and in others.
And the establishment with such cutting machining operation is formed with a variety of machine tools such as lathes, milling, drilling and in others.
The process of forming a non-machining or without cutting, also known as mechanical working processes. This means that the permanent deformation of the metal elastic plastic material passing through the area. The main objective of the metalworking process is to provide the desired shape and size of the metal under treatment the force applied from the outside. The process is used to achieve optimum mechanical properties of the metal and reduce the appearance of voids or cavities and then make the metal density.
Metal is usually done by plastic deformation due to the effects of the advantage given to the mechanical properties. Deformation in metals can be achieved by the application of mechanical force that is by heating the metal and then apply a relatively small force. The presence of impurities in the metal which then gets elongation in point, in the process it will be broken and removed from the metal. This ni also lowers harmful effects of these impurities and increase its mechanical strength.
This plastic deformation occurs due to stress caused to the metal, because the applied force reaches the yield point (yield point). Two unusual phenomena associated with plastic defromasi this is by slip deformation and deformation by twin formation. In the case of the constituent considered that each grain of fabricated metal unit numbers of cells are arranged in a number of areas, and slip or metal deformation occurs along the slip plane where shear stress imposed on the greatest amount of force applied.
In the latter case, the deformation occurs along two parallel planes, which moves diagonally across the unit cell. This field is called the field twin parallel and a part of the grain closed between them is known as the twins. On a macro scale, when plastic deformation occurs, the metal appears in solid shape along a specific direction, which depends on the process and direction of the applied force. Cristal or metal grain extended in the direction of the axis of the metal. Nevertheless, the axis of these metals can be easily seen under a microscope setelahpolishing and etsha matches from the metal surface. Visible lines called fiber direction lines. Deformation above can occur at room temperature or higher temperatures.
At higher temperatures, deformation occurs faster because the bonds between the atoms of the metal grains to be reduced. Plasticity, elasticity, malleability (capable software) is the material properties resulting resist deformation under an applied force permanently and therefore the nature of this important metal for metal working processes.
Plasticity is the ability of a material to undergo some degree of permanent deformation without rupture or failure. Plastic deformation will occur only after the area has been terlebihi elastic (passed). As the nature of the material is important in the formation (forming), ekstrudingdan plenty of hot and cold working process more. Materials such as clay (clay), lead etc are plastic at room temperature and is plastic at a temperature steel forging. These properties generally increases with increasing temperature.
Tenacity is material properties that make the material can be formed into a wire by application of tensile force (tensile). The material must be strong and resilient plastic. Tenacity is typically measured by the percentage of elongation and percentage reductions in areas that are often used as an empirical measure of tenacity. Resilient material typically used in engineering training.
Kemampulunakan (malleability) is the ability of a material to be formed into thin sheets without cracking (crack) with hot work or cold. The material should be soft plastic capable but not so important to be very strong. Material capable software typically used in engineering training.
RECRISTALISASI.
During prsoes plastic deformation in metal forming processes, the flow of plastic from the metal case and the shape of the item changed. If the plastic deformation occurs at higher temperatures, the grains began to grow at the location of the internal voltages. If the temperature is high enough, the new grain growth is accelerated and continued until the metal filled by (only) a new item.
The process of formation of new grains is known as recrystallization and is said to be completed when the metal structure consisting of all new items. The temperature at which recrystallization has been completed is known as the recrystallization temperature. At this point where the image lines are different between hot and cold workmanship. Mechanical workmanship of metal under the recrystallization temperature is referred to as the workmanship dingindan completed above this temperature but below the melting point or fuel known as hot work.
WORKING HEAT
Process of mechanically performed above the recrystallization temperature is known as the hot working process. Some metals like lead has a low recrystallization temperature and can be hot work at room temperature. However, most commercial metals requires heating. Nonetheless, this temperature should not be too high to achieve the solidus temperature, although the metal will burn and become unsuitable for use. In hot working, the temperature of the completion of the metalworking quite important because of the heat left behind after work to help the growth of grain. An increase in the grain size is the case with the process of combining the grain and it is a function of time and temperature. Grain growth resulted in lower mechanical properties or ugly. When hot work is completed above the recrystallization temperature, the resultant grain size will be good. Then to the process of heat at the metal / metal should be heated to a temperature below the solidus temperature, which after the completion of hot working, the temperature will remain slightly higher and as close as possible to the temperature recristalisation.
Effect of Heat Work on Mechanical Properties of MetalsThis process is generally formed on the metal is being held at the temperature at which the metal is not hardened. Some metals such as Lead (pb) and tin (Sn) (because they have a low crystallization temperature) can be hot work at room temperature.
Raising the metal temperature lowers the voltage needed to produce deformation and increase the likelihood of a number of deformation before excessive hardening occurs.
Hot work is the process whereby large deformation should be avoided so as not to cause hardening.
Hot work such as rolling processes improve grain structure.
Surface finish of the metal experiencing hot work is not as good cold working due to oxidation and scaling.
Too high a temperature causes a phase change and high heating the metal, while too low a temperature will cause excessive hardening.
Defects in metals such as blowholes (holes), internal porosity and cracks can be removed during the process of heat
During hot working, annealing (self-annealing) may occur and recrystallization occurred immediately after the plastic deformation. Annealing itself prevent hardening and loss of ductility.
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