Extrusion
Extrusion is a compressive and deformation process. The process entails squeezing a block of material such as Aluminium, forcing it through a die. The die has a job of reducing it’s diameter and increasing it’s length. This method results in a constant cross-sectional cut and a desired shape. The process of extrusion is mainly used in situations where the material can’t be hammered or bended due to their specific properties such as being too soft or too brittle. The common materials that can be extruded include metals such as Aluminium, Copper, Lead and steel, plastics, ceramics and concrete. The method of extrusion can be either semi-continuous or continuous.
Brief history of extrusion:
In 1797, an Englishman named Joseph Bramah
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This is because in indirect extrusion the cross-sectional area is restricted by both the volume and area of the stem’s biggest size. In Direct extrusion, the extruded material’s surface is affected by defects and impurities. Therefore this downfall must only be eliminated by having the billet chemically cleaned and wired brushed.
Advantages of hydrostatic extrusion
One advantage of using hydrostatic extrusion due to the fact that the process does leave behind billet residue on the walls of the container. Between the container and the billet, friction does not exist, this is a major advantage as lowers the amount of force needed. It also advantageous because the temperature required for the billets is much less, which in turn makes it a more economically viable process. The process, when operated at high pressures, results in the increase of ductility of the material. This is advantageous as more brittle materials can also undergo the extrusion
The raw bead expansion procedure was successful; the beads expanded and made terrific molds. While being heated in the mold the expansion of gasses caused the beads to expand. Our molds were in the shapes of spheres, one looked like a softball and the other looked like a regular sphere.
Then, the materials cool down slowly. Through this process, the dislocations of the structure reduce. The strength of materials drop and raise the toughness flexibility and ductility. Also, the nucleation and growth will occurs in annealing.
Die-forming of sheet metal has been around for thousands of years. Originally the metal was manipulated by hand and hammered into the depression, by utilizing crude grooves carved into wood or stone. This technique was used to make spouts, handles, and other forms. Since then, however; they have undergone a remarkable technological evolution. Mate-female conforming dies to create hollow forms by using hydraulic pressure or drop hammer pressure, changed die-forming forever (Paisin, 2013).
In additive manufacturing, parts are produced by slicing a CAD model into thin layers and then depositing material one layer at a time to create the 3D part. While current methods are very precise and have high resolutions, I have identified 3 main limitations of additive manufacturing.
CAD – One factor that is often overlooked when introducing this type of process into the manufacturing industry is having personnel trained in the appropriate operational software, such as CAD. When a 2D CAD image is created of the desired design what needs to be kept in mind is that this will also involve calculating bend allowances, inclusion of half etch detail and scaling. To allow for the etching process an etching compensating factor has to be taken into account. This includes drawing the outside profile larger than the finished component size this means holes and slots should be smaller to compensate. The amount of adjustment is directly proportional to the thickness of the metal being processed.
3D printing is primarily for rapid part prototyping and small-run production in a variety of industries. In the meantime, the term additive manufacturing has come to represent the use of 3D printing to create metallic components and final parts, differentiating from conventional subtractive manufacturing processes. 3D printing uses computer-generated designs to create build paths that reproduce a digital model through consolidation of materials with an energy source. The process typically uses a laser, a binder or an electron beam that solidifies material as it is directed along scanned over a pre-placed layer or the build path of material. This method has been used successfully with metals, polymers and ceramics. Metals are still in their infancy in terms of finished part production. Metallic parts produced with 3D printing frequently require additio...
However, the product has one significant weakness as it exhibits creep and or cold flow characteristics, under compressive loads, thus affecting the gasket’s performance, since frequent retightening is required. The point is most users of PTFE are unaware of the fact that several different materials can be used successfully for the same application. The question to ask is what product is right for your application.
The idea of printing and the mass production of images had been around for several hundred years at the time of the invention of lithography in the late 18th century. Lithography provided an easier method to printing that no longer involved carving out metal plates. Lithography utilized the chemical properties of oil and water to create a template that could be easily created and reused. The technique involves creating a base plate from a type of stone such as limestone. The desired image is then drawn onto the stone with a “crayon-like” object that leaves an oily substance on the surface. The surface of the stone is then etched and wetted with water. An oil-based ink is then applied over the entire surface, the ink will only adhere to the areas that are coated with the greasy substance and
-creates a strong surface and can be used as a thin layer for glazes or a thick layers for impasto
the desired shape of the product. The plastic in the mold is then allowed to cool
The way 3D printing works is by taking virtual designs from a special computer aided design or modeling software and “splits” them into separate cross-sections for the machine to use as a guide. The printer then lays down successive layers of the liquid or powdered material required (metal, plastic, paper, ceramics etc.) and eventually builds the model through these series of cross sections, creating the object desired. This printing layer by layer slowly develops the object.
to be fixed at controlled outer diameter. The wall thickness of the product is then
Autofrettage introduces compressive hoop stresses in the region surrounding the internal diameter, to reduce the magnitude of the hoop stresses developed there when the tube is pressurized. This may be accomplished in one of two ways, as described in sub-sections 3.1 and 3.2.
Extrusion Process: Extrusion was performed with a co-rotating twin-screw extruder (Model BTPL-1, Basic Technology Pvt. Ltd. India). The extruder screw and ply cutter were driven by 5 hp motor and a variable speed DC motor respectively. The barrel sections viz., feed zone, compression zone and metering zone was fitted with a gasket to prevent ...
The manufacturing process of steel container or drum which is also known as liquid carrying container involves many processes. Although, there are different sizes of steel containers and different manufacturing process in most steel container manufacturing industries lately. There are also thousands of different steel alloy used in the production of steel containers. Furthermore, steel containers are made of sheet metal by soldering, brazing, spot welding, and seam welding. In addition to this, The Process of making steel containers involves rolling of metal sheet; welding the seam, making 90 degree bent on top and bottom of the container, making number of beads (according to size) and lastly reduce the diameter of one side of the container; fitting of lid to the containers, testing like pressure; coating internal (epoxy phenolic coating or plain) and external (stoving enamel gloss of various colour).