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Aluminum extrusion

The process of extrusion is particularly adapted for the production of a variety of metal shapes. An extrusion press is capable of producing as many shapes as there are differently shaped dies to fit it. Intricate shapes can be produced by this process which cannot be made in any other manner, and many shapes which can be produced otherwise are often made by the extrusion process until it is possible to justify single-purpose equipment.

It is common usage to designate the capacity of extrusion presses by the number of tons pressure the press can put upon the metal to be extruded: in aluminum extrusion practice, presses vary from about 200 tons to as high as 5,000 tons. For convenience, the majority of small presses are built to operate in a vertical position. For structural reasons and because of other practical considerations, the larger presses are built to operate in a horizontal position. The commercial designs vary greatly, but in general metal is either extruded at the end of the ingot container farthest from the ram, or the metal is forced through the ram, which, in this case, is hollow. Solid and hollow shapes may be produced by extrusion. Hollow shapes, such as tubes, require a mandrel suitably held in the die opening so that metal flows through the die, around the mandrel. A press may be provided with a number of container® of different sizes in which the ingot is held during extrusion. Some of the larger presses will take ingots with a diameter of 14 inches and a length of 35 inches. The dimensions of extruded shapes are limited by the diameter of the ingot container and its length, and these two dimensions are in turn dependent upon the press capacity and the physical properties of the metal or alloy to be extruded, and, to a less extent, upon the kind of section desired.

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For extrusion the ingots are usually preheated and placed in the press. Depending upon the particular design of press, the die may be placed in position either before or after the press is charged. Pressure is then applied to advance the ram against the ingot and force the metal through the die opening. In some cases, more especially in smaller presses, the ram is stationary so that the container with the ingot to be extruded moves against the ram. During extrusion the pressure applied is controlled so that the metal flows through the die at a predetermined rate. With pure metal the rate of metal flow is not particularly important but with certain alloy compositions the rate of metal flow has a pronounced effect upon the surface of the extruded product, and also affects the physical properties. This is particularly true when the extruded material has a cross-section of irregular out-line. After   the   extrusion   operation   there   remains in the container a  certain  portion of the  charged  ingot. In most instances this butt portion is scrapped, especially when the physi­cal properties of the product are of prime importance.

The ingots used are, for the most part, cast in suitable molds. In some cases, however, the billet used may be a product of a working operation, as for example, rolled rounds. For the production of solid extruded sections a solid ingot is used, and for hollow sections a hollow ingot is used. Hollow ingots may be cast as such, but they may also be produced by a piercing operation on a solid ingot or billet.

Both pure metal and aluminum alloys are extruded. Pure metal is used for the production of molding and such articles as do not require the physical properties obtained in strong alloys. Aluminum alloys are employed in the production of many structural shapes such as I-beams, channels, H-beams, angles, tees and special and intricate shapes which cannot be produced in any other manner, such as specially designed sections for aircraft construction. This class of product is usually heat treated after the extrusion operation. The extrusion process is also employed for the production of tubing blooms and to provide forging stock.

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Scrap Aluminium to Auto Components
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ENGLISH SUBTITLE AVAILABLE!! Metal Casting Casting our first copper ingot with my homebuilt charcoal foundry. We didn’t achieve to melt the copper on our first try since our first lid let to much heat escape, so we built a huge and heavy lid from a boardwalk plate, isolating it with some fire cement and also put a second metal plate as lid on the crucible itself for keeping the temperature better. Now, after pre-heating the foundry for about 15 minutes, we put the crucible inside and had about 2 kg of copper melt in another 10 minutes. The mold is a simple cake tin which is fortunately shaped like ingots are, so this worked out perfectly.

Classic Ingots are so named because they are reminiscent of the old West days of miners bullion. Each ingot is made using only .999+ fine silver casting grain and weigh 10 troy ounces each. When it comes to stacking, no other style of bullion can rival the attractiveness of a perfectly formed stack of Classic Ingot. Casting is only the first stage in production. After the product is cast, it is then cleaned of the outer layer of dirt to expose the bare metal. It is then stamped and mechanically polished. Each product is then check against our quality standards before leaving our doors.

This is the process of casting the 3 troy ounce medium ingots. The furnace temperature is 1950 F. This is made in a graphite mold