Castings for Cast-Parts

Aluminum’s journey from the Paleolithic to the Modern world

The history of the world is closely related to man’s use of metal tools. From the Paleolithic Era which is the first recorded use of stone tools, on to the Neolithic or New Stone Age with the improvement of these tools, and the end of this era being a revolution in tool use with metal tools becoming widespread. The next step for the revolution of tool use was the Copper Age, then the Bronze Age, then the Iron Age. These were the first metals.

Aluminum wasn’t widely used by man till the 19th century with scientific breakthroughs facilitating its rise towards being the most widely used metal today. Without aluminum, airplanes and automobiles would be costly and impractical to develop. The aerospace industry wouldn’t have its shuttles. Even such simple things as aluminum foil, aluminum cans, and modern food packaging need the metal.

Aluminum cast parts are in such modern objects as the computer you are using, the mobile phone you bring with you, the kitchen utensil you used for lunch today, and a lot more of our regular daily objects. The aluminum castings process developed by the science of metallurgy involves the heating of the metal and the pouring of the molten material into a pre-designed mold. This is how aluminum part castings are made. The process is repeated a hundredfold to make the parts needed to supply the world with this miracle metal.

Many years ago, aluminum was not that widely used. Extraction of the metal was difficult and costly. It was already regarded as a useful metal, but it was too expensive. Nowadays, thanks to a handful of scientists and engineers and pioneers, aluminum is here to stay.

The irony of aluminum

Aluminum cans, foil, silver paint. All these would not exist if aluminum were not present in the earth’s crust. Alternatively, they would be very expensive if Charles Martin Hall and Paul Héroult did not discover electrolysis, which is the method of extracting the metal from its ore nowadays. Fortunately, they did discover it. The Hall-Héroult process for the production of aluminum is the foremost process used in the metalworking industry today.

For the further commercial use of this abundant metal, metalworkers use the aluminum casting process to mass produce aluminum alloys. Die molding, hot isostatic pressing,
sand casting, composite mold casting, continuous mold casting, permanent mold casting, centrifugal casting, investment casting, and plaster casting; this is a list of the many ways of aluminum part castings. These metal parts have a number of uses in the aeronautic, automobile, electronic, and electrical industries. Die Cast Tooling.

Due to this silvery lightweight metal’s incredible versatility, aluminum cast parts are also found in such gadgets as transistors, computers, mobile phones, lawnmowers, cars, escalators, aircraft, conveyor belts, streetlamps, and some dental equipment. In addition, aluminum compounds are used in the production of glass, ceramics, antiperspirants, synthetic rubber, paint, paper, cosmetics, varnishes, and leather tanning.

If science and technology did not go forward as it did, aluminum would still be more expensive than gold today. The irony of aluminum is that of all the metals in the world it is the most abundant one, but it could not have been used as it is used today without a cost-efficient method of extracting the metal.

Processes of Aluminum

Some machineries, equipment, and modern electronic gadgets are manufactured for worldwide distribution. The manufacturing process requires speed and efficiency at no sacrifice to quality and cost. For products that are composed of aluminum parts, casting is the answer.

The aluminum casting process provides dimensional accuracy, high strength, a light weight, and a good surface finish. Other benefits of aluminum cast parts are its resistance to corrosion and its thermal and electrical conductivity. Aluminum Casting requires the metal to be molten when it is poured into molds. As the aluminum sets or hardens, it then takes the shape and details of its mold. The properties of this metal that make it ideal for all the ways of metal casting are its high melting point, its malleability, and its ductility.

Aluminum part castings are:

• diecasting, used for small detailed parts with the same thickness all throughout
• investment casting, for thin walled intricate precision small parts
• permanent mold casting, for high-volume larger than die casting pieces
• sandcasting, for larger pieces with complex shapes and varying wall thickness
• shell mold casting, like sandcasting but with better surface finish, more dimensional accuracy, and higher cooling rates
• EPC or evaporative pattern casting, for intricate patterns
• plaster casting, for fine details as well as close tolerances
• continuous casting, for non-porous casting of round, square, hexagonal rods and other long shaped aluminum products

Other metals that are used for similar processes are the low heat metals that include zinc, tin, lead and the high heat metals such as copper, silver, and copper alloys brass and bronze.

The process of making of aluminum cast parts entails value for product quality, above else. With this in mind, aluminum casters tend to give premium on following specifications right to the tilt. The basic agenda on the list is die construction, which is primarily made of aluminum casting tooling. Aluminum casting is made of alloy tool steels in at least two sections, namely the fixed die half and the ejector die half. In modern times, dies may carry cores, movable slides, or other sections for the production of threads, holes, and other features for the attainment of the desired shapes.

The fixed die half has sprue holes that makes it possible for the molten metal to enter the die and fill in the cavity. On the other hand, the ejector die half has runners and gates that lead the molten metal right into the cavity. Aside from these two sections involved in the aluminum casting process, dies also consist of locking pins (for purposes of securing the fixed die half and the ejector die half), ejector pins (for purposes of making the removal of the cast part easier), and openings (for purposes of cooling and lubricating the molten metal or cast).

When the chamber closes, the fixed die half and the ejector die half become one and remain locked together, thanks to the chamber’s hydraulic pressure. After a certain amount of time elapses (depending on the total projected surface area and the pressure required for the injection of the metal into the cavity), the aluminum casting process is completed and high quality aluminum castings parts are produced.

From forcing molten metal under high pressure into tooling cavities, products from and for cast parts are formed. Cast parts, as we know it, is one fine way to produce small to medium sized parts that has good and intricate details, delicately formed surfaces, and that has consistency in dimensions making it as a very welcomed addition in the part production industry.

Now, some of you may wonder what materials are used in this very clever process. With cast parts, raw materials and elements (or non-ferrous metals as they are properly called) like zinc casting, copper, aluminum casting, magnesium, lead, and tin based alloys are used. These non-ferrous metals, as their collective name suggests, contains no trace of iron. And although these are the materials that are commonly used, ferrous materials (or materials that has traces of iron) can also be used in this process.

And the process itself, you may ask? Well, a cast part begins with closing the mold after being sprayed with a lubricant. By spraying lubricant on the mold, the temperature of the die can easily be controlled and the removing the cast later on will be much easier. After this first step, molten metal that is under high pressure of around 10—175 MPa (1,500—25,000 psi) is shot into the die. This amount of pressure is kept once the die is filled and until it is totally solidified. Filling the die by using a high-pressure injection is done so that the whole cavity would be filled before parts of the entire casting hardens. Moreover, using a high-pressure injection helps makers avoid irregularities in form even if there are parts of the cast that are not easy to fill due to its irregular shape.

And with a process as long as this one, one can be sure that the results will be beautiful die casted parts.