Die Casting Metals

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The Aluminum Die Casting Process Explained

Wikimedia commons romaryThe process of aluminum die casting is actually very simple. However, understand it and all the components that play a part in it is a lot more complicated. Very simply put, when molten metal is poured into a mold, or die, under very high pressure, we call this die casting. The molds can be made in a range of different shapes, so that objects of all shapes and sizes can be formed. One of the great advantages of this is that a single mold can make thousands and thousands of products, which will all be exactly the same. This is why die casting is so popular in the mass production industry. Different hardened metals are used within the die casting process and each metal or metal alloy tends to have different properties and different requirements in terms of how it should be cast. All of these metals have levels of hardness that are unsurpassed in any other industry, which is why they are so popular. The most commonly used metals in die casting are zinc, magnesium and aluminum, with aluminum being the most popular.

History of Die Casting

Die casting first started at the beginning of the 19th century. Only zinc and lead were used in those days and die casts were only used in the printing industry. During these days, low pressure was used to inject the molds. However, the industrial revolution quickly changed all of this. A number of high pressure techniques were developed, including the semi-solid casting process and the squeeze casting process. These methods were far more effective, in essence revolutionizing how items were produced. It was the birth of mass production on a massive level. More and more alloys were developed to use in the die casting process as well, such as the ones mentioned previously but also copper. All of these now use injection through high pressure methods.

Mold and Die Casting Types

A die is made up of two parts. The first part is the ejector and the other part is the fixer. Dies are made of alloy steel, which will last and last even when subjected to molten metal. There are four main types of dies, being the single cavity die, the multiple cavity die, the unit die and, lastly, the combination die.

The single cavity die, obviously, only produces one component. Multiple cavity ties, on the other hand, create a number of either matching or equal parts. The unit die is used mainly in the production of making lots of different parts at the exact same time. The last one, the combination die, creates a range of different parts that can later be assembled.

When a die cast product is created, this is done by using very high pressure and speed. The molten metal, during this process, is injected inside the die. The way this is done can vary depending on the alloy that is used. By using both speed and high pressure, a casting comes out very smoothly and the degree of accuracy between each part is very high. The pressure that is put on each of the metals has to be maintained at all times, until such time as the metal is formed and completely solidified and the desired shape has been achieved. Once the metal becomes hard, the die is immediately opened and the product is removed. The die opens up and the product is left in the ejector mold, from where it can be removed by using the pins.

The Benefits and Disadvantages of Die Casting

Every process in the world has advantages as well as disadvantages and it is very important to recognize these. In terms of benefits, die casting offers parts with a very long service life. The tolerance is very high and the dimensions are far more accurate than any other type of production method can be achieved. Although the initial investment is high, the process itself is incredibly economical. This is because the mold can be used again and again. One of the greatest things about the process, however, is that it can be fully automated. This adds to the economic advantage of the process, because fewer members of staff are needed in the production of any item.

In terms of the drawbacks, as stated, the initial cost of investment is quite high. This is because creating a mold requires some highly trained engineers and a lot of work between the engineers and the manufacturing company. Another disadvantage is that the process is not limitless. For instance, the casting weight has to be around 30 grams in order to work properly. Also, the product that is being cast should not be any bigger than 24 inches (600 millimeters), which means some products cannot be made this way. Lastly, the process only works with metals and alloys that are high in elasticity.

Die Casting Automation

As stated, one of the greatest advantages of the Aluminum die casting process is that it can be fully automated. Companies like Dynacast, for instance, can help you in setting up the process and creating the same product again and again in an almost fully automated way. Modern enhancements are added and developed continuously and it is now possible to work with machines that fully automate the process. They are so designed that the quality of the finished product is always consistent. Indeed, the process can be fully automated from start to finish. Before molten metal is injected into a die, the die has to be lubricated and even this essential action can be done automatically. Pouring the metal into the chambers can also be done automatically, which not only increases productivity and efficiency, but also the health and safety of employees in a plant. There are two methods used in die casting manufacturing, being hot chamber die casting and cold chamber casting. The type of process that is used depends on which alloy has to be melted. Those alloys that have a high melting point have to go through a furnace first and are then injected in a cold chamber die. Both of these methods can also be fully automated.

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