Understanding Magnesium Die Castings And Processes

Die casting is used to refer to a casting process, which is done by forcing different kinds of highly pressurized molten metal into a mould cavity. This mould cavity is actually created by the use of steel dies, which are hardened and shaped by the use of a machine and are quite similar to injection moulds. The metals they use in the die casting process are non-ferrous, such as zinc, aluminum, copper, magnesium, as well as pewter and lead. They also make use of other tin-based alloys for die casting. There are two machines being used in the die casting process, namely the hot and cold chamber machines. Whether one is used instead of the other depends on the metals being casted. The equipment used in casting these metal dies are very expensive and count for major capital costs which limits the orders to high volumes.

What is Die Casting?

The making of parts for die castings is quite simple and involves only four steps which are what helps to keep the incremental costs per item very low. This makes it especially suited for large volume orders of small to moderate-sized castings. This is the reason why the die casting process tends to produce more castings as compared to other casting processes. Magnesium die casts, zinc die castings, and other metals used in the die casting process hold up well, which is why you will notice that die castings can be distinguished by their excellent surface finish as well as dimensional consistency. In magnesium die castings or other kinds metals used for die castings there are two variants from which you can choose from. One of them is pore-free die casting to help eliminate defects in gas porosity and they also make use of injection die casting variant which is especially useful in zinc castings so they can reduce scrap which can increase yield.

Different Metal Alloys for Different Uses

There are quite a number of metals being utilized in the die casting process. There is zinc, pewter, and magnesium. Each of these metals will have its own special use and purpose. If you want to talk about automobiles then you will want to learn about magnesium die castings. What makes magnesium die castings so popular on cars is the very structure of the metal itself. You see, magnesium is the lightest structural material you can find as it only weighs 1.8g/cm3. Magnesium is also the 8th most abundant element which you can find in the earth's crust which means there is no shortage of magnesium to be used. You can find this metal naturally occurring in Dolomite, Magnetite, Carnalite, and Chloride. You may wonder where magnesium is found and surprisingly enough, it can be found in sea water, brine, and other magnesium-bearing minerals which mean you get close to unlimited reserves of magnesium.

Advantages of Magnesium

So just why is magnesium such in high demand you may wonder. Granted it is available in nearly unlimited numbers seeing as they mined 350,000 metric tons in the year 1990 and 500,000 metric tons in the year 2005. However, there are other reasons for the increase in the production of magnesium die castings. For one, it is the lightest of all structural materials being 75% lighter than steel and 35% lighter than aluminum. Aside from the fact that it is lightweight, what makes parts made from magnesium die castings perfect for cars and other vehicles is they are very resistant to high impact. A lot of people put great stock in its high weight to strength ratio. Magnesium die castings have been discovered to have the capability of being cast into net shapes aside from having excellent dimensional stability and repeatability. Magnesium die castings are also 100% recyclable, which is why a lot of die-casting companies often use these in production.

How do You Choose an Alloy?

There are many types of magnesium alloys you can choose from. The selection is usually based on the environment where the part will function and the performance requirements of the components. For instance, the AZ791D alloy is most commonly used for die castings that involve very high pressure. This is the type of alloy that is most commonly used for parts used in power-trains and other mechanical components where the toughness of the metal is considered more important than any deformation capabilities. The next alloy utilized in die castings is the AM60B which is commonly used in producing automotive die castings which involve making safety components including a car's instrument panel and seat frames. This type of allow gives you excellent ductility. It also has one of the best energy absorbent properties plus it has a lot of strength and cast ability too. Another type of alloy you may be interested in is the AM50 which has lower aluminum content than the AM60 and has even more ductility to offer. Though it does have a slightly reduced strength and the casting ability is also slightly reduced. This alloy is typically used in procedures where the demands for elongation is beyond that of what the AM60 can offer.