Die-casting is one of the most reliable manufacturing methods for the production of metal components used in various industries. The process is widely used to produce a multitude of products and has revolutionized the industry in multiple ways.
The products made from die-casting, like other fabrication methods, are dependent on the type of metals utilized in the entire process. The type of metal used affects the overall visual appearance, durability, reliability, and final quality of the end product.
What is die-casting?
Understanding what the process entails is a key part of finding out the different types of metals used and the differences observed in the characteristics of the finished products.
Die-casting is a metal fabrication process that involves subjecting the molten metal to very high pressures in specifically shaped reusable metal dies. Die-casting enables the manufacturing of metal components with incredibly accurate specifications, smooth surfaces, and remarkable quality.
The main advantages of using the die-casting process are that it is relatively simple, fast, stable, and provides consistently good final results. The process begins when a steel mold is created into two (or more) sections to allow for the ejection of the castings. This mold has the ability to produce thousands of castings in very short periods of time. After being mounted on the machine, each section is arranged in a manner where one half is fixed and the other has the ability to move. They are clamped together with a machine which marks the beginning of the process. Molten metal is injected into the mold and is left to solidify. The two halves are then released and the final casting is removed.
What are the most commonly used die cast metals?
There are a variety of alloys and metals that can be utilized in the die-casting process. As mentioned earlier, the type of metal used influences the final characteristics of the manufactured products and these products have varied uses and applications.
The most commonly used metals in the process are zinc, aluminum, and magnesium. While several other options like copper, lead, brass, and tin exist, they are less common and are used only for specific projects.
The advantages of the three most commonly used metals are discussed below:
Aluminum is a very popular metal choice in die casting. Aluminum is a fairly light metal, which is ideal for manufacturing lightweight components with good strength. Aluminum is also able to withstand high temperatures and has more finishing options. Aluminum is also easy to cast and has optimal thermal and electrical conductivity. All of these characteristics combined make aluminum die-casting a very good choice for the production of parts in the technology, energy, automobile, and aerospace industries respectively.
Zinc is also comparable to aluminum in terms of popularity. It is mainly used in the production of automobile and medical equipment components. Zinc has a very distinct aesthetic look and zinc alloy die castings are perfect for manufacturing parts which require a sharp appearance. Zinc components also have smooth surfaces and can be plated or painted as per the specified need.
Zinc also has a low melting point and has less energy requirements when producing components while also extending the overall life of the mold used to shape the products, adding value to the entire process as a result. Zinc also has high corrosion resistance and is considered to be very durable, stable, and firm.
Among the three most popular metal choices, magnesium offers the greatest ease of machining. The incredible strength-to-weight ratio coupled with its lightness makes it the easiest alloy commonly used in die-casting. The advantages of using magnesium include better castability, resistance to hydrogen porosity, and superb fluidity compared to its aluminum and copper counterparts.
The metal is also known for its EMI (electromagnetic interference) and RFI (radio frequency interference) resistant properties which makes it the ideal choice for electrical components and connectors. The magnesium die casting metal is also used in the production of lab and medical equipment owing to these properties. Furthermore, magnesium is approximately 75% lighter than steel while having similar strength and superior dimensional stability, making it a good choice for complex net-shape and thin-walled casting applications.
Die-casting utilizes several different metals and the choice depends on the industry and project requirements. Each metal has its own strengths and weaknesses and its suitability depends on various use case scenarios. Die-casting has allowed the effective utilization of several metals and the potential for using more alloys is being investigated in order to obtain better-finished products.