From aerospace to appliance, automotive to furniture, and consumer electronics to military sectors, die casting is the most common manufacturing method used to produce products for various applications. In this article, let’s explore more about what is die casting, types, processes, materials, advantages, applications, and many more. Raidy Mold is a reliable custom mold manufacturer for die casting manufacturing.
What is Die Casting
Die casting is a manufacturing process that involves forcing molten metal under high pressure into a reusable mold. This metal shaping technique uses a specially designed mold, which is called a die. What is die cast metal made of? This die is generally made using hardened steel and precisely machined to create the desired shape of the final part.
This process begins with melting the metal to a precise temperature. Once molten, the metal is injected into the mold under pressure, which helps in filling even the smallest details of the mold cavity. It is important to note that there are variations in die casting techniques, but they all share this core principle — injecting molten metal into a metal die under immense pressure.
Die casting process is specifically ideal for non-ferrous metals, such as zinc, aluminum, magnesium, copper alloys, etc. These metals are known for their excellent castability, which means they will flow easily and solidify quickly within the die cavity. This ensures the formation of complicated shapes with minimal defects.
What is die casting used for? Die casting has various applications in a wide range of industries, such as furniture, automotive, aerospace, electronics, consumer goods, etc. Metal die casting method is used where high-volume production of consistent, high-quality components is relatively essential.
History of Die Casting
Die casting has its origins in the early to mid-19th century, when it was primarily used for casting printer parts like gears and bell cranks. During this period, the process was relatively simple. All the tools were generally made of iron and were coarse. In addition, metal fillings were poured by hand with the help of ladles.
Die casting evolved significantly throughout the 20th century, becoming a common method for high-volume metal component manufacturing. As technology advanced, die casting processes became more refined and automated. At present, fully automated production lines are very common.
However, the essence of die casting’s early techniques is still used in modern commercial applications. Even with modern advancements, there are instances where simple cavity tools are filled using hand ladles, showcasing the enduring adaptability and utility of die casting across diverse manufacturing environments.
The development of high-pressure machines and improved die materials made it possible to produce complex and high-quality castings on an industrial scale. Die casting played a significant role in the growth of the automobile industry, as it allowed for the mass production of complex engine parts. Today, die casting remains a vital manufacturing process used in a wide range of industries.
Advantages of Die Casting
There are a wide range of benefits of die casting manufacturing, which is why it is used in different applications. Here is a brief list of the common advantages:
Complicated Shapes and Thin Walls
With die casting manufacturing, producing intricate shapes with thin walls is relatively easy. The high pressure injection forces molten metal to fill even the most detailed cavities within the die. This allows for the production of lightweight yet strong components with complex geometries. This method is very ideal for applications like automotive pistons, consumer electronics, and more.
Precise and Accurate
Die casting uses robust metal dies that are machined to precise specifications. It uses castings that consistently match the desired dimensions and tolerances, which minimizes the need for post-processing. This precision is vital for applications that need tight tolerances, such as engine components, electronic housings, etc.
Quick Production
One major advantage of die casting is it is a rapid and efficient process. Once the die is set up, each casting cycle can be completed in seconds. This high production speed makes it ideal for mass production of identical parts, significantly reducing overall manufacturing time and cost.
Excellent Surface Finish
The smooth and consistent surface finish achieved through die casting minimizes the need for additional finishing processes. This reduces production time and cost while also enhancing the aesthetics and functionality of the final product. In addition to that, specific finishes or textures can be incorporated into the die design for specific applications.
High Strength-to-Weight Ratio
Die casting materials like aluminum, magnesium, and zinc alloys offer a good balance of strength and weight. This makes it easy to manufacture lightweight yet durable parts. This is a critical factor in industries like aerospace and automotive, where weight reduction is vital for fuel efficiency and performance.
Dimensional Stability
Die castings exhibit excellent dimensional stability, which indicates that they retain their shape and size over time with minimal distortion. This stability is essential for parts that need precise dimensions throughout their service life, such as machine components and structural elements.
Affordable in the Long Run
Due to die development, the initial initial cost of setting up a die casting operation can be high. However, the process becomes highly cost-effective for large production runs. The rapid production speed, minimal material waste, and reduced post-processing needs lead to significant cost savings per unit produced.
Versatility
Die casting methods can be used to work with a variety of non-ferrous metals, which allows manufacturers to produce components using different materials based on the specific application requirements. Due to its versatility, it is applicable to a wide range of industries, such as automotive, electronics, construction, consumer goods, and more.
Repeatability Because of the use of permanent metal dies, the die casting process ensures consistent and repeatable part production. Every casting precisely reflects the design of the die, minimizing the risk of variations in quality or dimensions across production batches.
Types of Die Casting
There are different types of die casting, and each type offers unique advantages in terms of material compatibility, production efficiency, and part complexity. We have mentioned 7 different types of die casting processes here:
Cold Chamber Die Casting
In cold-chamber die casting, a separate melting furnace heats the metal. The molten metal is then injected into the die cavity using a shot sleeve under high pressure. Once solidified, the shot sleeve retracts, and a new batch of molten metal is drawn from the furnace for the next cycle.
Cold-chamber die casting offers greater control over the metal temperature and cleanliness, making it suitable for a wider range of metals with higher melting points, such as aluminum, magnesium, and copper alloys. It allows for the production of thicker-walled castings and provides higher overall casting quality.
Hot Chamber Die Casting
In hot-chamber die casting, a molten metal reservoir is constantly maintained at a high temperature within the machine. A plunger forces the molten metal from the reservoir into the die cavity under pressure.
Hot-chamber die casting is a simpler and faster process compared to cold-chamber. It is ideal for low-melting-point metals like zinc, tin, and lead alloys. In addition, it offers a high production rate due to the readily available molten metal supply.
Gravity or Low-Pressure Die Casting
Gravity die casting, also known as low-pressure die casting, is a permanent mold casting process that uses gravity to fill the mold cavity with molten metal. In this process, molten metal is poured into the mold from a holding furnace or crucible.
Unlike other die casting methods, low-pressure die casting does not use high pressure to force the metal into the mold. This process is ideal for parts that require a good surface finish and are not too complex in shape. It is also a good option for casting large or thick-walled parts.
Pressure Die Casting
Pressure die casting is a general term that encompasses both hot-chamber and cold-chamber die casting processes. In both processes, metal is forced under high pressure into a reusable mold cavity. This process ensures rapid filling of the mold and produces parts with excellent mechanical properties, minimal porosity, and high dimensional accuracy.
Vacuum Die Casting
Vacuum die casting is a variation of cold-chamber die casting where air is evacuated from the die cavity before injecting the molten metal. This minimizes air bubbles and porosity in the casting, resulting in higher-quality parts with improved mechanical properties. Vacuum die casting is often used for critical components in the aerospace, automotive, and medical industries.
Squeeze Die Casting
Squeeze die casting is a process where molten metal is poured into a mold cavity and then squeezed under high pressure. This process is similar to forging and can produce castings with a very fine grain structure and high strength. Squeeze die casting is typically used for casting large, complex shapes.
Semisolid Die Casting
Semisolid die casting, also called thixoforming, is a process where a metal is cast that is in a semisolid state, between a liquid and a solid. This process can produce castings with improved mechanical properties and reduced porosity.
Main Die Casting Materials
Here are the most commonly used die casting materials:
Aluminum
Aluminum is one of the most widely used die casting materials due to its exceptional combination of properties. Common aluminum die casting alloys include A380, ADC12, A360, B390, and A383. Aluminum alloys flow easily into molds, allowing for the creation of intricate shapes with minimal casting defects.
It provides a high strength-to-weight ratio, making it ideal for applications where weight reduction is crucial, such as in aerospace and automotive components. A natural oxide layer forms on aluminum, protecting it from corrosion and making it suitable for outdoor applications.
Zinc
Zinc is another popular die casting material, particularly for small to medium-sized parts. Zinc is a relatively inexpensive metal, making it cost-effective for high-volume production. The lower melting point of zinc reduces energy consumption during the die casting process.
A common zinc die casting alloy is Zamak-3, which offers a good balance of strength, ductility, and castability. Zinc castings maintain their precise shapes after cooling, minimizing the need for post-processing. This material has a good affinity for plating, making it possible to achieve a variety of decorative and functional finishes.
Tin
Tin has an exceptionally low melting point, requiring less energy for the casting process and minimizing wear on the dies. Molten tin flows very easily, allowing for the creation of intricate details and thin walls in castings.
Tin is highly resistant to corrosion, making it suitable for applications exposed to moisture or harsh environments. This material has a low coefficient of friction, making it a good choice for parts that require smooth sliding surfaces.
Magnesium
Magnesium is a lightweight alternative to aluminum. It is the lightest weight among common die casting materials, making it ideal for applications where weight reduction is paramount, such as in aerospace and electronics.
Despite being lightweight, magnesium alloys can offer good strength for their weight. Similar to zinc, magnesium castings maintain their shape well after cooling, minimizing post-processing needs. In addition, it has good thermal conductivity, making it suitable for heat sink applications.
Copper
Copper is an excellent conductor of electricity, making it ideal for electrical components like connectors and terminals. It also conducts heat exceptionally well, making it suitable for heat sinks and other thermal management applications. Copper alloys are known for providing good strength and ductility, so these parts can withstand some deformation without breaking. Furthermore, some copper alloys exhibit good corrosion resistance.
Other Alloys
In addition to the common materials mentioned above, several other alloys can be used for die casting in specialized applications. These include lead, pewter, silicon tombac, zinc-aluminum alloys, and many more.
Die Casting Applications
Let’s explore some of the common applications of die casting and how it is used in various sectors:
Automotive Industry
In the automotive industry, engine components like blocks, cylinder heads, pistons, and transmission housings heavily rely on die casting. Their intricate shapes, thin walls, and high strength-to-weight ratio are perfectly suited for die casting’s capabilities. Additionally, die-cast components are crucial for safety systems like airbags and braking components, where precise dimensions and reliable performance are vital.
Electrical Industry
Die casting manufacturing process is used to produce electrical housings, enclosures, and heat sinks from materials like aluminum due to their excellent thermal conductivity. This allows for efficient heat dissipation, preventing overheating and ensuring optimal performance of electrical components.
Construction
Door handles, hinges, and other building hardware are manufactured via die casting. Die-cast aluminum can be used for lightweight yet robust building components like window frames or cladding panels, reducing overall building weight.
Aerospace Industry
Aircraft components like landing gear parts, wing components, and engine housings are manufactured using die casting procedures. Additionally, die-cast parts can be precisely machined to meet the demanding tolerances required for aerospace applications.
Appliance Industry
Die casting plays a significant role in the wide variety of appliances. Internal components of washing machines, refrigerators, and dishwashers, as well as decorative elements on appliances, can all be die-cast.
Furniture Industry
Die casting can be found in various furniture components, both functional and decorative. Chair legs, table bases, and decorative hardware can all be die-cast. This process allows for intricate designs with good structural integrity and a smooth surface finish. Die-cast aluminum can be ideal for furniture due to its lightweight nature, while other materials like zinc can offer a more decorative aesthetic.
Consumer Goods
Die casting process is used to manufacture countless consumer goods people use daily. Camera parts, tool housings, and even zipper components can be die-cast. This process allows for mass production of intricate shapes with good dimensional accuracy and a smooth finish, often at a competitive cost.
Toys
Die casting is widely used in the toy industry to produce durable and detailed toy parts. Materials like zinc are favored for their ability to create intricate shapes and withstand rough handling. Die-cast toys, such as model cars and action figures, are known for their quality and longevity, providing safe and enjoyable products for children.
Military
Components for firearms, ammunition, and even some military vehicles are made by using die casting. In some cases, specific alloys can be chosen for their corrosion resistance or other properties crucial for military applications.
Die Casting Process Steps
Die casting is a precise and intricate process that involves several key steps to produce high-quality metal parts. Here is a detailed breakdown of the die casting process steps:
Mold Design
The die casting process begins with the design of the mold, also known as the die. This mold is typically made from high-grade steel and consists of two halves: the cover half (stationary) and the ejector half (movable).
The mold design must account for the part’s specifications, including dimensions, shape, and complexity, as well as the material being used. Preheating and lubrication extend the life of the mold and improve the quality of the cast parts by preventing the molten metal from sticking to the mold surfaces.
Metal Preparation
The next step involves preparing the metal that will be used for casting. The chosen metal, such as aluminum, zinc, or magnesium, is melted in a furnace until it reaches the appropriate temperature and viscosity.
The molten metal must be free of impurities and properly alloyed to ensure the desired properties in the final cast part. Proper metal preparation is crucial for achieving the desired strength, durability, and finish in the cast parts. It ensures the metal flows smoothly into the mold and solidifies correctly.
Injection Process
Once the metal is prepared, it is injected into the mold cavity. In hot chamber die casting, the metal is drawn directly from the furnace and injected into the mold. In cold chamber die casting, the molten metal is ladled into the injection chamber before being forced into the mold. High pressure is applied to ensure the metal fills the mold cavity completely and precisely.
Casting Process
After the metal is injected into the mold, it begins to cool and solidify. The mold remains closed during this cooling period to ensure the part retains its shape and dimensional accuracy. The cooling time varies depending on the material and the complexity of the part.
Controlled cooling allows the cast part to solidify with the correct mechanical properties and minimal internal stresses, ensuring the strength and quality of the final product.
Finishing Process
Once the metal has solidified, the mold halves are opened, and the cast part is ejected using ejector pins. The part then undergoes trimming to remove excess material, such as flash, runners, and sprues.
Additional finishing processes, such as sanding, grinding, or machining, may be applied to achieve the required surface finish and precision. Surface treatments like painting, plating, or powder coating can also be added for enhanced appearance and corrosion resistance.
Die Casting vs Injection Molding
Both die casting and injection molding are commonly used manufacturing processes that create complex shapes. However, they differ in their materials and applications:
- Materials: Die casting uses molten metals like aluminum, zinc, magnesium, or copper alloys. Injection molding can handle a wider range of materials, including plastics, polymers, and even some metals.
- Applications: Die casting excels at producing high-strength, thin-walled metal components with a smooth finish, ideal for automotive parts, electronics housings, and tools. Injection molding is more versatile, suitable for complex plastic parts like toys, consumer goods, and medical devices.
- Speed and Cost: Die casting offers faster production cycles compared to injection molding for metal components. However, the cost of die casting molds can be higher due to the use of high-strength steel.
Die Casting vs Forging
Die casting and forging are both metalworking processes that can create high-strength components. Here is a breakdown of their key differences:
- Process: Die casting uses a mold to shape molten metal under high pressure. Forging heats solid metal and applies pressure to deform it into the desired shape.
- Material Properties: Die casting offers good dimensional accuracy and smooth surface finish. Forging results in a denser metal structure with improved grain flow, leading to higher strength and fatigue resistance.
- Applications: Die casting is ideal for complex shapes with thin walls. Forging excels in applications requiring high strength and durability, such as crankshafts, gears, and aerospace components.
- Cost: Die casting molds can be more cost-effective for high-volume production. Forging requires specialized equipment and often involves higher material waste, leading to potentially higher costs for complex shapes.
Die Casting vs Stamping
Die casting and stamping are both metal forming processes, but with distinct characteristics: Here are a few differences between these processes:
- Material and Thickness: Die casting can handle a wider range of metal thicknesses, including thin walls. Stamping is limited to thinner sheets of metal.
- Complexity: Die casting can produce more intricate shapes with three-dimensional features. Stamping is better suited for two-dimensional shapes with bends and cutouts.
- Strength: Die casting offers good strength for its weight. Stamped parts can be strengthened through additional forming techniques, but may not achieve the same strength-to-weight ratio as die castings.
- Cost: Die casting molds can be expensive, but the process is efficient for high-volume production of complex shapes. Stamping dies can be more cost-effective, but the process is better suited for simpler, high-volume parts.
Finding A Reliable Die Casting Factory?
When it comes to finding a reliable die casting factory, it’s essential to consider a company with proven capabilities in mold design, mold making, and the production of high-quality die casting parts. Raidy Mold is your one-stop shop for all your die casting and custom mood needs.
We offer a comprehensive service, handling everything from initial mold design and manufacturing to high-volume die casting production. At Raidy Mold, we have a team of 40 seasoned engineers, each with over 8 years of experience, who use advanced CAD/CAM technology to design and create precision molds tailored to your specific needs.
We are ISO-certified and maintain rigorous quality control protocols throughout the entire process. Our three strategically located production bases in China ensure efficient operations and a high production capacity. Our in-house manufacturing facility has an annual production capacity of 500 sets of molds. We have die casting machines ranging from 160T to 12000T.
Raidy Mold offers distinct advantages in mold design, mold making, and aluminum die casting, positioning clients at the forefront of their industries. Our streamlined processes ensure fast turnaround times, accelerating product development and market entry. We prioritize high cost performance across all our precision molding services, ensuring competitive pricing.
Conclusion
Die casting is a highly efficient and versatile manufacturing process that has become integral to many industries, including automotive, aerospace, electronics, and consumer goods. Its ability to produce complex, high-precision metal parts at high volumes makes it an invaluable technique for modern manufacturing.
Need custom molds for die cast manufacturing of your products? Contact Raidy Mold and our team will schedule a session to discuss your design requirements, offer a quote, and provide custom molds at an affordable price.
