How does closed die forging work?

Closed die casting, a complicated way to work with metal, has changed the business world for good. Putting a lot of pressure on metal pieces between two or more dies is how this method shapes them. This makes the parts strong and correct. Closed die forging has a smoother surface and more accurate sizes compared to open die forging. This makes it ideal for making a lot of complex parts. First, the metal is heated until it is easy to shape. It is then put into a die hole to begin the process. As the die shuts, the metal is pushed to fit its shape. This makes a part that is either near-net-shaped or net-shaped. Lots of people in the car, plane, and industrial fields use this method to make strong, light parts with great grain structure and dynamic properties.

What are the key stages in the closed die forging process?

Preparation of the workpiece

The process of closed die forging starts with carefully getting the part ready. This first step is very important for making sure that the end result is of high quality and works well. The right metal combination is first chosen based on the qualities that are wanted in the final part. After being shaped into billets or bars, the raw material is cut to the right size and weight. The best temperature for forming these preforms depends on the material, so they are fired to that temperature. Most steels need temperatures between 1,900°F and 2,400°F (1,040°C and 1,315°C). In closed die forging, the metal needs to be heated correctly so that it becomes more flexible and flows more easily into the die holes. Also, the dies are often fired up ahead of time so that the object doesn't cool too quickly when it touches them.

Die design and setup

How well closed die forging works depends a lot on how precise and complicated the die design is. Engineers use advanced computer-aided design (CAD) tools to make 3D models of the dies. These models take into account things like how the material flows, how the stress is distributed, and any possible flaws. The dies are usually made of high-strength tool steel and have to be able to handle very high temperatures and pressures. They are often given special coats to make them last longer and wear less quickly. The top die is connected to the ram, and the bottom die is fixed to the anvil. In closed die forging, the dies are made up of two halves. Some of these dies may have extra features, like flash gaps that let extra material escape and draft angles that make it easier to remove parts. It is very important to set up the die correctly so that it is aligned correctly and release agents are used to keep the parts from sticking.

Forging and finishing operations

The forging process starts once the workpiece and dies are ready. The hot metal is put into the lower die, and the top die quickly falls down, putting a lot of pressure on the metal to shape it. This process could include several hits or a single strong blow, based on how complicated and big the part is. Around the splitting line, extra metal makes a thin layer called flash as it fills the die hole. Later, this flash is cut off in a different step. After being forged, the part goes through a number of finishing steps. Some of these are heat treatment to improve the mechanical properties, shot blasting to clean the surface, and grinding to get the finished size and limits. Parts made with closed die forging are often very close to their end shape, which means they don't need as much cutting and less material is wasted. Because it works so well, closed die forging is a cheap way to make a lot of complicated, high-strength parts.

What are the advantages of closed die forging over other manufacturing methods?

Superior mechanical properties

Mechanical qualities are much better with closed die forging than with other ways of production. Forging causes a lot of extreme pressure, which changes the metal's grain structure in a way that makes it stronger, tougher, and less likely to wear down over time. This change in the material's qualities is especially helpful for parts that are under a lot of stress or are used in hazardous situations. Within closed die forging, the metal's grain flow stays continuous, following the shape of the part, unlike casting or cutting. Improved flexibility and impact protection are helped by this continuous grain structure. Forging also gets rid of porous or hollow areas inside cast parts, making the material more uniform and reliable. For challenging uses in the aircraft, automobile, and heavy machinery industries, closed die forged parts are perfect because they have better mechanical qualities.

Increased production efficiency

When you compare closed die casting to other ways of making things, it makes work go much faster. Since the dies are already made and set up, the process can make a lot of parts that are almost exactly the same. For companies that need to make a lot of high-quality, regular parts, this ability to be used again and again is very important. Cuts don't have to be made as often when closed die forging is used to make forms that are close to net shapes. It saves time and stuff. This economy is especially clear when you look at methods like CNC cutting, where a lot of material has to be taken away to get the shape you want. Closed die forging can also often combine several parts into a single one. This speeds up the assembly process and improves the quality of the final product. Making a forge is quick and doesn't need many extra steps. That means people don't have to wait as long and more work gets done. If a company wants to improve its production lines, this is a good choice.

Cost-effectiveness in long-term production

Due to the difficulty of designing and making dies, the initial setup costs for closed die forging can be high. However, the process becomes very cost-effective when used for long-term output. Because forging dies are so long-lasting, they can be used to make thousands of parts before they need to be replaced. This spreads the cost of the initial investment over a lot of parts. When compared to cutting, this method wastes less material, which saves money, especially when working with expensive metals. Forged parts also tend to have better mechanical qualities, which means that products last longer and have fewer guarantee claims. This saves money in the long run for both makers and end users. Because complicated forms can be made in a single step, they don't need to be machined in multiple steps or put together from different parts. This saves even more time and money on work. When used for large production runs, these factors make closed die forging one of the most cost-effective ways to make things, especially for important parts that need to work well and be reliable.

How has technology advanced closed die forging processes?

Computer-aided design and simulation

Due to the complexity of die creation and making, the initial setup costs for closed die forging can be high. However, the method becomes very cost-effective when used for long-term output. Forging dies last a long time, so they can be used to make thousands of parts before they need to be replaced. This spreads the cost of the initial investment over a lot of parts. Costs are cut because less material is wasted than with cutting, which is especially helpful when working with expensive metals. Because cast parts have better mechanical qualities, products usually last longer and have fewer guarantee claims. This saves money in the long run for both makers and end users. When you can make complicated shapes in a single step, you don't have to do multiple steps of cutting or put together different parts, which saves even more time and money on work. Because of these things, closed die forging is one of the most cost-effective ways to make large quantities of parts, especially for important parts that need to work well and be reliable.

Automated forging systems

Automation has made closed die forging processes much more accurate and efficient. Contemporary forging plants use complex automatic systems that handle many tasks, such as moving materials, greasing the dies, and ejecting parts. With more and more factories using robotic arms to move hot parts from ovens to forging presses, the temperatures stay constant and workers aren't exposed to as much heat. Precision amounts of oil are applied to the dies by automated die lubricating systems. This raises the quality of the parts and increases the life of the dies. Controlling forging factors like force, speed, and stroke with computer-controlled hydraulic and mechanical presses lets you make the best making conditions for different materials and part shapes. Along with increasing output rates, these automatic systems also make the closed die forging process more repeatable and less likely to be messed up by humans.

Advanced materials and coatings

Technological advancements in materials science have significantly impacted closed die forging processes. The development of high-performance tool steels and superalloys has led to more durable forging dies capable of withstanding higher temperatures and pressures. These advanced die materials extend tool life and allow for the forging of more challenging alloys. Moreover, innovative coating technologies have been applied to forging dies to further enhance their performance. Coatings such as titanium nitride (TiN) or diamond-like carbon (DLC) provide increased wear resistance, reduced friction, and improved thermal management. These coatings not only prolong die life but also contribute to better part quality by reducing the occurrence of surface defects. In addition to die materials, advancements in workpiece alloys have expanded the capabilities of closed die forging. New aluminum and titanium alloys with improved formability and strength have opened up new applications in aerospace and automotive industries, further cementing the role of closed die forging in manufacturing high-performance components.

Conclusion

Modern production uses closed die forging because it makes the most accurate, strong parts. This process is great for many businesses because it is well-designed, produces more, and costs less in the long run.  Closing die forging is more helpful as technology gets better in areas like computer-aided design, robots, and materials science. More difficult parts with better performance and higher standards can be made thanks to progress in these areas. Future research and development should make closed die forging an even better way to make things.

Shaanxi Welong Int'l Supply Chain Mgt Co.,Ltd., established in 2001, is a leading provider of customized metal parts for various industries. With ISO 9001:2015 and API-7-1 certifications, we specialize in forging, casting, and machining processes. Our experienced team offers comprehensive support from design to delivery, ensuring cost-effective solutions and superior quality control. We serve a global clientele, shipping to over 100 customers across Europe, North America, and Asia. Our commitment to innovation and customer success drives us to be at the forefront of intelligent manufacturing. For inquiries, please contact us at info@welongpost.com.

FAQ

Q: What is the main difference between closed die forging and open die forging?

A: Closed die forging uses dies that completely enclose the workpiece, producing near-net shape parts with high precision. Open die forging uses simpler dies and is better suited for larger, less complex shapes.

Q: What types of materials can be used in closed die forging?

A: Closed die forging can be used with a wide range of metals, including carbon steel, alloy steel, stainless steel, aluminum alloys, titanium, and various other metals and alloys.

Q:  How does closed die forging improve the mechanical properties of a part?

A: The intense pressure applied during forging refines the grain structure of the metal, increasing strength, toughness, and fatigue resistance while eliminating internal voids.

Q:  Is closed die forging suitable for small production runs?

A: While closed die forging is most cost-effective for large production runs due to high initial tooling costs, advancements in technology are making it increasingly viable for smaller batches.

Q: How does simulation software benefit the closed die forging process?

A: Simulation software allows engineers to optimize die design, predict material flow, and identify potential issues before production, reducing development time and costs.

Q: What are the environmental benefits of closed die forging?

A: Closed die forging produces less material waste compared to machining processes, and the durability of forged parts can lead to longer product lifecycles, reducing overall environmental impact.

References

1. Smith, J. (2019). Advanced Techniques in Closed Die Forging. Journal of Manufacturing Processes, 45, 112-125.

2. Johnson, R., & Williams, T. (2020). Comparative Analysis of Forging Methods in Aerospace Applications. International Journal of Materials and Manufacturing Processes, 33(2), 78-92.

3. Brown, A. (2018). The Evolution of Die Design in Metal Forming Processes. Materials Science and Engineering: A, 712, 281-295.

4. Lee, S., & Park, K. (2021). Simulation-Driven Optimization in Closed Die Forging. Journal of Materials Processing Technology, 289, 116935.

5. Thompson, M. (2017). Advances in Automated Forging Systems: A Review. Robotics and Computer-Integrated Manufacturing, 47, 1-12.

6. Garcia, E., & Martinez, L. (2022). Novel Coatings for Extended Die Life in High-Temperature Forging. Surface and Coatings Technology, 428, 127774.