Cold extrusion
Cold extrusion is a process of shaping material which employs formed dies through which a metal bar is passed. This is done without making use of heat, as is done in some other forging processes, and is therefore called cold forging. Cold extrusion can be used to create components with a wide range of properties not achievable with similar extrusion processes, especially for components with complex shapes or intricate geometries.
The process of cold extrusion begins by carefully selecting the correct type of metal for the product being created. Once the metal is chosen, it must pass through a series of designed dies, or punches. As the metal passes through these dies, the shape of the dies is imprinted onto the metal, forming the desired shape of the product being created. As the metal travels through the dies, the molecules inside the nodes of the metal are compressed and reformed to create the product’s shape.
Before any metal is passed through the dies, it must be prepared and treated to smooth out any flaws or imperfections. Otherwise, the product may come out of the cold extrusion process with numerous issues such as cracks, holes, or weak points in the product. Typically, the metal is rolled, heated and then had to form the required shape before being passed through the dies in order to create the desired shape.
Cold extrusion has numerous advantages over other types of forging processes. First, cold forming dies are typically less expensive than those for hot forging, due to the fact that the dies do not need to be designed to withstand the higher temperatures of hot forging. Second, cold extrusion often allows for the creation of products with precise geometries, since the dies are designed with precise angles and shapes. Finally, the metals used in the cold extrusion process can be heat-treated and re-annealed to increase the strength, hardness, and wear-resistance of the finished product.
There are numerous industries that benefit from the use of cold extrusion. Automotive, aerospace, oil and gas, rail, and agricultural industries all make use of cold extrusion to create specific components for their respective products. In gasoline engines, cold extrusion has been used to create pistons with precise shapes and intricate geometries. In automotive applications, cold extrusion is often used to create components like engine blocks, brakes, and axles. Aerospace, propulsion, and rail industries also benefit from the use of cold extrusion, as it allows for the creation of components with detailed geometries and precise shapes.
Though cold extrusion has numerous advantages over hot working processes, the process does have some drawbacks. Cold extrusion can be difficult and time-consuming, as the process requires precise planning and careful execution. Additionally, mistakes made during the formation process can be difficult to fix, requiring reworking of the product or replacement of specific components.
Overall, cold extrusion is a useful process, offering cost and time savings, along with the ability to create components with precise shapes and geometries. The process can be used to create components in a wide range of industries, from automotive to aerospace and even agricultural. Careful planning and execution are essential for a successful cold extrusion process, and mistakes made during the process can be costly and difficult to fix.
