Introduction
Rotary extrusion is the process of using a specialized tool and dies to shape metal or metal alloys. This type of forming process is used to make metal parts with complex shapes, such as gears, shafts, rods and splines. Rotary extrusion is a fast and cost-effective way to produce metal components with tight tolerances.
History
The origin of rotary extrusion is not entirely clear. It is generally accepted that the process was first used in the early 1900s for producing parts for the automotive industry. Since then the process has been used for an ever-growing list of products including aircraft components, medical parts and more recently for making highly-specialized electronic parts.
Process Description
Rotary extrusion involves the use of a specialized tool, a circular die and a rotating ram. The rotating ram is used to push the metal or metal alloy through the die cavity in a rotary motion. As the metal passes through the die, it is shaped into the desired final part in much the same way as when using hot or cold extrusion.
Rotary extrusion can be done in either a closed or open die. Open die rotary extrusion is typically used when creating simple shapes such as rods, rods with splines or complex with external threads. Closed die rotary extrusion is used when more intricate shapes are required. In this process, the material is squeezed into the die by the ram, resulting in components with tight tolerances and smooth finishes.
Advantages
Rotary extrusion offers several advantages over traditional hot or cold extrusion processes. One of its primary advantages is that it allows for complex shapes to be formed quickly and accurately with minimal material waste. Additionally, the tooling costs for rotary extrusion are often much lower than those for other types of extrusion processes.
Finally, rotary extrusion can be used to produce parts with tighter tolerances than those achievable with other extrusion processes. Since the ram is constantly pushing the material through the die at the same rate, the final shape of the part is much more consistent.
Disadvantages
The primary disadvantage of rotary extrusion is that it can only be used to create symmetrical parts. Additionally, there are certain materials, such as soft metals and some alloys, that can be difficult or impossible to extrude using rotary methods.
Conclusion
Rotary extrusion is a process of producing complex shapes from metal or metal alloys. It offers several advantages over traditional hot or cold extrusion methods, including faster production speeds, lower tooling costs and tighter tolerances. While the process does have certain disadvantages, such as a limited flexibility for producing asymmetrical parts, these drawbacks are outweighed by the processs many advantages.
