What is cavity cold extrusion?

What is cavity cold extrusion?

The cold forging is one of the fastest-growing forging technology in the metal forming industry because of the numerous benefits its offers. With the cold forging technology, the workpiece or the material to be formed is extruded at room temperature. The workpiece is put into the mold cavity and applied compression force at a specific speed to produce plastic deformation out of the mold to obtains the desired shape. There are various types of cold forging, and cavity cold extrusion is one of the widely used technologies.

The cavity cold extrusion technology is a forging method where the hardened extrusion head acts as the die. The plastic deformed metal takes the shape of the extrusion head or the punch. That’s why it is also referred to as a chipless molding processing. The technology was widely used in the 1970s and ‘80s because of the many advantages over other cold extrusion methods.

The Types of Cavity Cold Extrusion

There are two main types of the cavity cold extrusion technologies you can select from depending on your needs. They include the closed and open cold forging molding. Here are crucial facts that you need to know about these types of cavity cold extrusions:

1. Open Cold Extrusion

Open cavity cold extrusion does not have the metal blanks constrained around like it is with the closed type of forging. The process includes deforming the piece of metal between multiple dies, but the material is not completely enclosed. The material is altered through a series of movements until the desired shape and size is obtained.

The open cavity cold forging method is suitable for simple shapes and shallow depths and how low precision is not an issue. Open cavity cold extrusion may result in defects such as the cracking of the blanks. So, reliable safety measures are recommended to ensure the quality of the products.

2. Closed Cold extrusion

This cavity cold extrusion molding includes compressing the metal blank or the billet under high compression force to fit the space between the extrusion head and the mold or enclosed die impression. In this case, the space to be filled is usually the shape that’s to be obtained. Because of the set-up, the cold extrusion system requires more mold extrusion pressure to form the required product shape and size.

This type of cavity cold extrusion also requires some safety effects to protect the workpiece from splashing and cracking. The punch or the extrusion head should also be protected from breaking.

Advantages and Disadvantages of Cavity Cold Extrusion

If you choose to go cavity cold extrusion technology, you will enjoy many benefits and some limitations. Here are just some of the major pros and cons of cavity cold forging:

Advantages:

1. The cold forging method offers one of the highest utilization of the materials
2. The process provides one of the best production efficiency.
3. Good for mass production as you can use same squeeze head multiple times
4. Higher quality surface roughness
5. Can be used for complex shapes
6. High strength and more durable forged products

Disadvantages:

1. You need a large machine to produce the large compression force
2. Requires a more specialized extrusion force to deliver the required products