Impact Extrusion is a metal processing technology that places a metal blank in a die. Under high-speed impact or pressure, the metal blank undergoes plastic deformation inside the die, ultimately forming the desired product shape.

What is extrusion

Extrusion is a metal-forming process typically used to create linear products with a fixed cross-sectional profile. It is accomplished by forcing metal (or other material) through a die with the desired solid or hollow cross-section.

There are several benefits to extrusion. First, many shapes can be made through extrusion, often with very complex designs. It can also be used on otherwise brittle metals since the stresses involved are only compression and shear. The finished parts also tend to have an excellent surface finish.

While impact extrusion is one method, there are a variety of extrusion options available to manufacturers. These include the standard hot and cold extrusion processes as well as friction extrusion. Another similar process is drawing, the only difference being that the metal is pulled through a die rather than pushed through it.

What is the impact extrusion process?

What distinguishes impact extrusion from other processes is that the workpiece is forced through an aperture at a much higher speed than other methods. The first step in the impact extrusion process is to take a block of metal and place it into a press. The press may be mechanical or hydraulic and can cycle up to 60 times per minute.

The punch then pushes the block into the die at great speed, forcing the block’s metal to reshape around the punch while conforming to the outside of the die. This action controls the final shape of the workpiece, both inside and outside. Lubricants can be added as needed to facilitate this process.

One strike is enough to form the block into its new shape, and then a reverse strike is used to eject the metal from the die. There are three types of impact extrusion operations. A forward strike is where the block is pushed into the die. A reverse strike forces the block around the punch. A combined strike is where the block is pushed into the die and around the punch simultaneously.

It is important to note that the thickness of the workpiece is directly related to the gap between the punch and the die. This means that the thinner the workpiece, the tighter the tolerances. Also, as mentioned earlier, the surface finish of the finished piece will be better than the starting piece. The aluminum’s grain structure is refined during this work-hardening process, strengthening the metal in its new form.

Metal extrusion can be subdivided into the following categories based on the direction of the extrusion flow and the medium through which the force is applied.