Extrusion forging is an ideal technology to save material and be able to obtain hollow forms not feasible by other forging processes. JG Automotive is a supplier and manufacturer of direct extrusion or reverse extrusion or also indirect, as adapted to the part.
Extrusion is a process used to create objects with defined and fixed cross-section. The material is pushed or withdrawn through a die of a desired cross-section.
The two main advantages of this process over manufactured processes are the ability to create very complex cross sections with materials that are brittle, because the material only encounters compression and shear forces. In addition the end pieces are formed with excellent surface finish. It can be direct or indirect extrusion.
Direct extrusion, also known as front extrusion, is the most common extrusion process. This works by placing the bar in a strongly reinforced container. The bar is pushed through the die by the spindle. There is a reusable dummy block between the spindle and the bar to keep them separate.
The major disadvantage of this process is the force required in the extrusion of the bar by the frictional force due to the need for the bar to travel through the container completely. That is why the greatest force required is at the beginning of the process and decreases as the bar is depleted.
In indirect extrusion, also known as delayed extrusion, the bar and the container move together while the die is stationary. The die is held in place by a support which should be as long as the container. The maximum length of the extrusion is given by the strength of the column of the carrier. As the bar moves with the container, the friction is eliminated.
Advantages: A 25 to 30% reduction in frictional force, allows the extrusion of long bars, there is a less tendency for the extrusion to crack or break because there is no heat formed by the friction, the coating of the container will last longer due to Less use.