The Hot Extrusion Process - How It Is Performed And What Are Its Sub Activities


The extrusion process can be grouped into hot extrusion, warm extrusion and cold extrusion. These three types vary in the temperatures to which metals are caused to undergo and many other factors. To make things clearer, let me start by defining the term extrusion.

What is extrusion?

Extrusion is a procedure used in metals to transform them into different shapes. The end products are then used in several industries such as automobile and aircraft firms. The process of transforming the metal is carried out by pushing it into a number of dies until the required shape is achieved. Machineries and devices that come in various sizes and functionalities are used to do things easier and more effectively.

What is hot extrusion?

Hot extrusion can also be called hot working. It is the procedure where a piece of metal is bent or melted by applying heat greater than its recrystallization temperature.

Hot extrusion may include many sub-processes and they include drawing, forging, rolling and rotary puncturing.

In drawing, tensile forces are used to lengthen a metal. You can do any of the given drawing forms: sheet, bar, tube or wire drawing.

In forging, localized compressive pushes do the job. There are a minimum of seven most standard types and they are: drop, roll, press, upset, automatic hot, net-shape, near-net-shape, and induction forging.

In the process of rolling, a pair or series of rolls are used where a metal stock can easily penetrate. Flat, ring, and foil rolling are just three of the usual rolling processes used now.

In rotary piercing, seamless tubing that has thick walls is formed. The process has two kinds: the Stiefel process and the Mannesmann process.

What are the positive aspects of hot extrusion over the other extrusion techniques?

Some of the advantages of doing hot extrusion are listed below:

1. The material created via hot extrusion is more ductile compared to the material produced via other procedures.

2. It is much easier to perform hot extrusion because it requires less force and energy.

3. During the deformation process, the pores seen in the metal are reduced in size or are totally closed up.

4. Because this process is done at extremely high temperatures, chemical inhomogeneities are curtailed or are totally eliminated.

But, just like other factors in this world, hot extrusion also has disadvantages. Here are some:

1. There might be harmful reactions that may result from the exposure of the metal to the atmosphere of the surroundings.

2. You may need to invest in costly machineries like an induction heater or a diesel furnace.