The Hot Extrusion Process - How It Is Performed And What Are Its Sub-Processes
The extrusion process can be grouped into hot extrusion, warm extrusion and cold extrusion. These three forms differ in the temperatures to which metals are caused to undergo and many other aspects. To make things clearer, let me start by defining the word extrusion.
What is extrusion?
Extrusion is a process used in metals to convert them into different forms. The end products are then utilized in several businesses such as automobile and aircraft companies. The process of transforming the metal is done by pushing it into a series of dies until the required shape is achieved. Machineries and equipment that come in different sizes and functionalities are used in order to do things quicker and more efficiently.
Hot extrusion can also be known as hot working. It is the procedure where a piece of metal is bent or melted by using heat greater than its recrystallization temperature.
Hot extrusion may require various sub-processes and they are drawing, forging, rolling and rotary perforating.
In drawing, tensile forces are used to stretch a metal. You may well do any of the given drawing forms: sheet, bar, tube or wire drawing.
In forging, localized compressive forces do the job. There are at least seven most standard types and they include: drop, roll, press, upset, automatic hot, net-shape, near-net-shape, and induction forging.
In the process of rolling, a pair or line of rolls are used where a metal stock can pass through. Flat, ring, and foil rolling are simply three of the usual rolling processes used today.
In rotary piercing, smooth tubing that has thick walls is created. This technique has two kinds: the Stiefel process and the Mannesmann process.
What are the positive aspects of hot extrusion over the other extrusion processes?
Some of the advantages of doing hot extrusion are the following:
1. The material produced via hot extrusion is more ductile compared to the material produced via other methods.
2. It is much easier to perform hot extrusion as 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 performed at quite high temperatures, chemical inhomogeneities are curtailed or are totally eradicated.
But, just like other elements in this world, hot extrusion also has weaknesses. Here are some:
1. There might be harmful reactions that may cause from the exposure of the metal to the atmosphere of the surroundings.
2. You may need to invest in costly equipments like an induction heater or a diesel furnace.
