Advantages & Disadvantages of Aluminum Extrusion

“Extrusion is a forming process as opposed to a material removal process. Heated material, such as aluminum, is forced through an opening to form a shaped profile. In aluminum extrusion, raw aluminum is first heated and then shaped into the desired part by pushing it through a die using a plunger.”

Aluminum extrusion can be understood with one example that It is similar to squeezing toothpaste; the force applied can be likened to the force applied when you squeeze a tube of toothpaste with your finger, and when you squeeze, the toothpaste appears in the shape of a tube opening. Of course, the actual situation is much more complicated than this, when you need to use the aluminum extrusion process it is best to communicate with an experienced engineer, our engineers have decades of experience in the aluminum extrusion industry and can answer your questions quickly, and we offer a free quote service, you can check our Aluminum Extrusion Service page. To get back to the point, this article will explain to you some basic facts about aluminum extrusion: the extrusion process; the shapes that can be extruded; the advantages and disadvantages, and some tips for using aluminum extrusion.

What are the Types of Aluminum Extrusion Molding? 

There are two types of extrusion processes, direct and indirect. With direct extrusion, the die head remains stationary and the moving punch forces the metal through it. In contrast, in indirect extrusion the billet remains stationary while the die at the end of the plunger moves against the billet, creating the pressure needed for the metal to flow through the die.

 Direct Extrusion

Direct extrusion, also known as forward extrusion, is the most common extrusion process. It works by placing the billet into a thick-walled container. The billet is pushed through the die by a plunger or screw. The main disadvantage of this process is that the force required to extrude the billet is greater than that required by the indirect extrusion process because of the force introduced by friction due to the need for the billet to pass through the entire length of the vessel. Therefore, the maximum force required is at the beginning of the process and decreases as the billet is used up.

Indirect Extrusion

In indirect extrusion (also known as reverse extrusion), the billet remains stationary while the die at the end of the plunger moves toward the billet, thus eliminating frictional forces. This results in the following advantages.

• 25% to 30% less friction, which allows for larger blanks to be extruded, higher speeds, and increased ability to extrude smaller cross-sections
• Less likelihood of extruded part breakage due to the absence of heat generated by friction
• Longer vessel liner life due to less wear
• More uniform use of billets, so extrusion defects and coarse-grained peripheral areas are less likely to occur

The disadvantages are

• Impurities and defects on the surface of the billet can affect the surface of the extrusion. To solve this problem, the billets can be wire brushed, machined, or chemically cleaned before use
• It is not as versatile as direct extrusion because the cross-sectional area is limited by the maximum size of the stem