Difference between forward extrusion and reverse extrusion of aluminum profile

In this paper, we will explore the forward extrusion and reverse extrusion of aluminum profile extrusion methods, and discuss the differences between the two extrusion methods.

Forward extrusion

The extrusion method classified according to the direction is mainly based on whether the running direction of the extrusion shaft is opposite or opposite to the moving direction of aluminum products. If the direction is opposite, it is the forward extrusion of aluminum profiles.

Forward extrusion is a quite fundamental method. Due to its complex operation, strong flexibility and lubrication of extrusion surface, it is more mature and widely used in the forming and processing of aluminum and aluminum alloy materials.

What should be paid attention to in forward extrusion is that during extrusion, there will be sliding friction between the aluminum profile blank and the extrusion barrel, which is not conducive to the extrusion of aluminum products in most cases. Because this will make the moving speed of aluminum products not constant, resulting in uneven stress in all parts of aluminum products, The quality of the extruded final aluminum profile is uneven; Friction alone consumes more than 40% - 30% of the energy; Due to the heat generated by fierce friction, as the relative speed between the extrusion of aluminum products and the die wall will improve, the die loss will increase, and the service life will increase accordingly.

Reverse extrusion

If the extrusion axis moves in the opposite direction, it is called the extrusion axis.

Aluminum profile back extrusion method is mainly used for cold extrusion forming of various aluminum alloy die casting; And the hot extrusion molding of pipes and profiles such as aluminum alloy round pipes, among which high-strength aluminum alloy is absolutely more used. There is no need for absolute sliding between the metal blank and the extrusion barrel wall during reverse extrusion, and the required extrusion pressure and extrusion energy consumption are absolutely low. Therefore, on the equipment with the opposite degree, reverse extrusion can deform the aluminum profile more greatly, or extrude the alloy with higher deformation resistance.

It is different from the forward extrusion of aluminum profile processing, but the operation of reverse extrusion technology is more complex, and the gap time corrects the extrusion length. Therefore, the appearance of aluminum products during reverse extrusion is relatively difficult to control its quality. Special extrusion tools and equipment are required, and the use of reverse extrusion is limited to a certain extent. In recent years, with the successful development of public reverse extruder and the development of tool and die technology, the technology of aluminum alloy reverse extrusion will be used more and more.