Aluminum profile extrusion bubble foaming problem

Aluminum profile extrusion bubble foaming problem reason analysis

Aluminum profile is a kind of metal material that we can often see in our daily life. It is often used in aerospace, transportation, transportation, construction, navigation and other fields. Its importance is self-evident. But aluminum profile in the process of processing often appear a variety of problems, such as the surface of the aluminum bubble is a common problem, the surface of the bubble will affect the appearance of the aluminum profile quality, for some of the surface smoothness and beauty requirements of the customer will be a big problem. So how to prevent the formation of bubbles on the surface of aluminum profiles?

The first step is to find out why the air is getting in. Reasons for bubbles on the surface of aluminum profile :

1. After long time work of the extrusion cylinder, the size of the cylinder is not balanced, resulting in poor gas removal in the cylinder, and the deformation of the metal surface flow out of the elastic zone at the front end, resulting in bubbles in the aluminum profile.

2, Billet or dies with water and oil, water and oil volatilized into gas in high temperature and high pressure metal flow is rolled into the surface of aluminum forming gas.

3, The surface of the aluminum billet has grooves or pores in the organization of the aluminum billet in the thick pier into the gas, the gas into the metal surface when the aluminum extrusion.

4, Hot shear furnace air residue. Aluminum extrusion is generally with hot shear furnace will be heated into short billets and then sent into the press extrusion, because the aluminum billet heated to the critical point so the shear surface deformation will be more severe, especially the edge part is particularly easy to retain air.
5, The air residual in the extrusion cylinder because the diameter of the aluminum billet is smaller than the diameter of the extrusion cylinder, the extrusion needs to apply pressure on the aluminum bar, the aluminum bar will be thick until the whole extrusion cylinder is filled, at this time if the air is not all out of the air will be squeezed into the aluminum bar, extrusion aluminum will form bubbles.

6, The formation of air residue at the junction of two aluminum bars if the shear surface of the aluminum bar is not very smooth, it is easy to carry air in the junction of two aluminum billets, resulting in bubbles in some industrial aluminum profiles.
7, improper oil caused air residues.

8, Butt end is too thin. In order to save materials, extrusion of aluminum billet last leave allowance is too little, pull when the shear metal die tap hole, shunt empty inside the gap.

9, Die design is not reasonable. Chamber of solid die is too big, can make the air flow easily.