How to avoid forming welding lines during extrusion of industrial aluminum profiles

Industrial aluminum profiles in extrusion production often encounter such problems, extruded aluminum profiles above can obviously see a dark line, through the entire aluminum profile. We usually call it a weld line, but it should be called a junction line. The welded line is because the metal flowing through the mold will be separated when the aluminum rod is extruded and then joined, so only the shunt mold will have the phenomenon of the welded line. The extruded tube cannot completely avoid the welded line.

There are two kinds of welding line formation, one is the underpressure welding line, the other is the superheat welding line. The main cause of underpressure welding line is insufficient pressure and small extrusion. The main reason for the formation of superheated welding lines is the high temperature. Let's learn how to avoid or reduce the formation of industrial aluminum profile welding lines.

1, the mold design should be reasonable layout of the mold hole, increase the volume of the welding room, improve the structure of the shunt bridge and so on. Try to control the position of the welding line on the non-decorative surface.

2, before extrusion production of industrial aluminum profiles, the mold should be nitriding and polishing.

3, the extrusion temperature is properly reduced, the outlet temperature is controlled at 490~510℃, the outlet quenching strength is strengthened, the grain is suppressed, which is conducive to the improvement of the welding line fringe.

4, the increase of extrusion ratio is conducive to the welding of profiles, improve the quality of the weld, for this reason, the existing section is re-arranged, so that the extrusion ratio reaches 30~80.

5, the alloy composition of 6063 industrial aluminum profiles is adjusted, Mg is increased to 0.65%, Si is increased to 0.55%, and the aging process of 170℃ for 5 hours can improve the mechanical properties of profiles by 5~10%

6. When anodizing industrial aluminum profiles, the oxidation process is changed to pickling process, which is conducive to the improvement of welding line stripes.

7, the use of reverse extrusion, seamless pipe extrusion process.

Extrusion ratio calculation formula: extrusion cylinder area/section area.

Extrusion ratio: One of the important parameters to measure whether the profile can be extruded in this extruder. The extrusion ratio is too small, the deformation of the profile products is insufficient, the density and surface quality are not good, the extrusion ratio is too large, the mold deformation is too severe, the extrusion is difficult, the profile size is difficult to guarantee, and even the blocking die. The ideal value is 40-80