The extrudable size range of aluminum alloy tubes varies with different extrusion methods. The maximum outer diameter, minimum inner diameter and minimum wall thickness of aluminum alloy tubes extruded by conventional piercing needle extrusion method are 600 ~ 650mm, 5~ 15mm and 2 ~ 5mm, respectively. Due to the strength and rigidity of piercing needle, the minimum inner diameter and wall thickness of extruded aluminum alloy pipe are greatly limited. Among them, the minimum inner diameter and minimum wall thickness of the soft aluminum alloy aluminum alloy pipe can be taken as the lower limit of the above range, while the hard aluminum alloy can be taken as the upper limit. In addition, when the outer diameter of the aluminum alloy pipe is large, the minimum wall thickness of the aluminum alloy pipe is usually not less than 5% of the outer diameter of the aluminum alloy pipe. Aluminum alloy tubes with an outer diameter of over 500mm are usually formed by reverse extrusion.
Compared with the piercing needle extrusion method, the aluminum alloy tube with thin and uniform wall thickness and small eccentricity can be formed by using Confrom split die extrusion. However, considering the quality of welding seam, the maximum outer diameter of aluminum alloy tube that can be formed on the same extrusion equipment or extruded with the same extrusion barrel is smaller than that of piercing needle extrusion.
With Conform continuous extrusion technology, aluminum alloy tubes with an outer diameter of 10 mm and a wall thickness of less than 0.5mm can be produced.
With the continuous improvement of cold-rolled tube and drawing tube technology, the minimum wall thickness of aluminum alloy tube can reach 0.1~0.2mm or less.
At present, the maximum diameter of extruded tube produced on 350MN large vertical extruder (reverse extrusion) can reach I500mm; It can reach l000mm on 196MN horizontal extruder. The minimum outer diameter of the extruded tube can reach 5mm. The maximum diameter of the cold-rolled tube can reach more than 120mm, and the minimum diameter is less than 15mm. The diameter of cold-drawn thin-walled tubes is 3 ~ 500mm, and large thin-walled tubes with a diameter of 3000mm can be rolled by spinning.
With continuous automatic production line or coil drawing method, aluminum alloy tubes with a length of 1000mm can be produced.