Alloy aluminum tube profiles are mainly produced by extrusion method, while wire rod is produced by tensile method. The most commonly used extrusion processes are forward extrusion and reverse extrusion. Forward extrusion is the most widely used in design and production, reverse extrusion can reduce the extrusion force by 30%~40%, the extrusion speed is relatively high, and the structure and performance of the product are uniform, but the equipment structure, tool assembly, and production operation are relatively complex, which limits its scope of use.
Extruded alloy aluminium pipes and profiles are subjected to the ingot heating-extrusion-finishing process, and for heat-treatable aluminium alloys, quenching is also carried out. The building profiles are extruded and then quenched and finished in line with air cooling. The thin-walled pipe adopts the production process of first extruding to produce the tube blank and then cold working, and the secondary extrusion method is often used to produce the production process of small specification of the extruded tube blank and then cold processing for the cemented alloy small-diameter pipe.
There are two methods of cold working of tube blanks: cold rolling and drawing. The cold rolling method has a large amount of deformation per pass (the elongation coefficient can reach up to 8-10), which can be rolled from the blank to close to the thickness of the finished product at one time, but the equipment price is high and the tool manufacturing is also more complicated. The equipment and tools of the stretching method are relatively simple, the specifications are easy to change during production, the size of the product is accurate, the surface is smooth, but the deformation of each pass is small (the elongation coefficient is within 2), the production process is many, and the yield is low. For hard alloy and high-magnesium aluminum alloy pipes, the production process of cold rolling the extruded tube blank and then stretching out the finished product is generally adopted. Pure aluminum and alloy aluminum tubes are mostly extruded and stretched. Pure aluminum and alloy aluminum pipes below φ30mm can be made by coil stretching process with high production efficiency and yield, and shipped in a coil. In the process of cold rolling and drawing, several intermediate annealing is generally carried out. After processing to the size of the finished product, the finished product must be heat treated and finished according to the delivery requirements.
The aluminum alloy wire adopts the production process of hot extrusion-annealing-drawing-heat treatment-finishing. The aluminum wire used for conductors is mainly produced in the wire factory, and the production process of producing aluminum wire rod and then stretching is generally adopted by continuous casting and rolling.
The production of alloy aluminum pipe is based on pure aluminum and aluminum alloy strip with good weldability as blanks, first pretreatment, cutting the strip blank into the required width of the welded pipe, and then through forming-welding-finishing and other processes, the thin-walled welded pipe is produced, or it is continued to be processed as a stretched pipe blank. This process has a lower production cost compared to the extrusion-rolling-drawing or extrusion-drawing method, but the compressive strength of the pipe is not as good as that of seamless pipe.