Compared with other methods, the production of
aluminum profiles by hot extrusion has the following advantages:
1. It can obtain aluminum profiles with high rib with larger area and higher precision than hot die forging, pass rolling and other methods;
2. It is in a state of three-way compressive stress during extrusion, and can use aluminum alloy materials with poor plasticity to produce large aluminum profiles;
3. It can carry out multi-variety, multi-specification and small-batch production, easy to change molds, reduce labor intensity and save auxiliary time;
4. Simple operation, high productivity, low mold cost, high material utilization rate, so the total cost is low;
5. Porous hollow aluminum profiles and aluminum profiles with large heads can be extruded from solid billets, which cannot be achieved by other methods.
The production of aluminum profiles by hot extrusion has the following disadvantages:
(1) A large-tonnage extruder is required, and the design and manufacture of such equipment is difficult and the cost is high.
(2) The shape and rib spacing changes (such as radial) or the aluminum profiles with transverse ribs cannot be extruded;
(3) Large-scale high-specific pressure circular extrusion cylinders or flat extrusion cylinders are required, and large-scale special complex molds are required, and these molds have a short life when extruded under high temperature, high pressure, and high friction conditions, or are easily deformed, affecting the precision of aluminum profiles is relatively high;
(4) It is more difficult to extrude flat-width aluminum profiles with a width greater than 1mm and a web wall thickness less than 3mm (or a width-thickness ratio greater than 150), especially the aluminum profiles extruded from hard aluminum alloys;
(5) In order to obtain flat and wide aluminum profiles with a width greater than 1mm, it is necessary to use a hollow billet to extrude a ribbed round tube, and the splitting and flattening process of the round tube is very complicated, and the quality is difficult to guarantee.
Nevertheless, with the advancement of science and technology, the above problems are being gradually solved. Compared with mechanical cutting, chemical cutting, pass rolling, hot die forging, pressure casting and other methods, hot extrusion is still the best method for producing large and thin-walled complex aluminum profiles.