Aluminum pipes are a hollow product having a square, round, rectangular or shaped cut. Due to their merits, they are in demand in the metal rolling market. Consider how to bend an aluminum pipe.
Production methods and technical characteristics of aluminum pipes
Renting is done in several ways:
- extrusion of aluminum parts with a round section;
- cold deformation (drawing, flashing and calibration);
- according to the principle of stainless steel rolling: strip or sheet welding.
Modern technologies allow to produce cost-effective products of high quality. The main feature of aluminum is its low weight. Its density (ρ = 2.7 t/m³) is more than 3 times less than ρ of carbon steel (7.85 t/m³). There are other advantages of non-ferrous metal:
- wear resistance;
- high resistance to moisture;
- frost resistance;
- excellent weldability;
- high electrical and thermal conductivity;
- environmental friendliness;
- resistance to rust.
One of the disadvantages of aluminum parts is low strength. But this property is compensated by the ease of deformation of the metal without changing the basic characteristics. Excellent ductility allows you to design and build complex engineering solutions. For the production of profiles, aluminum alloys with copper, magnesium, zinc, and other metals are more often used. They are more durable, well tolerate variable force effects.
Aluminum pipes are not difficult to transport, loading is not difficult. Profile pipes are inexpensive, easy to install.
Aluminum is virtually maintenance free. Due to its advantages, pipes made of this metal are widely used in manufacturing, construction and other industries:
- Manufacture of furniture, advertising, commercial equipment.
- Railings, fences, gazebos and other structures in suburban areas and areas adjacent to private houses.
- Agriculture. Due to its high water resistance and wear resistance, aluminum rolled metal is actively used in the installation of drainage systems. Agricultural crops also do not have a negative impact on this metal.
- A bent pipe is used in the assembly of structures with hinged facades.
- The drilling rig elements are constructed from aluminum parts. Due to the high throughput, the risk of congestion in the system is reduced to zero. Aluminum rolled metal can withstand the aggressive effects of hydrocarbons for a long time.
- Laying of sewer systems. Waste water and other active substances do not act on the metal in question.
- Aluminum parts are often used in ventilation systems, as they are easy to give the desired configuration, it is easy to cut with a grinder.
In addition to these areas, aluminum pipes in products perform a decorative function: lattices, display frames, wall cladding.
Important! The aesthetically pleasing appearance of the metal is perfect for the manufacture of interior items.
Difficulties of bending
For the use of aluminum parts in the manufacture of furniture, decorative and other purposes, it is important to bend them correctly. Despite its ductility, metal is unpredictable when deformed, especially in hollow products. The complexity of bending pipes made of aluminum and alloys is due to many factors:
- Processing of products in order to give them anti-corrosion resistance increases strength, but reduces ductility.
- Rolled tubular products made by hot extrusion and extrusion are sensitive to bending stresses.
- Duralumin and alloys with manganese have low ductility.
Taking this into account, the preparation of the product for subsequent bending consists in determining the grade of the alloy and the conditions for its preliminary heat treatment. If there is no product certificate, verification is carried out in the following ways:
- studying the markings on the end sections of pipes, checking with the reference book;
- tapping with a hammer on the part — a sonorous sound indicates an increased hardness of the material;
- soft alloys stick to the file.
If you rub the duralumin products with your hand, there will be no traces left on it.
There are the following bending technologies:
- Process the original workpiece on a pipe bending machine with an elastic mandrel, for example, rubber.
- It is possible to bend a tube with a diameter of up to 20 mm in one step using a cold bending device.
- If it is necessary to process a more complex spatial contour or a larger diameter pipe, the workpieces are heated. Rubber or composite drones are used.
- Reducing the zone with tensile stresses. For this, a moving roller is used.
The bending of parts in one plane can look like:
Tubes with two bends at 135º — a duck, if the bend is 3 (the central angle is straight, the extreme ones are 135º) — a bracket, at 45º — 135º — a branch, and in the form of a semicircle — a kalach.
Whichever option for processing the workpiece is used, the main thing is to avoid defects in the bending process. This is achieved by the right choice of method and tool.
Special mechanisms are used to bend pipes. They are called pipe benders and are distinguished by the principle of operation. The tool can be used both in production and at home. Profile and round pipes are processed. There are such pipe benders:
- Spring. The element to be bent is placed in a spring before the process starts. Then apply a cold or thermal processing method to the workpiece, at the end of which remove the spring.
- Lever or Volnov mechanism. The workpiece is placed in a special form that corresponds to a certain diameter. The technology does not require pipe heating. Bending occurs under the action of lever force.
- Crossbow. The workpiece is strengthened in a structure equipped with a bending segment. The device pushes the pipe.
Using the tool allows you to both bend and straighten an aluminum part of different configurations and diameters. In this case, the risk of damage is minimal, almost equal to zero. In specialized equipment, the following methods can be used:
- push through. The aluminum part is pushed between rollers, one of which deflects it. The result is an arcuate bend with a small radius.
- rental. A pipe with a diameter of 1 to 10 cm is rolled between bending rollers. Their size must exactly match the diameter of the workpiece. The procedure is carried out with a three-roll tool in several passes. It performs bends in the form of an arc, ring, spiral. With the help of such a mechanism, it is possible to bend both a profile and a round pipe.
- Pressure treatment. The process takes place using stamps that bend parts from the outside. Another option is hydroforming. In this case, to process the pipe, water or oil is poured into it under pressure.
- Running in. For this method, a rolling element of a pipe bender is used, which bends the part under pressure. The process is not accompanied by heating. In zones without pressure, the product bends in the opposite direction.
If there is no special tool at hand, aluminum parts can be bent without a pipe bender.
Processing products at home without tools
How to bend a pipe with your own hands, when there is no machine and tools, and it is not practical to buy? You can also process a part at home or in a garage without a pipe bender using the following methods:
- To reduce the brittleness of aluminum and the load force, heat the bend area with a conventional gas burner. Plain paper will help to understand that the part is ready for deformation. It must be placed above the heated zone and wait until it smokes — this is a signal to start bending. This method is not suitable for anodized aluminum.
- To process the workpiece, use a template with the required bending radius. It is easy to carve from wood impregnated with creosote. Place the original element on the template and secure it carefully. Take a rubber mallet and with light blows give the desired shape of the fold.
- An aluminum tube with a small diameter (15 — 20 mm) can be processed without a tool by putting a steel spring on the outer surface. Pour sand into the inside of the workpiece and insert a metal rod. Grasping the ends of the rod, crimp according to the template.
- Fill the tube with sand, fix the ends of the workpiece on two reference planes. With a rubber mallet, form a bend in the area that is on weight. The method is well suited for workpieces with a rectangular cross section.
Thus, if it is necessary to make repairs at home or independently make a decorative element from aluminum pipes, everyone will be able to bend the details with their own hands.
Recommendations for implementation and typical mistakes
Before starting the process, the part should be cleaned of dirt and dust. Do not use an abrasive brush. Cleaning should be done carefully so as not to tear off the oxide film.
Important! After bending, the length of the tube may change. Therefore, form the desired segment after processing.
When using a gas burner to increase plasticity, the part should be bent immediately upon reaching the required degree of heating, without allowing it to cool. Do not process pipes that are bent along their entire length. This defect indicates the low quality of the product. In addition, the products should not have foreign inclusions, burrs, chips, scratches, cracks.