Generally, 1xxxx, 3xxx, 5xxx aluminum alloys are mostly bendable.1060,1100 and 1050 aluminum sheet can be easily bent but with low strength. 3003, 3005 and 3a21 are often used to be bent with medium strength. Among 5000 series, 5052 aluminium alloy with H32 temper is often used and it has no cracks after folding at 90 degrees.
6000 and 7000 series aluminum alloys have high hardness, so they are not used to be bent in general cases. The medium-thick aluminum plates do not require bending. If bent, it must be annealed to O temper before bending.
The bending process of aluminum alloy usually includes the following steps: pre-bending, heating, bending and cooling. During this process, the mechanical properties, temperature changes, stress distribution and other factors of the aluminum alloy will affect its fracture behavior.
1. Pre-bending: Before bending, the aluminum alloy is pre-bent to cause plastic deformation. The size and angle of pre-bending will affect the stress distribution and fracture behavior during subsequent bending.
2. Heating: During the bending process, the aluminum alloy is heated to increase its temperature. Temperature changes have an important impact on the mechanical properties and fracture behavior of aluminum alloys.
3. Bending: Bending aluminum alloy under heating conditions. Factors such as bending angle, force and time will affect the stress distribution and fracture behavior of aluminum alloys.
4. Cooling: After the bending is completed, the aluminum alloy is cooled. Cooling rate and time will affect the microstructure and mechanical properties of aluminum alloys, thereby affecting their fracture behavior.
The bendable aluminium sheets may break during the bending process, depending on their mechanical properties, temperature changes, stress distribution and other factors. During the bending process, if the stress of the aluminum alloy exceeds its strength limit, or if the temperature decreases and the mechanical properties decrease, it may cause fracture. In addition, the microstructure and grain size of aluminum alloys also affect their fracture behavior.
In practical applications, the bending method and parameters should be reasonably selected based on the chemical composition, microstructure and bending conditions of the aluminum alloy to ensure safety and service life. At the same time, monitoring and detecting the bending process of aluminum alloys can help promptly detect and solve fracture problems.