First of all, we have to make it clear that titanium tubing can be bent. Many people ask whether titanium tubing can be bent because titanium tubing is generally thinner, and titanium alloy tubing strength is higher, making it difficult to bend. Pure titanium is easy to bend because of its low strength, which will not be described here, while high-strength 6Al-4V titanium tubing is too strong to be bent, and even Grade 5 titanium tubing can not be produced through the milling process. CNC bending technology can use medium-strength titanium tubing (3Al-2.5V) and thin-walled titanium tubing. In addition, there are specialized bending equipment and methods for bending titanium tubing, such as heating the outside of the bending section using a heating nozzle to achieve high-precision bending. It shows that the bending and forming technology of titanium alloy tubing has been developed and applied to a certain extent.
It is important to note that the bending and forming process of titanium tubing may encounter some challenges. For example, due to its advantages of high strength and lightweight, corrosion resistance, and high-temperature resistance, titanium tubing is challenging to realize the forming and manufacturing of difficult-to-form structures such as small bending radius bends under room-temperature conditions. In addition, the widespread use of titanium tubing in civil and military aircraft is also affected by the fact that bending and tube fitting technologies are not yet fully mature.
Despite these challenges, process optimization and innovative tooling design can improve the bendability of titanium tubing, making it possible to form small bend radius tubing. In addition, transfluid Germany has many years of experience in tube bending and end-forming operations on an aerospace scale, suggesting that there are already successful applications for titanium tube bending and forming technology in specific areas.
CNC bending technology
CNC bending technology in the bending processing of titanium tubes is mainly applied through the following aspects:
1. High precision and efficiency: CNC bending machines are capable of high-precision and high-efficiency bending processing, which is especially important for titanium tube processing that requires precise control.
2. Multi-step programming and automated operation: CNC bending machine supports multi-step programming, which can complete the processing of multiple parts simultaneously, significantly improving work efficiency. At the same time, its high degree of automation reduces manual intervention and lowers production costs.
3. Suitable for titanium tubes of different shapes and sizes: CNC bending machines are equipped with moulds, allowing them to bend workpieces of various shapes, including titanium tubes. It enables CNC bending technology to be widely used in the processing of titanium tubes to meet different design requirements.
4. Applicable to processing unique materials: CNC bending technology is particularly suitable for processing unique materials, such as titanium alloys and other high-strength materials. The CNC bending machine can accurately control the temperature and pressure during processing, avoiding damage to the material and ensuring processing quality.
5. Improve product quality and reliability: CNC bending technology can achieve higher quality control standards in the processing of titanium tubes. For example, by simulating and analyzing the evolution of the weave of titanium tubes during CNC bending, the processing parameters can be optimized, and the product’s reliability and performance can be improved.
The application of CNC bending technology in the bending processing of titanium tubes is mainly reflected in its high precision, high efficiency, multi-step programming capabilities, applicability to different shapes and sizes of titanium tubes, intelligence, flexibility, and the applicability of unique materials processing. These features make CNC bending technology indispensable in titanium tube processing.
Heated winding and flattening control
Bending of titanium tubes by the controlled method of heated winding and flattening involves the following steps and technical points:
1. Pre-deformation and practical constraints: Pre-deformation of the tube before bending and practical constraints are applied during the bending process to control the flattening of the cross-section. This method is based on deforming the pipe before bending, applying effective constraints during the bending process, and designing counter-deformation moulds with variable curvature cavities.
2. Heating method: Adopt the principle of CNC heating and bending, heating the mould through the opening of heating holes on the bending and forming mould and then warming the pipe to the target temperature through heat conduction. Select the heating method according to the pipe size to ensure that the pipe can be bent at the appropriate temperature.
3. Temperature control: Using electric heating elements and thermocouples, the heating temperature should be controlled between 150°C and 260°C. This helps to improve the bending performance of the titanium alloy tubes and reduces the defects caused by uneven temperature.
4. Localized thermal field improvement: Localized thermal field improvement improves the deformability of hard-to-deform titanium tubing and bend formability. This method allows fittings with small bending radii, which is especially important for high-pressure piping systems with extremely demanding service requirements.
5. Optimization of process parameters: The effects of process parameters on the thinning and flattening of thin-walled titanium tubes during differential temperature shear bending are investigated, and the forming limits of bent tubes under experimental conditions are obtained by combining the response surface method. By optimizing the process parameters, such as the friction between the dies, the bending stroke H, and the radius of the outer corner Ra, etc., the degree of thinning and flattening of the tube can be effectively controlled.
6. Integral warming of inner and outer sides and control of temperature difference: The study shows that the integral warming of the inner and outer sides of the pipe can significantly reduce the flattening of the cross-section, the degree of corrugation, and the degree of wall thickness thinning of high-strength titanium tubes. Compared with the overall warming, the bending performance can be further optimized by controlling the temperature difference between the inner and outer sides.
By applying the above methods and technical points, the flattening of titanium tubes during heating and bending can be effectively controlled to improve the quality and efficiency of bending and forming.
Hydraulic rotary bending technology
The application of hydraulic rotary tension bending technology in titanium tube bending mainly involves realizing the bending and forming of titanium tubes by driving the rotary and tensile actions through the hydraulic system. This method combines the rotary and tensile actions to effectively control the shape and accuracy of the titanium tube during the bending process.
First, the hydraulic system provides the necessary force and control to ensure that the titanium tube maintains the desired shape and size during the bending process. By adjusting the pressure and flow rate of the hydraulic system, the degree and speed of bending of the titanium tubing can be precisely controlled, resulting in high-precision bending and forming.
Second, the rotary action is generated by hydraulic cylinders or other actuators capable of applying an axial tensile force to the titanium tube while performing the rotary operation. This combination of rotation and tension helps offset some of the tangential compressive stresses on the concave side of the bore during pure bending, thereby suppressing wall thickness problems and the bent tube’s wrinkling.
In addition, hydraulic rotary bending technology allows titanium tubing to be heated during the bending process to improve its mechanical properties and reduce the risk of material fracture. This can be achieved with equipment such as heating nozzles, which soften the titanium tube material and reduce the yield strength, making bending easier and more precise.
Hydraulic rotary drawing technology provides an effective solution for high-precision bending of titanium tubing by combining rotary and tensile actions and appropriate heating treatments. This method improves the precision and efficiency of bending and forming and ensures that the properties of titanium tubes are not damaged during the bending process.
FD Titanium offers titanium tubing with bending service. Any requirements please send us your drawings.
Therefore, titanium tubes can be bent, mainly pure titanium tubes and medium-strength 3Al-2.5V titanium alloy tubes. However, the bending and forming process requires consideration of the material properties and the use of appropriate equipment and technological methods and may require process optimization and innovative tooling design for specific applications.
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