Core Techniques for GR5 Titanium Alloy Bending: Precision Control of Key Processes

In the precision components of aerospace and high-end medical devices, GR5 titanium alloy (Ti-6Al-4V) has become an irreplaceable core material due to its high strength, light weight, and exceptional corrosion resistance. However, this " performance champion" poses significant challenges during bending processes, where issues like cracking and springback can easily occur if not handled carefully, ultimately affecting product quality. Today, we will deconstruct the critical considerations for GR5 titanium alloy bending, helping you effortlessly overcome these technical challenges!

Preheating and Temperature Control: Ensuring Processing Safety 

Due to its poor plasticity at room temperature, GR5 titanium alloy is highly prone to cracking during low-temperature bending. Therefore, preheating the workpiece before processing is essential. The preheating temperature must be strictly controlled within the range of 200-400°C. This temperature range effectively enhances the material's plasticity, creating favorable conditions for bending.At the same time, the risk of localized overheating must be cautioned. When the temperature exceeds 500°C, the grains of GR5 titanium alloy will coarsen rapidly, leading to a sharp decline in mechanical properties. It is recommended to use an infrared thermometer to monitor the workpiece temperature in real-time, ensuring uniform heating and precise temperature control, thereby avoiding quality risks at the source.

Bending Speed and Pressure: Low-Speed Precision with Scientific Compensation

Due to the "strain aging" characteristic of GR5 titanium alloy, rapid bending can easily lead to stress concentration. Therefore, the bending process must adopt a low-speed mode, with the rate controlled at ≤5 mm/s. A steady operation helps reduce stress accumulation and prevents workpiece damage.The optimal bending pressure should be determined through trial bends. Insufficient pressure may cause significant springback in the workpiece. Since the springback rate of GR5 titanium alloy is much higher than that of ordinary steel, a compensation allowance of 10%–15% must be reserved. Conversely, excessive pressure may trigger wrinkling or cracking at the bend, directly impacting product qualification rates.

Tooling and Lubrication: Ensuring Compatibility to Minimize Friction Losses

The quality of the tooling directly determines the precision of the bending process. Given the high hardness of GR5 titanium alloy, it is essential to use high-strength tooling materials such as H13 hot-work tool steel. Its excellent wear resistance and thermal stability effectively resist wear during processing, ensuring consistent bending accuracy.

Furthermore, prior to bending, a high-temperature specialized lubricant containing molybdenum must be applied to the contact areas between the workpiece and the tooling. This step not only significantly reduces friction resistance and prevents surface scratches on the workpiece，but also avoids adhesion between the tooling and the workpiece, ensuring a smoother bending process.

Post-Processing and Quality Inspection: Multiple Checks to Ensure Quality

After the bending process is completed, residual internal stress remains within the workpiece. If not eliminated in time, this stress may lead to deformation during subsequent use. To address this, stress relief annealing is required. The workpiece should be maintained at a temperature of 550-600°C for 1-2 hours to thoroughly release the internal stresses, ensuring dimensional stability of the final product.

Quality inspection serves as the final critical defense, focusing on three key aspects:

1.Bending Angle Tolerance: Strictly adhere to the GB/T 3621 standard, controlling the tolerance within ±1° to ensure assembly accuracy.

2.Surface Defects: Conduct meticulous inspections for issues such as cracks or indentations, which could compromise the product's appearance and service life.

3.Mechanical Properties: Test the tensile strength at the bend area; it must retain over 90% of the base material's strength to ensure reliability in complex working environments.