An Overview of Key Manufacturing Processes for Titanium Equipment

In the field of titanium equipment manufacturing, selecting the appropriate processing technologies is crucial for ensuring equipment quality, performance, and cost control. Due to the unique physical and chemical properties of titanium, its processing techniques involve specific requirements and challenges compared to other metallic materials. We have conducted an in-depth report on several common manufacturing processes used in titanium equipment production; the following section will provide a detailed introduction to these processes based on our findings.

Bending and Forming: A Common Process of Plasticity and ElasticityBending and forming is a fabrication process that combines plastic and elastic deformation, and it is one of the most common forming methods in titanium equipment manufacturing. During the bending processspringbackis a critical factor that must be considered. While the bending angle for titanium can typically exceed 90°, it must adhereminimum bend radiusrequirements to ensure structural integrity and quality.

For titanium pipes with a diameter of less than 50mmcold bendingcan be employed. While cold bending is relatively straightforward, it is highly recommended to performstress-relief annealingafterward. This is because residual stresses develop within the pipe during cold bending; if not promptly eliminated, these stresses may compromise the performance and service life of the titanium component.

Hot bendingof titanium pipes is categorizedstretch bendingandpush bending, depending on the force application. During hot bending, the heating temperature is generally controlled between 177°C and 350°C (though titanium alloys can be heated up to 427°C). Within this temperature range,yield strengthof titanium decreases by 25% to 50%, while its ductility improves. This results in a minimal springback angle and low gas contamination. These characteristics allow hot bending to achieve superior precision, meeting the rigorous demands of titanium equipment fabrication.

Stamping and Forming: Diverse Approaches to Titanium's Unique PropertiesStamping and forming titanium and its alloys is relatively challenging, as their bend radii are larger than those of conventional steel and non-ferrous metals. To achieve effective stamping, several methods are commonly utilized: cold forming, hot forming, and pre-forming followed by hot sizing.

• Cold Forming:Primarily used for thin-walled workpieces with minimal deformation, large bend radii, and lower dimensional precision requirements. For larger deformations, a combination of cold stamping and intermediate annealing is employed. A final stress-relief anneal is mandatory after cold stamping to ensure dimensional stability.

• Hot Forming:The preferred choice for complex shapes and high-deformation components. Depending on the temperature, it is divided:

  • Low-temperature forming (200 - 350°C):Capable of handling deformations up to 40%.

  • High-temperature forming (600 - 800°C):Suitable for thick slabs and large-scale components with significant deformation. Heating methods include heating the die, heating the blank, or heating both simultaneously. Post-forming surface treatments, suchsandblasting and pickling, are required to remove the oxide scale and contamination layer.

• Hot Sizing after Pre-forming:This involves creating a pre-formed part through conventional stamping, followed by heated rectification on specialized machinery. This effectively eliminates residual stress and springback, ensuring the final part meets precise geometric tolerances.

Spinning: A Versatile Integration of Process AdvantagesSpinning combines the characteristics of forging, extrusion, drawing, bending, and rolling. This process offers several distinct advantages: excellent deformation conditions with wide-range control, high material utilization (saving 20% - 50% in material costs), and superior surface finish with tight dimensional tolerances. These benefits have led to the widespread adoption of spinning in high-precision titanium equipment manufacturing.

Tube Expansion: A Reliable Method for Titanium Tube-to-Tube-Sheet JoiningWidely used for joining titanium tubes to tube-sheetsexpansionis a mechanical connection method that achieves sealing and fastening through the deformation of both components. It is a critical step in manufacturing shell-and-tube heat exchangers. For titanium connections,expansion degree (internal diameter expansion rate)is ideally 1% - 6%, or up to 5% if measuredwall reduction rate.

There are three primary expansion methods:

1. Mechanical Expansion:Simple to operate and widely used.

2. Flexible (Hydraulic/Rubber) Expansion:Better accommodates deformations to improve joint quality.

3. Explosive Expansion:Utilizes explosive energy for high-efficiency, high-strength bonding, though it requires specialized operational expertise.

In summary, the various processing technologies in titanium equipment manufacturing-including bending, stamping, spinning, and tube expansion-each possess distinct characteristics and specific areas of application. In practical production, it is essential to strategically select and integrate these processes based on the specific requirements of the equipment, the intrinsic properties of the titanium material, and prevailing production conditions. Such a balanced approach ensures the superior quality and performance of titanium equipment, ultimately driving the continuous advancement of the titanium manufacturing industry.