The Four Most Commonly Used And Core Forming And Joining Processes in Titanium Equipment Manufacturing

Titanium materials  are difficult to process: they are prone to oxidation when heated, and springback and cracking during cold working. The core bottleneck in equipment manufacturing lies in forming and joining. Industry practice shows that three forming processes-bending, stamping, and spinning-plus expansion joining as a core connecting process, are the four key technologies for titanium equipment manufacturing, which directly determine the precision, performance, and service life of equipment.

 

 

Bending forming is the most widely used basic process in titanium equipment manufacturing, achieving the required shape through plastic deformation and springback control. It is commonly used for deep-sea, chemical, and aerospace pipe fittings. Titanium alloys exhibit large springback in cold bending and coarse grains at high temperatures; the core lies in precise temperature and pressure control.

 

The process is divided into cold bending and hot bending:

Cold bending is suitable for titanium tubes < 50 mm, with a minimum bending radius ≥ 3 times the tube diameter, requiring stress-relief annealing.

Hot bending is used for high-precision parts, with temperature-controlled processing and anti-oxidation protection, complying with ASTM B338 standards.

 

China has achieved technological breakthroughs by adopting a gradient temperature + dynamic pressure process, with cold bending performance superior to national standards, meeting the requirements of extreme working conditions such as 10,000-meter deep-sea applications.

 

 

Stamping forming forms titanium sheets into shapes via dies under pressure, highly efficient for mass production. It is widely used for complex components in aerospace and chemical vessels. Titanium is prone to cold work hardening and cracking, and grain coarsening at high temperatures, requiring precise temperature control at 427–800 °C.

 

The process is divided into cold and hot stamping:

Cold stamping is suitable for thin-walled small parts, with deformation ≤ 15%, requiring annealing to remove hardening.

Hot stamping includes low-temperature and high-temperature variants, adapted for medium-thick and thick-plate complex parts, with a maximum deformation of 60%.

 

China's titanium stamping technology is internationally advanced. The titanium wing panels of the C919 aircraft achieve lightweight and high performance through high-temperature servo stamping. Complex components adopt pre-forming and heat-assisted straightening to ensure precision and stability.

 

 

Spinning forming is a high-efficiency forming process for titanium materials, processing rotary parts via spinning rollers. It improves material utilization by 20%–50% compared with conventional forging, delivering excellent precision and surface quality. It is commonly used for high-end products such as satellite gas cylinders and heads.

 

The process is divided into conventional spinning and power spinning, with core control of rotating speed and feed rate. Thin-walled parts feature high precision, while thick-walled parts require hardening control. It has been applied on a large scale in China, achieving significant weight reduction, efficiency improvement, and cost reduction for products.

 

 

Expansion joining is the core process for connecting titanium tubes and tube sheets in titanium equipment. It works by plastically expanding titanium tubes via external force to fit tightly with the tube sheet holes, solving the problems of titanium embrittlement and leakage easily caused by welding. It provides a longer sealing life without damaging titanium properties, making it critical for the safe operation of titanium equipment in chemical and nuclear power industries.

 

The core of expansion joining lies in controlling three parameters: expansion rate, wall thickness reduction rate, and expansion pressure. It is mainly divided into three methods: mechanical expansion, flexible expansion, and explosive expansion.

 

China's innovative applications have achieved remarkable results. The titanium tube heat exchanger using flexible hydraulic expansion at Sinopec Maoming Company has operated continuously for 5 years without leakage under high-pressure and high-temperature conditions, with a service life 3 times that of conventional welding, saving 200,000 RMB in maintenance costs annually. Meanwhile, parameter optimization via finite element simulation has improved connection stability.

 

Ruihang, a manufacturer of titanium and non-ferrous metal products, is specialized in R&D, production and sales. Our sales team is standing by to provide you with customized support. For more details, please feel free to contact us by email: Sam.Rui@bjrh-titanium.com.