Welding Titanium: Benefits, Challenges, and Industry Practices

In this technical article, we discuss the advantages and disadvantages of welding titanium using TIG welding (Gas Tungsten Arc Welding), plasma welding (PAW), and orbital TIG welding (Orbital GTAW).

If you want to read more about TIG welding, you can read our technical article here .

Titanium and titanium alloys are becoming increasingly popular in high-tech industries, from aviation and aerospace to offshore and marine. This is due to titanium's unique combination of high strength, low weight and high corrosion resistance. However, welding titanium is not the easiest, as there are strict requirements for the welding process. Therefore, titanium is a material that requires careful control and specialized methods.

Welding processes for titanium

NASA/Johnson Space Center has a publication on detailed process specifications for welding titanium. The publication mainly covers the processes TIG welding, plasma welding and orbital TIG welding.

Automated or orbital welding provides consistent quality and good control over heat input, and minimal variation in weld properties. Plasma welding is suitable for thicker parts due to its deep penetration, while orbital TIG welding allows for welding of complex shapes with low risk of failure (e.g. pipes and narrow components).

Advantages of welding titanium

According to NASA specifications, the main advantages of welding titanium include:

• High quality and good control
  Automatic or orbital welding provides stable results, reduces human error and ensures even heat input .
• Limited Heat-Affected Zone (HAZ)
  Controlled heat input reduces structural changes, deformation and residual stresses in the material, and preserves the mechanical properties of titanium.
• Good penetration and ability to handle thicker sections
  Plasma welding provides deep penetration, while orbital TIG welding allows for precise welding in pipes and tight geometries.
• Protection against contamination
  Titanium reacts readily with oxygen, nitrogen and hydrogen at high temperatures. Removing air and using a pure inert gas (such as argon) around the weld area prevents oxidation and embrittlement of the weld.
• Quality assurance
  Strict quality control and inspection ensures that welds meet the required mechanical and functional standards (such as NASA requirements).

Challenges and disadvantages

As mentioned earlier in the article, welding titanium can be difficult. Some of the challenges when welding titanium can be:

• High demands on cleanliness and process control
  Even small amounts of contamination can lead to porosity, embrittlement and weld defects. The gases must be extremely clean, and surfaces must be free of oils, oxides or other contaminants.
• Limited process choices
  Not all welding processes are suitable; for example, MIG welding (GMAW) is considered unsuitable for titanium, due to unstable arc and high risk of contamination.
• Dependence on operator skills
  Manual welding is more variable and dependent on experience, while automated processes require specialized equipment and start-up costs.
• High cost and time consumption
  The processes often require extensive preparation, specialized equipment, and careful inspection. These processes increase costs, even as they improve quality.
• Material-specific challenges
  Titanium has low thermal conductivity, which can lead to local overheating, high temperature gradients and structural changes if heat input is not carefully controlled.

Summary

Welding titanium requires a combination of metallurgical knowledge, precise processes and strict quality requirements.

Advantages such as high strength, low weight, good corrosion resistance and the possibility of precise and consistent welding make titanium attractive for critical applications. At the same time, the material's sensitivity to contamination and heat input requires careful process control.

The use of automated processes such as orbital TIG welding and plasma welding, combined with inert gas protection and strict inspection procedures, enables high quality to be achieved. High quality can be achieved even in components with complex shapes, with limited risk of defects.

Source: NASA (Structural Engineering Division)