Titanium is Earth’s ninth most abundant element. Small amounts are found in almost every kind of rock there is. The element is used in many products people use every day, including things like mobile phones, scissors, and bicycle frames. It is also used in surgical instruments, metal implants used to help repair bone injuries, tennis rackets, and various types of prostheses.
Titanium has been called the “go-to metal for marine and aerospace applications.” This is because it is as strong as steel but weighs nearly half as much. It is highly resistant to the types of corrosion found in marine environments. The metal is also used extensively in power generation and desalination.
There are some unique challenges that come with welding titanium and it has a reputation for being a difficult metal to work with. General welders often ask if it is possible to create a quality titanium weld. They ask what steps they need to take when welding titanium to be sure the weld is successful and maintains its corrosive resistance.
Issues That May Arise Working With Titanium
Welding with titanium can be difficult even though, at first glance, it may appear to be similar to steel welding. Some of the specific issues that must be considered are:
- Titanium reacts strongly to environmental chemicals when subjected to high temperatures. Oxygen can infiltrate and corrupt the weld, making it brittle and prone to cracking or premature fracturing.
- Welding in ambient air may contaminate titanium which can lower the fatigue resistance and notch toughness of the weld.
- Titanium is particularly subject to corrosion from chlorine found in the welder’s sweat or in cleaning compounds. In powder form, titanium is highly flammable.
- Friction from grinding wheels can generate enough heat to provide the contaminates that compromise the effectiveness of the weld.
Despite all of these concerns, titanium is a “highly desirable” choice for use in many industries, including defense and aerospace.
Pointers for Welding With Titanium
Despite the challenges that come with welding titanium, with proper preparation, quality titanium welds can be achieved. Some pointers for successful titanium welding include:
Choose high-grade titanium. The first step is to choose high-quality titanium, at least Grade 5.
Environmental cleanliness. The metal should not be touched by bare hands since body oils, grease, and grime can easily contaminate the titanium. Wear lint-free gloves, like ones made of nitrile.
Parts should be kept wrapped and sealed from the environment. They should be stored in a clean, dry area. Joint surfaces must be smooth and completely free of any contamination.
A dedicated workstation. Due to the high risk of cross-contamination from other metals, a workspace dedicated only to titanium welding is a must. This includes dedicated tools that come with a dedicated workstation. Any contamination of the metal will destroy its corrosion resistance and overall performance.
How to Evaluate the Success of the Titanium Weld
Welders can determine the success of the weld by looking at the color of the completed weld. Generally, an acceptable weld is shiny and silver as soon as the weld is completed.
There is a color scale titanium welders use to determine if the weld is unsuccessful. Blue, purple, or brown indicate there is a serious problem with the weld that may result in product failure. Unfortunately, there is no fix. The joint will have to be cut away and the process started all over again.
This is important information for welders new to titanium welding. Discoloration of other metals, such as stainless steel or nickel-based alloys is normal. The discolored portion can be brushed away, but this is not true of discoloration of a titanium weld.
Contact Arizona’s Leader in Welding Supplies
Vern Lewis Welding Supply, Inc., with eight locations throughout the state of Arizona, maintains a complete supply of products needed for successful titanium welding. The professionals at Vern Lewis can help you choose the proper tools for titanium welding, and answer questions about how to be sure your welding environment and welding procedure will enable you to make successful welds when using this temperamental metal.
For more information, contact us online or call 602-633-7481.
Sources:
- https://www.arc-zone.com/blog/joewelder/2013/01/13/tips-for-welding-titanium/
- https://www.arc-zone.com/pdf/Welding_Titanium.pdf
- https://weldingheadquarters.com/
- https://geology.com/articles/titanium/
- https://weldguru.com/titanium-welding/
- https://www.excelco.net/welding-techniques/titanium-welding-unique-benefits-unique-challenges-unique-risks/
- https://www.millerwelds.com/resources/article-library/only-as-strong-as-the-weld-best-practices-for-welding-titanium-tube-pipe
