The integration of titanium into motorsport, particularly in racing car manufacturing, has played a crucial role in enhancing performance by reducing weight and improving safety. As racing cars evolved, fusion welding became essential, with lightweight titanium gradually replacing traditional steel components. However, fabricating titanium alloys presents significant challenges due to the material's sensitivity to atmospheric contamination during welding.
The Role of Titanium in Racing Car Development:
Titanium first gained prominence in racing car technology during the mid-1960s, particularly in North America. The Canadian-American Challenge Cup (Can-Am) allowed for innovative approaches, creating the Ti22 car, one of the first to use titanium extensively. These cars, designed by Peter Bryant, were lighter and stronger than their steel counterparts, setting new performance standards in the racing industry.
Challenges in Welding Titanium:
Welding titanium is challenging due to its susceptibility to contamination from atmospheric gases like oxygen, nitrogen, and hydrogen, which can cause cracking and other defects. To overcome these challenges, the welding process must include protection for the molten weld pool and the heat-affected zones (HAZ). This protection often involves using an inert gas environment, such as argon, within an enclosure.
Bob Lee faced these challenges when recreating the Ti22 MkII in 2015. He successfully used a Flexible Welding Enclosure® and an oxygen monitor to weld the car's critical titanium components, ensuring high-quality results without contamination.
Advantages of Flexible Welding Enclosures:
Modern, flexible welding enclosures offer significant advantages over traditional metal glove boxes, including cost savings, a smaller footprint, and greater flexibility. These enclosures, developed by companies like Huntingdon Fusion Techniques Ltd, are made from UV-stabilized engineering polymers and provide multiple access points, robust oxygen content control, and easy movement and storage.
Ensuring Weld Quality:
Maintaining low oxygen levels in the purge gas is crucial for welding titanium. The PurgEye® Nano Weld Purge Monitor® can measure oxygen levels down to 10 ppm, ensuring the welds are free from discoloration and retain their mechanical properties. This technology was effectively used in the Ti22 MkII, demonstrating its reliability by achieving a solid finish in a Long Beach Grand Prix race.
The Role of Titanium in Racing Car Development
As racing cars have evolved, integrating fusion welding into manufacturing has become essential. While improvements in engine design have greatly enhanced track performance, reducing weight and refining aerodynamics have also been vital. Additionally, ongoing safety innovations are crucial for protecting drivers in case of accidents.
Welding has become increasingly significant in producing racing car body parts, with lightweight titanium replacing traditional steel components. However, fabricating titanium alloys requires a far higher level of skill than working with steel due to the difficulty of forming and welding titanium.
In the mid-1960s, titanium became a pivotal element in advancing racing car technology, significantly improving sports car performance, particularly in North America. The Canadian American Challenge Cup (Can-Am), introduced in 1966, featured cars with few technical restrictions, allowing for innovations like using titanium in their construction.
The Ti22 car, designed by Peter Bryant and built in the USA, was one of the first to use titanium extensively. Titanium components, being more robust and nearly half the weight of steel, provided a competitive edge. The Ti22 MkI and MkII cars, built in 1969 and 1970, set new performance standards, achieving several podium finishes and scoring more points in Can-Am racing than any other American-built car.
Challenges in Welding Titanium
When Bob Lee set out to recreate the Ti22 MkII in 2015 in the USA, he faced significant challenges, particularly in welding sensitive titanium components. Titanium is highly susceptible to contamination from atmospheric gases like oxygen, nitrogen, and hydrogen during welding, leading to cracking due to increased tensile strength and reduced flexibility.
A standard gas shroud can protect the molten weld pool to avoid these issues, but the cooling weld and its heat-affected zones (HAZ) require additional protection. The underside of the weld also needs to be shielded using an efficient gas purge. Atmospheric contamination is best avoided by welding within an enclosure filled with inert argon gas. While metal glove boxes are available, they can be prohibitively expensive.
Lee addressed this challenge using a Flexible Welding Enclosure® and an oxygen monitor. This setup allowed him to weld all the critical titanium components of the Ti22 MkII, including roll bars, braces, suspension parts, and other essential elements.
Advantages of Flexible Welding Enclosures
Modern flexible welding enclosures, such as those developed by Huntingdon Fusion Techniques Ltd, offer several advantages over traditional metal glove boxes. These include significant cost reductions, a smaller floor footprint, and the availability of various sizes to suit different needs.
Technical Specifications:
These enclosures are highly flexible, easy to move and store, and can be customised to meet specific customer requirements. They provide a large viewing area, multiple access points, and robust oxygen content control using instruments like the PurgEye® Nano Weld Purge Monitor®.
Ensuring Weld Quality
For high-quality welding of titanium alloys, it is crucial to maintain the oxygen content in the purge gas below 0.005% (50 ppm). The PurgEye® Nano can measure oxygen levels down to 10 ppm, ensuring that the welds are free of discolouration and retain their mechanical properties.
The recreated Ti22 MkII has already demonstrated the success of these advanced welding techniques by competing prominently in a Long Beach Grand Prix race, finishing 4th. The consistent performance of the titanium welds, especially in critical suspension components, underscores the effectiveness of the technology.
Conclusion
Advanced welding technology, such as flexible enclosures and precise oxygen monitoring, has successfully fabricated titanium components in motorsport, where safety and performance are paramount. The early success of the Ti22 MkII provides a promising outlook for the broader adoption of these technologies in motorsport and potentially in road vehicles, where the combination of reduced weight and high strength is increasingly desirable.
