The research team behind the European Union (EU)-funded "QualiTi" project has developed a new testing system for titanium-made airplane parts that improves by 20 percent manufacturing-related defects' detection, even if the probability of such flaws causing any potential incidents is very low.
Despite its desirable natural characteristics (incredibly strong in proportion to its weight), titanium can develop tiny sub-surface defects, such as cracks. This can pose some potential hazards on board. Researchers say three incidents of engine failure over the last 20 years can be attributed to defective titanium parts, with one - a crash at Sioux City, Iowa, in July 1989 - costing 111 lives.
The novel system and the improvement it brings in defect detection could make skies safer and also cut titanium inspection costs – potentially totalling annual savings of €21 million in Europe and €75 million worldwide.
“We’re working to give the public even more confidence in flying,” says Harshad Virji Halai of TWI, the Cambridge, UK-based engineering and research company coordinating the QualiTi project.
The project team developed an automated quality control system for the inspection of titanium billets, the metal castings that have yet to be processed into a finished good. The new control system combines the best elements of two existing systems: Phased Array (PA) ultrasonics, which is better at inspecting the entire depth range of the billet; and Eddy Current (EC) technology, which is used for examining a 5mm margin beneath the billet’s surface. “As an integrated system, QualiTi could detect defects much earlier in the production process and could significantly reduce the likelihood of defective parts entering service,” says Halai.
As well as being central to technological development, partnership and collaboration were important to the project in a much wider sense, involving SMEs from several European countries (Spain, Italy and France) that operate in this very special business segment such as Vermon, Tecnitest, and I.S.O.Test.
“More than half of the companies involved with material testing in the EU are SMEs. The role of SMEs in the project was crucial in clearly defining the scope of the research into those areas which were most critical to the inspection process and in ensuring the project deliverables were able to be applied in practice,” adds Halai.
European SMEs who manufacture and supply hardware in Non-Destructive Testing (NDT) –the checks on material properties that do not permanently alter the article - or who provide inspection services to aerospace companies would now be in a key position to benefit from the reported QualiTi’s breakthroughs, which are expected to help them remain competitive in the global market for inspecting safety-critical aerospace parts and equipment. This global market is worth €600 million.
The project was finalised in February 2011 and was supported by an EU grant of €1.1 million. QualiTi’s technology is expected to be commercially launched in the coming years.