Airbus brews Scandium smackdown for carbon Dreamliner
A riveting chapter in Boeing and Airbus' rivalry
Zis unfortunate little carbon machine, c'est une boîte d'herbe de puanteurs - regard, l'avion scandium par M'sieu Worstall!
Airbus has taken a very different route, they've decided to go play with scandium. The reason that we rivet planes together is because welding aluminium is a right bitch, much more so than making them out of carbon fibre. Al welds are also not very strong, horribly prone to cracking and in general just not the sort of thing that you want to do with something highly stressed like an airframe. At which point enter scandium, my favourite rare earth metal. Adding a small amount (0.1 per cent say) to the Al-Mg alloys which planes are made of makes the welding much, much easier. It also makes those welds much stronger. So much so that the design team thinks that it should be possible to make the fuselage out of such Sc containing alloys, weld it all together and thus eliminate the rivets.
No, it's not a zeppelin, it's an Airbus A380.
That design team includes Airbus themselves, the University of Oxford and Qinetiq all playing with research originally done at UMIST. It's also at times included your humble author as a supplier of that delightful scandium.
Now, whether it's all going to work is at present unknown, that's why it is called research after all. But there are interesting pointers. Sc has been used in bike frames (bicycle, not motor) for more than a decade now and I know that one Taiwanese manufacturer simply makes all of his frames using Al Sc. He's got two lines, one very expensive and branded as containing that lovely metal and another no name line. He's found that what he saves on the welding costs so overwhelms the cost of the Sc (which is high, $4,000 a kg for the oxide at present, maybe $5 to $10 on the materials costs for a bike frame) that it's cheaper to use it even when he can't charge a premium for its use. The no name line is thus, in metallurgical terms, exactly the same as the high cost one. So we do have some at least real world information that this might be a good idea.
But whether scandium beats carbon fibre as a solution to the rivet problem? As yet still unknown. Scandium plus welding would certainly be much cheaper on the assumption that it really does work and passes all of the tests required for a new aerospace alloy (not surprisingly, these are more complex than those on a bike frame. The most a failure of the latter can do is ruin one's crotch or day, catastrophic failure of an airframe is more of an event.) Yet carbon fibre is further ahead in the getting ready for prime time stakes. Which might mean that the c-fibre solution gets cheaper faster as is usually true with methods that are in actual production.
But there it is, the two basic experiments being undertaken by the two major airframe manufacturers. One is an experiment about us, small planes and point to point versus vast buses in the sky with a hub and spoke model of travel. The other is entirely different approaches to how to get rid of the humble rivet. ®
I should of course declare my interest: I've been supplying Airbus' scandium research program for over a decade now. Boeing has yet to spend a red cent with me. The bastards.
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