Rolls-Royce has produced the largest ever civil aero engine component using 3D printing, working with the new National Centre for Additive Manufacturing at the Manufacturing Technology Centre
Rolls-Royce has produced the largest ever civil aero engine component using 3D printing. Working with the Manufacturing Technology Centre (MTC) in Coventry, which last week opened its new National Centre for Additive Manufacturing and Aerospace Research Centre, the British company printed the front bearing for a Trent XWB-97 engine, which is made from titanium and 1.5m across — about the size of a tractor tyre.
The component was not made in a single piece; it contains 48 aerofoil-shaped vane components, which were also made by additive manufacturing. The project also involved Sheffield University and 3D printing specialist Arcam, whose electron-beam machines were used to build the vanes. ”One of the things that was key to us is the MTC can analyse the powders — the core building material — manufacture the part and provide the analysis so we can assess the parts’ integrity before we assemble the component,” commented Clive Grafton-Reed, head of laser processes at Rolls-Royce. “This has given us a good understanding of how we can recycle powder, which is core for the business case of the process, and how to classify flaws in the process.”
The project also helped the MTC develop methods for working with large volumes of powders. ”When these machines came in, they could handle an 80-hour build, which as the longest that they’d been needed to do,” said Grafton-Reed. ”But we needed them to run for 120 hours, so it had to be robust and stable for 50 per cent longer than anything it had been asked to do before. The knowledge and learning from that has gone into the latest incarnation of Arcam’s machine, which is the same size but has greater capabilities, and the new users of the machine will get the benefit of our experience.”
The new machines have an electron-beam filament rated for 6-700 hours, and also incorporate active cooling of the built part; because titanium powder is flammable, the printing process must be carried out in a vacuum, which means radiative cooling tends to be slow. Active cooling allows the part to cool in 8-9 hours rather than 18 hours with previous machines.
Electron-beam machines produce larger parts at a faster rate than laser, explained Grafton-Reed. The surface finish is rougher, ”but these parts were going to be machined before assembly anyway so that wasn’t a problem.”
Rolls-Royce has been using additive techniques for around five years to repair components, but is now gearing up to use it to make larger components from scratch, often where previously they would have been cast. “The project has been a key step in proving the industrial viability of the process, and shortening manufacturing lead times in this application by more than 30 per cent compared to developing components of this type using conventional methods of manufacturing,’ commented MTC chairman Clive Hickman. “There is no doubt that additive manufacture has the potential to transform manufacturing in the future.”
The engine bearing has been put through a series of ground trials, and Rolls-Royce plans to fly it for the first time later this year, when it will be installed into an engine on the company’s A380 flying test bed.
The MTC’s National Centre for Net Shape and Additive Manufacturing was funded from a £60million grant for aerospace technology development at the MTC, awarded by Chancellor George Osborne last year. While not yet fully equipped — its powder atomisation facilities are yet to be installed — it employs 30 engineers, which will rise to 50 by the end of next year. “It’s no exaggeration to say that almost every field of human endeavour, from how we travel, to what we make and use in everyday life, to what we eat, to how we treat injury or illness is likely to be touched by this revolutionary technology,” said MTC chief technologist Prof David Wimpenny.
Additive manufacturing enables parts which are too complex to be produced using existing manufacturing techniques to be made at the touch of a button. This is giving designers unrivalled freedom, unlocking their creativity and fostering a new generation of entrepreneurs able to explore new market opportunities without the high barriers to entry associated with conventional manufacturing. Moreover, it is possible to make a single part which is composed of several materials, each printed precisely where required to give the desired properties.”
InnovateUK chief executive Ruth McKernan added: “These ground-breaking facilities will further reinforce the MTC and the HVM Catapult’s capabilities as a world-class high value manufacturing research and technology organisation.”
Probably a silly question, is there a particular reason why they could not have used an inert atmosphere (that facilitated convective cooling) rather than use a vacuum?
The vacuum is actually needed for the electron beam to work correctly as you don’t want electrons colliding with particles in the air.
A truly remarkable achievement. Clive Grafton-Reed and the team at Rolls-Royce, the Engineers at Arcam and MTC all deserve high praise and kudos for their work in pushing the boundaries of additive manufacturing. And dare we say it to the government for funding the MTC so that the facilities are available.
But (why is there always a but?) I still get frustrated by the hyperbole dished out when talking about additive manufacturing. Phrases like “Additive manufacturing enables parts which are too complex to be produced using existing manufacturing techniques to be made at the touch of a button” and “unlocking their creativity and fostering a new generation of entrepreneurs able to explore new market opportunities without the high barriers to entry associated with conventional manufacturing”. This example didn’t happen at the touch of a button and the costs of doing it are clearly eye-wateringly high.
And then “It’s no exaggeration to say that almost every field of human endeavour …. is likely to be touched by this revolutionary technology”. Oh come on! Yes, this a brilliant piece of work and it may well revolutionise some aspects of aerospace manufacturing, but that is not mainstream production of goods for the 99.999% of all other human endeavour.
Dear Anonymous 1
I think you’ll find electron beams are not keen on gases of any sort, flammable or not.
I wish I understood how research funding works a bit better. Arcam is a Swedish company, I believe. Has the UK taxpayer just given them a commercial advantage for free? I would not be surprised if there is no UK competitor to it but it still seems a little odd.
I suppose that the aim is accomplished but is it wrong to say that now any aero engine maker in the world can do what RR can do and the UK won’t get a penny?
Bearings used to have balls and rollers and plains.
Since when did they get vanes?
Electron beam welding machines need a total or near total vacuum to work so I assume the same for a 3d printer using the same heat source.
If there was “atmosphere” involved it would be very difficult to focus the beam of electrons and lots of kinetic energy would be lost and dissipated as the electrons impinged on other particles.
Again, I marvel at the skill and abilities of the obviously multi-discipline (and presumably well disciplined!)Engineers who have developed and created this item. I also note the ‘nay-sayers’ :
I am reminded of Benjamin Franklin’s comment when asked by an (as it happens female) observer “What is the use of electricity?”
“Madam, what is the use of a new-born baby?”
Mike B
To Anonymous 2 – this ALM technology and the others that will follow from it will, in time, replace almost all other forms of manufacture. Right now they are limited in application and expensive, but when these two restrictions are removed there would be little incentive to not use them. Working in a very (and I mean very) closely related area I can assure you that ALM is how almost all hardware of this type will be produced within a decade or two. Other types of goods will probably follow in the decades to come. ALM is improving in leaps and bounds at the moment, so that what was impossible three years ago has now become routine. The perception in our corner of industry is that ALM is here to stay and will gradually replace almost every other manufacturing process. I note that the vanes still need to be machined at present, again that will certainly change as resolution is improved to the point where it exceeds traditional machining processes.
Electrons get ionised in an atmosphere. Other metal additive methods SLM/DMLD etc. all use an inert atmosphere.
The reality of this process of current state of the art of ALM is that constraints are placed on the design to support manufacturability. E.g. you cannot have internal voids without holes. Additionally how does one post-process a design with complexity – mallet and chisel.
Increasing the build time is not really a cornerstone achievement. Time is just a mere side effect of increase in build volume, that in this case places difficulties on consumables. Furthermore the ability to produce a part right first time is the biggest concern of the technicians running the machine which has a good certainity of failure
Repeatability, and defect free manufacture of components are produced from the machine are critical areas that need to be addressed by the Additive Industry before serious adoption can be made by leading industrial players.
Funding for research by EPSRC/ Innovate UK favours UK partners (academic and industry). The MTC on the other hand is presumably just an entity.
The consensus in the AM community is that it will not replace other traditional mass manufacturing methods but rather provide a tool to produce high performance/value components.
I think this is absolutely outstanding and brilliant! Congratulations to the gentlemen (and ladies) who made this possible on the east side of the pond.
Is this new bearing some sort of air bearing where the vanes produce the lifting air for the surfaces? I am unfamiliar with it.
Re Stuart’s question – ” bearings used to have balls & rollers & plains – since when did they get vanes?”
The actual component in question is a F.B.H. ( FRONT BEARING HOUSING) so is not actually a BEARING in itself but houses the front BEARING.
The vanes/aerofoils are for the core air supply.
On the comments re “bearing” with no balls 🙂
I reckon either the author missed the noun “housing” after the adjective “bearing”, or the editor decided it is not significant enough to keep it in the post:)
Clearly the pictured is not a bearing, and I don’t believe anyone would aspire to produce a 1.5 m diameter titanium bearing for any application :))