Rolls-Royce is using an increasing number of lasers in a number of different ways within its factories to bring down costs and up productivity.
Speaking at a conference for AILU, Clive Grafton-Reed, from Rolls-Royce UK, said lasers are the third most used technology within Rolls Royce now and most of its laser-based activity is within the drilling of turbines and combustors within its engines.
Drilling
The lasers have to drill a diverse range of shaped cooling holes for the company’s engine parts and it is now getting to the stage where the lasers need to keep up with the company’s designers. ‘The design guys draw nice smooth lines and we have to try to reproduce that,' said Grafton-Reed. 'Previously it was the motion system that held us up, but now it’s the lasers and they need to be improved to keep up with our designs.’
He added: ‘Hole drilling to us is a huge part of our business.’ The company uses a Laserdyne 500 NGV for drilling NGVs (Nozzle Guide Vanes) and blades, which has improved shaped hole processing compared to previous machines, because of the device’s beam director facility.
And the latest machine that Rolls-Royce has received from Lasertec is a PowerDrill 80 machine, which is used to drill NGVs and blades too and has fast linear drive axes and a torque axis to significantly reduce cycle times, according to Grafton-Reed.
The turbine systems have Laserdyne, Lastec (Lumonics), Amchem (Winbro) and Lasertec machines and the combustors are drilled using a range of lasers, including the Lasertec PowerDrill 130 and the Laserdyve 780 and 790.
The company also has plans for the future of laser drilling including modulating the laser pulses as a hole is being made and using ablation to create holes of a greater quality and give greater design flexibility.
Laser Welding
Rolls-Royce has also used lasers for its welding processes, although this makes up a smaller part of its laser business, as Grafton-Reed said: ‘We do not do a great deal of this compared to the drilling.’
The company uses the Trumpf TLC1005 6-axis machine for its laser welding and is hoping to replace its current TIG (Tungsten Inert Gas) welding with the laser version.
‘We can get better results using laser welding compared with TIG,’ according to Grafton-Reed who cited several advantages of using laser welding including: reduced distortion, which has led to less rework and distortion correction for the company, more consistent welds, no vacuum chamber is required, and there are cost savings.
‘We are yet to go into production for laser welding, but we have successfully demonstrated it within our factories,’ Grafton-Reed added.
Future tech
Rolls-Royce is looking to up its use of lasers, and is focusing on more diverse ways to use them, with more wavelengths and different powers, within its business.
Direct Laser Deposition (DLD) is a Rolls-Royce patented process for producing abradable seals in engines, which the company jointly developed with TWI and Trumpf, based on the DMD505 kit. ‘DLD has had a great impact on getting engines to run longer and saves a fortune for us,’ said Grafton-Reed.
The company is also looking into using ultra-short pulse length lasers for cold processing and using fibre lasers, particularly within its welding applications.
But Grafton-Reed thinks the cost of using fibre lasers, as with other innovative laser tech, needs to mature, as he added: ‘Fibre lasers we see as able to change our world [but] our factories run 24/6 and anything in those factories must run for the same amount of time so everything must be economic.’
