An enormous new market for lasers and optical systems
Prof. Claus Emmelmann was recently nominated for the 2015 German Future Prize. In collaboration with Airbus and Concept Laser, his Laser Zentrum Nord is working to establish additive manufacturing (commonly known as 3D printing) in aircraft production. In an interview, the expert explains how the technology will develop and what impulses from this we can expect to see on the laser and imaging markets.
Congratulations Professor Emmelmann. Very few people manage to get into the top three contenders for the Future Prize. With your partners at Airbus and Concept Laser, you are propagandizing an additive manufacturing revolution. Why is 3D printing so revolutionary?
Emmelmann: Many experts are now talking about a revolution. The cost and innovation potentials are enormous. Developing components layer by layer enables completely new products to be manufactured. These include lightweight components with varying wall thicknesses or with cavities inside the component. The introduction of conformal cooling channels, hydraulic and pneumatic lines is also possible. Or also the option of manufacturing assemblies in one piece from many individual parts. This involves enormous changes in supply and production chains. Assembly costs are reduced, supply chains become shorter, and certification expenditure also decreases. Not least, spare parts can be printed on site, instead of having to store them and transport them to where they are needed. There are enormous benefits for customers. And because there is no need to construct tools and molds, additive manufacturing is often less expensive than conventional production methods. With Airbus, so far we have implemented a €10,000 filler neck for the A400 M in 3D printing for €4,000. Tooth caps made from cobalt-chromium, on which dentures are constructed cost €10 each when milled but just €3 when printed. And with more efficient system technology, further cost reductions are realistic.
System concepts are moving in the direction of multi-laser technology...
Emmelmann: ...through which enormous productivity increases will be achieved. For example, a machine with four lasers can now build up 50 cm³ material per hour, compared to 5 cm³ with one laser. I believe that with semiconductors and optimized machine engineering, in the medium term we will see build-up rates of 500 cm³ and in the long term, up to 5,000 cm³. Companies should start training their designers now, since they will have to change their way of thinking in order to leverage the full potential of the technology. They can now design the inside of components almost freely, whereas in the past this was completely or virtually inaccessible from a production aspect. Especially in the aerospace industry, we are having more and more success merging assemblies made from dozens of individual parts into one assembly. We need a specific design for additive manufacturing and new supply chains have to be organized.
What demands does additive manufacturing place on laser technology?
Emmelmann: With increasing build-up rates, we can expect to see an increase in the number of lasers in the systems—possibly also with different power ratings. The first system builders are now using powerful lasers in the kilowatt class for rapid exposure of the component core, while lasers in the power class 100 to 500 watts melt on the finer surface. For this to function properly, the design and exposure processes must be coordinated exactly. It is a complex process to integrate several lasers and control them in overlapping work areas. Another trend: More powerful lasers. The first systems with 5-kW lasers are on the market. A similar power is also needed for laser deposition welding. The technology is still very new. We will have to wait and see which materials will be successful in which markets.
A short word about lasers: These days it is mainly YAG and Yb fiber lasers that are in use. Will this change?
Emmelmann: In view of the high beam quality, the good level of efficiency and the good price performance ratio (€/W), I don’t really see any alternative. Whether direct diodes will manage the leap into the required power ranges is questionable. If yes, this would be an energy-efficient alternative. I think as well as the power, another issue will be the wavelength. Green lasers are interesting. And of course, it would be wonderful if in additive manufacturing we could use adjustable lasers with many different wavelengths.
Are the demands for precision high?
Emmelmann: Compared to other areas in which lasers are used, not particularly. In additive manufacturing, precision is more a question of the powder. This starts with particle sizes from 20 µm and corresponding focus sizes between 30 and 50 µm. Laser producers are used to much lower resolutions. It is not so much the precision that is challenging, but more the interaction between lasers and scanners.
The industry wants automation and in-line quality controls in 3D printing. Does this open up opportunities for optical technologies apart from lasers?
Emmelmann: Definitely! Quality is very important, as in the process we are not only redefining the geometry but also all the component properties. The objective is to qualify the process and components precisely in the laboratory and to define the parameters for the printing process. Their compliance must be monitored with sensors, for which pyrometric, camera and UV emission methods would be suitable as well as optical computer tomography and many other optical methods. This is a focus of our research – an enormous new market is evolving for lasers and optical systems.
Will the 3D printing revolution also result in the end of laser cutting and welding?
Emmelmann: At present, the world market for laser systems for material processing is €8 billion, a large part of which is for laser cutting and a smaller part for laser welding and laser ablation. In terms of sales revenue, laser processes are niche markets compared to conventional welding, cutting and milling technologies. This may change with 3D printing. In the metalworking area alone the world market is expected to grow from the current €1 billion to €100 billion within ten years; about 30% of this, that is €30 billion, will be spent on the systems. Considering this alone, you can see that additive manufacturing should become the largest sales market for laser technology in production. It will take away market shares from conventional processes—including laser processes—and replace them in the process chains.
Prof. Dr.-Ing. Claus Emmelmann is Head of the Institute of Laser and System Technologies (iLAS) at Hamburg University of Technology and CEO of LZN Laser Zentrum Nord GmbH. He was recently nominated for the 2015 German Future Prize for the project "3D Printing in Civil Aircraft Manufacturing—a Production Revolution is Taking Off".
© Copyright Ansgar Pudenz