Lighter + more complex = additive Oerlikon employee Ludo Bautmans belongs to a group of men and women who transform an entire industry sector
Already as a student, Ludo Bautmans made a decision to be a lifelong learner. That he would one day belong to the group of men andi women who transform an entire industry sector is a fact he would never have considered even in his wildest dreams. He spoke with BEYOND SURFACES about how suppliers and manufacturers in the turbine industry are facing challenges due to additive manufacturing and how Oerlikon is providing assistance.
"It couldn’t be more exciting anywhere else at the moment than it is right here.” Ludo Bautmans, Application Engineering Manager in Oerlikon’s Additive Manufacturing business unit, makes a hand gesture that includes not only his office in Holland’s Lomm, but encompasses the entire tri-border region between The Netherlands, Germany and Belgium: “We’re at the centre of what’s happening! The leading protagonists in the ongoing development of additive manufacturing are to be found here within a radius of only 100 kilometres. This includes the universities of Leuven and Aachen, the Fraunhofer Institute for Laser Technology (ILT) and ICTM Aachen, the Aachen Center for Additive Manufacturing and many researchers and companies working in the area of additive manufacturing that are concentrating their efforts on specific topics such as electronics, equipment assembly and software. And we work together with all of them because we are part of a ‘Consortium Study’ with a long-term focus that deals with processes, materials and applications for additive manufacturing as well as with questions concerning the topics of productivity, cost-effectiveness, design and process quality!"
For two and one half decades with Oerlikon Metco, Ludo Bautmans has researched the question of how to make turbines even more efficient. As the head of the Eldim research department and a member of the worldwide R&D team, he began dealing with the topic of metal-based additive manufacturing (AM) very early on in the game. He was also involved from the start when, after the acquisition of Metco by the Oerlikon Group, a separate “Additive Manufacturing” business unit was established. In the meantime, the number of staff in the AM team at Oerlikon is already in the three-digit range.
Light, complex components are suited perfectly for additive manufacturing
"Metal-based additive manufacturing is today often used only in development. This saves manufacturers and suppliers time and expense in the testing and validation phase, because expensive tooling is only needed for series production. However, additive manufacturing is going to radically change entire sectors, and the transformation has already begun. Bautmans cites an example: “Fuel nozzles used to be fabricated conventionally, but today this is often done additively. Especially light, complex components are perfectly suited for AM – and in turbines, there are plenty of light, complex parts."
"For him, the fuel nozzles are only just the beginning: “A number of large suppliers are developing their own internal departments for additive manufacturing, or they are buying out start-ups. But the technology is developing unbelievably fast and the demand for additively manufactured components will soon be so great, especially in the aircraft and energy turbine market, that it will no longer be possible to satisfy it in these in-house departments. Smaller suppliers as well will soon either want to or have to engage in additive manufacturing and these are frequently unable to afford their own AM departments. This means it is only a matter of time until the market opens wide for additive manufacturing and thus for third-party suppliers such as Oerlikon!"
Layer by layer
Not only turbine manufacturers, but other industry sectors as well are constantly on the lookout for new ways to build more functionality into components and to increase their performance. In most cases, however, this also makes their geometries more complex, and that means that producing them conventionally becomes difficult or can become a bottleneck in the production chain. In contrast to conventional fabrication of workpieces in which material is removed from a solid block by milling, drilling and grinding until the desired shape is achieved, in additive manufacturing, a workpiece is built up layer upon layer, which means that the complexity of a part is insignificant for the additive manufacturing (AM) process.
Tuning materials to get the most
out of them
In contrast to the 3D printing of plastic components, metal-based additive manufacturing is significantly more complex. “Here, it’s not enough to just get the material and a printer and take off with them!” As an engineer in the Additive Manufacturing business unit, Bautmans is working on the question of how the materials portfolio needs to be modified for application in additive manufacturing and what materials are best suited for which applications.
"The material is already being offered by Oerlikon. In collaboration with my work colleagues, the independent research institutes here in Aachen and in the framework of projects by the ‘Consortium Study’, I am working on making it usable for additive manufacturing. This entails modifying the chemical composition of a material as well as its parameters – you could say we are ‘tuning’ it to get the most out of it for the respective application. And, of course, we are also looking at the most suitable surface treatments and heat treatment approaches."
But all of that is still not enough for an additively manufactured component to satisfy the requirements of turbine manufacturers. A whole series of production steps must be mastered, from application techniques and post-treatment, on to trial runs, inspections and quality control.
An entire process sequence for a new technology
"During my studies, a professor explained to me that my choice of a career would mean that I would have to remain a learner throughout my entire working life. And how right he was! Thanks to additive manufacturing, I have the chance as an engineer and researcher to be involved right from the start in the development of a new technology. That is unbelievably exciting and the speed at which this technology is developing is breathtaking, even for someone like me who is involved at such a fundamental level", says Bautmans.
Oerlikon Metco has decades of experience in metal-based powders, while Oerlikon Balzers is a pioneer in surface solutions. Together, they cover the entire process sequence which additive manufacturing requires. “Soon, we will be producing many other parts for turbines using additive manufacturing – including even significantly more complex parts and at a much higher speed than in the past – and then, the only question I will still have is when additive manufacturing will replace traditional production,” says the engineer with a view towards the not-too-distant future.
Solutions for turbines
Oerlikon Metco’s Eldim technology specializes in components and the machine processing of turbines. For the Aero Turbines, mainly light weight seal carrier rings and sheet metal seal segments are created from nickel, cobalt and stainless metal sheets. For Industrial Gas Turbines, raw castings are received and finished using non- conventional technologies such as ELectro DIscharge Machining, Electrochemical Machining (ECM), Electrochemical Drilling as well as high-temperature vacuum brazing and diffusion treatments. As such, grooves, pockets, tip cavities and cooling holes are added to housings made using superalloy castings, thus maximizing the turbine’s efficiency.