Also known as additive manufacturing, 3D printing has been around since the 1980s. Back then, only plastics were used, since they offered the perfect mix of characteristics for making prototype components that would later be mass-produced by traditional stamping or injection molding machines, milling machines or lathes.
In view of the possibilities it offers, today’s additive manufacturing can barely be compared to the 3D printing of a few years ago. In the industrial sector, it drives the development and manufacture of high-tech components. As a process that complements casting and milling, it makes it possible to create innovative high-priced components made of metals, polymers or ceramics that in most cases already perform better than their conventionally manufactured counterparts. Indeed, applications are proliferating in fields such as power generation, aerospace, health care, rail transportation, the automotive industry, and motorsports.
An Optimized Twin
“Additive manufacturing has developed into an independent production route that makes it possible to create completely innovative components and structures in small batches as well as in individualized mass production runs,” says Roland Busch, Chief Operating Officer, CTO and Member of the Managing Board of Siemens AG. For example, 3D printing makes it possible to produce chassis for racing cars, complex components for aircraft engines, hip joints, and gas turbine blades. It is also a useful way to make spare parts for machines that have been operating for decades, for example in trains or power plants. If an upgrade is desired, the digital twin of an original component can quickly be optimized before the replacement is produced. Indeed, in view of its many profound advantages, it’s no wonder that 3D printing is regarded as a key industrial technology of the future.
The global market for additive manufacturing is booming – and so is the market for associated printing materials, machines, software, and services. Analysts estimate that the volume of this market, which amounted to €9.7 billion in 2017, will reach €26 billion by 2021.
Traditional machine tools have geometrical limits on the components they can produce, but 3D printing leaves these limits far behind. The 3D printing process makes it possible to design almost any kind of complex structure. This means that the shape of a component can be designed in line with its function. For example, interior channels that help to cool off components that are exposed to high temperatures, such as gas turbines parts, can only be created with the help of additive manufacturing.
In addition, such components can be made lighter without sacrificing stability. And because of optimized designs, components benefit from less wear and tear, and a longer service life.
Data-Driven Production Processes
The revolution in industrial production that is now underway thanks to advances in additive manufacturing would itself not have been possible without the comprehensive digital transformation of production processes, from design and engineering software, and simulation tools for printing all the way to control and monitoring of printers. “All of these elements have to interlock smoothly,” says Ingomar Kelbassa, who heads Siemens’ Company Core Technology Additive Manufacturing. “Ultimately it’s not so much the individual technology that makes the success of 3D printing possible – it’s the whole package.”
A gas turbine burner needs a new head. It’s digitally designed, simulated, and optimized on a computer. The complete production process is also tested in a virtual environment.
Then it’s time: a thin layer of metal powder is applied.
The heat of a laser beam solidifies the powder to create the first metal layer.
The platform, together with the component, is lowered a few micrometers.
A new layer of metal powder is applied.
Again, the laser traces the contour of the component.
Layer by layer, the new burner head is melted onto the existing component.
Today, additive manufacturing already offers a range of unique opportunities – and not just in power generation. Thanks to increasing digitalization, it is rapidly becoming a standalone production method or complementing conventional methods in hybrid manufacturing. The future of 3D printing has only just begun.
People say that additive manufacturing will set off a revolution in industrial production. How would you assess its potential?
Meboldt: The special thing about this technology is that you can switch back and forth almost seamlessly between the virtual world and the real one and make things without using any tools. For over 20 years, additive manufacturing in the form of “rapid prototyping” has been an indispensable part of product development. Today this technology enables completely digitized manufacturing routes that end in series-produced products, which can be realized only through 3D printing. The industrial success of additive manufacturing ultimately depends on the usefulness of these products rather than on the technology itself.
Some companies still complain that in many cases this technology is not yet capable of manufacturing products that are ready for mass production.
Meboldt: Consider precision casting, which was being practiced in ancient Egypt. By comparison, our experience with 3D printing has been extremely short. Nonetheless, the results of 3D printing are already very impressive. In other words, the fact that 3D printing has not yet reached certain milestones is not an argument against it. Besides, it’s constantly being improved. In addition, if I successfully use 3D printing in series production, I can’t simply copy existing components. The design process and the value chain have to be rethought from scratch. But if you’ve made the effort, this process opens up hitherto undreamed-of possibilities. And these new possibilities are not only in the fields of design and functionality. They also enable us to save massive amounts of time and money in development and production.
To what extent does Siemens fulfill the preconditions for the industrialization of additive manufacturing?
Meboldt: Siemens has all the skills that a driver of additive manufacturing must have – and today it’s already demonstrating the benefits this process brings. In this area, Siemens is combining three important elements: process control, software, and application areas such as gas turbines, for which it’s already printing components such as gas turbine blades. Of course, you have to make sure that flexible decision-making processes are possible in spite of the company’s enormous size.
What do you think additive manufacturing will look like in the years ahead?
Meboldt: Normally, nobody is interested in how a thing is produced. With 3D printing it’s different, because here we have a technology that is being introduced simultaneously in the children’s room and at the level of company management. As a result, this technology is being extremely overrated. The day will never come when all the components that are produced today by means of molding, milling and injection molding are additively manufactured instead. But that isn’t our goal. Instead, 3D printing is a new production process that makes completely new innovative solutions possible in the process chain, in design, and in the area of materials. That’s why we shouldn’t underestimate additive manufacturing either. If companies wait for the market to become gigantic, they will miss the boat.
“Siemens is a pioneer in the field of additive manufacturing,” says Roland Busch. “No other company in the world offers such a comprehensive portfolio for the digital value chain. It ranges from optimized design to printer simulation, all the way to process monitoring.” This is a deliberately holistic approach that enables industrial customers to focus on their products – but that’s not all. More importantly, this approach creates the basis of trust on a new manufacturing route can be established.
Last but not least, Siemens can also point to its expertise in this regard. The first 3D-printed burner tips for gas turbines were produced in adapted printers by the EOS company in 2013. In 2014, employees at Siemens Mobility in Erlangen opened a competence center for additive manufacturing that designs and produces spare parts for rail transport and also offers advice to customers. In 2016 Siemens acquired 85 percent of the shares in Materials Solutions in the UK, one of the leading global companies for additive manufacturing. One year later, Siemens engineers were the first in the world to successfully print and test blades for gas turbines. Not long after that, the blades were followed by printed burners from a Siemens plant in Finspång, Sweden. The burners have been successfully operating in a commercial gas turbine since 2017. For the field of energy, Siemens is planning to qualify a total of 200 components for manufacture by means of 3D printing by 2025.
In addition, since 2018 Siemens has been supporting Hackrod, a U.S. startup that is using Siemens Product Lifecycle Management (PLM) software to design a chassis for a futuristic racing car. Hackrod plans to produce automotive frames in a 3D printer as big as a garage. So it’s no wonder that additive manufacturing is one of the 14 company-wide innovation fields in which Siemens invested €500 million in fiscal 2017/18. These funds were invested not only in Siemens’ own product innovations but also, and primarily, in its 3D printing portfolio.
To make sure the good news about 3D printing is heard throughout the company, Siemens Corporate Technology established a Berlin-based AM (Additive Manufacturing) Design Lab. The Lab is helping Siemens engineers discover the design potential of this technology. “This is a creative space where I can rethink the design process even for purely functional products such as switchgear,” says Ursus Krüger, who set up the AM Design Lab and heads the Additive Manufacturing research group in Berlin. Siemens has also established a similar lab in Erlangen for customers. Known as the Additive Manufacturing Experience Center (AMEC), the lab, which is operated by Siemens’ Digital Factory division, allows customers to explore 3D printing and experience the individual steps of the printing process.
Additive manufacturing offers industry the opportunity to establish a new production route that has unique potential. In spite of its countless possibilities, AM has still not reached a level of maturity where it can produce any desired component at the push of a button. For example, a printed component can become warped or deformed because of differences in temperature during the laser melting process. That’s why researchers are focusing on how to make the path from component design to production a routine process.
This kind of routine is especially important when it comes to metal printing, whose products are often used in critical equipment such as motors and turbines. Siemens has already reached the necessary degree of reliability for several components for gas turbines. That’s one reason why EOS, a renowned printer producer, relies on control technology from Siemens for the metal printers in its new M300 series.
Security in the Cloud
Of course, industrial printers and software are not the whole story. Companies have to think carefully about how to integrate additive manufacturing into their production processes in the future. For example, they could become more agile by printing certain components only on demand rather than storing components in warehouses. That would make them more flexible – and save space.
In a further step, they could save their design data in the cloud. This points to the promising possibility of companies being able to print components anywhere – for example, in remote regions where customers would otherwise have to wait for days for spare parts to be delivered. However, the security of digital production plans would have to be guaranteed. “We’re working on ways to guarantee data security, such as encryption and blockchain,” says Kelbassa. “The potential advantages are so great that developers in the 3D printing community will certainly find a solution there as well.”