Technical University of Ostrava’s Petr Štefek on the benefits of 3D metal printing

3D printed lattice structures, photo: Vojtěch Koval

3D printing has on caught more and more in recent years, both on the hobby and industrial ends of the market. At VŠB, the Technical University of Ostrava, students can get a close-up look and experience in Additive Manufacturing in industry manufacturing both in polymers and metal.

3D printed lattice structures,  photo: Vojtěch Koval
I spoke to the university’s Petr Štefek, Vice-Rector for Commercialization and Cooperation with Industry, asking him about work conducted at the school’s Innovation Support Centre and the benefits of Selective Laser Melting.

“SLM (or Selective Laser Melting) is the industry standard when it comes to 3D printing. It is used primarily in the automotive, aerospace or medical industries. Simply put, it has proven to be an excellent tool especially for fast prototyping. If you use conventional manufacturing methods for prototyping it costs a lot of money because first you need to create casting moulds, and then wait when the foundry is available, and it takes a lot of time to create small parts.

“But with 3D printing you have many advantages. Let’s say you need to create a small part for an end-user product you will get it on your desk within a few days. If you use conventional method it will take a few months. So arguably the biggest gain is a huge speeding up in the development process.”

That is a big difference indeed. And because of the system, I imagine it is also easier to introduce modifications into the design on the computer much more quickly: if you have a mould and something is off, you have to go back and the whole laborious process is repeated. That’s not the case here.

“SLM, the industry standard, is used primarily in the automotive, aerospace and medical industries.”

“That is correct and if you are not convinced with your design you can redo it quickly. By the way, you can do more than just prototyping it is also suitable for creating parts for end-used products for cars or for the aerospace industry.”

I was looking at some of the pictures of parts which had been 3D printed and one thing they had in common was similar structuring, along a honeycomb or grid, to reinforce strength but at the same time leave plenty of empty space, to shave off un-needed weight.

“That is the second big advantage of Additive Manufacturing because you can use generative design for structural topology optimization to make it as light-weight as possible. Weight plays an especially significant role in the aerospace industry, so if you need to take off 40 percent weight in a part which is used ten times in a plane, for example, in seats, that is where you see the rewards.

3D printed lattice structures,  photo: Vojtěch Koval
“Nowadays you see hundreds and even thousands of such parts in civic aircraft. But most are definitely not used in any critical systems, certainly not in engines or in anything like that.”

From what you are saying 3D printing in metal has become fairly commonplace in industry: how long has it been in use?

“That is a good question. I would say that it has been 20 years in the making and I would say it will take another 20 to fully adopt SLM or other future technology which follows, to be used most broadly in aerospace.”

We talked about the structure and the shape of some of the items printed: is it the case that, using narrow AI, a part will be better reinforced, strengthen in areas than if it had been made by traditional means, cast or welded? And not only that, but that the program working with input data makes the decision itself?

“That’s right. I should say that those are very special software applications. We use some of them at the university but by and large they are very expensive and they are broadly used right now only by the very biggest companies in the world, such as Airbus and Boeing.”

“One advantage is that you can use generative design for structural topology optimization to make it as light-weight as possible.”

At the university you obviously cooperate closely with the private sector, I can’t imagine it any other way, how many 3D printers do you have at your facility?

“We have two machines, one for Selective Laser Melting, which we have been talking about. That one is for alloy prototypes. We use stainless steel and other better steel with better hardness and is useable for tools and moulds, for example. The second machine is a plastic 3D printer Plastics, of course, are suitable for end-user products.

“When it comes to operating these machines there are safety steps and procedural steps to follow, but the process is very safe, there are also all kinds of safety guards, as some alloys can be toxic in the process. The risk though is very small.”

To what degree are the machines available to students at the university?

3D printed rocker,  photo: Vojtěch Koval
“Our centre is open-access so if you are a student at the university, for example, of mechanical engineering and you are interested in 3D printing it is not a problem to come and take part in real world projects for the private sector, in a helping capacity.

“To be honest, though less students are interested in the manufacturing possibilities than for example in centres in neighbouring countries like Germany. I am not sure why that it, because these kinds of things attract a lot of students abroad but we hope that this will change.”

What are some firms with whom you have worked?

“One is a great Ostrava-based company called Invent Medical which does an amazing job in the field of prosthetics and other medical products for small children including helmets. This is a company built on the concept of Industry 4.0. They are one of the most progressive firms in Ostrava and even the Czech Republic.”

“3D printing is an evolution, not a revolution.”

That is always great to hear. Speaking of which, one of the things that is often asked about is just how much Industry 4.0 will change the world. We have talked about the positives but there are also fears over the loss of jobs and other effects.

“Firstly, I would say that is not a revolution but about evolution. 3D printing will certainly have an impact on design but it is the same as automation and robotisation: it will impact jobs in the industry but I think related emerging industries will offer new employment opportunities. There will be big challenges and we need to be preparing the ground for the next generation of 3D printers. It is an evolution.”