Part 1 of an in-depth Q&A with one of 3D printing’s leading experts.

Ehsan Toyserkani has seen a lot throughout his long career in 3D printing. He holds more than a dozen patents and he’s currently leading one of the top research labs in the world. If there’s anyone who can dispel the myths about this technology — not just among the public but among engineering professionals — it’s him.

We sat down with Prof. Toyserkani to discuss his career in additive manufacturing and how the industry and technology are often misunderstood.

engineering.com: What initially attracted you to 3D printing and how have your interests in it shifted over the course of your career?

Toyserkani: I think it goes back to October 1999 when I was choosing a topic for my PhD program, and my supervisors gave me the authority to choose any topic that I liked as long as it could be done at the University of Waterloo. That was great! So, I was doing some literature review and I came across an emerging technology under development at different universities and research centers in Europe and the USA known as laser metal fabrication or laser consolidation.

My Master’s degree and some previous work experience I had were related to feedback control and in-situ monitoring, so I decided to come up with some sort of integration of feedback control into this particular class of additive manufacturing, which is called laser directed energy deposition these days.

That decision proved to be a very critical moment in my academic career because it opened up a lot of research and development opportunities for me, as well as enabling me to secure a faculty position at the University of Waterloo in 2004.

Since then, my R&D efforts have been consolidated under a broad and dynamic field of additive manufacturing, including laser directed energy deposition, as well as laser powder bed fusion and binder jetting.

It sounds like you were anticipating where the industry was heading, given how much we hear about in-situ monitoring and closed loop control in AM these days.

It might have been a little too early, actually. The first patent I filed in 2002 was related to closed loop control of laser cladding (which was the terminology we used in those days) using multiple sensors, to improve the geometrical features of printed components. But the industry wasn’t really aware of additive at that time, so the patent wasn’t very well received.

After fifteen years or so, around 2016 or 2017, the patent came to the attention of many, many companies and we’ve been able to come up with a lot of R&D programs with companies in the USA and Canada. Unfortunately, by that point we were coming to the end of the patent’s 20-year lifespan.

Are there any other patents you’re proud of?

There are many, but one that’s been very effective when it comes to industrial applications is a technology we’ve developed for printing strain gauges on non-planar surfaces of high-value components for aerospace using aerosol jet printing. That’s been in collaboration with GE Aerospace over the last several years, and we have five or six patents from that already.

With this type of 3D printed sensor, you can measure residual stresses at high temperatures. The efficiency of most propulsion systems is very low — we’re talking about 60-70% — and in order to improve that, you need to increase the temperature in the combustion chamber, which requires better materials and, obviously, better instruments.

Now, those better materials have been developed: super alloys that can stand up to 1,800C or even higher. But, for certification purposes, the aerospace industry requires sensors that can stand up to those same high temperatures. They don’t want bulk sensors, because those can interfere with airflow, so what they want is a thin film that can be printed on any location on a turbine blade, for example.

You’re printing sensors directly onto the turbine blades?

Yes, but we can’t go with just one deposition, because it’s not just the sensor layer you need to print, but the insulation layer as well. It’s challenging because you need to inject a specific material — palladium chromium — that can withstand high temperatures, you have to sinter it, and then at the end you have to recoat it with an aluminum insulation layer for protection. If you can do all that, you have a way to verify the components made from those specific super alloys.

You oversee the Multi-Scale Additive Manufacturing Laboratory at the University of Waterloo, which is among the top 3D printing research labs in the world, and certainly the most advanced in Canada. Are there any particular milestones from MSAM you’d like to highlight?

We’re hosting more than $25 million worth of equipment and we’re one of the few labs at the University of Waterloo operating off campus. In terms of milestones, I usually start by saying that I have been so blessed to work with so many talented people. For example, one of the co-directors of the lab is Dr. Mihaela Vlasea, who is my former PhD student. We have many alumni founders of companies that are returning to the lab as well as a lot of engineers who are working in the 3D printing industry.

These kinds of collaborations with industrial leaders is another milestone. We’ve partnered with GE Aerospace, Siemens and Safran Landing Systems, to name a few. I’ve already mentioned the one project with GE, but we’ve also had some great multidisciplinary research projects.

One I ran back in 2007 with Mount Sinai Hospital in Toronto involved a novel 3D printing technology to make biodegradable bone implants with complex shapes from calcium polyphosphate. That project was extremely beneficial for them and for us because we all learned a lot. In fact, they just got FDA clearance for human finger bones, so we’ve started printing those for them a few times a year.

On the subject of students you’ve worked with in the lab, there’s a common sentiment that younger generations of engineers are likely to have more familiarity with 3D printing because they’ve grown up with it. Has that been your experience?

Absolutely! The skill gap is a major problem in the additive manufacturing sector; it’s one of the challenges that the industry is still facing. That’s why we’re educating people about the merits and benefits of the technology as well as its challenges and shortcomings so they can find the right applications for additive.

There are a lot of misconceptions among the public and among engineers when it comes to additive manufacturing, so if we can train people correctly, they can go to work in different industries and push the technology forward. If people aren’t trained properly, these misconceptions can grow significantly, not only in the public, but with engineers as well.

Are there any particular misunderstandings about AM among engineers that you see often?

Yes, there are many. Among engineering professionals, there are a lot of misconceptions that could be considered non-scientific or even preconceived notions based on conceptual misunderstandings. For example, when I’m talking to industry professionals who are new to additive, many think that all additive manufacturing technologies are the same. This is not correct. Based on the ASTM/ISO standard, we have seven classes of AM, but each class has different branches: when you look at directed energy deposition, there’s laser-based DED, electron beam DED, arc welding, and so on. Understanding the differences between them is critical to understanding the right process parameters for your application.

There’s also a misconception that additive manufacturing is an easy task, and I can tell you it’s not. There are some people who think that AM can be immediately adapted to any manufacturing process without significant R&D, but this is often a major challenge — not just the technology but the supply chain logistics, quality assurance and so on.

Another one I’ve heard from within the AM industry is that it can always save energy and have a smaller CO2 footprint. This is not correct. If you just take a conventional part and give it to someone to print for you, the amount of energy and money that you have to put into it is potentially higher than conventional methods. Many people think that direct adoption of AM from conventional methods is feasible, but in many cases it’s not. You need to design for additive to get the benefits from it.

Actually, many people think that design for additive (DfAM) is the same as conventional design, but that’s completely wrong. Successful additive manufacturing requires a deep understanding of the technology and DfAM is very important. If you don’t have a good understanding of DfAM, the outcome becomes very disappointing. We have seen that ourselves, where people without the right knowledge get so frustrated with the technology because they did not do their adoption through the right pathway.

Then there are the misperceptions that have been around a long time:

Additive parts are weak. No, they can be stronger than conventional parts, though the costs may be higher, so you really need to do that lifecycle assessment to be sure.

Additive is only good for prototyping. No, it can be adopted for serial production. There are companies we’re working with today that are using additive for production but unfortunately, because of confidentiality, many of these companies do not talk about this type of serial production. But even in our lab, we’re working with companies that are producing four or five thousand additive parts per year for the energy sector.

No post processing is required for additive. This is wrong. Typically, we say that the entire process should be considered holistically, from the feedstock all the way to the end part application.

Continued in Part 2: Challenges and opportunities in metal additive manufacturing.