31/08/2018

Prof. Dr. Christiane Stephan-Scherb looking through the "X-Cor II” device

Modeling three-dimensional structures, visualizing processes: Sometimes all you need is a bit of creativity.

Source: BAM

Prof. Dr. Christiane Stephan-Scherb is a junior professor at the FU Berlin and researches high-temperature corrosion in the Materials Engineering Department at the BAM. The trained mineralogist applies her experience from working on solar cells to the classic field of materials engineering: Corrosion research.

Ms. Prof. Dr. Stephan-Scherb, what are you researching right now?

I am working on a very classic topic here. Most of my experience is actually in solar energy research, but right now I’m working on high-temperature corrosion. I am investigating what happens to high-performance materials subjected to reactive gases at high temperatures. In practical terms this means: A hot reactive gas such as SO2, sulphur dioxide, reacts with metal - at a power plant for example. Corrosive reactions will then occur on the surfaces and interfaces at temperatures over 500 °C. When corrosion occurs, thin layers grow on the steel and at the same time, the reaction will start eating away at the material and damaging it. We take a closer look at the thin layers that form under these conditions. We want to have a better understanding of the early stages of corrosion, so we can make more precise determinations about the corrosion behaviour of materials.

Why is it important to be able to more accurately predict corrosion behaviour?

Corrosion is very costly and causes serious hazards each year. When, for example, superheater pipes burst, causing major damage, this is often the result of corrosion. It is an extremely important field that traditionally has been well-researched as well. We want to better understand how materials can be designed to reduce corrosion. Ideally we want to be able to give recommendations on how alloys should be customised to form protective layers under specific conditions of use.

What approach to research do you bring to the table as a mineralogist?

Corrosion research has a long tradition at the BAM. We are examining a few new aspects. We are taking a closer look at the corrosion process through the crystal structures formed. These are crystallisations at the nanometre level. And we also examine the special connections that form at points in time during the degradation process. X-ray diffraction and absorption spectroscopy allow us to observe the crystallisation process during the degeneration process. With our systems, we try to follow the corrosion reactions on the metal surfaces in the real-world environment in real time and combine this approach with classic metallographic analytics.

How did you get involved in corrosion research?

In corrosion research, I discovered an insanely exciting field of science. There is a lot to consider when you're investigating corrosive processes. A lot of different factors come together. The various metal and gas components that interact with each other for example, where a variety of different processes are occurring simultaneously. This interplay is fascinating to me. As junior professors, we have the privilege of doing a little more fundamental research, which I have always found very interesting.

What gets you excited about your work?

I am simply excited about the world of research opportunities that this field presents me with and the questions that remain unanswered. I am convinced that we can learn something new every day. I’m always having to take a closer look at some aspect or another. That’s what drives my research. I am always thinking: We’ve got to examine this thoroughly before we progress any further here. That’s why I chose a career in science after completing my studies. Understanding things in detail is very important to me.

Besides the attention to detail, what is important to you in your work?

In addition to efficiency, I also consider ecological aspects. One of the things I find really exciting is the possibilities presented when you design materials with certain characteristics by combining different metals. You have to be very precise in your considerations while doing that though. The more elements an alloy contains, the harder it is to extract the valuable materials again. So it’s very important to make sure new materials are processed efficiently, starting during production. We have to think ahead. It’s not enough to have a material with optimal characteristics that will be stable over long time. It is also necessary to preserve resources by recycling valuable materials and using material-efficient procedures. Using the resources the earth gives us responsibly is really important to me. I also try to imbue my students with that value as early on as possible.

You also teach at the FU as a junior professor – a welcome change of scene?

I really like to teach, because I think I also learn a lot in the process. Especially when I completely redo old lectures, I take a look at things again from a different perspective. Students also sometimes ask questions that I never would have thought of, because it seemed obvious after all of the years in research. But maybe it isn’t that cut and dried. Being a professor always involves two things. Scientific curiosity must be satisfied, knowledge created. But the professor is also responsible for training the next generation. I think we have a big responsibility there.

Where do you get the creative inspiration for your research?

I am the mother of two young children and when I look at them, I always think that scientists are people who are still kids at heart. Children do experiments all day long in order to understand the world and we are basically doing the same thing. Our experiments are just a little bit more complicated. I’m also rediscovering a completely new side of building bricks and Legos. It’s amazing what all you can do with them: make models of three-dimensional structures, visualise processes. Sometimes all you need is a bit of creativity. I really must say: We could still learn a lot about creativity from children.