New EPFL professor Anirudh Raju Natarajan to contribute to NCCR MARVEL’s phase III

Anirudh Raju Natarajan grew up in the south Indian city known as Chennai (formerly Madras), going to school there before studying Metallurgical and Materials Engineering at the Indian Institute of Technology Madras. After graduating, he moved to the U.S. for grad school, spending a year at the University of Michigan in Ann Arbor before moving to the University of California, Santa Barbara. After receiving an M.S in Materials Science and Engineering from the University of Michigan and a Ph.D. in Materials from UCSB, he continued there as a post-doc before being offered, last year, a position as a tenure-track Assistant Professor of Materials Science in the School of Engineering at EPFL. Since arriving, he has set up the laboratory of materials design and simulation (MADES), where he will focus on the computational design and discovery of advanced engineering materials. In his free time, he enjoys cooking (and is particularly proud of a vegan biryani recipe he recently perfected) and running by the lake. He’s also looking forward to exploring the mountains of Switzerland.  

Interview by Carey Sargent, EPFL, NCCR MARVEL

Were you always interested in science?

As a kid I recall going to this place in Chennai where a glass blower made tiny figurines that really fascinated me. It got me interested in understanding how glass is made and that started me on my journey towards materials science. I especially enjoy working in the area of materials theory because it allows me to combine my passion for physics and mathematics with my interests in materials science. Being able to design the next generation of engineering materials on a computer is very exciting for me!

What attracted you to EPFL?

The excellence in research and education at EPFL made it an ideal institution for me to begin this new chapter of my academic career. I’ve always been very impressed by EPFL’s strength in materials science and more specifically in the field of materials theory. I look forward to collaborating with the world-class researchers here at EPFL. Further, the academic culture is very well set up for the success of junior faculty. What’s front and center, here at EPFL, is the desire to do great science that has a long-lasting impact on society. That very much excites me. 

What will be the main research focus areas of your MADES group be over the next 5- 10 years?

My laboratory (MADES) uses theoretical methods to enable the design and discovery of the next generation of high-performance engineering materials. We use a multiscale approach that connects the electronic structure of a solid to its thermodynamic, kinetic and mechanical properties at the mesoscale. Starting from the electronic structure and the atomic scale, we use quantum mechanics to understand how atoms bond and then take that to the next level using statistical mechanics. Statistical mechanics helps us use the information at the atomistic scale and coarse-grain it to quantify the mesoscale behavior of materials. We employ cutting edge theoretical tools to rigorously predict materials properties from first principles. Coupled with machine-learning techniques, these quantitative models enable us to computationally explore a wide range of materials chemistries and processing conditions in metallic alloys.

One class of materials we are studying is commonly referred to as high-entropy alloys. These are attractive materials for high-temperature aerospace applications and are typically made by mixing several elements together. My laboratory is predicting structure-property-processing relationships in these complex materials with the ultimate goal of designing alloys that are strong and resistant to corrosion even at elevated temperatures. Another area of interest is the development of lightweight materials for automotive applications. We are exploring the role of kinetic and thermodynamic pathways to form strengthening features such as precipitates and grain boundaries within these materials and their macroscopic relationship to strength. Finally, we are also designing materials for additive manufacturing. Additive manufacturing is an extremely complicated processing technique that subjects materials to complex temperature, stress and composition gradients. We are adapting our theoretical models to enable the design of novel material chemistries and processing protocols for the additive manufacturing of metallic alloys.

Where do you see synergies with NCCR MARVEL?  

The MARVEL ecosystem provides a great opportunity for the collaborative development of new methods and materials. I look forward to working with all the researchers that are part of NCCR MARVEL to use the methods that have been developed within the center and bring some of our own techniques to expand the palette of tools within MARVEL. The researchers within the center have a deep understanding of materials design and I look forward to adding to their expertise with efforts from my laboratory.

What’s the biggest challenge to pursuing a scientific career?

I think the biggest challenge in a scientific career is finding the right questions to ask. Asking the right questions can unlock new areas of scientific research. Of course, it is important to then also come up with the right answers – but it is the first step of asking the question that is crucial to solving important problems.  

What do you consider to be your top two papers?

1. On the early stages of precipitation in dilute Mg–Nd alloys

The first was more of a series of papers. It was enabled by a collaborative project based out of the University of Michigan where we were trying to understand the physical metallurgy of magnesium alloys. Like at EPFL, we were working with experimentalists and theorists—who were all coming together to build better magnesium alloys. Being able to work within this collaboration was very exciting and I learned a tremendous amount from everyone associated with it. I was working with experimentalists to ensure that our predictions could be validated and working with theorists to use our models in longer length scale techniques to predict the macroscale behavior of magnesium.  I thought it was an intellectually rewarding experience and I am extremely proud of the results that we achieved within this collaborative project.

2. Connecting the Simpler Structures to Topologically Close-Packed Phases

The second paper was inspired by concepts that were introduced to me during my undergraduate education but mystified me. There are these phases, called Laves phases, that are observed in several alloys including steels, magnesium, and refractory alloys. They are typically not desirable and alloy designers try to avoid their formation. What is very interesting about them is that they have a very complex crystal structure and their formation mechanisms were (at that time) unknown. In this paper, we were able to show how materials can undergo structural phase transformations to form these Laves phases. To me, it was a Eureka moment as I finally understood the crystallography of these phases and the reason for their formation in metallic alloys.