September 13, 2017 – Niyanth Sridharan grew up in a family that indulged his questions by using real-world examples to explain scientific concepts. That natural curiosity still drives the materials researcher today as he explores additive manufacturing techniques at the Department of Energy's Oak Ridge National Laboratory.
“Every time my uncles visited they taught me scientific concepts. I never really knew what metallurgy was until my uncles encouraged me to explore it,” Sridharan said. He credits their influence for his desire to pursue a career in engineering.
“One of my uncles used to quiz me on simple scientific phenomena like surface tension and used real-world examples. Learning about science through these examples is a great way to kindle interest and spark an emotion that makes problem sets come to life,” he said.
Sridharan went on to earn his undergraduate degree in metallurgy at PSG College of Technology in Coimbatore, India. He then worked for an oil and gas company in India maintaining a power plant. The first few years at the plant were fun, but after a while the work became monotonous, he said. “That’s when I decided to earn a Ph.D.”
While deciding on his doctoral studies, Sridharan recalled his work as an undergraduate at the Indira Gandhi Center for Atomic Research, a national laboratory in India. “My mentor was the head of the welding metallurgy group and he knew Dr. Suresh Babu. I read some of Suresh’s papers and was very interested in the work he was doing at Ohio State University.” Niyanth pursued and received acceptance into Ohio State to earn his graduate degree under Babu’s mentorship.
When Babu moved from Ohio State to the University of Tennessee, Knoxville, Sridharan followed and became a student at the Bredesen Center for Interdisciplinary Research and Graduate Education, which encourages entrepreneurship in addition to academics. During that time, he began working as a graduate student at the Department of Energy’s Manufacturing Demonstration Facility (MDF) at ORNL, in the Deposition Science and Technology group. After earning his doctorate in 2016, Sridharan continued his work at the MDF as a postdoctoral researcher.
Sridharan’s Ph.D. work revolved around a process known as ultrasonic AM. One of the challenges with the technology is that the sonotrode—the tool used to make vibrations during the ultrasonic AM process—would deform when trying to weld steel. Niyanth proposed coating the sonotrode with a much harder, wear-resistant material using the Direct Metal Deposition System, thereby enabling the ultrasonic system to deposit steels and nickel-based superalloys in addition to aluminum. The project was a success.
“Translating simple scientific theory to solve problems is an extremely satisfying feeling and why I hold research close to my heart,” Sridharan said. “Taking an already-developed scientific base and using it as a springboard for utilizing additive techniques is the best way to address problems that impact industry today.”
In another collaboration, Sridharan worked on a lab-directed research and development (LDRD) program to fabricate control plates for the high flux isotope reactor (HFIR) led by Kurt Terrani of the Nuclear Fuel Materials group.
“I was very impressed by the way an LDRD project brings people with diverse scientific backgrounds together to work on a problem,” Sridharan said. He helped Terrani and his team fabricate and irradiate alloys for fast reactors to understand material performance under irradiation.
One of the benefits of working at ORNL is you never stop learning, Sridharan said. “For the HFIR project, we saw something strange yet interesting, which we are still trying to understand. When irradiating a material with neutrons, normally the material would lose ductility but increase in strength. In this case, the aluminum fabricated using AM increased in strength and ductility.”
Sridharan said he would like to teach one day, following in the footsteps of family who took the time to explain science to him as a child. “I hope to gain as much knowledge as possible from everyone around me so when I am in an academic setting, I can use the bridges I’ve built at ORNL to aid in my research as well as help my students.” ORNL is a great way to have one foot in early-stage applied science and another foot in fundamental research, he added.
“I have a set of basic scientific problems in my lab notebook which haven’t been solved by anyone. I plan to solve them before retirement.” Sridharan quotes his advisor Babu when he notes that “Research is not about having all the answers and more about asking the right questions.”
UT-Battelle manages ORNL for the DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/. – by Nadya Ally