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ORNL Undergraduate Research Profile: Rafael Martinez-Rodriguez

Undergraduate student explores uses of rare earth element cerium

ORNL Intern Rafael Martinez Rodriguez

In the Science Undergraduate Laboratory Internship Program at Oak Ridge National Laboratory, Rafael Martinez-Rodriguez researched aluminum-cerium alloys in an effort to increase the demand of the rare earth element cerium and provide a thermally stable aluminum alloy for use in the automotive industry.

As use of handheld electronics and alternative energy technologies increase worldwide, people are becoming more reliant on rare earth elements, naturally occurring elements used in the production of these items. The United States does not produce many of these commonly used chemical elements. In order to attain energy security, researchers have dedicated time to jump-starting domestic production.

Rafael Martinez-Rodriguez, a mechanical engineering student at the University of Puerto Rico-Mayagüez, joined the initiative at Oak Ridge National Laboratory (ORNL) through the Science Undergraduate Laboratory Internship (SULI) Program. He contributed to research within the Critical Materials Institute, a multidisciplinary research effort focused on technologies that make better use of materials and eliminate the need for materials that are subject to supply disruptions.

With guidance from his mentors, Zachary Sims, a physicist in the Materials Science and Technology Division, and Orlando Rios, Ph.D., a staff scientist in the Critical Materials Institute, Martinez-Rodriguez focused on aluminum-cerium alloys. Though cerium makes up half of the rare earth content in the United States, a market for the element does not exist. Unlike existing aluminum alloys, components made with aluminum-cerium alloys possess high-temperature stability and are priced similar to more traditional aluminum alloys. A heightened heat tolerance makes these alloys appealing for use in the automotive industry for internal combustion engines. As these engines function at a higher temperature, they will increase fuel efficiency. Aluminum-cerium alloys could improve rare earth mining because it would increase the demand and value of cerium.

“My project involved characterizing the effect of heat treatments on the microstructure of aluminum-cerium alloys using scanning electron microscopy. As far as the big picture, this project has the potential to increase the demand of cerium,” Martinez-Rodriguez said.

At first, heat treatments did not significantly affect the mechanical properties or microstructure of the alloy. Initially this was viewed as a challenge for the application of the alloy in modern industry; however, the resistance to heat treatment also exhibits the thermal stability of aluminum-cerium alloys. Targeting higher temperature regimes at shorted time scales led the team to its first successful heat treatment scheme.

While Martinez-Rodriguez enjoyed his time in the lab, he also found attending seminars and tours beneficial to his overall understanding of a national laboratory operation.

“I found the experience to be really worthwhile. I was able to obtain new skills and further develop as a researcher and as a professional,” Martinez-Rodriguez explained. “I would definitely recommend the program because it prepares individuals for future endeavors by providing useful skills regardless of what career path they choose.”

After his semester in the SULI Program, Martinez-Rodriguez returned to Puerto Rico to complete his bachelor’s degree. Though he is set to start a full-time position after graduation, he intends to earn a master’s degree while working, a task he feels prepared for as a result of his research experience at ORNL.

“The skills I gained will help me tackle a professional career with useful knowledge and will allow me to perform better,” Martinez-Rodriguez said. “The lab skills I learned will definitely add value to my technical career.”

The SULI program is sponsored by the Department of Energy Office of Science’s, Office of Workforce Development for Teachers and Scientists (WDTS) and administered by the Oak Ridge Institute for Science and Education (ORISE), managed by ORAU.