His goal: to equip structural metallic materials to last much longer under extreme temperatures and loading.
Jean-Charles Stinville has received a National Science Foundation CAREER award that will support his search for ways to extend the lifetimes of metallic materials used in extreme environments.
Metals are commonly used to provide structure across a huge range of applications. However, their functional lifetimes are often limited by fatigue caused by repeated loading: deformation occurs at the atomic scale, eventually weakening the metallic material to the point that it cracks.
Under the new five-year, $632K award, entitled “Leveraging Plastic Deformation Mechanisms’ Interactions in Metallic Materials to Access Extraordinary Fatigue Strength,” Stinville will pursue a fundamental understanding of how materials deform at extreme temperatures, and will seek ways to modify existing metallic materials so they resist fatigue.
More specifically, Stinville, who is an assistant professor in the Department of Materials Science & Engineering and the Materials Research Lab, is looking for ways to “pre-deform” materials under extremely low or high temperatures to put them into states in which they are less susceptible to subsequent deformation caused by repeated loading, very high or low temperatures, or thermal cycling.
The CAREER work will be unusual in that Stinville is not pursuing the typical slow development of new materials, but the rapid development of a novel approach for modifying existing materials to make them dramatically more robust. The effort will involve the use of automation and high-throughput measurements, in combination with high-resolution imaging and advanced analysis tools, to accelerate the identification of fundamental deformation mechanisms in extreme conditions.
While most research in extreme-temperature metals has concentrated on high-temperature applications, Stinville said there has been growing interest in exploring cryogenic temperatures. He believes that’s an important development, because “a dual focus on both high and cryogenic temperatures is necessary in metals to address new technological developments related to energy, transportation, and space applications.”
What are examples of such developments? One is growing interest in the use of hydrogen as an energy carrier. Hydrogen is transported in liquid form, but must be kept below −253°C to remain liquid. Many components of liquid hydrogen delivery and storage systems are exposed both to such cryogenic temperatures and to repeated thermal and mechanical stresses. Hydrogen reservoirs for future hydrogen-powered airplanes are an example of such systems. Space exploration is another area in which the management of extreme temperatures would be similarly critical.
Stinville’s ultimate goal is to find solutions that will allow metallic structures to last for a very long time despite having to endure such extreme conditions.
The difference between materials’ behavior at ordinary temperatures and at extreme temperatures is nontrivial. In fact, materials’ “fundamental processes are totally different” at extreme temperatures, said Stinville, particularly for metallic materials at cryogenic temperatures.
“Approaching near absolute zero, metallic materials exhibit a markedly different set of deformation processes,” he said. “This distinctive behavior under such low-temperature conditions presents a fascinating area of study.”
Stinville’s earlier work has already proven that while many forms of pre-deformation will weaken a material, certain extreme pre-deformation states significantly improve the material’s properties. He will now work to build a fundamental understanding of which of the innumerable possible forms of pre-deformation are the beneficial ones. If his proposed approach is successful, he anticipates that it will be transformative, not merely enhancing materials by a small increment but dramatically improving their ability to resist extreme conditions.
“The challenge is to find the pre-deformation states,” he said. “And the possibilities are infinite!”
According to NSF’s website, Faculty Early Career Development (CAREER) grants are its “most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.”