For his CAREER project, Pierron aims to understand the  mechanisms responsible for fatigue crack initiation in nanocrystalline metals. Nanocrystalline metals exhibit extraordinary mechanical properties and can combine ultra-high strength with considerable ductility. However, there is so far little quantitative, mechanistic-based understanding of their fatigue properties, such as the observed improved fatigue limit compared to their coarse grained counterparts. The proposed research offers original contributions to obtainamechanistic insight into the length-scale effects in fatigue processes.

“We have developed a technique to perform fatigue tests at the nanoscale inside a transmission electron microscope,” Pierron states. “Our apparatus applies cyclic deformation onto the specimens and records both applied force and displacement, while the evolution of the microstructure associated with cyclic plasticity can be observed using transmission electron microscopy. Alternatively, the fatigue tests can also be performed outside of the microscope to investigate the environmental effects on the fatigue properties. This technique can be used for a large range of nanostructures, and is employed specifically for ultrathin nanocrystalline metallic films in this project.”

Dr. Bill Wepfer, Woodruff School Chair, offers his congratulations by stating, “Dr. Pierron’s activities in the mechanics of small-scale materials, with an emphasis on fracture and fatigue provide a vital contribution to our programs and aligns closely with President Obama’s Advanced Manufacturing Partnership. Olivier is also an exceptional classroom instructor!”

An additional and integral part of this project is the development of a summer enrichment program for high school students, focused on the failure analysis of materials. The program will be developed and implemented with the collaboration of high school teachers, graduate and undergraduate students from Georgia Tech who are interested in a teaching career.

The CAREER Program offers the NSF’s most prestigious awards in support of junior faculty who exemplify the role of teacher-scholars through outstanding research, excellent education, and the effective integration of research and education within the context of the mission of their organizations.

Pierron’s award in the amount of $550,000 over five years will provide support for this research. There are currently 27 Woodruff School faculty members with a CAREER Award.