Month: May 2016

Fe microparticle work with Technion group (Israel) was published in Nature Scientific Report.

Roman Kositski, Oleg Kovalenko, Seok-Woo Lee, Julia R. Greer, Eugen Rabkin, Dan Mordehai, “Cross-split of dislocations: an athermal and rapid plasticity mechanism,”Nature Scientific Report 2 25966 (2016) – [link].


[Abstract]: The pathways by which dislocations, line defects within the lattice structure, overcome microstructural obstacles represent a key aspect in understanding the main mechanisms that control mechanical properties of ductile crystalline materials. While edge dislocations were believed to change their glide plane only by a slow, non-conservative, thermally activated motion, we suggest the existence of a rapid conservative athermal mechanism, by which the arrested edge dislocations split into two other edge dislocations that glide on two different crystallographic planes. This discovered mechanism, for which we coined a term “cross-split of edge dislocations”, is a unique and collective phenomenon, which is triggered by an interaction with another same-sign pre-existing edge dislocation. This mechanism is demonstrated for faceted α-Fe nanoparticles under compression, in which we propose that cross-split of arrested edge dislocations is resulting in a strain burst. The cross-split mechanism provides an efficient pathway for edge dislocations to overcome planar obstacles.


Lee’s Capstone Senior Design Team won the second place in the MSE final capstone presentation!

Lee’s Capstone Senior Design Team (Michael McGeever, Jeremy Higgins and Amy Hernadez) won the second place ($1,000) in the MSE final Capstone presentation! I am very proud of their achievement over the year! The title of the project was “Reliable rapid repair using additive manufacturing (sponsored by Sikorsky).”


(From left to right: Jeremy, Mike, and Amy)