Ryan Collette, a PhD candidate in the Metallurgical and Materials Engineering department, is conducting an atomistic modeling and transmission electron microscopy study on the stability of the subgrain cellular structures of additively manufactured materials during neutron irradiation. The intent is to see if, and under what conditions, the enhanced strength and ductility seen in AM steels and Inconels continues when those materials are placed in a nuclear reactor. The discovery of enhanced strength/ductility in AM steels and Inconels is relatively new. Ryan’s work will be some of the first work to test neutron irradiation of those materials. Additionally, he and Dr. Behnam Amin-Ahmadi have identified some nanoscale structures in heat treated AM stainless steel that have not previously been documented. The structure in question is an ordered arrangement of dislocations that appears similar in form to a chain-link fence. It occurs during heat treatment of the material as the dislocation-rich walls of the subgrain cellular structures relax to a lower energy state. This finding may provide some insight regarding the sustainable benefits of the cellular structures over long-term exposure to heat and radiation. Ryan hopes to complete his doctoral work by May 2020. His advisor is Dr. Jeffrey King.

OUR MEMBERS: