Date of Award

2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

First Advisor

Frederic Sansoz

Second Advisor

Laura Webb

Abstract

Solute segregation in grain boundaries (GBs) is used in design to stabilize nanocrystalline alloys. While analyzing GB segregation energy as a spectrum allows for a more in-depth analysis of the effects of GB atomic structure on solute segregation, this method inherently ignores solute-solute interaction by nature of considering one solute at a time. Here we develop an efficient molecular statics (MS) algorithm for determining the local effect of solute-solute interaction on GB segregation. We apply this algorithm to a Σ9 (221) symmetric tilt grain boundary in a bicrystal as well as a randomly oriented polycrystal for Ni and Cu solutes in Ag. The findings suggest that small changes in average segregation energy between one and two solutes correlate directly to the effect of a fixed solute on its local environment through solute-solute interactions. This work shows that this methodology succeeds to accelerate the study of complex segregation behavior such as heterogeneous and homogeneous tendencies.

Language

en

Number of Pages

54 p.

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