2020-01-07December 22018-12December 2https://hdl.handle.net/10657/5839Nanocrystalline materials have applications in numerous fields due to their high strength. Grain growth is prevalent in nanocrystalline materials and leads to a decrease in material strength. Zener pinning has proven to be effective in hindering grain growth and thus, maintain the strength of the material. In this work, atomistic simulations were performed to understand and visualize the effect of Zener pinning in restricting grain boundary motion, and hence grain growth. The simulations were performed on two different grain boundary structures, ∑ 5 and ∑ 17 by varying the particle diameter and distance between the particles and compare these results with that of structures without any particles. The impact of adding high particle volume fraction (up to 50%) in Ag polycrystals to produce ultrahigh strength materials is also discussed. The yield strength of these nanocomposites was evaluated by varying particle volume fraction, particle size and inter-particle spacing. The highest yield strength observed in Ag nanocomposites was found to be about 5 times the strength of nanocrystalline Ag. The possible strengthening mechanisms responsible for this huge increase are discussed based on molecular dynamics results.application/pdfengThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).Molecular dynamicsNanocrystallineZener pinningNanocomposites2020-01-07Thesisborn digital