Engineering Commons^™

Integrated Computational Materials Engineering (Icme) Investigation Of Electrical Conductivity And Thermodynamic Stability For Precipitation Strengthened Al-Zn-Zr And Al-Zn-Ni Ternary Alloys, Oladeji Fadayomi

Dissertations, Master's Theses and Master's Reports

High electrical conductivity Al-Zn-TM (TM=Transition metals) alloys with improved mechanical properties and thermal resistance are developed with an integrated computational material engineering (ICME) strategy. From a series of ab initio density functional theory (DFT) simulations assessing combinations of ternary alloys, Al-Zn-Ni and Al-Zn-Zr are determined as alloys with relatively high electrical conductivity compared to several other ternary Al alloy combinations. The zero-temperature stable structure of precipitates formed in these alloys are determined from computed enthalpy of formation as L1₂, with particular focus of examining the influence of Zn on stabilizing the desired L1₂ precipitate phase.

Scanning transmission …

Effect Of Development Of Scandium Trialuminide Precipitates On Corrosion And Mechanical Behavior In Aluminum-Magnesium Alloys, Carson Williams

Dissertations, Master's Theses and Master's Reports

Development of aluminum alloys has seen an increase in attention in recent years. The 5xxx series of Al-Mg alloys has the potential to provide strong, lightweight materials in various industry applications, however issues with strain formability and corrosion hinder the development of these alloys. The addition of Sc for developing Al₃Sc precipitates provides considerable precipitation strengthening as well as grain refinement characteristics that can help mitigate these issues. Alloys with varied Mg content were analyzed for heat treatment aging responses and precipitate formation, changes in mechanical behavior related to the Portevin-le Chatelier effect, and effects on intergranular corrosion …

Investigating Microalloying Elements To Accelerate Zirconium Trialuminide Precipitation In Aluminum Alloys, Philip D. Staublin

Dissertations, Master's Theses and Master's Reports

Precipitation of the L1₂-structured coherent Al₃Zr trialuminide phase in aluminum-zirconium alloys increases the alloy strength. Precipitation of a more refined dispersion of Al₃Zr can further increase the strength of these alloys. The addition of microalloying elements which bind to zirconium may accelerate the precipitation kinetics, allowing for nucleation of a greater number of precipitates and faster precipitate growth. Zirconium binding energies are computed for a wide range of elements, based on which the elements tin, antimony, and tellurium were selected for investigation. Ternary Al-Zr-X alloys (X = Sn, Sb, Te) were cast and heat …