Investigating Microalloying Elements to Accelerate Zirconium Trialuminide Precipitation in Aluminum Alloys

Author

Philip D. Staublin, Michigan Technological UniversityFollow

Date of Award

2019

Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Materials Science and Engineering (MS)

Administrative Home Department

Department of Materials Science and Engineering

Advisor 1

Paul Sanders

Committee Member 1

Douglas Swenson

Committee Member 2

Gregory Odegard

Abstract

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 treated isochronally. All three additions resulted in a reduced mean precipitate radius in the peak aged condition, with tin demonstrating the most potent effect. Possible mechanisms for acceleration of Al₃Zr precipitation include nucleation on solute clusters and a reduced zirconium diffusion barrier in the presence of microalloying elements.

Recommended Citation

Staublin, Philip D., "Investigating Microalloying Elements to Accelerate Zirconium Trialuminide Precipitation in Aluminum Alloys", Open Access Master's Thesis, Michigan Technological University, 2019.

https://doi.org/10.37099/mtu.dc.etdr/914