Title

DEVELOPMENT OF PRECIPITATION HARDENABLE AL-SC-ZR-HF QUATERNARY ALLOYS THROUGH THERMODYNAMIC MODELING, AND ROOM-TEMPERATURE AND ELEVATED TEMPERATURE HARDNESS

Author

Matthew J. Wong, Michigan Technological University

Date of Award

2014

Document Type

Master's Thesis

Degree Name

Master of Science in Materials Science and Engineering (MS)

College, School or Department Name

Department of Materials Science and Engineering

Advisor

Paul G. Sanders

Abstract

Aluminum alloyed with small atomic fractions of Sc, Zr, and Hf has been shown to exhibit high temperature microstructural stability that may improve high temperature mechanical behavior. These quaternary alloys were designed using thermodynamic modeling to increase the volume fraction of precipitated tri-aluminide phases to improve thermal stability. When aged during a multi-step, isochronal heat treatment, two compositions showed a secondary room-temperature hardness peak up to 700 MPa at 450°C. Elevated temperature hardness profiles also indicated an increase in hardness from 200-300°C, attributed to the precipitation of Al₃Sc, however, no secondary hardness response was observed from the Al₃Zr or Al₃Hf phases in this alloy.

Recommended Citation

Wong, Matthew J., "DEVELOPMENT OF PRECIPITATION HARDENABLE AL-SC-ZR-HF QUATERNARY ALLOYS THROUGH THERMODYNAMIC MODELING, AND ROOM-TEMPERATURE AND ELEVATED TEMPERATURE HARDNESS", Master's Thesis, Michigan Technological University, 2014.

https://doi.org/10.37099/mtu.dc.etds/870