Structural Characterization and Thermoelectric Performance of ZrNiSn Half-Heusler Compound Synthesized by Mechanical Alloying

Thermoelectric (TE) ZrNiSn samples with a half-Heusler atomic structure were synthesized by mechanical alloying (MA) and consolidation by either Spark Plasma Sintering (SPS) or hot pressing (HP). X-Ray diffraction patterns of as milled powders and consolidated samples were compared and analyzed for phase purity. Thermal conductivity, electrical conductivity and Seebeck coefficient are measured as a function of temperature in the range 300 K to 800 K and compared with measurements reported for high temperature solid state reaction synthesis of this compound. HP samples, compared to SPS samples, demonstrate increased grain growth due to longer heating times. Reduced grain size achieved by MA and SPS causes increased phonon scattering due to the increased number of grain boundaries, which lowers the thermal conductivity without doping the base system with addition phonon scattering centers. Mechanical characterization of the samples by microindentation and depth sensing indentation for hardness and elastic modulus will be discussed.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Year

2010

Author dc:creator

• Germond, Jeffrey

Contributors dc:contributor

• Schilling, Paul
• Herrington, Paul
• Verges, Melody

• Mechanical Alloying
• Milling
• Heusler
• half Heusler alloy
• Thermoelectric materials
• Thermoelectric properties
• Spark plasma sintering
• Hot Pressing
• Seebeck coefficient
• Electrical conductivity
• Thermal conductivity
• Figure of merit
• Grain refinement
• Mechanical properties
• Indentation
• Nanoindentation
• Depth sensing indentation
• Microindentation
• Vickers
• X-ray diffraction
• Phonon scattering

Repository record dc:identifier

https://scholarworks.uno.edu/td/1197

OAI identifier oai:identifier

oai:scholarworks.uno.edu:td-2180