Effects of sintering on grain growth and density in trivalent cation doped zirconia

Oh, Hyunkyung

Permalink

https://hdl.handle.net/2142/121452 Copy

Description

Title

Effects of sintering on grain growth and density in trivalent cation doped zirconia

Author(s)

Oh, Hyunkyung

Issue Date

2023-07-17

Director of Research (if dissertation) or Advisor (if thesis)

Krogstad, Jessica A

Department of Study

Materials Science & Engineerng

Discipline

Materials Science & Engr

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• Sintering
• YSZ
• Microstructures

Abstract

Yttria stabilized zirconia has been widely used in applications due to its good thermal stability and ionic conductivity. Especially, in order to have better ionic conductivity, a dense microstructure with large grain size is desirable given the typically negative effect of grain boundaries on ionic conductivity. In this work, doped zirconia samples with various dopant concentration (15mol% YO1.5, 30mol% YO1.5, 30mol% YbO1.5 and 30mol% GdO1.5) are studied. The powders were made by using the reverse co-precipitation method. Two-step sintering was used to make dense samples with large grain size and investigated how this sintering method affects grain size and density. The first sintering step was spark plasma sintering (SPS) and the second sintering step was pressureless conventional sintering (CS). The grain growth that occurred during both sintering steps was different depending on the concentration of dopant and the type of dopant due to the different surface energy and cation diffusivity. The density unexpectedly decreased between the first sintering step (SPS) and the second sintering step (CS). It is tentatively attributed to the influence of high heating rate of SPS and high sintering temperature of conventional sintering.

Graduation Semester

2023-08

Type of Resource

Thesis

Copyright and License Information

Copyright 2023 Hyunkyung Oh

Owning Collections