27-750 spinel final notes
TRANSCRIPT
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Effect of Ytterbium on Grain Growth in Magnesium
Aluminate Spinel
George Ferko
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Applications of Spinel
Courtesy of TA&T
Courtesy of Armorline
• Armored windows• Radomes
• Desirable Properties• Hardness• Fracture toughness• Transparency
Courtesy of Animesh Kundu
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Experimental Procedure for Pressureless Sintering
• Powder doping (500 ppm Yb)• Uniaxial pressing (35 Mpa)• CIPing (275 Mpa)• Sintering (1800°C)• Sectioning, grinding, and
polishing• EBSD
Baikowski S30CR Powder Purity
S (ppm) 800-900
K(ppm) 40
Na(ppm) 11
Fe(ppm) <10
Ca(ppm) <10
Si(ppm) <10
Benameur et al., J. Am. Ceram. Soc. 94[5] (2011)
9/27/12 27-750 Texture, Microstructure, and Anisotropy
EBSD Data ProcessingRaw Data Grain Dilation Pore Data Removal
SEM Signal Overlay SEM Signal Grain Size Data
9/27/12 27-750 Texture, Microstructure, and Anisotropy
1 Hour Sample ComparisonFr
eque
ncy
Grain Diameter (μm) Grain Diameter (μm)
9/27/12 27-750 Texture, Microstructure, and Anisotropy
2 Hour Sample ComparisonFr
eque
ncy
Grain Diameter (μm) Grain Diameter (μm)
9/27/12 27-750 Texture, Microstructure, and Anisotropy
4 Hour Sample ComparisonFr
eque
ncy
Grain Diameter (μm) Grain Diameter (μm)
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Grain Growth
3.5 3.6 3.7 3.8 3.9 4 4.1 4.20
0.20.40.60.8
11.21.41.61.8
2
Undoped
500 ppm Yb-doped
log(t) (s)
log(
Ḡ) (
μm)
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Grain Size Distribution ComparisonYb-doped Samples
1 Hour
2 Hour
4 Hour
Undoped Samples
1 Hour
2 Hour
4 Hour
Freq
uenc
y
Grain Diameter (μm) Grain Diameter (μm)
Freq
uenc
y
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Log-Normal Example
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.50
102030405060708090
100
Undoped - 1 Hour - CDF
Cumulative Distribution Function
Cum
ulati
ve P
erce
nt
0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.516.526.536.546.556.566.576.586.596.5
Log-Normal - CDF
Cumulative Distribution Function
Cum
ulati
ve P
erce
ntVs.
=
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Probability Plots for Gamma and Log-NormalYb-doped SamplesUndoped Samples
1 Ho
ur
2 Ho
ur
4 Ho
ur
9/27/12 27-750 Texture, Microstructure, and Anisotropy
Thank you!
Questions?