PM-25In Situ High Temperature Observation of Ceramics Thermal Barrier Coating by Transmission Electron Microscopy

Microscopy ◽  
2017 ◽  
Vol 66 (suppl_1) ◽  
pp. i30-i30
Author(s):  
Shogo Kikuchi ◽  
Manabu Tezura ◽  
Masao Kimura ◽  
Tokushi Kizuka
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Thermal Barrier Coating ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Transmission Electron ◽  
Temperature Observation

New Technique for Successful Thermal Barrier Coating Specimen Preparation for Transmission Electron Microscopy

2000 ◽  
Vol 6 (3) ◽  
pp. 231-236
Author(s):  
M.R. Brickey ◽  
J.L. Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermally Grown Oxide ◽  
Thermal Barrier ◽  
Specimen Preparation ◽  
Ion Milling ◽  
New Approach ◽  
Barrier Coating ◽  
Transmission Electron ◽  
Thermal Histories

Abstract Reliability of thermal barrier coatings (TBC) hinges on the adhesion of a thermally grown oxide scale to an insulative ceramic topcoat and an underlying metallic bondcoat. The width of the scale and its interfaces makes transmission electron microscopy (TEM) an appropriate tool for its analysis. However, specimen preparation has proven to be a challenging obstacle leading to a dearth of TEM research on TBCs. A new approach to cross-section TBC TEM specimen preparation is described. The principal advantages of this technique are reproducibility, reduced specimen damage, and time savings resulting from decreased ion milling. This technique has been successfully applied to numerous TBC specimens with various thermal histories.

New Technique for Successful Thermal Barrier Coating Specimen Preparation for Transmission Electron Microscopy

2000 ◽  
Vol 6 (3) ◽  
pp. 231-236 ◽  
Author(s):  
M.R. Brickey ◽  
J.L. Lee
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermally Grown Oxide ◽  
Thermal Barrier ◽  
Specimen Preparation ◽  
Ion Milling ◽  
New Approach ◽  
Barrier Coating ◽  
Transmission Electron ◽  
Thermal Histories

AbstractReliability of thermal barrier coatings (TBC) hinges on the adhesion of a thermally grown oxide scale to an insulative ceramic topcoat and an underlying metallic bondcoat. The width of the scale and its interfaces makes transmission electron microscopy (TEM) an appropriate tool for its analysis. However, specimen preparation has proven to be a challenging obstacle leading to a dearth of TEM research on TBCs. A new approach to cross-section TBC TEM specimen preparation is described. The principal advantages of this technique are reproducibility, reduced specimen damage, and time savings resulting from decreased ion milling. This technique has been successfully applied to numerous TBC specimens with various thermal histories.

scholarly journals Thermal Stability of Rare Earth-PYSZ Thermal Barrier Coating with High-Resolution Transmission Electron Microscopy

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1206
Author(s):  
Savisha Mahalingam ◽  
Abreeza Manap ◽  
Salmi Mohd Yunus ◽  
Nurfanizan Afandi
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Mixed Oxide ◽  
Mixed Oxides ◽  
Thermal Barrier ◽  
Barrier Coating ◽  
Transmission Electron ◽  
Α Al2o3

Durability of a thermal barrier coating (TBC) depends strongly on the type of mixed oxide in the thermally grown oxide (TGO) of a TBC. This study aims on discovering the effect of thermal stability in the TGO area containing mixed oxides. Two different bondcoats were studied using high-resolution transmission electron microscopy: high-velocity oxygen fuel (HVOF) and air-plasma spray (APS), under isothermal and thermal cyclic tests at 1400 °C. The HVOF bondcoats were intact until 1079 cycles. In comparison, APS failed at the early stage of thermal cycling at 10 cycles. The phase transformation of topcoat from tetragonal to the undesired monoclinic was observed, leading to TBC failure. The results showed that the presence of transient aluminas found in HVOF bondcoat helps in the slow growth of α-Al2O3. In contrast, the APS bondcoat does not contain transient aluminas and transforms quickly to α-Al2O3 along with spinel and other oxides. This fast growth of mixed oxides causes stress at the interface (topcoat and TGO) and severely affects the TBC durability leading to early failure. Therefore, the mixed oxide with transient aluminas slows down the quick transformation into alpha-aluminas, which provides high thermal stability for a high TBC durability.

Effect of Coupled Conditions of Thermal Cycle and Dump Environment on Conductivity of 5mol% Yttria Stabilized Zirconia

2013 ◽  
Vol 591 ◽  
pp. 245-248 ◽  
Author(s):  
Jin Feng Xia ◽  
Hong Qiang Nian ◽  
Tao Feng ◽  
Hai Fang Xu ◽  
Dan Yu Jiang
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Thermal Cycle ◽  
Oxygen Sensor ◽  
Yttria Stabilized Zirconia ◽  
Cyclic Change ◽  
Stabilized Zirconia ◽  
Transmission Electron

In some applications such as automotive oxygen sensor, 5mol% Y2O3stabilized zirconia (5YSZ) is generally used because it has both excellent ionic conductivity and mechanical properties. The automotive oxygen sensor would experience a cyclic change from high temperature (engine running) environment to the low temperature damp environment (in the tail pipe when vehicle stops). The conductivity change with coupled conditions of thermal cycle and dump environment in the 5mol%Y2O3ZrO2(5YSZ) system was examined by XRD,Impedance spectroscopy and transmission electron microscopy (SEM) in this paper.

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