Microstructure and Thermal Diffusivity of Micro- and Nano-Sized YSZ

Grzegorz Moskal

doi:10.4028/www.scientific.net/MSF.638-642.900

Paper Titles

Influence the Thermal Process of the Removing the Varnish Coats to the Cleanness of the Surface Aluminium Scrap
p.876

Unconventional Glow Discharge Nitriding of 316L Austenitic Steel
p.882

Control of Polymorphism and Mass-Transfer in Al₂O₃ Scale on Alumina Forming Alloys
p.888

Influence of Annealing on the Microstructure and Wear Performance of Diamond/NiCrAl Composite Coating Deposited through Cold Spraying
p.894

Microstructure and Thermal Diffusivity of Micro- and Nano-Sized YSZ
p.900

Internal Stress in EB-PVD Thermal Barrier Coating under Heat Cycle
p.906

Application of the Concept of Local Fatigue Strength after Shot Peening of Notched Components Based on Numerical Simulations
p.912

In Situ Observations of the Densification Behavior of WC-FeAl-B Composites during Liquid Phase Sintering
p.921

Experimental Study on Drilling Process of CFRP Composite Laminate
p.927

HomeMaterials Science ForumMaterials Science Forum Vols. 638-642Microstructure and Thermal Diffusivity of Micro-...

Microstructure and Thermal Diffusivity of Micro- and Nano-Sized YSZ

Abstract:

The thermal barrier coatings (TBC) enable to lower temperature (at approx. 170°C) of operating elements in a hot section of gas turbine to a range, which enables to operate for a long time in conditions of high temperature influence and prolongs operation of them even three or four times. Usually, the TBC coverings are constructed of four layers: • superalloys on a base of nickel; • outer ceramic zone, from which low thermal conduction is required. It is, in most cases, ZrO2 oxide stabilized with Y2O3 (YSZ – yttria stabilized zirconia), material of one of lowest values of thermal conductivity in high temperature of a rank 2.3 Wm-1K-1 in 1000°C for 100% density and thermal expansion of a rank 11×10-6°C-1, what enables to reduce thermal stresses. Usually, thickness of an outer ceramic layer is within a range 250-375μm; • bond coat of a type Ni(Co)CrAlY or diffusion layer of a type (Ni,Pt)Al; • layer of barrier oxides, accrueting as a result of temperature growth TGO (thermally grown oxide). In the present study characterization of conventional micro-sized YSZ powders stabilized by 8% of yttria and in comparison nano-sized YSZ will be presented. The tests performed showed that the monoclinic phase content in the nanocrystalline powder is approx. 8.8%, and approx. 7.5% in the conventional powder. The chemical composition analysis and test of powder microstructure were also performed. Carbon, sulphur and gas nitrogen contents were determined and the results received were similar. The surface morphology and powder microstructure on the cross-sections were also characterized. The standard powder with spherical shape and relatively smooth surface is predominant. The internal structure is characterized by the presence of tiny sintered particles and low porosity. The nanocrystalline powder tests showed the presence of particles in the form of tiny polyhedrons with bimodal size distribution of particles (approx. 1μm and 10μm).

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Periodical:

Materials Science Forum (Volumes 638-642)

Pages:

900-905

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.638-642.900

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Online since:

January 2010

Authors:

Grzegorz Moskal

Keywords:

Low Conductivity, Nano, Thermal Barrier Coating (TBC), Thermal Diffusivity, YSZ

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References

[1] M. Konter, M. Thumann: J. of Materials Processing Tech. 92-117, 2001, pp.386-390.

Google Scholar

[2] D. Stover, C. Funke: J. of Materials Processing Tech., 92-93, 1999, pp.195-202.

Google Scholar

[3] J.F. Li, et al.: J. of Materials Processing Technology, 160, 2005, pp.34-42.

Google Scholar

[4] M. Hetmańczyk, L. Swadźba, B. Mendala: J. of Achievements in Materials and Manufacturing Engineering, 24(2), 2007, pp.372-381.

Google Scholar

[5] L. Swadźba, G. Moskal, B. Mendala, T. Gancarczyk: Archives of Materials Science and Engineering, 28, 12, 2007, pp.757-764.

Google Scholar

[6] G. Moskal: J. of Achievements in Materials and Manufacturing Engineering, 22 (2), 2007, p.3134.

Google Scholar

[7] G. Moskal, L. Swadźba, T. Rzychoń: J. of Achievements in Materials and Manufacturing Engineering, 22 (2), 2007, pp.31-34.

Google Scholar

[8] L. Swadźba, G. Moskal, B. Mendala, T. Gancarczyk: J. of Achievements in Materials and Manufacturing Engineering, 21 (2), 2007, pp.81-84.

Google Scholar

[9] C.G. Levi: Current Opinion in Solid State and Materials Science, 8, 2004, pp.77-91.

Google Scholar

[10] C. C Berndt: J. Thermal Spray Technol., 2001, 10(1), 147-181.

Google Scholar

[11] H. Chen, X. Zhou, and C. Ding: J. Eur. Ceram. Soc., 2003, 23, pp.1449-1455.

Google Scholar

[12] T.A. Taylor: Surface Coatings Technol., 1992, 54/ 55, pp.53-57.

Google Scholar

[13] R.E. Taylor, X. Wang, and X. Xu: Surface Coatings Technol., 1999, 120- 121, pp.89-95.

Google Scholar