Thermal barrier ZrO2-Y2O3 obtained by plasma spraying method and laser melting

• Autorzy: Kobylańska-Szkaradek K.
• Języki publikacji: EN

Abstrakty

EN

Purpose: Purpose: The aim of the paper is to determine the influence of laser melting upon the selected physical properties of ZrO2 - Y2O3 ceramic coatings deposited by APS (Air Plasma Spraying) method on super-alloys which function as TBC (Thermal Barriers Coatings). Design/methodology/approach: Laser melting which helps eliminate pores and other structural defects of coatings should contribute to the improvement of their density and durability as thermal barriers. In order to prove the assumptions made in the paper, coatings featuring varied porosity and deposited upon the nickel base super-alloys surface with the initially sprayed NiCrAlY bond coat have been subjected to laser melting and then their structure, thermal conductivity and thermal life prediction in the conditions of cyclic temperature changes from 20 to 1200oC have been examined. Findings: It has been revealed that the coatings featuring low porosity laser melted on part of their thickness and heated up to about 700oC demonstrate the highest thermal life prediction under the conditions mentioned and at slightly lower thermal conductivity. Research limitations/implications: Low wettability of metal by ceramic which results from various surface tensions of these materials is the cause of their lower adhesion to the substrate during laser melting all through their thickness. It is so because delaminations occur between phases the boundary and cracks. Practical implications: The worked out conditions of laser melting might be used in the process of creation of TBC which feature high working durability upon super-alloy elements. Originality/value: It has been found that homogenization of chemical composition of coatings occurs during laser melting leading to the reduction of ZrO2 - Y2O3 phase with monoclinic lattice participation as well as to the reduction of structural stresses which accompany this phase transformation during heating and cooling process.

Słowa kluczowe

EN

composites; thermal barrier coatings; TBC; air plasma spraying; laser treatment; properties

PL

kompozyty; powłoki barierowe termiczne; natryskiwanie plazmowe; obróbka laserowa; właściwości

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2006
• Tom: Vol. 17, nr 1-2
• Strony: 77--80
• Opis fizyczny: Bibliogr. 14 poz., rys., tab., wykr.

Twórcy

autor

Kobylańska-Szkaradek K.

• Institute of Physics, Silesian University of Technology, ul. Krasinskiego 8, 40-019 Katowice, Poland

Bibliografia

• [1] M.J. Stiger, and all: Thermal Barrier Coatings for the 21st Century, Zeitschrift fur Metallkunde, 90 (1999) pp. 1069-1078.
• [2] R. Wing, Materials World , v. 8, 3 (2000) p. 10.
• [3] T. Sakuma, Phase Transformation and Microstructure of Partially-Stabilized Zirconia, Transactions of the Japan Institute of Metals, vol. 29, no. 11 (1988) pp. 879-893.
• [4] H.G. Scott, Phase relationships in the zirconia-yttria system, Journal of Materials Science 10, 1975,pp. 1527-1535.
• [5] J.R. Brandon, R. Taylor, Phase stability of zirconia-based thermal barrier coatings Part II. Zirconia-ceria alloys, Surface and Coatings Technology, 46 (1991) pp. 91-101
• [6] Reiners G, and all Properties and characterization of thermal spray coatings, Proceedings of the 15 the International Thermal Spray Conference, Nice France v. 1 (1998) pp. 629–632.
• [7] V.Teixeira and all, Proceedings of the 8th National Thermal Spray Conference, ed.C. Berndt, ASM International, Houston, USA (1995) pp. 515–520.
• [8] J.A. Haynes and all, Characterization of alumina scales formed during isothermal and cyclic oxidation pf plasma sprayed TBC systems at 11500 C, Oxidation of Metals, 52, 1/2 (1999) pp. 31–76.
• [9] V. Teixeira and all, Residual stress analysis of PVD and plasma sprayed thermal barrier coatings during thermal cycling, Proceedings of the 5th International Conference Residual Stresses – ICRS?5, ed. T. Ericson Sweden, June, v. I, (1997) pp. 436–441.
• [10] V.Teixeira and all, Effects of deposition temperature and thermal cycling on residual stress state in zirconia – based thermal barrier coatings, Surface and Coatings Technology, 120–121 (1999), pp. 103–111.
• [11] Load capacity of gas turbine blades under the influence of non-stationary thermal and loading field, Ukrainian Academy of Science – Soviet Union, Institute of Strength Problems at Naukovaia Dumka” Kiev (1975), p. 146–153.
• [12] Sulzer-Metco the Coatings Company, Materials Guide, Revised December (1999).
• [13] K. Kobylańska-Szkaradek, The influence of laser treatment upon structure and properties ZrO2 – Y2O3 ceramic coatings as thermal barriers, Zeszyty Naukowe Politechniki Śląskiej – Mechanika (Scientific Journal of Silesian University of Technology – Mechanics), nr 154, Gliwice (2005).
• [14] K. Kobylańska-Szkaradek, Investigation some properties of thermal barrier coatings, Inżynieria Materiałowa, (Material Engineering), nr 3, (140), (2004), pp. 604-60