scholarly journals Inelastic Deformation of Freestanding Plasma-sprayed Thermal Barrier Coatings(Thermal Barrier Coating Systems for Gas Turbines)

2010 ◽  
Vol 76 (767) ◽  
pp. 802-811
Author(s):  
Masayuki ARAI ◽  
Xiaohong WU ◽  
Koji FUJIMOTO
Keyword(s):  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Inelastic Deformation ◽  
Thermal Barrier ◽  
Special Issue ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
Plasma Sprayed

Effects of Powder Morphology, Microstructure, and Residual Stresses on Thermal Barrier Coating Thermal Shock Performance

1996 ◽  
Author(s):  
J. Wigren ◽  
J.-F. de Vries ◽  
D. Greving
Keyword(s):  
Residual Stresses ◽  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
Thermal Barrier ◽  
Spray Parameters ◽  
Powder Morphology ◽  
Barrier Coatings ◽  
Barrier Coating

Abstract Thermal barrier coatings are used in the aerospace industry for thermal insulation in hot sections of gas turbines. Improved coating reliability is a common goal among jet engine designers. In-service failures, such as coating cracking and spallation, result in decreased engine performance and costly maintenance time. A research program was conducted to evaluate residual stresses, microstructure, and thermal shock life of thermal barrier coatings produced from different powder types and spray parameters. Sixteen coatings were ranked according to their performance relative to the other coatings in each evaluation category. Comparisons of residual stresses, powder morphology, and microstructure to thermal shock life indicate a strong correlation to thermal barrier coating performance. Results from these evaluations will aid in the selection of an optimum thermal barrier coating system for turbine engine applications.

Effect of Spinel Growth on the Delamination of Thermal Barrier Coatings

2011 ◽  
Vol 462-463 ◽  
pp. 389-394 ◽  
Author(s):  
Wei Xu Zhang ◽  
Yong Le Sun ◽  
Tie Jun Wang
Keyword(s):  
Growth Rate ◽  
Service Life ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Unit Area ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
Thermal Growth ◽  
Plasma Sprayed

The spinel growth induces undulation of the thermal growth oxide layer and decreases the service life of plasma-sprayed thermal barrier coatings. An analytical model is introduced to investigate the effect of spinel growth on the delamination of thermal barrier coating. The analytical results show that the number per unit area and the growth rate of spinel have significant influence on the delamination of thermal barrier coating. The stiffer and thicker thermal barrier coating is more easily to delaminate from the bond coat due to the existence of spinels. The effect of spinel on the delamination cannot be neglected. How to reduce the growth rate and the number of spinel is a key problem to prolong the service life of thermal barrier coatings.

A study of suspension plasma-sprayed insulated pistons evaluated in a heavy-duty diesel engine

2019 ◽  
Vol 21 (6) ◽  
pp. 987-997 ◽  
Author(s):  
Anders Thibblin ◽  
Ulf Olofsson
Keyword(s):  
Fuel Consumption ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Heat Losses ◽  
Specific Fuel Consumption ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
Plasma Sprayed

Thermal barrier coatings can be used to reduce the heat losses in heavy-duty diesel engines. A relatively new coating method for thermal barrier coatings is suspension plasma-spraying. Single-cylinder engine tests have been run to evaluate how heat losses to piston, cylinder head and exhausts as well as the specific fuel consumption are influenced by coating pistons with two different suspension plasma-sprayed thermal barrier coatings and one atmospheric plasma-sprayed thermal barrier coating, and comparing the results to those from an uncoated steel piston. The two suspension plasma-sprayed thermal barrier coatings showed reduced heat losses through the piston and less heat redirected to the cylinder head compared to conventional atmospheric plasma-sprayed thermal barrier coating, while one suspension plasma-sprayed coating with yttria-stabilized zirconia as top coat material showed increased exhaust temperature. However, the indicated specific fuel consumption was higher for all tested thermal barrier coatings than for an uncoated engine. The best performing thermal barrier coating with respect to indicated specific fuel consumption was a suspension plasma-sprayed coating with gadolinium zirconate as top coat material.

Depletion Model of Aluminum in Bond Coat for Plasma-Sprayed Thermal Barrier Coatings

2009 ◽  
Vol 75 ◽  
pp. 31-35 ◽  
Author(s):  
Chang Che ◽  
G.Q. Wu ◽  
Hong Yu Qi ◽  
Z. Huang ◽  
Xiao Guang Yang
Keyword(s):  
Mathematical Model ◽  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Bond Coat ◽  
Thermal Exposure ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
Plasma Sprayed

The aluminum depletion of NiCrAlY bond coat in an air-plasma-sprayed thermal barrier coating (TBC) has been studied by experimental and simulative approaches. Upon thermal exposure, Al depletion regions were observed. The depletion of aluminum is resulting from Al diffusion towards the surface of bond coat and into substrate. A mathematical model of Al depletion was presented. The model is able to explain the observed results in a qualitative way and has been shown that Al depletes within the bond coat by diffusion.

Development and Performance Evaluation of Thick Air Plasma Sprayed Thermal Barrier Coatings

2000 ◽  
Author(s):  
Z.Z. Mutasim ◽  
Y.L. Nava
Keyword(s):  
Thermal Barrier Coating ◽  
Thermal Barrier Coatings ◽  
Ceramic Coatings ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Barrier Coatings ◽  
Barrier Coating ◽  
And Performance ◽  
Plasma Sprayed ◽  
Industrial Gas Turbine

Abstract Air plasma sprayed thermal barrier coatings have been widely used to reduce metal wall temperatures of industrial gas turbine combustor liners. Thermal barrier coatings provide thermal gradients, with the goal of reducing the liner wall temperature to acceptable levels as a result of their low thermal conductivity. A typical thermal barrier coating consists of a 0.1-0.2 mm MCrAlY bond coating and a 0.25-0.35 mm thick 8 wt.% yttria stabilized zirconia ceramic top coating. A method to increase thermal barrier coating effectiveness is the application of thicker ceramic coatings. Development and performance testing of 0.5-0.8 mm thick ceramic coatings are discussed in this paper. Cyclic oxidation tests that simulate industrial gas turbine environments were conducted. Thermal barrier coating degradation-mechanisms were determined from microstructural evaluation of thermally exposed samples.

Mechanical Properties of Thermal Barrier Coatings at Room Temperature

2005 ◽  
Vol 290 ◽  
pp. 336-339 ◽  
Author(s):  
G. Guidoni ◽  
Y. Torres Hernández ◽  
Marc Anglada
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Room Temperature ◽  
Inconel 625 ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Bending Tests ◽  
Four Point Bending ◽  
Barrier Coating ◽  
Plasma Sprayed

Four point bending tests have been carried out on a thermal barrier coating (TBC) system, at room temperature. The TBC system consisted of a plasma sprayed Y-TZP top coat with 8 % in weight of Yttria, a bond coat of NiCrAlY and a Ni-based superalloy Inconel 625 as substrate. The TBC coating was deposited on both sides of the prismatic specimens. Efforts have been done in detecting the damage of the coating by means of Maltzbender et al [1] model.

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