High-Temperature Oxidation Resistance Mechanism and Thermal Shock Performance of CoCrTaAlY/YSZ Thermal Barrier Coatings Fabricated Using Plasma Spraying and Laser Cladding

2019 ◽  
Vol 46 (8) ◽  
pp. 0802007
Author(s):  
顾振杰 Zhenjie Gu ◽  
雷剑波 Jianbo Lei ◽  
窦俊雅 Junya Dou ◽  
郭津博 Jinbo Guo
Keyword(s):  
High Temperature ◽  
Thermal Shock ◽  
Oxidation Resistance ◽  
Plasma Spraying ◽  
Thermal Barrier Coatings ◽  
High Temperature Oxidation ◽  
Resistance Mechanism ◽  
Thermal Barrier ◽  
Temperature Oxidation ◽  
Barrier Coatings

The Effect of Laser Glazing on High Temperature Oxidation Resistance of Thermal Barrier Coatings

2012 ◽  
Vol 433-440 ◽  
pp. 315-318
Author(s):  
Seyid Fehmi Diltemiz ◽  
Melih Cemal Kushan
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Thermal Barrier Coatings ◽  
Gas Turbines ◽  
High Temperature Oxidation ◽  
304 Stainless Steel ◽  
Thermal Barrier ◽  
Laser Glazing ◽  
Temperature Oxidation ◽  
Barrier Coatings

Thermal barrier coatings (TBCs) have been widely used by aero and land based gas turbines to protect hot section parts from oxidation and thermal loads. These coatings are generally consisting of multiple layers of coating (usually two) with each layer having a specific function. TBCs are generally deposited with air plasma spray (APS) or electron beam physical vapor deposition (EB-PVD) techniques. In this paper plasma sprayed TBCs were deposited on to 304 stainless steel substrates then ceramic surfaces were glazing with Nd-YAG laser. Metallographic examinations were applied to the samples to investigate microstructural changes in glazed ceramic layer. Both glazed and as-coated samples were subjected to oxidation tests to measure the high temperature oxidation resistance. The tests showed that, laser glazing is beneficial to oxidation resistance of TBCs. This improvement is attributed to sintering of zirconia layer which act as oxygen barrier and formed during glazing process.

Effect of Spray Distance on the Microstructure and High Temperature Oxidation Resistance of Plasma Spray-Physical Vapor Deposition 7YSZ Thermal Barrier Coating

2021 ◽  
Vol 1035 ◽  
pp. 511-520
Author(s):  
Wen Long Chen ◽  
Min Liu ◽  
Xiao Ling Xiao ◽  
Xin Zhang
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Thermal Barrier Coatings ◽  
Physical Vapor Deposition ◽  
High Temperature Oxidation ◽  
Thermal Barrier ◽  
Spray Distance ◽  
Temperature Oxidation ◽  
Barrier Coatings ◽  
7Ysz Coating

In order to study the effect of spray distance on the structure and high temperature oxidation resistance of feather-columnar thermal barrier coatings, the feather-columnar ZrO2-7wt. % Y2O3 (7YSZ) thermal barrier coatings were prepared at spray distances of 650 mm, 950 mm, 1100 mm, 1250 mm, and 1400 mm by plasma spray-physical vapor deposition (PS-PVD) technology. The surface roughness, micro morphology, and porosity of the sprayed 7YSZ coating were analyzed by 3D surface profiler, SEM, XRD, etc., and the impedance spectrum characteristics of the 7YSZ coating were characterized by electrochemical alternating current (AC) impedance technology. In addition, the high temperature oxidation resistance test of 7YSZ coating under different spray distances was carried out at a temperature of 1000 °C to study the influence of spray distance on the high temperature oxidation resistance of 7YSZ coating. The research results show that the surface roughness and porosity of feather-columnar 7YSZ coating increased sequentially with the increase of spray distance. At the same time, The YSZ grain boundary resistance value increased exponentially as the porosity of the coating increases. Where the spray distance was in the range of 650 mm and 1250 mm, the high temperature oxidation rate constant of the coating increased with the spray distance. However, the spray distance was greater than 1250 mm, and the spray distance had no significant effect on the high temperature oxidation resistance of the coating.

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