Fabrication and thermal shock resistance of multilayer γ-Y 2 Si 2 O 7 environmental barrier coating on porous Si 3 N 4 ceramic

2016 ◽  
Vol 36 (3) ◽  
pp. 689-695 ◽  
Author(s):  
Chao Wang ◽  
Meng Chen ◽  
Hongjie Wang ◽  
Xingyu Fan ◽  
Hongyan Xia
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Porous Si ◽  
Environmental Barrier ◽  
Environmental Barrier Coating ◽  
Barrier Coating ◽  
Shock Resistance

Study on Thermal Shock Resistance of Nano-CeO2–Y2O3 Co-Stabilized ZrO2 (CYSZ) Ceramic Powders Thermal Barrier Coating of Aircraft Engine

2019 ◽  
Vol 14 (11) ◽  
pp. 1597-1605
Author(s):  
Yang Lyu ◽  
Xuan Shao ◽  
Wen-Xue Wang ◽  
Hui Tang
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Thermal Shock Resistance ◽  
Ceramic Coatings ◽  
Precipitation Method ◽  
Thermal Barrier ◽  
Ceramic Powders ◽  
Alloy Matrix ◽  
Barrier Coating ◽  
Shock Resistance

In this paper, nano-CeO2–Y2O3 co-stabilized ZrO2 ceramic powders (CYSZ) were firstly prepared by co-precipitation method, and CYSZ powder was spray-granulated, followed by thermal plasma spraying of nano-CYSZ thermal barrier coating on 35Cr2Ni4 MoA alloy matrix. After XRD and SEM analysis, the five CYSZ ceramic coatings (CeO2 content 0, 1, 5, 10, 15 mol%) prepared were tetragonal phase structures before and after the thermal shock experiment, and the thickness of CYSZ ceramic coating was about 200 μm. Adding appropriate amount of nano CeO2 promoted the formation of micro-cracks in the coating, released the coating stress, slowed down the thermal shock damage process, and prevented the transformation from t-ZrO2 to m-ZrO2. The AFM morphology showed that the coating surface grains grow vertically after thermal shock cycle, which indicated that the entry of Ce4+ into ZrO2 lattice resulted in lattice distortion and made the grains more stable. When the content of CeO2 is 1 mol%, the thermal shock resistance excellent is 84 times. Therefore, the addition of CeO2 can effectively improve the thermal shock resistance performance of CYSZ thermal barrier coating, meeting the requirements of high temperature working conditions of aeroengine and hot-end components.

scholarly journals Thermal shock resistance of yttrium aluminium oxide Y3Al5O12 thermal barrier coating for titanium alloy

2020 ◽  
Vol 14 (1) ◽  
pp. 6514-6525 ◽  
Author(s):  
Mohammed A. Almomani ◽  
Mohamad I. Al-Widyan ◽  
Sulaiman M. Mohaidat
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Operating Temperature ◽  
Thermal Barrier ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barrier Coating ◽  
Shock Resistance

The high strength-to- weight ratio of titanium alloys allows their use in jet engines. However, their use is restricted by susceptibility to oxidation at high temperatures. In this study, the possibility of increasing the operating temperature of titanium alloys through using Yttrium Aluminum Oxide (YAG) as a thermal barrier coating material for Ti-6Al-4V substrate is studied. The study concludes that YAG can be utilized to increase the operating temperature of Ti-6Al-4V titanium alloy from around 350 °C to 800 °C due to its low thermal conductivity and phase stability up to its melting point. In addition, its lower oxygen diffusivity in comparison with the standard YSZ material will provide a better protection of the titanium substrate from oxidation. In this work, coating was created using atmospheric plasma spray. X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) were used to examine coatings' composition and structure. The coating was characterized by thermal shock test, Vickers hardness test and adhesion strength test. X-ray diffraction indicated that the coating was of a partially crystalline Y3Al5O12 composition. The coating was porous with excellent thermal shock resistance at 800 oC, with a Vickers micro-hardness of 331.35 HV and adhesion strength of 17.6 MPa.

scholarly journals Thermal Shock Resistance and Thermal Insulation Capability of Laser-Glazed Functionally Graded Lanthanum Magnesium Hexaluminate/Yttria-Stabilised Zirconia Thermal Barrier Coating

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3865
Author(s):  
Muhammed Anaz Khan ◽  
Annakodi Vivek Anand ◽  
Muthukannan Duraiselvam ◽  
Koppula Srinivas Rao ◽  
Ramachandra Arvind Singh ◽  
...  
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coating ◽  
Thermal Insulation ◽  
Thermal Shock Resistance ◽  
Functionally Graded ◽  
Thermal Barrier ◽  
Laser Glazing ◽  
Heat Management ◽  
Barrier Coating ◽  
Shock Resistance

In this work, functionally graded lanthanum magnesium hexaluminate (LaMgAl11O19)/yttria-stabilised zirconia (YSZ) thermal barrier coating (FG-TBC), in as-sprayed and laser-glazed conditions, were investigated for their thermal shock resistance and thermal insulation properties. Results were compared with those of a dual-layered coating of LaMgAl11O19 and YSZ (DC-TBC). Thermal shock tests at 1100 °C revealed that the as-sprayed FG-TBC had improved thermal stability, i.e., higher cycle lifetime than the as-sprayed DC-TBC due to its gradient architecture, which minimised stress concentration across its thickness. In contrast, DC-TBC spalled at the interface due to the difference in the coefficient of thermal expansion between the LaMgAl11O19 and YSZ layers. Laser glazing improved cycle lifetimes of both the types of coatings. Microstructural changes, mainly the formation of segmentation cracks in the laser-glazed surfaces, provided strain tolerance during thermal cycles. Infrared rapid heating of the coatings up to 1000 °C showed that the laser-glazed FG-TBC had better thermal insulation capability, as interlamellar pores entrapped gas and constrained heat transfer across its thickness. From the investigation, it is inferred that (i) FG-TBC has better thermal shock resistance and thermal insulation capability than DC-TBC and (ii) laser glazing can significantly enhance the overall thermal performance of the coatings. Laser-glazed FG-TBC provides the best heat management, and has good potential for applications that require effective heat management, such as in gas turbines.

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