Processing, microstructures and properties of thermal barrier coatings (TBCs) by plasma spraying (PS)

Chen, L.

doi:10.1533/9780857090829.2.132

Cited by 10 publications

(19 citation statements)

References 47 publications

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“…Since the 1960s, plasma sprayed thermal barrier coatings (PS-TBCs) have been used in diesel engines, aerospace and land-based gas turbine to reduce the surface temperature of hot section parts by 100°C to 200°C [114]. Although EB-PVD TBC coatings have superior strain/stress tolerance and smoother surface, the PS method is widely used in the gas turbine industry because of its low cost, high production efficiency, large range of coating thickness and easy control of compositions [11,114]. All metals, ceramic and polymer materials, can be sprayed with plasma spraying processes [115].…”

Section: Air Plasma Spraying (Aps)mentioning

confidence: 99%

“…Figure 3-22 (a) demonstrates the air plasma spray process [119]. A typical plasma spray system consists of: (1) a spray gun, to melt and accelerate the powder particles, (2) a feeder which supplies the powder to the gun, (3) gases as a media to generate the plasma and to carry the powder, (4) maybe a robot for controlling the torch and part movement, and (5) a power supply for the torch and control system [114]. Figure 3-22 (b) shows a typical plasma spray system using a direct current electric arc between two electrodes in the spray gun.…”

Section: Aps Deposition Processmentioning

confidence: 99%

“…The plasma spraying parameters can influence the temperature and velocity of particles hence the splat size and shape. The splats are usually about 1-50 μm thick and 10-50 μm in diameter [114,123]. Several layers of splats form a horizontal lamella and the boundaries between lamellae are distinctively visible on the cross sections of the coatings due to the differences in contrast (darker area usually contains more oxygen).…”

Section: Microstructure Of Aps Coatingsmentioning

confidence: 99%

“…The high porosity of APS coatings results from the rapid solidification of lamellae. These pores and voids, with varying shapes and sizes, are usually found to be oriented parallel or perpendicular to the coating surface [114]. Splashing that happens during APS deposition process makes APS coatings more random-shaped.…”

Section: Microstructure Of Aps Coatingsmentioning

confidence: 99%

“…Cross section showing microstructure of lamellar APS coating [121] Schematic of typical plasma-sprayed coating[114,123] …”

mentioning

confidence: 99%

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Cyclic and Isothermal Oxidation Resistance of ASPS Thermal Barrier Coating Systems

Li¹

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To systematically study the oxidation performances of thermal barrier coatings (TBCs) deposited by axial suspension plasma spraying (ASPS) method, isothermal and cyclic oxidation tests were conducted at a peak temperature of 1080C. The TBC systems are based on two different nickel-base superalloy substrates (CMSX-4 or IN738LC), platinum aluminide bond coat and yttria stabilized zirconia (8YSZ) top coat with either vertical cracks (VC) or columnar structure. After the oxidation tests, the samples were analyzed using a scanning electron microscope (SEM) and an X-Ray diffractometer. Samples with IN738LC substrate demonstrated longer isothermal oxidation lives whereas samples with CMSX-4 substrate showed greater cyclic oxidation lives. Outward elemental diffusion (of W and Ta) in TBC system containing CMSX-4 contributed to reduced isothermal oxidation life while the mismatch of coefficients of thermal expansion (CTE) between TGO, bond coat and substrate was believed to be responsible for early failure of TBC system with IN738LC substrate. TBC systems with columnar YSZ overall had longer isothermal oxidation life while vertically cracked YSZ seemed to result in longer cyclic life. Cr2O3 and spinels (CS), in addition to thermally grown aluminum oxide (TGO), were detected on tested TBC samples. The growth of spinels highly depended upon a coating's accessibility to oxygen and test duration and was found to contribute the spallation of the coating layer.iv

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Section: Air Plasma Spraying (Aps)mentioning

confidence: 99%

Section: Aps Deposition Processmentioning

confidence: 99%

Section: Microstructure Of Aps Coatingsmentioning

confidence: 99%

Section: Microstructure Of Aps Coatingsmentioning

confidence: 99%

“…Cross section showing microstructure of lamellar APS coating [121] Schematic of typical plasma-sprayed coating[114,123] …”

mentioning

confidence: 99%