305 Thermal Insulator Performance of Porous Ceramic Coatings Deposited by Plasma-Spray Process

The PS-PVD method is a promising technique for production of ceramic coatings from the vapor phase on gas turbine components. The resulting layers combine benefits of coatings made by the plasma spray method and other methods of Physical Vapor Deposition. The plasma spray process is carried out under reduced pressure (~ 200 Pa) and with the use of a gun applied in the method (the LPPS torch 0C3P). The PS-PVD enjoys many of the benefits of plasma spray methods combined with relatively low production costs and overall better properties. One of the significant costs of coating manufacturing by this method is the use of helium as process gas to generate plasma. The authors attempted to form a ceramic coating from ZrO2, where a mixture of argon and nitrogen in various proportions was used. The resulting layers were analyzed by XRD, LFA, SEM-EDS.

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A comparative study on corrosion behavior of ceramic coatings via plasma spray process in 3.5% NaCl solution

Bulletin of the Faculty of Engineering. Mansoura University ◽

10.21608/bfemu.2020.94531 ◽

2020 ◽

Vol 43 (1) ◽

pp. 31-35

Author(s):

Dalia Ahmed

Keyword(s):

Comparative Study ◽

Corrosion Behavior ◽

Plasma Spray ◽

Ceramic Coatings ◽

Nacl Solution ◽

Spray Process ◽

Plasma Spray Process

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2CaO･SiO2-CaO･ZrO2 Thermal Barrier Coating Formed by Plasma Spray Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.522-523.239 ◽

2006 ◽

Vol 522-523 ◽

pp. 239-246 ◽

Cited By ~ 1

Author(s):

Noriyuki Mifune ◽

Yoshio Harada

Keyword(s):

Thermal Shock ◽

Thermal Barrier Coating ◽

Plasma Spray ◽

Ceramic Coatings ◽

Thermal Barrier ◽

Combustion Gas ◽

Bond Coating ◽

Spray Process ◽

Plasma Spray Process ◽

Barrier Coating

The applicability of 2CaO·SiO2-CaO·ZrO2 ceramic coatings as thermal barrier coatings (TBCs) was investigated. Coatings consisting of various ratios of 2CaO·SiO2-CaO·ZrO2 bond-coated with NiCrAlY were prepared using the plasma spray process. The structure of the coatings was characterized by scanning electron microscopy and X-ray diffraction analysis. The resistance of the coatings to thermal shock was evaluated with acoustic emission techniques under a thermal cycle from 1273 K to room temperature, and the hot corrosion resistance of the coatings was investigated with V2O5 and Na2SO4 at 1273 K for 3 h. The 2CaO·SiO2-10~30mass%CaO·ZrO2 coatings had excellent thermal shock resistance, because the coatings contained a vertical micro-crack in a single flattened ceramic particle. These coatings possessed excellent corrosion protection preventing direct contact between the corrosive ashes and a NiCrAlY bond coating. The CaO in the coating reacted with vanadium compounds and inhibited the penetration of corrosive ashes to the bond coating. The developed 2CaO·SiO2-20mass%CaO·ZrO2 thermal barrier coating on stationary vanes was evaluated in an actual gas turbine. The ceramic coating did not separate from the bond coating and reacted with SOx in combustion gas to produce a stable sulfate (CaSO4), which fixed in the coating. The TBC effectively protected the metal substrate of the vanes in practical operating condition for 25,000 h.

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