THERMAL SHOCK PROPERTIES OF YTTRIA-STABILIZED ZIRCONIA COATINGS DEPOSITED USING LOW-ENERGY VERY LOW PRESSURE PLASMA SPRAYING

2015 ◽  
Vol 22 (05) ◽  
pp. 1550061 ◽  
Author(s):  
LIN ZHU ◽  
NANNAN ZHANG ◽  
RODOLPHE BOLOT ◽  
HANLIN LIAO ◽  
CHRISTIAN CODDET
Keyword(s):  
Thermal Shock ◽  
Plasma Spray ◽  
Thermal Shock Resistance ◽  
Low Pressure ◽  
Low Energy ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Shock Resistance

Yttria-stabilized zirconia (YSZ) coatings have been frequently used as a thermal protective layer on the metal or alloy component surfaces. In the present study, ZrO 2-7% Y 2 O 3 thermal barrier coatings (TBCs) were successfully deposited by DC (direct current) plasma spray process under very low pressure conditions (less than 1 mbar) using low-energy plasma guns F4-VB and F100. The experiments were performed to evaluate the thermal shock resistance of different TBC specimens which were heated to 1373 K at a high-temperature cycling furnace and held for 0.5 h, followed by air cooling at room temperature for 0.2 h. For comparison, a corresponding atmospheric plasma spray (APS) counterpart was also elaborated to carry out the similar experiments. The results indicated that the very low pressure plasma spray (VLPPS) coatings displayed better thermal shock resistance. Moreover, the failure mechanism of the coatings was elucidated.

Very low pressure plasma sprayed yttria-stabilized zirconia coating using a low-energy plasma gun

2011 ◽  
Vol 105 (4) ◽  
pp. 991-996 ◽  
Author(s):  
Lin Zhu ◽  
Nannan Zhang ◽  
Rodolphe Bolot ◽  
Marie-Pierre Planche ◽  
Hanlin Liao ◽  
...  
Keyword(s):  
Low Pressure ◽  
Low Energy ◽  
Yttria Stabilized Zirconia ◽  
Zirconia Coating ◽  
Stabilized Zirconia ◽  
Plasma Gun ◽  
Pressure Plasma ◽  
Low Pressure Plasma ◽  
Plasma Sprayed

Improving Thermal Shock Resistance of Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings by Laser Remelting

2012 ◽  
Vol 472-475 ◽  
pp. 2502-2507
Author(s):  
Zong Yin Duan ◽  
Dong Sheng Wang
Keyword(s):  
Thermal Shock ◽  
Thermal Barrier Coatings ◽  
Thermal Shock Resistance ◽  
Yttria Stabilized Zirconia ◽  
Thermal Barrier ◽  
Laser Remelting ◽  
Stabilized Zirconia ◽  
Barrier Coatings ◽  
Shock Resistance ◽  
Plasma Sprayed

This paper deals with the microstructure and thermal shock behavior of laser remelting of yttria-stabilized zirconia (YSZ) thermal barrier coatings (TBCs) deposited by plasma spraying. The microstructures of the coatings were analyzed by scanning electron microscopy (SEM). It was found that the as-sprayed ceramic coating had laminated structure with high porosity. However, the coating exhibited a dense lamellar-like layer with segment cracks on the remained plasma-sprayed porous layer. Thermal shock experiments for the two kinds of TBCs were performed by water quenching method. Testing result showed that the laser-remelted TBC had better thermal shock resistance than the as-sprayed one. The damage mode of the as-sprayed TBC was great-size whole spalling. In contract, the failure mechanism of the laser-remelted one was mainly local pelling. Segmented cracks of the top ceramic coatings caused by laser remelting improved the stress accommodation and were mainly attributed to the enhancement for thermal shock life of TBC.

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