Thermal shock resistance of yttria-stabilized zirconia with Palmqvist indentation cracks

2003 ◽  
Vol 23 (1) ◽  
pp. 107-114 ◽  
Author(s):  
G. Fargas ◽  
D. Casellas ◽  
L. Llanes ◽  
M. Anglada
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Shock Resistance

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.

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.

scholarly journals Comparing the influence of different kinds of zirconia on properties and microstructure of Al2O3 ceramics

2016 ◽  
Vol 23 (4) ◽  
pp. 407-412
Author(s):  
Wenfeng Li ◽  
Suping Li ◽  
Xiangchong Zhong
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Room Temperature ◽  
Yttria Stabilized Zirconia ◽  
Modulus Of Rupture ◽  
Monoclinic Zirconia ◽  
Stabilized Zirconia ◽  
Microstructure Characteristics ◽  
Shock Resistance ◽  
Room Temperature Strength

AbstractThis paper compared the influence of fused zirconia-corundum (AZ40), monoclinic zirconia (m-ZrO2), and 3 mol% yttria-stabilized zirconia (3Y-ZrO2) on physical properties at room temperature, hot modulus of rupture, and thermal shock resistance of Al2O3 ceramics, and their relationships with microstructure changes were investigated. It was found that m-ZrO2 or 3Y-ZrO2 addition promoted the process of sintering densification and enhanced the room temperature strength and the hot modulus of rupture of Al2O3 ceramics, and the effect of the latter was more distinct, while those of the sample with AZ40 addition decreased. In addition, the three kinds of ZrO2 were beneficial to improving the thermal shock resistance of Al2O3 ceramics. All these changes had close relationships with the changes of corresponding microstructure characteristics (including distribution of particles, degree of contact between crystals, grain boundary solid solution, microcrack density) and phase composition.

Thermal Shock Behavior of Calcia Stabilized Zirconia Ceramics with Porosity Gradient Structure

2009 ◽  
Vol 631-632 ◽  
pp. 435-440
Author(s):  
Qiang Shen ◽  
Chang Lian Chen ◽  
Fei Chen ◽  
Qi Wen Liu ◽  
Lian Meng Zhang
Keyword(s):  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Bending Strength ◽  
Gradient Structure ◽  
Monoclinic Zirconia ◽  
Stabilized Zirconia ◽  
Zirconia Ceramics ◽  
The Matrix ◽  
Shock Resistance ◽  
Thermal Shock Behavior

Porous calcia stabilized zirconia ceramics (CSZC) with closed pores were presurelessly sintered by adding different contents of zirconia hollow balls. CSZC FGM with porosity gradient structure was then fabricated by laminating five layers with designed contents of zirconia hollow balls. The porosity, microstructure, and bending strength of the obtained CSZC samples were characterized. The results show that the hollow balls distribute uniformly and are well bonded with the matrix, and the porous structure is mainly composed of closed pores. The porosity of the CSZC increases linearly from 5.7 % to 31.6 % when the content of zirconia hollow balls increases from 0 % to 30 %, and the bending strength decreases rapidly from 297 MPa to 30 MPa. The thermal shock behavior of the CSZC and FGM was evaluated using air-quenching technique. It is shown that the residual bending strength of the quenched samples increases after several quenching cycles, and the samples are damaged by thermal shock after eight thermal cycles because of the production of monoclinic zirconia. FGM samples with porosity gradient structure can endure above twelve thermal shock cycles and exhibits better thermal shock resistance.

Microstructures, Thermal Shock Resistance and Isothermal Oxidation Resistance of Nanostructured Ceria Stabilized Zirconia Coatings

2011 ◽  
Vol 189-193 ◽  
pp. 160-164
Author(s):  
Wen Quan Wang ◽  
Wen Biao Gong ◽  
Da Qian Sun
Keyword(s):  
Thermal Shock ◽  
Oxidation Resistance ◽  
Thermal Shock Resistance ◽  
Isothermal Oxidation ◽  
Stabilized Zirconia ◽  
Grain Structures ◽  
Nanostructured Ceria ◽  
Shock Resistance ◽  
Columnar Grain ◽  
Plasma Sprayed

Microstructures, thermal shock resistance and isothermal oxidation resistance of plasma-sprayed nanostructured ceria stabilized zirconia (CSZ) coatings were investigated. The results revealed that the nanostructured CSZ coatings mainly included two kinds of typical microstructures, nanosized CSZ particles embedded in the so-called matrix and micrometer-sized columnar grain structures of CSZ similar to those of the conventional coatings. Compared with the conventional CSZ coatings, the nanostructured CSZ coatings were denser and had finer and fewer porous structures and microcracks. Further study showed that the nanostructured CSZ coatings had higher thermal shock resistance and isothermal oxidation resistance compared with conventional CSZ coatings. The improved properties of the nanostructured CSZ coatings were attributed to the better coating toughness and decreased porosities and microcracks in the coatings.

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