Evolution of mechanical properties of thermal barrier coatings subjected to thermal exposure by instrumented indentation testing

2016 ◽  
Vol 42 (8) ◽  
pp. 10242-10250 ◽  
Author(s):  
C.C. Li ◽  
T. Wang ◽  
X.J. Liu ◽  
Z.H. Zheng ◽  
Q. Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Thermal Exposure ◽  
Thermal Barrier ◽  
Indentation Testing ◽  
Instrumented Indentation ◽  
Barrier Coatings

Microstructural Evolution and Mechanical Properties of Vertical-Cracked Thermal Barrier Coatings in Thermal Exposure

2012 ◽  
Vol 512-515 ◽  
pp. 1040-1044 ◽  
Author(s):  
Zhe Lu ◽  
Sang Won Myoung ◽  
Tae Sik Jang ◽  
Kang Hyeon Lee ◽  
Je Hyun Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Barrier Coatings ◽  
Total Porosity ◽  
Thermal Exposure ◽  
Thermal Barrier ◽  
Air Plasma ◽  
Barrier Coatings ◽  
Plasma Sprayed ◽  
Intrinsic Feature

The effects of intrinsic feature of feedstock in air plasma-sprayed (APS) coatings on the microstructure and mechanical properties of vertical-cracked thermal barrier coatings (TBCs) were investigated in thermal exposure. The microstructure after the thermal exposure for 400 h is densified, while after the thermal exposure for 800 h various defects such as interlamellar cracks and the vertical and horizontal cracks are newly developed, even though the total porosity is decreased. The microstructure of the TBC prepared with 204 C-NS is more porous than that of the TBC with 204NS, showing higher mechanical properties and better thermal stability in the TBC with 204 NS.

Mechanical Properties of Thermal Barrier Coatings at Room Temperature

2005 ◽  
Vol 290 ◽  
pp. 336-339 ◽  
Author(s):  
G. Guidoni ◽  
Y. Torres Hernández ◽  
Marc Anglada
Keyword(s):  
Mechanical Properties ◽  
Thermal Barrier Coatings ◽  
Room Temperature ◽  
Inconel 625 ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Bending Tests ◽  
Four Point Bending ◽  
Barrier Coating ◽  
Plasma Sprayed

Four point bending tests have been carried out on a thermal barrier coating (TBC) system, at room temperature. The TBC system consisted of a plasma sprayed Y-TZP top coat with 8 % in weight of Yttria, a bond coat of NiCrAlY and a Ni-based superalloy Inconel 625 as substrate. The TBC coating was deposited on both sides of the prismatic specimens. Efforts have been done in detecting the damage of the coating by means of Maltzbender et al [1] model.

Improving Contact Damage Resistance of Thermal Barrier Coatings by Incorporating Buffer Layer

2009 ◽  
Vol 620-622 ◽  
pp. 319-322
Author(s):  
Sung Il Jung ◽  
Young Seok Sim ◽  
Jae Hyun Kim ◽  
Je Hyun Lee ◽  
Yeon Gil Jung ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Thermal Barrier Coatings ◽  
Dwell Time ◽  
Thermal Exposure ◽  
Thermal Barrier ◽  
Lower Stress ◽  
Stress Strain ◽  
Barrier Coatings ◽  
Bond Coats ◽  
Tbc Systems

The effects of the introduction of a buffer layer between the bond and top coats on the indentation stress-strain behavior and the contact damage were investigated in air-plasma sprayed (APS) zirconia (ZrO2)–based thermal barrier coatings (TBCs). The microstructure is relatively continuous in the TBC system with the buffer layer, showing Zr, Ni, Cr, and Mg elements between the top and bond coats, whereas the Zr element suddenly disappears by passing the interface between the top and bond coats. The TBC system with the buffer layer shows less strain than that without the buffer layer in the higher stress regions above about 1.3 GPa, while both TBC systems become soft by forming the top coat in the lower stress regions compared with the substrate. The stress–strain curve in both TBC systems is dependent on the dwell time of thermal exposure condition. The TBC system with the buffer layer shows the lower stress-strain curves than that without the buffer layer in thermal cycles with the relatively short dwell time of 1 h, showing the reverse trend with the relatively long dwell time of 10 h. Subsurface damage in substrate is reduced at both indentation loads of P = 500 N and P = 2000 N by introducing the buffer layer, independent of thermal exposure. Therefore, the TBC system with the buffer layer is more efficient in protecting the substrate from contact environments than that without the buffer layer, showing cracking or delamination between the top coat and the buffer layer in the TBC system with the buffer layer.

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