Comparative investigation of the effect of composition and porosity gradient on thermo-mechanical properties of functionally graded thick thermal barrier coatings deposited by atmospheric plasma spraying

2021 ◽  
Author(s):  
Zahra Mohammadzaki Goudarzi ◽  
Zia Valefi ◽  
Pejman Zamani ◽  
Saied Taghi-Ramezani
Keyword(s):  
Mechanical Properties ◽  
Plasma Spraying ◽  
Thermal Barrier Coatings ◽  
Comparative Investigation ◽  
Functionally Graded ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings

scholarly journals Thermal Stability of YSZ Thick Thermal Barrier Coatings Deposited by Suspension and Atmospheric Plasma Spraying

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 984
Author(s):  
Shiqian Tao ◽  
Jiasheng Yang ◽  
Minglong Zhai ◽  
Fang Shao ◽  
Xinghua Zhong ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Thermal Barrier Coatings ◽  
Thermal Aging ◽  
Thermal Exposure ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Aps Coatings ◽  
Steel Substrates

Two types of segmentation-crack structured yttria-stabilized zirconia (YSZ) thick thermal barrier coatings (>500 μm, TTBCs) were deposited onto the stainless steel substrates using atmospheric plasma spraying (APS) and suspension plasma spraying (SPS) process, respectively. In this work, thermal aging behaviors, such as the microstructures, phase compositions, grain growth, and mechanical properties of APS TTBCs and SPS TTBCs, were systematically investigated. Results showed that both as-sprayed TTBCs exhibited a typical segmentation-crack structure in the through-thickness direction. APS coatings mainly comprised of larger columnar crystals, while a large number of smaller equiaxed grains existed in SPS coatings. Both of the coatings underwent tetragonal-monoclinic phase transformation after 155 °C/40 h heat treatment. The poorer phase stability of SPS TTBCs may have a connection with smaller grain size. Thermal-aged APS and SPS coatings exhibited a significant increase in H and E values with the rising of thermal aging temperature, and for the samples that thermal aged at 1550 °C, the H and E values increased sharply during initial stage then decreased after 80 h due to the phase decomposition. The segmented APS coatings had weak bonding between the lamellaes during thermal exposure, which caused the mean Vickers hardness value of APS TTBCs to be much lower than that of SPS TTBCs.

Sign in / Sign up

Export Citation Format

Share Document