TY - JOUR
T1 - Segregation and microstructural evolution at interfaces of atmospheric plasma sprayed thermal barrier coatings during thermal cycling
AU - Liu, Y. Z.
AU - Hu, X. B.
N1 - Funding Information:
This work was supported by Natural Science Foundation of Zhejiang Province (No. LY18E050027), Natural Science Foundation of Ningbo Municipality (No. 2018A610145) and Joint Funds of NSFC-ZJ (No. U1609208).
Funding Information:
This work was supported by Natural Science Foundation of Zhejiang Province (No. LY18E050027 ), Natural Science Foundation of Ningbo Municipality (No. 2018A610145 ) and Joint Funds of NSFC-ZJ (No. U1609208 ).
PY - 2020/4/5
Y1 - 2020/4/5
N2 - Segregation and microstructural evolution at interfaces of thermal barrier coatings (TBCs) during thermal cycling were systematically investigated using scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The as-sprayed TBCs were thermally cycled between 1100 °C and ambient temperature up to 3000 cycles. Results show that phosphorus, sulfur, and yttrium co-segregate at the top coat (TC)/bond coat (BC) interface after 3000 cycles. The above co-segregation at the BC/substrate interface was delayed by 1000 cycles. Chemical components of thermally grown oxide (TGO) layers at both the TC/BC and BC/substrate interfaces change from O and Al to O, Al, Cr, Co and Ni as the thermal cycling proceeded. The corresponding oxides in the TGO layers evolved from α-Al2O3 to α-Al2O3, Cr2O3, NiO and spinel phases. Controlled by the element diffusion rate and selective internal oxidation, evolution of the thickness of the TGO layers followed a natural logarithmic law.
AB - Segregation and microstructural evolution at interfaces of thermal barrier coatings (TBCs) during thermal cycling were systematically investigated using scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The as-sprayed TBCs were thermally cycled between 1100 °C and ambient temperature up to 3000 cycles. Results show that phosphorus, sulfur, and yttrium co-segregate at the top coat (TC)/bond coat (BC) interface after 3000 cycles. The above co-segregation at the BC/substrate interface was delayed by 1000 cycles. Chemical components of thermally grown oxide (TGO) layers at both the TC/BC and BC/substrate interfaces change from O and Al to O, Al, Cr, Co and Ni as the thermal cycling proceeded. The corresponding oxides in the TGO layers evolved from α-Al2O3 to α-Al2O3, Cr2O3, NiO and spinel phases. Controlled by the element diffusion rate and selective internal oxidation, evolution of the thickness of the TGO layers followed a natural logarithmic law.
KW - Element segregation
KW - Interfacial oxidation
KW - Microstructural evolution
KW - Oxidation kinetics
KW - Scanning transmission electron microscopy (STEM)
KW - Thermal barrier coatings (TBCs)
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U2 - 10.1016/j.jallcom.2019.153026
DO - 10.1016/j.jallcom.2019.153026
M3 - Article
AN - SCOPUS:85077746053
VL - 819
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
M1 - 153026
ER -