H. Zhihai, Xi’an Jiaotong University, Xi'an city,Shaanxi Province, China; W. Haijun, National Key Laboratory for Remanufacturing, Beijing, China
The ZrO2–3wt%Y2O3-18wt%CeO2(C-YSZ)/NiCoCrAlY functionally graded TBCs (FG-TBCs) system were prepared by a unique processing method that low melt point metal and high melt point ceramic were be fed to the different temperature regions of plasma plume for suitable melting through dual and inner powder feed ports based on the recently developed Supersonic Plasma Spray (S-PS) system. The thermal shock test of FG-TBCs samples was performed using a self-designed multi-functional rotational thermal shock tester, which the heating-cooling curves and surface morphology of specimens can also be observed by a CCD metalloscope and recorded on line by means of accessorial computer system, to evaluate the thermal shock resistance of samples when them were heated by a high heat flux of oxygen-acetylene flam to 1200º
C in a time interval of 15~20s and followed water-quenched to ambient temperature. The FG-TBCs system exhibit excellent thermal shock resistance due to its structure was still perfect without any spallation after thermal shock test over 200 cycles.Keyword: Supersonic Plasma Spray(S-PS); Functionally graded TBCs (FG-TBCs); Thermal shock test;
Summary: The ZrO2–3wt%Y2O3-18wt%CeO2(C-YSZ)/NiCoCrAlY functionally graded TBCs (FG-TBCs) system were prepared by a unique processing method that low melt point metal and high melt point ceramic were be fed to the different temperature regions of plasma plume for suitable melting through dual and inner powder feed ports based on the recently developed Supersonic Plasma Spray (S-PS) system. The thermal shock test of FG-TBCs samples was performed using a self-designed multi-functional rotational thermal shock tester, which the heating-cooling curves and surface morphology of specimens can also be observed by a CCD metalloscope and recorded on line by means of accessorial computer system, to evaluate the thermal shock resistance of samples when them were heated by a high heat flux of oxygen-acetylene flam to 1200ºC in a time interval of 15~20s and followed water-quenched to ambient temperature. The temperature fields and thermal stresses distribution along with thickness and radial of disk plate samples were calculated by means of ANSYS limited element method. The influences of evolving of finely lamellate microstructure mixed by alloy and ceramic with gradient along the thickness direction and the cracks increasing and extend gradually with thermal cycles increasing on thermal shock resistance of FG-TBCs were investigated.
Keyword: Supersonic Plasma Spray(S-PS); Functionally graded TBCs (FG-TBCs); Thermal shock test; Temperature fields; Thermal stresses distribution
