Phase transformations in air plasma-sprayed yttria-stabilized zirconia thermal barrier coatings

Microstructure formation in plasma-sprayed functionally graded NiCoCrAlY/yttria-stabilized zirconia coatings

Functionally graded NiCoCrAlY/yttria-stabilized zirconia coatings were fabricated by plasma spraying using mechanically alloyed, plasma-spheroidized NiCoCrAlY/yttria-stabilized zirconia (YSZ) composite powders. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) analysis revealed that oxidation of aluminum, chromium and yttrium in the NiCoCrAlY alloy occurred in th...

Calibration of Raman spectroscopy in the stress measurement of air-plasma-sprayed yttria-stabilized zirconia.

Thermal barrier coatings (TBC) are used widely on a range of components that operate at high temperatures. We report measurement of the factor that is required to convert the Raman shift to stress for air plasma sprayed yttria (7 wt %) stabilized tetragonal zirconia (ZrO(2)) (YSZ) thermal barrier coatings. The factor is evaluated for the as-coated condition and also following a heat treatment a...

Morphology and thermal conductivity of yttria-stabilized zirconia coatings

An electron beam directed vapor deposition method was used to grow 7 wt.% Y2O3–ZrO2 (7YSZ) coatings and the effects of substrate rotation upon the coating porosity, morphology, texture, and thermal conductivity were explored. As the rotation rate was increased, the texture changed from Æ111æ to Æ100æ. Under stationary deposition, the coatings were composed of straight columns, while low-frequen...

WEAR REESISTANCE OF NANOSTRUCTURED AND CONVENTIONAL YTTRIA-STABILIZED ZIRCONIA COATINGS

Partially stabilized zirconia (PSZ) has been proven to be an excellent candidate as a thermal barrier coating (TBe) for hot sections in, for instance, heat or internal combustion engines and gas turbine parts. The main functions of these coatings are reducing heat losses, reducing fuel consumption, increasing efficiency, and extending durability and life. One of the main problems involved is we...

Failure analysis of suspension plasma sprayed thermal barrier coatings