TUTCRIS - Tampereen teknillinen yliopisto

TUTCRIS

Fabrication and Characterization of Amorphous Alumina-Yttria-Stabilized Zirconia Coatings by Air Plasma Spraying

Tutkimustuotosvertaisarvioitu

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut1302-1311
Sivumäärä10
JulkaisuJournal of Thermal Spray Technology
Vuosikerta23
Numero8
DOI - pysyväislinkit
TilaJulkaistu - 25 marraskuuta 2014
OKM-julkaisutyyppiA1 Alkuperäisartikkeli

Tiivistelmä

Almost fully amorphous coatings of near-eutectic alumina-yttria-stabilized zirconia (Al2O3-YSZ) were prepared by air plasma spraying using Al2O3and 8 mol.% YSZ crystalline-mixed powders. The coatings consist of mostly an amorphous phase with a small amount of nanocrystals. Various characterization techniques were used to understand coating formation and the origins of the different phases within the coatings. The formation of the mostly amorphous structure is attributed to the high glass-forming ability of Al2O3-YSZ and the appropriate plasma spraying conditions. A small number of nanocrystals are produced during crystallization of the incoming molten droplets or by recrystallization of the solidified splats by accumulated heat. Scanning electron microscopy shows that the coatings have a dense, layered structure with low porosity, and bright-field transmission electron microscopy images indicate sharp interface rather than grit-blasted wavy surface between splats and substrates in the coatings. The as-sprayed amorphous coatings crystallized at around 920 °C and micro-hardness of the as-sprayed amorphous coatings was 8.12 GPa.