A transmission electron microscopy study of the microstructures present in alumina coatings produced by plasma spraying.

Autor: Guilemany, J., Nutting, J., Dougan, M.
Zdroj: Journal of Thermal Spray Technology; Dec1997, Vol. 6 Issue 4, p425-429, 5p
Abstrakt: Alumina coatings deposited onto steel substrates by plasma spraying were studied using transmission electron microscopy. A number of allotropes of alumina distinct from the alpha-alumina of the starting powder were identified. The as-sprayed coatings consist primarily of metastable gamma-alumina and amorphous/nanocrystalline material. Areas of alpha-alumina were observed, generally in conjunction with the twinned metastable phases delta- and theta-alumina, and these were interpreted as resulting from solid-state transformation from the gamma phase, due to the annealing action of subsequent passes of the plasma torch. The absence of such phases from the first- and last-deposited layers is further evidence for such a mechanism. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
Externí odkaz: