Title

Thermo-physical processes in cerium nitrate precursor droplets injected into high temperature plasma

Authors

Authors

A. Saha; S. Seal; B. Cetegen; E. Jordan; A. Ozturk;S. Basu

Abbreviated Journal Title

Surf. Coat. Technol.

Keywords

Cerium nitrate; Solution precursor plasma spray process; Modeling of; thermal spray; Coating morphology; Droplet breakup; SPRAY-PYROLYSIS; BARRIER COATINGS; PARTICLES; FLAME; HEAT; Materials Science, Coatings & Films; Physics, Applied

Abstract

The thermo-physical phenomena inside a droplet during its flight in a thermal plasma flow have been modeled for SPPS processes using cerium nitrate precursor. The different thermo-physical stages encountered during droplets' flight include aerodynamic breakup, rapid vaporization of solvent and precipitation, internal pressurization with shell rupture and rapid heating of volumetrically precipitated ceramic particle. The effects of injection type (transverse versus axial) and initial size of the droplets on the final deposit layer microstructure have been studied. The results show that for axial injection the heating process is very rapid and smaller droplets ( < 10 mu m) undergo full pyrolization resulting in favorable microstructure. On the contrary for transverse injection the heating process is slower as the droplets are injected in the outer shear layer of plasma where the temperature and velocity both are much lower than the core of the plasma. The larger droplets ( > 20 mu m) have better chances of getting pyrolized in the case of transverse injection. It was also observed that the angle of trajectory of the droplets after primary (first) precipitation does not have much effect on the final microstructure. (C) 2008 Elsevier B.V. All rights reserved.

Journal Title

Surface & Coatings Technology

Volume

203

Issue/Number

15

Publication Date

1-1-2009

Document Type

Article; Proceedings Paper

Language

English

First Page

2081

Last Page

2091

WOS Identifier

WOS:000265391800003

ISSN

0257-8972

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