VPS-mullite-coatings for oxidation protection of structural components operated at high temperatures in air atmosphere

Conference · Fri Dec 30 23:00:00 EST 1994

OSTI ID:160447

Henne, R ^[1]; Muehlhan, C ^[2]; Braue, W; Schneider, H ^[3]

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1. German Aerospace Research Establishment, Stuttgart (Germany). Inst. for Technical Thermodynamics
2. Univ. of Duisburg (Germany). Inst. for Materials and Technology
3. German Aerospace Research Establishment, Cologne (Germany). Inst. for Materials Research

Mullite coatings have been deposited on silicon nitride (Si{sub 3}N{sub 4}) by vacuum plasma spraying (VPS) in order to improve the oxidation resistance of the substrate material. The VPS torch applied for spraying of the mullite is equipped with a specially adapted nozzle which generates a very fast plasma jet with a broader and more homogeneous temperature and flow profile. Both properties are advantageous to get very dense mullite coatings at improved deposition efficiency. The influence of VPS parameters, of properties of the Si{sub 3}N{sub 4} substrate, of the mullite spraying powder constitution and morphology on the microstructural and mechanical properties of the coatings, and especially on the coating-substrate bonding relationships were investigated.

• OSTI ID: 160447
• Report Number(s): CONF-940684--; ISBN 0-87170-509-5
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARGON
CRACKS
HYDROGEN
INTERFACES
MELTING
METALLOGRAPHY
MICROSTRUCTURE
MULLITE
OXIDATION
PLASMA ARC SPRAYING
POROSITY
POWDERS
SCANNING ELECTRON MICROSCOPY
SILICON NITRIDES
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION