Details
| Original language | English |
|---|---|
| Pages (from-to) | 79-84 |
| Number of pages | 6 |
| Journal | Materials Research Society Symposium - Proceedings |
| Volume | 555 |
| Publication status | Published - 1 Aug 1999 |
| Event | 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998' - Boston, MA, USA Duration: 30 Nov 1998 → 3 Dec 1998 |
Abstract
Pulser Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 μm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.
ASJC Scopus subject areas
- Materials Science(all)
- General Materials Science
- Physics and Astronomy(all)
- Condensed Matter Physics
- Engineering(all)
- Mechanics of Materials
- Engineering(all)
- Mechanical Engineering
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In: Materials Research Society Symposium - Proceedings, Vol. 555, 01.08.1999, p. 79-84.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Mullite diffusion barriers for SiC-C/C composites produced by pulsed laser deposition
AU - Fritze, H.
AU - Schnittker, A.
AU - Witke, T.
AU - Rüscher, C.
AU - Weber, S.
AU - Scherrer, S.
AU - Schultrich, B.
AU - Borchardt, G.
PY - 1999/8/1
Y1 - 1999/8/1
N2 - Pulser Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 μm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.
AB - Pulser Laser Deposition (PLD) allows the ablation of nonconductive and high melting point target materials and the preparation of films with complex composition. High energy impact leads to melting and evaporation of the target material in a single step. In case of mullite ablation, the flux of the metal components is stoichiometric. Under reduced pressure the oxygen content in the layers decreases. However, after a short oxidation treatment, the formation of mullite in the coating is completed, as confirmed by IR spectroscopy and XRD investigations. For a commercial Si-SiC precoated C/C material, the effectiveness of additional PLD mullite layers as outer oxidation protection is tested in the temperature range 773 K < T < 1873 K. Mullite coatings with a thickness of 2.5 μm improve the oxidation behaviour significantly. Because of SiO2 formation at the mullite-SiC interface, all samples exhibited a mass increase upon oxidation. For oxidation durations of three days, only amorphous SiO2 is formed at the mullite-SiC interface. The inward diffusion of oxygen across the outer mullite-containing layer controls the kinetics of the reaction, as was deduced from 18O diffusivity measurements in PLD mullite layers. At temperatures close to the eutectic temperature (1860 K), mullite can seal defects. The calculated oxidation rates resulting from the diffusion parameters in SiO2 and mullite are close to the thermogravimetric data.
UR - http://www.scopus.com/inward/record.url?scp=0032591091&partnerID=8YFLogxK
U2 - 10.1557/PROC-555-79
DO - 10.1557/PROC-555-79
M3 - Conference article
AN - SCOPUS:0032591091
VL - 555
SP - 79
EP - 84
JO - Materials Research Society Symposium - Proceedings
JF - Materials Research Society Symposium - Proceedings
SN - 0272-9172
T2 - 1998 MRS Fall Meeting - The Symposium 'Advanced Catalytic Materials-1998'
Y2 - 30 November 1998 through 3 December 1998
ER -