DLR-Logo -> http://www.dlr.de
DLR Portal Home | Impressum | Kontakt | English
Schriftgröße: [-] Text [+]

CVD-Coating of Fabric Sheets in Combination with the LSI-Process

Frieß, M. und Krenkel, W. und Nestler, K. und Marx, G. (2001) CVD-Coating of Fabric Sheets in Combination with the LSI-Process. In: High Temperature Ceramic Matrix Composites, Seiten 199-204. Wiley- VCH. 4th International Conference on High Temperature Ceramic Matric Composites (HT-CMC 4), München, 1-3. Oktober 2001. ISBN 3-527-30320-0.

Dieses Archiv kann nicht den gesamten Text zur Verfügung stellen.


Due to short processing times and fairly low manufacturing costs the Liquid Silicon Infiltration Process (LSI) developed at the DLR in Stuttgart is a well established process to produce ceramic matrix composites (CMC) without any fiber coating [1]. The key step is the liquid silicon infiltration of porous carbon/carbon composites (C/C) whose distinct microstructure is formed in the preceding pyrolysis step of carbon fiber reinforced plastics (CFRP). These were produced by resin transfer molding (RTM) in a first step. This process leads to C/C-SiC composites being characterized by high mass-specific properties in combination with an extreme thermal shock stability. By applying special process pa-rameters the microstructure as well as the physical properties can be tailor-designed to match spe-cific requirements. However, compared to CMCs reinforced with coated fibers [2-5], C/C-SiC has a low damage tolerance and tensile strength since the fiber matrix bonding (FMB) is too high. An improvement can be achieved by a fiber pretreatment at about 600 °C prior to composite manufacturing [6]. However, the superior properties of composites manufactured with coated fibers cannot be achieved. Unfortunately, single fiber coating increases CMC costs considerably [7]. In order to overcome this problem, woven C-fabrics have been coated with pyrolytic carbon (pyC) and then submitted to the LSI-process yielding dense C/C-SiC. In a first step, C-fabric sheets (30 mm in width and 300 mm in length) were coated with pyC in both a CVD hot wall and alternatively in a CVD cold wall reactor under static condi-tions at about 900 °C. Toluene was used as a precursor whereas argon served as a carrier gas. Deposition times ranging from 10 to 20 min resulted in an increase in weight of 50 to 250 mg corre-sponding to a mean layer thickness of 39 to 189 nm on each single fiber. The pyC-coated C-fabrics exhibited increased stiffness with increased coating thickness as well as reference samples were submitted to the conventional LSI-process. Besides SEM-investigations on the pyC-coating, this paper reports on the physical and the mechanical properties of the composites manufactured via LSI-processing in all stages – CFRP, C/C and especially C/C-SiC.

Dokumentart:Konferenzbeitrag (Paper)
Zusätzliche Informationen: LIDO-Berichtsjahr=2002,
Titel:CVD-Coating of Fabric Sheets in Combination with the LSI-Process
AutorenInstitution oder E-Mail-Adresse der Autoren
Nestler, K.TU Chemnitz
Marx, G.TU Chemnitz
Erschienen in:High Temperature Ceramic Matrix Composites
Seitenbereich:Seiten 199-204
HerausgeberInstitution und/oder E-Mail-Adresse der Herausgeber
Verlag:Wiley- VCH
Stichwörter:CMC, ceramic, manufacture, silicon-based materials, LSI, reentry, coating
Veranstaltungstitel:4th International Conference on High Temperature Ceramic Matric Composites (HT-CMC 4), München, 1-3. Oktober 2001
Veranstalter :DGM/DLR
HGF - Forschungsbereich:Verkehr und Weltraum (alt)
HGF - Programm:Weltraum (alt)
HGF - Programmthema:W RP - Raumtransport
DLR - Schwerpunkt:Weltraum
DLR - Forschungsgebiet:W RP - Raumtransport
DLR - Teilgebiet (Projekt, Vorhaben):NICHT SPEZIFIZIERT
Standort: Stuttgart
Institute & Einrichtungen:Institut für Bauweisen- und Konstruktionsforschung
Hinterlegt von: elib DLR-Beauftragter
Hinterlegt am:16 Sep 2005
Letzte Änderung:14 Jan 2010 22:22

Nur für Mitarbeiter des Archivs: Kontrollseite des Eintrags

Hilfe & Kontakt
electronic library verwendet EPrints 3.3.12
Copyright © 2008-2013 Deutsches Zentrum für Luft- und Raumfahrt (DLR). Alle Rechte vorbehalten.