Interface characterization of ceramic fiber-reinforced Ti alloy composites manufactured by infrared processing

Journal Article · Wed May 01 04:00:00 EDT 1996 · Metallurgical Transactions, A

DOI:https://doi.org/10.1007/BF02649875· OSTI ID:260354

Warrier, S G; Lin, R Y ^[1]; Chen, S H; Wu, S K ^[2]

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1. Univ. of Cincinnati, OH (United States). Dept. of Materials Science and Engineering
2. National Taiwan Univ., Taipei (Taiwan, Province of China). Inst. of Materials Science and Engineering

Interfacial reactions between several ceramic fibers (SCS-0, SCS-6, and carbon fibers) and a liquid titanium-nickel-copper alloy were investigated using electron microscopic analysis. Composite specimens were produced using a rapid infrared manufacturing (RIM) process. In SCS-0/Ti alloy composites, SiC dissolved in the alloy. The main reaction product was discontinuous agglomerates of titanium carbide which formed from the reaction between dissolved carbon and titanium. Polygonal precipitates of Ti{sub 5}Si{sub 3}, which are believed to have formed during cooling, were also noticed. Two distinct interface morphologies were observed in these composites: uniform fronts caused by isothermal dissolution and scalloped fronts formed as a result of an accelerated dissolution mechanism caused by localized heating. The presence of the accelerated dissolution mechanism suggests that SiC fibers cannot be infiltrated with liquid titanium alloys without applying a coating. In the C/Ti system, carbon fibers reacted with the liquid alloy to form a continuous layer of Ti{sub x}C{sub 1{minus}x}. Further growth of this layer occurred by the diffusion of carbon atoms across the reaction product. In SCS-6/Ti alloy composites, free carbon present in the coating formed a discontinuous layer of Ti{sub x}C{sub 1{minus}x}, whereas SiC particles dissolved in the alloy. Although the coating present on SCS-6 fibers moderately retarded reactions in the SiC/Ti alloy composite system during infrared liquid infiltration, it is recommended that the fibers be coated with pure carbon to effectively limit the attack of the fiber by molten titanium.

• Sponsoring Organization: USDOE
• OSTI ID: 260354
• Journal Information: Metallurgical Transactions, A, Journal Name: Metallurgical Transactions, A Journal Issue: 5 Vol. 27; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
CARBON FIBERS
CHEMICAL REACTIONS
COMPOSITE MATERIALS
COPPER ALLOYS
DIFFUSION
DISSOLUTION
ELECTRON MICROSCOPY
FABRICATION
IMPREGNATION
INTERFACES
INTERMETALLIC COMPOUNDS
LIQUID METALS
MICROSTRUCTURE
MORPHOLOGY
NICKEL ALLOYS
SILICON CARBIDES
TITANIUM ALLOYS