scholarly journals Fabrication of full-scale fiber-reinforced hot-gas filters by chemical vapor depostion. Final report, November 1, 1994 -- December 32, 1995

1996 ◽  
Author(s):  
R.G. Smith ◽  
J.H. Eaton ◽  
D.J. Pysher ◽  
M.A. Leitheiser
Keyword(s):  
Chemical Vapor ◽  
Full Scale ◽  
Final Report ◽  
Fiber Reinforced ◽  
Hot Gas ◽  
Chemical Vapor Depostion

Fiber-Reinforced Composites for Gas Turbine Applications

1992 ◽  
Author(s):  
D. P. Stinton ◽  
R. A. Lowden ◽  
T. M. Besmann
Keyword(s):  
Gas Turbines ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Forced Flow ◽  
Matrix Composites ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Infiltration Process ◽  
Hot Gas ◽  
Filament Wound

Fiber-reinforced SiC matrix composites are being considered for application in hot-gas turbines. A forced-flow thermal-gradient chemical vapor infiltration process has been developed to fabricate composites of thick-walled tubular geometry common to many components. Fibrous preforms of different fiber architectures (3-dimensionally braided and filament wound) have been investigated to accommodate components with different mechanical property requirements. This paper will discuss the fabrication of tubular fiber-reinforced SiC matrix composites and their mechanical properties.

Characterization of interfaces in CVD-coated nicalon fiber-reinforced SiC

1989 ◽  
Vol 47 ◽  
pp. 556-557
Author(s):  
K.L. More ◽  
R.A. Lowden
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Chemical Vapor ◽  
Chemical Vapor Infiltration ◽  
Frictional Stress ◽  
Fiber Reinforced ◽  
Pull Out ◽  
Carbon Coated ◽  
Fiber Matrix

The mechanical properties of fiber-reinforced composites are directly related to the nature of the fiber-matrix bond. Fracture toughness is improved when debonding, crack deflection, and fiber pull-out occur which in turn depend on a weak interfacial bond. The interfacial characteristics of fiber-reinforced ceramics can be altered by applying thin coatings to the fibers prior to composite fabrication. In a previous study, Lowden and co-workers coated Nicalon fibers (Nippon Carbon Company) with silicon and carbon prior to chemical vapor infiltration with SiC and determined the influence of interfacial frictional stress on fracture phenomena. They found that the silicon-coated Nicalon fiber-reinforced SiC had low flexure strengths and brittle fracture whereas the composites containing carbon coated fibers exhibited improved strength and fracture toughness. In this study, coatings of boron or BN were applied to Nicalon fibers via chemical vapor deposition (CVD) and the fibers were subsequently incorporated in a SiC matrix. The fiber-matrix interfaces were characterized using transmission and scanning electron microscopy (TEM and SEM). Mechanical properties were determined and compared to those obtained for uncoated Nicalon fiber-reinforced SiC.

Synthesis by plasma-enhanced chemical-vapor deposition and characterization of siliconlike films with hydrophobic functionalities for improved long-term geometric stability of fiber-reinforced polymers

2008 ◽  
Vol 23 (4) ◽  
pp. 1042-1050 ◽  
Author(s):  
A. Cremona ◽  
E. Vassallo ◽  
A. Merlo ◽  
A. Srikantha Phani ◽  
L. Laguardia
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
High Strength ◽  
Scratch Resistance ◽  
Fiber Reinforced Polymers ◽  
Fiber Reinforced ◽  
Water Contact ◽  
Fiber Failure

Amorphous siliconlike films with hydrophobic functionalities have been deposited by plasma-enhanced chemical-vapor deposition on carbon-fiber-reinforced polymer (CFRP) unidirectional laminates used for micromechanical applications where high strength-to-weight and high stiffness-to-weight ratios are required. To improve long-term geometrical stability in ultrahigh-precision machine structures, hydrophobic CFRP materials are desirable. Three layers have been grown with different plasma-process parameters from a mixture of hexamethyldisiloxane, O2, and Ar. Chemical composition, water contact angle, surface energy, morphology, and tribological properties have been evaluated to choose the one that best fulfills hydrophobicity, wear, and scratch resistance. Wear tests have also been carried out on CFRP laminates coated with a polyurethane layer to compare the wear performance of the above specimens with that of a conventional hydrophobic coating. Scanning electron microscope images show a very good adhesion of the films to the composite substrate because the failure of the film and of the substrate (such as fiber failure) take place simultaneously.

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