Tensile, Flexural, and Shear Properties of Neutron Irradiated SiC/SiC Composites with Different Fiber-Matrix Interfaces

2005 ◽  
Vol 2 (2) ◽  
pp. 12884 ◽  
Author(s):  
T Nozawa ◽  
K Ozawa ◽  
S Kondo ◽  
T Hinoki ◽  
Y Katoh ◽  
...  
Keyword(s):  
Shear Properties ◽  
Fiber Matrix ◽  
Sic Composites

scholarly journals Hydrothermal Corrosion Behaviors of Constituent Materials of SiC/SiC Composites for LWR Applications

Ceramics ◽  
2019 ◽  
Vol 2 (4) ◽  
pp. 602-611
Author(s):  
Shoko Suyama ◽  
Masaru Ukai ◽  
Megumi Akimoto ◽  
Toshiki Nishimura ◽  
Satoko Tajima
Keyword(s):  
Corrosion Resistance ◽  
Residual Strength ◽  
Pure Water ◽  
Operating Conditions ◽  
Raw Material ◽  
Stoichiometric Ratio ◽  
Sic Fibers ◽  
Corrosion Behaviors ◽  
Fiber Matrix ◽  
Sic Composites

The corrosion behaviors of SiC/SiC composite constituent materials in pure water at operating conditions, such as 300 °C and 8.5 MPa, were studied for potential application in accident-tolerant light water reactor (LWR) fuel cladding and core structures. Five kinds of SiC fibers, four kinds of SiC matrices, and three kinds of fiber/matrix interphase materials were examined in autoclaves. The potential constituent materials for future use in SiC/SiC composites were selected by considering corrosion rates and residual strength characteristics. The mass changes and the residual strength of each specimen were measured. SEM images of the surface layers were also inspected. The SiC fibers, regardless of their purity, crystallinity or stoichiometric ratio, decreased in strength due to the hydrothermal corrosion. For its part, the hydrothermal corrosion resistance of CVD-SiC, as a SiC matrix, was found to be affected by manufacturing conditions such as raw material gas type and synthesis temperature, as well as post-machining morphology. The CVD-carbon (CVD-C), as a fiber/matrix interphase material, showed good hydrothermal corrosion resistance. In order to protect the SiC fibers and the SiC matrices from hydrothermal corrosion, it would appear to be necessary to apply a dense CVD-C coating to both every fiber and the entire surface of the SiC matrices.

Oxidation-Protection Methodology for Long-Term use of Carbon-Carbon Fiber-Matrix Composites in Oxidizing Ambients

2002 ◽  
Vol 755 ◽  
Author(s):  
Ilan Golecki ◽  
Karen Fuentes ◽  
Terence Walker
Keyword(s):  
Carbon Fiber ◽  
Time Profile ◽  
Matrix Composites ◽  
Weight Changes ◽  
Carbon Foams ◽  
Fiber Matrix ◽  
Sic Composites ◽  
Multi Phase ◽  
Temperature Time

ABSTRACTA methodology is described for protecting Carbon-Carbon fiber-matrix composite (C-C) components from oxidation for extended use in oxidizing ambients for lifetimes of the order of 10,000 hours, from room temperature to 650°C. This time-temperature profile is relevant to applications such as airborne heat exchangers. Weight changes of oxidation-protected, pitch-fiber based C-C coupons in flowing dry air at 650°C are presented. Two types of external protective approaches are compared: (a) multi-phase, borophosphate-based fluidizing overseal coatings applied directly to C-C, and (b) the same overseal coatings applied to CVD SiOxCy coated C-C. The latter, dual-coating approach provides an effective engineering solution for the above temperature-time profile and is particularly applicable to thin (0.1–3 mm thick), complex-shaped articles. The behavior of inert substrates (oxidized silicon) with the same overseal coatings is compared to the behavior of the C-C substrates. This approach can be applied with optional modifications to suit other environmental conditions, and other carbon-containing materials, such as carbon foams and C-SiC composites.

Effect of Silicon Carbide Interlayers on the Mechanical Behavior of T800-HB-Fiber-Reinforced Silicon Carbide-Matrix Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1844-1846 ◽  
Author(s):  
Xin Gui Zhou ◽  
Hai Jiao Yu ◽  
Bo Yun Huang ◽  
Jian Gao Yang ◽  
Ze Lan Huang
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Three Dimensional ◽  
Bending Test ◽  
Matrix Composites ◽  
High Mechanical Strength ◽  
Three Point Bending ◽  
Carbide Matrix ◽  
Fiber Matrix ◽  
Sic Composites

The influence of the fiber/matrix interlayers on the mechanical properties of T800-HB fiber (a kind of carbon fiber) (the fibrous is three-dimensional four-directional braided) reinforced silicon carbide (SiC) matrix composites has been evaluated in this paper. The composites were fabricated through PIP process, and SiC layers were deposited as fiber/matrix interlayers by the isothermal CVD process. Fiber/matrix debonding and relatively long fiber pullouts were observed on the fracture surfaces. The mechanical properties were investigated using three-point bending test and single-edge notched beam test. The T800-HB/SiC composites exhibited high mechanical strength, and the flexural strength and fracture toughness were 511.5MPa and 20.8MPa•m1/2, respectively.

Mechanical Property Study of the Fiber-Matrix Interface in SiC/SiC Composites

2006 ◽  
Author(s):  
Eric L. Jones ◽  
Sergey Yarmolenko ◽  
Devdas Pai ◽  
Jag Sankar
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Interfacial Shear ◽  
Fatigue Properties ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Fiber Matrix ◽  
Sic Composites

The fiber-matrix interface between ceramic fibers and ceramic matrix plays a major role in the fatigue properties and toughness of continuous fiber reinforced ceramic matrix composites (CMCs). Boron Nitride (BN) is a widely used fiber coating material that provides a weak bond between the fiber and matrix. A weak fiber-matrix interface increases the strength and toughness of the overall CMC. Single fiber push-out tests were performed to study interfacial shear strength as a main parameter defining fatigue properties and toughness of SiC/SiC composites. The fiber-matrix interfacial shear strength was studied in melt infiltrated Hi-Nicalon/BN(CVI)/SiC composites exposed to various temperature and loading conditions, similar to those that are used in actual applications. Hi-Nicalon fibers with diameters of 13-14.5 μm were pushed out from samples with thicknesses ranging from 125-280 μm using a spherical tip with a 1 μm radius and 90° conical shape. Interfacial shear strength was calculated from sliding load, fiber diameter and sample thickness. Due to significant scattering, 30 individual push tests in every sample were used to obtain the average interfacial shear strength. The virgin sample has a shear strength of 20 MPa which is higher than tensile tested samples (12 MPa). Annealing of a virgin specimen for 100 hours at 1000°C slightly increased shear strength up to 21.5 MPa while annealing at 1100°C and 1200°C led to significant increase of shear strength up to 29 and 39 MPa correspondingly. This effect is associated with BN degradation at temperatures >1000°C.

Stress-Strain Response in SiC/SiC Composites under Cyclic Loading

2007 ◽  
Vol 353-358 ◽  
pp. 1406-1409 ◽  
Author(s):  
Jun Ji Ohgi ◽  
S. Tanaka ◽  
T. Kuramoto ◽  
M. Suzuki ◽  
Koichi Goda
Keyword(s):  
Cyclic Loading ◽  
Interfacial Strength ◽  
Maximum Load ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Fracture Load ◽  
Stress Strain ◽  
Pull Out ◽  
Fiber Matrix ◽  
Sic Composites

The tension-tension fatigue tests for SiC/SiC composites were performed under the conditions that the maximum load Pmax was 80-90% to the fracture load of the tensile tests and the stress ratio was Rσ = 0.5. The composites exhibited a width in stress-strain hysteresis loop under one load cycling. In some cases the mean strain εmean gradually increase with increasing in number of cycles. These variations would reflect the developments of the fatigue damage at the fiber/matrix interface during the cyclic loading process. The pull-out lengths of the fibers for the fatigued- and not fatigued-specimens were measured through the SEM observations after the tensile test. In all materials, the average pull-out length of fibers in fatigued material was larger than in not fatigued material because the cyclic loading affected on the fiber/matrix interfacial strength.

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