scholarly journals Deuterium Retention Properties of SiC/SiC Composites as Plasma Facing Materials for Fusion Reactors after Deuterium Irradiation at Elevated Temperatures

2015 ◽  
Vol 58 (5) ◽  
pp. 173-176
Author(s):  
Yuji NOBUTA ◽  
Tomoaki HINO ◽  
Yuji YAMAUCHI ◽  
Takashi NOZAWA
Keyword(s):  
Elevated Temperatures ◽  
Fusion Reactors ◽  
Plasma Facing Materials ◽  
Deuterium Retention ◽  
Sic Composites

Mechanical Behavior of 2D C/SiC Composites at Elevated Temperatures under Uniaxial Compression

2011 ◽  
Vol 462-463 ◽  
pp. 1-6 ◽  
Author(s):  
Tao Suo ◽  
Yu Long Li ◽  
Ming Shuang Liu
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Carbon Fiber ◽  
Mechanical Behavior ◽  
Uniaxial Compression ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Carbon Matrix ◽  
Structural Applications ◽  
Sic Composites

As Carbon-fiber-reinforced SiC-matrix (C/SiC) composites are widely used in high-temperature structural applications, its mechanical behavior at high temperature is important for the reliability of structures. In this paper, mechanical behavior of a kind of 2D C/SiC composite was investigated at temperatures ranging from room temperature (20C) to 600C under quasi-static and dynamic uniaxial compression. The results show the composite has excellent high temperature mechanical properties at the tested temperature range. Catastrophic brittle failure is not observed for the specimens tested at different strain rates. The compressive strength of the composite deceases only 10% at 600C if compared with that at room temperature. It is proposed that the decrease of compressive strength of the 2D C/SiC composite at high temperature is influenced mainly by release of thermal residual stresses in the reinforced carbon fiber and silicon carbon matrix and oxidation of the composite in high temperature atmosphere.

The Stability of BN Interfacial Coatings in CFCC Systems During Oxidation and Exposure to Moisture

1997 ◽  
Vol 3 (S2) ◽  
pp. 729-730
Author(s):  
K.S. Ailey ◽  
K.L. More ◽  
R.A. Lowden
Keyword(s):  
Elevated Temperatures ◽  
Impurity Content ◽  
Chemical Vapor ◽  
Ceramic Matrix Composites ◽  
Chemical Vapor Infiltration ◽  
Forced Flow ◽  
Crystallographic Structure ◽  
Matrix Composites ◽  
Sic Composites ◽  
The Stability

The mechanical reliability of ceramic matrix composites (CMCs) at elevated temperatures in oxidative environments is primarily dependent upon the chemical and structural stability of the fiber/matrix interface. Graphitic carbon coatings have traditionally been used to control the interfacial properties in CMCs, however, their use is limited in high temperature oxidative environments due to the loss of carbon and subsequent oxidation of the fiber and matrix. Thus, BN is being investigated as an alternative interfacial coating since it has comparable room temperature properties to carbon with improved oxidation resistance. The stability of BN interfaces in SiC/SiC composites is being investigated at elevated temperatures in either flowing oxygen or environments containing water vapor. The effect of several factors on BN stability, including crystallographic structure, extent of BN crystallization, and impurity content, are being evaluated.Nicalon™ fiber preforms were coated with ≈ 0.4 μm of BN by CVD using BCl3, NH3, and H2 at 1373 K. The coated preforms were densified using a forced-flow chemical vapor infiltration (FCVI) technique developed at ORNL.

High Velocity Impact Damage Assessment in SiC/SiC Composites

2014 ◽  
Author(s):  
Christopher R. Baker ◽  
Emmanuel Maillet ◽  
Gregory N. Morscher ◽  
Andrew L. Gyekenyesi ◽  
Sung R. Choi ◽  
...  
Keyword(s):  
Gas Turbines ◽  
High Speed ◽  
Elevated Temperatures ◽  
Impact Damage ◽  
Ceramic Matrix Composites ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Sic Composites ◽  
Actual Damage ◽  
Damage Condition

Foreign object damage in gas turbines presents serious safety and financial concerns. As the aerospace industry draws closer to implementing ceramic matrix composites (CMCs) in gas turbines, the corresponding behavior in these materials after such events needs to be understood. To address this requirement, several silicon infiltrated fiber reinforced SiC/SiC coupons were impacted with high speed projectiles with velocities up to 360 m/s with an impact rig built at the University of Akron and NAVAIR. The resulting damage states were assessed using several non-destructive evaluation (NDE) techniques and compared to actual damage condition observed through the sectioning of impacted coupons. Ultimately, the true consequence of the damage was revealed by measuring the post-impact, residual strengths via uniaxial tensile tests to failure at both room and elevated temperatures. Lastly, the NDE results revealed a complicated damage morphology consisting of in-and-out-of plane damage that significantly affected the retained mechanical properties.

scholarly journals Study of deuterium retention in/release from ITER-relevant Be-containing mixed material layers implanted at elevated temperatures

2013 ◽  
Vol 438 ◽  
pp. S1113-S1116 ◽  
Author(s):  
K. Sugiyama ◽  
C. Porosnicu ◽  
W. Jacob ◽  
J. Roth ◽  
Th. Dürbeck ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Mixed Material ◽  
Deuterium Retention

EFFECT OF TEST TEMPERATURE ON THE CHARACTERIZATION OF MELT INFILTRATED SiC/SiC COMPOSITES

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3793-3798
Author(s):  
SANG-PILL LEE ◽  
JIN-KYUNG LEE ◽  
YUN-SEOK SHIN ◽  
DONG-SU BAE ◽  
JONG-BACK LEE ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Bending Test ◽  
Molten Silicon ◽  
Temperature Property ◽  
Three Point Bending ◽  
The Matrix ◽  
Melt Infiltration ◽  
Matrix Region ◽  
High Temperature Property ◽  
Sic Composites

The high temperature property of SiC/SiC composites fabricated by the melt infiltration (MI) process has been investigated. SiC/SiC composites reinforced with BN/SiC double coated Hi-Nicalon SiC fibers were fabricated by infiltrating molten silicon into a braiding fibric preform containing C and SiC particles. The mechanical properties of MI- SiC/SiC composites were carried out at the elevated temperatures using the three point bending test. The microstructure of MI- SiC/SiC composites was examined by means of SEM and EDS. The matrix region of MI- SiC/SiC composites represented the chemical fluctuation depending on the composition ratio of Si and C elements. The flexural strength of MI- SiC/SiC composites greatly decreased at the temperatures higher than 1100 °C, due to microstructural instabilities such as interfacial debonding and matrix oxidation.

scholarly journals Design, Fabrication, and Testing of Ceramic Joints for High Temperature SiC/SiC Composites

2000 ◽  
Author(s):  
M. Singh ◽  
Edgar Lara-Curzio
Keyword(s):  
Silicon Carbide ◽  
Shear Strength ◽  
Elevated Temperatures ◽  
Stress Rupture ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Carbide Matrix ◽  
Sic Composites ◽  
Stress Rupture Testing

Various issues associated with the design and mechanical evaluation of joints of ceramic matrix composites are discussed. The specific case of an affordable, robust ceramic joining technology (ARCJoinT) to join silicon carbide (CG-Nicalon™) fiber-reinforced-chemically vapor infiltrated (CVI) silicon carbide matrix composites is addressed. Experimental results are presented for the time and temperature dependence of the shear strength of these joints in air up to 1200°C. From compression testing of double-notched joint specimens with a notch separation of 4 mm, it was found that the apparent shear strength of the joints decreased from 92 MPa at room temperature to 71 MPa at 1200°C. From shear stress-rupture testing in air at 1200°C it was found that the shear strength of the joints decreased rapidly with time from an initial shear strength of 71 MPa to 17.5 MPa after 14.3 hours. The implications of these results in relation to the expected long-term service life of these joints in applications at elevated temperatures are discussed.

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