scholarly journals Modeling environmentally induced property degradation of SiC/BN/SiC ceramic matrix composites

2017 ◽  
Vol 101 (3) ◽  
pp. 973-997 ◽  
Author(s):  
Triplicane A. Parthasarathy ◽  
Brian Cox ◽  
Olivier Sudre ◽  
Craig Przybyla ◽  
Michael K. Cinibulk
Keyword(s):  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sic Ceramic

scholarly journals Improved thermal stability of SiCf/SiC ceramic matrix composites fabricated by PIP process

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim
Keyword(s):  
Thermal Stability ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Sic Fiber ◽  
Sic Ceramic ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Thermal Deterioration ◽  
Thermal Stability Of

Improvement of the thermal stability of continuous SiC fiber reinforced SiC ceramic matrix composites (SiCf/SiC CMC) by the pre-treatment of SiC fillers and the suppression of oxidation during polymer impregnation and pyrolysis (PIP) process were investigated. Dense SiCf/SiC CMCs were fabricated using the slurry infiltration and PIP process under a purified argon atmosphere. Structure and mechanical properties of the SiCf/SiC CMC heated at different temperatures were evaluated. The flexural strength of the SiCf/SiC CMC decreased only 15.3%after heating at 1400 ?C, which exhibited a clear improvement compared with the literature data (49.5% loss), where severe thermal deterioration of SiCf/SiC composite occurred at high temperatures by the crystallization and decomposition of the precursor-derived ceramic matrix. The thermal stability of the SiCf/SiC CMC fabricated by PIP process was improved by the pre-treatment of SiC fillers for removing oxides and the strict atmosphere control to prevent oxidation.

Erosion in an MI SiC/SiC Ceramic Matrix Composite (CMC)

2019 ◽  
Author(s):  
M. J. Presby ◽  
C. Gong ◽  
S. Kane ◽  
N. Kedir ◽  
A. Stanley ◽  
...  
Keyword(s):  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Erosion Behavior ◽  
Sic Ceramic ◽  
Material Systems ◽  
Nominal Density ◽  
Analytical Tools ◽  
Matrix Hardness

Abstract Erosion phenomenon of ceramic matrix composites (CMCs), attributed to their unique architectural configurations, is markedly different from conventional monolithic ceramic counterparts. Prior to further integration of CMCs into hot-section components of aeroengines subject to erosive environments, their erosion behavior needs to be characterized, analyzed, and formulated. The erosion behavior of a 2-D woven melt-infiltrated (MI) SiC/SiC CMC was assessed in this work as a function of variables such as particle velocity and size. The erosion damage was characterized using appropriate analytical tools such as optical and scanning electron microscopy (SEM). A phenomenological erosion model was developed for SiC/SiC CMC material systems with respect to kinetic energy of impacting particles in conjunction with nominal density, matrix hardness and elastic modulus of the SiC/SiC CMCs. The model was in reasonable agreement with the experimental data.

scholarly journals Thermomechanical Characterization of SiC/SiC Ceramic Matrix Composites in a Combustion Facility

Ceramics ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 407-425 ◽  
Author(s):  
Ragav P. Panakarajupally ◽  
Michael J. Presby ◽  
K. Manigandan ◽  
Jianyu Zhou ◽  
George G. Chase ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Mechanical Loading ◽  
High Velocity ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Fatigue Loading ◽  
Matrix Composites ◽  
Front Side ◽  
Sic Ceramic ◽  
Combustion Environment

A combustion facility which includes uniaxial mechanical loading was implemented that enables environmental conditions more akin to jet engine environments compared to conventional static environment tests. Two types of woven SiC/SiC ceramic matrix composites (CMCs), melt-infiltrated (MI) and chemical vapor infiltrated (CVI), were subjected to fatigue loading in the combustion facility and under isothermal furnace conditions. Some CVI test coupons were coated with a multilayer environmental barrier coating (EBC) of mullite + ytterbium monosilicate using slurry infiltration process to demonstrate the performance with a coating. Combustion conditions were applied using a high velocity oxy fuel gun on the front side of the specimen and mechanical loading was applied using a horizontal hydraulic MTS machine. All the specimens considered were subjected to tension-tension fatigue loading at 100 MPa, stress ratio of 0.1 and specimen front-side surface temperature of 1200 ± 20 °C. Nondestructive evaluation (NDE) methods, such as electrical resistance (ER), was used as an in-situ health monitoring technique. Similar fatigue tests were performed in an isothermal furnace for comparison. A much lower fatigue life was observed for the uncoated specimens tested under combustion conditions in comparison to isothermal furnace condition. This difference in fatigue life was attributed to damage associated with added thermal stress due to the thermal gradient and higher rate of oxidative embrittlement due to the presence of high velocity combustion gases in the combustion environment. EBC coating increased the fatigue life in combustion environment. However, EBC coated specimens experienced spallation in the high-velocity flame due to the presence of micro cracks in the coating surface. Fracture surfaces of the failed specimens were investigated under the scanning electron microscope (SEM) to determine the extent of oxidation and damage.

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