scholarly journals Preparation and Properties of C/SiC Composites Reinforced by High Thermal Conductivity Graphite Films

2020 ◽  
Author(s):  
Jiajia Zhao ◽  
Rong Cai ◽  
zhaokun Ma ◽  
Kaixuan Zhang ◽  
Hengliang Liang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Mass Loss Rate ◽  
Ceramic Matrix Composites ◽  
Ablation Rate ◽  
High Thermal Conductivity ◽  
Matrix Composites ◽  
Ablation Resistance ◽  
Linear Ablation ◽  
Graphite Film ◽  
Sic Composites

Abstract Ablation resistance as one important factor affecting the service life of SiC ceramic matrix composites that is highly valued in aerospace science and technology. In this study, high thermal conductivity (HTC) graphite films and carbon fibers reinforced C/SiC composites simultaneously, fabricating by precursor infiltration and pyrolysis (PIP) technology, to improve the ablation resistance of C/SiC composites. Three C/SiC composites were prepared from different quantity ratios of 2D fiber cloth to HTC graphite film with values of 1:0, 1:1, and 1:10. The microstructure, mechanical properties, thermal conductivity and ablation performance of C/SiC composites after plasma ablation test at 1500 °C for 600 s were investigated. The results showed that with the increase of graphite films’ contents, the thermal conductivity of composites was increased from 9.78 W/(m·K) to 333.34 W/(m·K). Additionally, the mass loss rate reduced from 1.18 to 0.74 mg/s and the linear ablation rate reduced from 0.64 to 0.18 mm/s, indicating that the addition of graphite films could effectively improve the ablation resistance of C/SiC composites.

Preparation and Properties of 2D C/SiC-TaC Composites

2008 ◽  
Vol 368-372 ◽  
pp. 1771-1773 ◽  
Author(s):  
Yu Di Zhang ◽  
Chang Rui Zhang ◽  
Hai Feng Hu ◽  
Yong Lian Zhou
Keyword(s):  
Fracture Toughness ◽  
Mass Loss Rate ◽  
Volume Ratio ◽  
Leading Edge ◽  
Ceramic Matrix Composites ◽  
Tantalum Carbide ◽  
Space Vehicles ◽  
Matrix Composites ◽  
Sic Composites ◽  
Powder Content

Ultra high temperature ceramic matrix composites (UHTCC) are being considered as the most promising materials for leading edge and nose cap of hypersonic spacecrafts, reusable space vehicles and so on. In the paper, 2D carbon fiber cloth reinforced silicon carbide-tantalum carbide (2D SiC-TaC) UHTCC was fabricated by slurry-pasting and precursor infiltration pyrolysis process (PIP). Influences of the volume ratio (10, 20, 30, 60, 80 and 100%) of TaC powder on mechanical properties and ablative resistance of 2D C/SiC-TaC composites were studied. The results showed that the relative density of composites with 60vol% TaC powder was the highest, the flexural strength of the composites reached 356MPa and the mass loss rate and recession rate were 0.0116g/s and 0.026mm/s respectively, while those of C/SiC composites were 0.0166g/s and 0.062mm/s respectively. Moreover, the higher TaC powder content, the smaller the fracture toughness of the composites was. The fracture toughness of the 2D C/SiC-TaC composites with 100vol% TaC powder was only 8.69 MPa-m1/2, while that of C/SiC composites was over 15.0 MPa-m1/2.

Effect of temperature on matrix multicracking evolution of C/SiC fiber-reinforced ceramic-matrix composites

2020 ◽  
Vol 39 (1) ◽  
pp. 189-199
Author(s):  
Longbiao Li
Keyword(s):  
Strain Energy ◽  
Ceramic Matrix Composites ◽  
Critical Value ◽  
Matrix Cracking ◽  
Interface Debonding ◽  
Matrix Composites ◽  
Temperature Dependent ◽  
Damage State ◽  
The Matrix ◽  
Sic Composites

AbstractIn this paper, the temperature-dependent matrix multicracking evolution of carbon-fiber-reinforced silicon carbide ceramic-matrix composites (C/SiC CMCs) is investigated. The temperature-dependent composite microstress field is obtained by combining the shear-lag model and temperature-dependent material properties and damage models. The critical matrix strain energy criterion assumes that the strain energy in the matrix has a critical value. With increasing applied stress, when the matrix strain energy is higher than the critical value, more matrix cracks and interface debonding occur to dissipate the additional energy. Based on the composite damage state, the temperature-dependent matrix strain energy and its critical value are obtained. The relationships among applied stress, matrix cracking state, interface damage state, and environmental temperature are established. The effects of interfacial properties, material properties, and environmental temperature on temperature-dependent matrix multiple fracture evolution of C/SiC composites are analyzed. The experimental evolution of matrix multiple fracture and fraction of the interface debonding of C/SiC composites at elevated temperatures are predicted. When the interface shear stress increases, the debonding resistance at the interface increases, leading to the decrease of the debonding fraction at the interface, and the stress transfer capacity between the fiber and the matrix increases, leading to the higher first matrix cracking stress, saturation matrix cracking stress, and saturation matrix cracking density.

Influence of Anisotropic Thermal Conductivity on Overall Cooling Effectiveness on a Film Cooled Leading Edge

2021 ◽  
pp. 1-22
Author(s):  
Carol Bryant ◽  
James L. Rutledge
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Film Cooling ◽  
Leading Edge ◽  
Ceramic Matrix Composites ◽  
Internal Cooling ◽  
Matrix Composites ◽  
Edge Region ◽  
Turbine Engine ◽  
Anisotropic Thermal Conductivity

Abstract Increasing interest in the use of ceramic matrix composites (CMCs) for gas turbine engine hot gas path components requires a thorough examination of the thermal behavior one may expect of such components. Their highly anisotropic thermal conductivity is a substantial departure from traditional metallic components and can influence the temperature distribution in surprising ways. With the ultimate surface temperature dependent upon the internal cooling scheme, including cooling from within the film cooling holes themselves, as well as the external film cooling, the relative influence of these contributions to cooling can be affected by the directionality of the thermal conductivity. Conjugate heat transfer computational simulations were performed to evaluate the effect of anisotropy in the leading edge region of a turbine component. The leading edge region is modeled as a fully film-cooled half cylinder with a flat afterbody. The anisotropic directionality of the thermal conductivity is shown to have a significant effect on the temperature distribution over the surface of the leading edge. While structural considerations with CMC components are often paramount, designers should be aware of the thermal ramifications associated with the selection of the CMC layup.

Characterization and Thermal Decomposition Process of ZrC Ceramic Organic Precursor

2013 ◽  
Vol 591 ◽  
pp. 20-25
Author(s):  
Ming Wei Chen ◽  
Hai Peng Qiu ◽  
Wei Gang Zhang ◽  
Jian Jiao ◽  
Ruo Gu Wang
Keyword(s):  
Pyrolysis Product ◽  
Ceramic Matrix Composites ◽  
Matrix Composites ◽  
Thermal Decomposition Process ◽  
Promising Candidate ◽  
Organic Precursor ◽  
Ceramic Precursor ◽  
Ablation Resistance ◽  
Sic Ceramic ◽  
On Line

The pyrolysis ceramic dynamic process of ZrC ceramic precursor was characterized by means of on-line TG-DSC-FTIR-MS coupling technique, and the conversion mechanism of ZrC ceramic was investigated based on XRD, SEM, TEM and XRF. ZrC ceramic could be obtained at 1400°C lower than theoretic temperature when Zirconium element is reduced by carbon from ZrO2. The results showed that ZrC ceramic precursor presented storage stability and excellent solubility in toluene. Ethanol, carbon dioxide, acetone and tetrahydrofuran (THF) were given off before heat treatment at 1100°C, and the pyrolysis product held in the form of ZrO2 and amorphous carbon. ZrC crystals were gradually formed when heated up to 1200°C and obtained completely at 1400°C. This ZrC ceramic precursor provides promising candidate for oxidation resistance and ablation resistance ZrC-SiC ceramic matrix composites.

Dynamic Mechanical Properties of 2D-C/SiC and 2D-SiC/SiC

2019 ◽  
Vol 956 ◽  
pp. 244-252
Author(s):  
Xiao Ju Gao ◽  
Chao Li ◽  
Hasigaowa ◽  
Zhi Peng Li ◽  
Yu Guang Bao ◽  
...  
Keyword(s):  
Strain Rate ◽  
Room Temperature ◽  
Ceramic Matrix Composites ◽  
Rate Sensitivity ◽  
Ceramic Matrix ◽  
Dynamic Mechanical Properties ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Mechanical Behaviors ◽  
Sic Composites

The quasi-static and dynamic compressive mechanical behaviors of two kinds of fiber reinforced SiC-matrix composites including 2D-C/SiC and 2D-SiC/SiC were investigated. Their compressive behaviors of materials at room temperature and strain rate from 10-4 to 104 /s were studied. The fracture surfaces and damage morphology were observed by scanning electron microscopy (SEM). The results showed that the dynamic failure strengths of the two kinds of fiber reinforced SiC-matrix composites obey the Weibull distribution. The Weibull modulus of the two materials were 13.70 (2D-C/SiC) and 5.66 (2D-SiC/SiC), respectively. It was found that the two kinds of fiber reinforced ceramic matrix composites presented a transition from brittle to tough with the decrease of strain rate. The 2D-SiC/SiC materials demonstrated a more HYPERLINK "http://dict.cnki.net/dict_result.aspx?searchword=%e6%98%be%e8%91%97%e7%9a%84&tjType=sentence&style=&t=remarkable"significant strain rate sensitivity and smoother fracture surface compared to the 2D-C/SiC composites, implying that the former composites present brittle features. This was because the SiC/SiC composites possessed high bonding strength in interface of fiber/fiber and fiber/matrix is very strong.

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.

scholarly journals Utilization of SiC and Cu Particles to Enhance Thermal and Mechanical Properties of Al Matrix Composites

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2770 ◽  
Author(s):  
Dongxu Wu ◽  
Congliang Huang ◽  
Yukai Wang ◽  
Yi An ◽  
Chuwen Guo
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
High Thermal Conductivity ◽  
Low Density ◽  
Matrix Composites ◽  
Thermal And Mechanical Properties ◽  
Cu Content ◽  
Sic Particles ◽  
Al Matrix Composites ◽  
Al Matrix

In this work, SiC and Cu particles were utilized to enhance the thermal and mechanical properties of Al matrix composites. The ball-milling and cold-compact methods were applied to prepare Al matrix composites, and the uniform distribution of SiC and Cu particles in the composite confirms the validity of our preparation method. After characterizing the thermal conductivity and the compressibility of the prepared composites, results show that small particles have a higher potential to improve compressibility than large particles, which is attributed to the size effect of elastic modulus. The addition of SiC to the Al matrix will improve the compressibility behavior of Al matrix composites, and the compressibility can be enhanced by 100% when SiC content is increased from 0 to 30%. However, the addition of SiC particles has a negative effect on thermal conductivity because of the low thermal conductivity of SiC particles. The addition of Cu particles to Al-SiC MMCs could further slightly improve the compressibility behavior of Al-SiC/Cu MMCs, while the thermal conductivity could be enhanced by about 100% when the Cu content was increased from 0 to 30%. To meet the need for low density and high thermal conductivity in applications, it is more desirable to enhance the specific thermal conductivity by enlarging the preparation pressure and/or sintering temperature. This work is expected to supply some information for preparing Al matrix composites with low density but high thermal conductivity and high compressibility.

scholarly journals Mechanical Properties and Failure Behavior of 3D-SiCf/SiC Composites with Different Interphases

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Deng-hao Ma ◽  
En-ze Jin ◽  
Jun-ping Li ◽  
Zhen-hua Hou ◽  
Jian Yin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Shear Strength ◽  
Ceramic Matrix Composites ◽  
Failure Behavior ◽  
Matrix Composites ◽  
Static Mechanical ◽  
Sic Composites ◽  
Polymer Infiltration ◽  
Static Mechanical Properties

Continuous silicon carbide fiber-reinforced silicon carbide ceramic matrix composites (SiCf/SiC) are promising as thermal structural materials. In this work, the microstructure and static mechanical properties of 3D-SiCf/SiC with PyC, SiC, and PyC/SiC and without an interface prepared via polymer infiltration and pyrolysis (PIP) were investigated systematically in this paper. The results show that the microstructure and static mechanical properties of SiCf/SiC with an interphase layer were superior to the composites without an interlayer, and the interface debondings are existing in the composite without an interphase, resulting in a weak interface bonding. When the interphase is introduced, the interfacial shear strength is improved, the crack can be deflected, and the fracture energy can be absorbed. Meanwhile, the shear strength of the composites with PyC and PyC/SiC interfaces was 118 MPa and 124 MPa, respectively, and showing little difference in bending properties. This indicates that the sublayer SiC of the PyC/SiC multilayer interface limits the binding state and the plastic deformation of PyC interphase, and it is helpful to improve the mechanical properties of SiCf/SiC.

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