Preparation and Characterization of SiC/SiC Micro Ceramic Matrix Composites

2014 ◽  
Vol 1058 ◽  
pp. 170-175 ◽  
Author(s):  
Ming Wei Chen ◽  
Hai Peng Qiu ◽  
Jian Jiao ◽  
Xiu Qian Li ◽  
Yu Wang ◽  
...  

SiC continuous fiber reinforced SiC ceramic matrix composites (SiCf/SiC CMCs) and SiC fiber reinforced SiC micro ceramic matrix composites (SiCf/SiC micro-CMCs) were prepared through polymer impregnation pyrolysis (PIP) progress, then the structures, mechanical properties and forming mechanisms of SiCf/SiC CMCs were investigated. Results showed that volume shrinkage of SiC matrix occurred, and pyrolysates with bamboo-like layered structure were attached to the surface of SiC multifilament gradually. Furthermore, the mechanical properties of SiCf/SiC micro-CMCs were consistent with SiCf/SiC CMCs, so the PIP process parameters for the preparation of SiCf/SiC CMC might be optimized primarily through SiCf/SiC micro-CMCs, which could enhance the design and preparation efficiency of SiCf/SiC CMCs obviously.Key word: polymer impregnation pyrolysis progress, micro ceramic matrix composites, forming mechanism

2021 ◽  
Vol 15 (2) ◽  
pp. 164-169
Author(s):  
Jian Gu ◽  
Sea-Hoon Lee ◽  
Daejong Kim ◽  
Hee-Soo Lee ◽  
Jun-Seop Kim

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.


1995 ◽  
Vol 10 (3) ◽  
pp. 602-608 ◽  
Author(s):  
Hyun-Ho Shin ◽  
Randolph Kirchain ◽  
Robert F. Speyer

Additions of O to 9 mol % Ta2O5 to a lithia-alumina-silica glass-ceramic matrix Nicalon SiC-reinforced composite increased the elastic modulus and ultimate strength of the composite. The additive fostered sphereulitic growth of β-eucriptite solid solution crystals which concentrated Ta2O5 at sphereulite boundaries and adjacent to the fiber-matrix carbon-rich interphases. These regions reacted with the interphases as well as soluble carbon monoxide gas to convert them to TaC. The former reaction was shown to be thermodynamically favorable above 983 °C, while the latter was favorable above 1249 °C. The improvement in mechanical properties was attributed to TaC particulate reinforcement, and suggests a simple glass-ceramic route to the fabrication of particulate-reinforced ceramic matrix composites.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1581 ◽  
Author(s):  
Jianjun Sha ◽  
Shouhao Wang ◽  
Jixiang Dai ◽  
Yufei Zu ◽  
Wenqiang Li ◽  
...  

In order to understand the influence of the mechanisms of ZrC nanoparticles on the high-temperature mechanical properties of C-SiC ceramic matrix composites, the mechanical properties were measured from room temperature (RT) to 1600 °C under vacuum. The microstructures features were characterized by scanning electron microscopy. In comparison with the composites without ZrC nanoparticles, the ZrC-modified composite presented better mechanical properties at all temperatures, indicating that the mechanical properties could be improved by the ZrC nanoparticles. The ZrC nanoparticles could reduce the residual silicon and improve the microstructure integrity of composite. Furthermore, the variation of flexural strength and the flexural modulus showed an asynchronous trend with the increase of temperature. The flexural strength reached the maximum value at 1200 °C, but the highest elastic modulus was obtained at 800 °C. The strength increase was ascribed to the decrease of the thermally-induced residual stresses. The degradation of mechanical properties was observed at 1600 °C because of the microstructure deterioration and the formation of strongly bonded fiber–matrix interface. Therefore, it is concluded that the high temperature mechanical properties under vacuum were related to the consisting phase, the matrix microstructure, and the thermally-induced residual stresses.


Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1633 ◽  
Author(s):  
Longbiao Li

In this paper, the temperature-dependent vibration damping in C/SiC fiber-reinforced ceramic-matrix composites (CMCs) with different fiber preforms under different vibration frequencies is investigated. A micromechanical temperature-dependent vibration damping model is developed to establish the relationship between composite damping, material properties, internal damage mechanisms, and temperature. The effects of fiber volume, matrix crack spacing, and interface properties on temperature-dependent composite vibration damping of CMCs and interface damage are analyzed. The experimental temperature-dependent composite damping of 2D and 3D C/SiC composites is predicted for different loading frequencies. The damping of the C/SiC composite increases with temperature to the peak value and then decreases with temperature. When the vibration frequency increases from f = 1 to 10 Hz, the peak value of composite damping and corresponding temperature both decrease due to the decrease of interface debonding and slip range, and the damping of 2D C/SiC is much higher than that of 3D C/SiC at temperature range from room temperature to 400 °C. When the fiber volume and interface debonding energy increase, the peak value of composite damping and the corresponding temperature decreases, mainly attributed to the decrease of interface debonding and slip range.


2014 ◽  
Vol 602-603 ◽  
pp. 422-425 ◽  
Author(s):  
Xiao Ting Huang ◽  
Shu Guang Chen ◽  
Hao Ran Sun ◽  
Yu Feng Chen ◽  
Hai Long Liang ◽  
...  

continuous carbon fiber reinforced silicon carbide (Cf/SiC) ceramic matrix composites were prepared by precursor infiltration pyrolysis and chemical vapor infiltration (PIP-CVI process), in which the honeycomb sandwich structure preforms were fabricated by the three dimensional braid method. In this paper, the microstructure and the bending strength were observed and analyzed by SEM and three point bending method. The results of the study show that: The Cf/SiC ceramic matrix composites, which were lightweight and high strength, were prepared by that technique. The composite samples have a fiber volume fraction of 20%, a density of 0.38 g/cm3 and a flexural strength of 3.81 MPa. The honeycomb sandwich fiber reinforced ceramic matrix composite with a light weight, corrosion resistance and excellent physical and mechanical properties is a kind of structure and functional ceramic materials, which can realize the structure and the requirement of heat integration.


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