Microstructural Characterization of Carbon Fiber-Reinforced Laminated Matrix Composites of Silicon Carbide and Carbon

1998 ◽  
Vol 4 (S2) ◽  
pp. 568-569
Author(s):  
K. A. Appiah ◽  
Z. L. Wang ◽  
W. J. Lackey

Silicon carbide composites are known for high-temperature strength retention, creep resistance, high elastic modulus and light weight. Laminated matrix composites (LMC's) with a matrix of alternating layers of silicon carbide (SiC) and carbon (C) with carbon fiber reinforcements possess added toughness in addition to the desirable properties of SiC composites mentioned above. The improved toughness results from both the laminated matrix, which offers a tortuous path to crack propagation, and the energy expended in fiber debonding during fracture. Microstructural analyses of LMC's are necessary to help the processing effort to achieve structures with the desired properties. In this work, a preliminary examination of the microstructure of the laminated matrix composite is undertaken using TEM.Specimens for TEM examination were prepared by cutting slices from a bulk sample of ∼ 1 mm thickness with a low-speed diamond saw. The slices were then ground to no less than 200 μm thickness to prevent the slices from breaking.

2018 ◽  
Vol 2018 ◽  
pp. 1-15
Author(s):  
Keqiang Zhang ◽  
Lu Zhang ◽  
Rujie He ◽  
Kaiyu Wang ◽  
Kai Wei ◽  
...  

Carbon fiber-reinforced silicon carbide (Cf/SiC) ceramic matrix composites have promising engineering applications in many fields, and they are usually geometrically complex in shape and always need to join with other materials to form a certain engineering part. Up to date, various joining technologies of Cf/SiC composites are reported, including the joining of Cf/SiC-Cf/SiC and Cf/SiC-metal. In this paper, a systematic review of the joining of Cf/SiC composites is conducted, and the aim of this paper is to provide some reference for researchers working on this field.


Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.


Author(s):  
Andi Udayakumar ◽  
M. Rizvan Basha ◽  
Sarabjit Singh ◽  
Sweety Kumari ◽  
V. V. Bhanu Prasad

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Deng-hao Ma ◽  
En-ze Jin ◽  
Jun-ping Li ◽  
Zhen-hua Hou ◽  
Jian Yin ◽  
...  

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.


2015 ◽  
Vol 816 ◽  
pp. 33-39
Author(s):  
Zheng Luo ◽  
Xin Gui Zhou ◽  
Jin Shan Yu ◽  
Fei Wang

Silicon carbide (SiC) fiber reinforced SiC matrix composites (SiC/SiC) were fabricated by precursor impregnation and pyrolysis (PIP) process with a new precursor polymer, liquid polyvinylcarbosilane (LPVCS). The molding process was conducted during the cross-linking reactions of LPVCS for the first PIP cycle. The influences of molding pressure and molding time on the flexure properties of the SiC/SiC composites were studied. The results indicated that the optimal molding pressure and molding time were 3MPa and 5h respectively due to the fine interfacial bonding between fiber and matrix. The density of the SiC/SiC composites was 2.16g/cm3. The flexural strength and fracture toughness of the SiC/SiC composites were 637.5MPa and 29.8MPa·m1/2 respectively.


2002 ◽  
Vol 755 ◽  
Author(s):  
Ilan Golecki ◽  
Karen Fuentes ◽  
Terence Walker

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.


2013 ◽  
Vol 13 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M.A. Malika ◽  
K. Majchrzak ◽  
K.N. Braszczyńska-Malik

Abstract Cast magnesium matrix composites reinforced with silicon carbide particles were investigated by using Raman microscopy. 3C, 4H and 6H polytypes of SiC particles were identified in the investigated composites. Additionally, Mg2Si compound was detected by Raman microscopy in the composites microstructure.


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