Rapid densification of porous carbon–carbon composites by thermal-gradient chemical vapor infiltration

Golecki, I.; Morris, Robert C.; Narasimhan, D.; Clements, Nancy

doi:10.1063/1.113974

Cited by 49 publications

(11 citation statements)

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“…The performance of C/C composites at different temperatures is shown in Table 1. The preform was densified using the chemical vapor infiltration method (CVI) [26,27], then graphitized to form a kind of C/C woven composite material. Because the C/C composite materials were brittle, machining and water cutting would have caused a large amount of waste and low flatness.…”

Section: Introductionmentioning

confidence: 99%

Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

2019

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The performance of joint structure is an important aspect of composite material design. In this study, we examined the compression shear bearing capacity of the adhesively bonded single-lap joint structure of high-temperature-resistant composite materials (C/C composite materials). The test pieces were produced in accordance with the appropriate ASTM C1292 standard, which were used for the compression shear test. The failure morphology of the layer was observed by a digital microscopic system and scanning electron microscope. The experimental result shows that the load on the test piece increased nonlinearly until the failure occurred, and most of the adhesive layer exhibited cohesive failures at three temperature points (400, 600, and 800 • C), while the interface failures occurred in a small part of the adhesive layer. A numerical analysis model was established using ABAQUS finite element software. The simulation results were compared with the test results to verify the correctness of the model. On the basis of correctness of the model verified by comparing the simulation results and the test results, the influences of temperature and overlapped length on the joint compression shear performance were studied through the validated simulation method. Numerical results showed that the ultimate load of the joint decreased with increases in temperature and that the distribution trends of the shear stresses in the overlapped length direction were substantially the same for joints of different overlapped lengths.Adhesively bonded joints nonetheless have some disadvantages due to their processing and associated overlapping. The bearing capacity of adhesively bonded joints is considerably affected by the manufacturing process, application environment, geometric dimensions, and the gap between adhesive layers. In particular, for bonded composite structures used in extreme environments such as high temperature and high humidity, joint strength presents an obvious dispersion. The strength of the adhesive changes with the temperature, resulting in changes in the bearing capacity of the joint. Although an adhesive layer has a strong shear capacity, its peeling resistance is poor. A reasonable structure should be designed based on the direction of the maximum load so that the joint can transfer the load as much as possible in the form of shearing. For example, in an adhesively bonded single-lap structure, the peeling stress at both ends of the adhesive layer increases due to secondary bending [6], resulting in failure of the adhesive layer. To reduce the torque generated by an eccentric load, the thin plate is usually selected as the adherend of an adhesively bonded single-lap structure. However, for materials with high brittleness such as C/C composite materials and C/SiC materials, the composite material undergoes brittle fracture if the adhesive strength is large when a thin plate is used for the single-lap joint. Therefore, in practical applications, a scarf joint [7] is used, or alternately the single-lap structure of bri...

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Section: Introductionmentioning

confidence: 99%

Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

2019

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“…The matrix is infiltrated between the fibers by Chemical Vapor Infiltration, i.e., a gas-phase route [45]. During this process, the tortuosity of the preform plays an important role by limiting the deposition in the composite core [46]. As a consequence, the composite material at the end of the process still contains about 10% pore volume.…”

Section: Composites With Woven Architecturementioning

confidence: 99%

Modelling of carbon–carbon composite ablation in rocket nozzles

Vignoles¹,

Aspa²,

Quintard³

2010

Composites Science and Technology

113

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“…[12] Currently, thermal gradient CVI (TCVI) with a vaporized precursor has attracted more attention because of its high deposition rate, about one or two orders of magnitude larger than in classical isothermal CVI. [13][14][15] In this work, both insitu catalytic growth of CNFs on fibers and fast infiltration of CNFs/CFs hybrid multiscale felts were completed in a single step using TCVI processes with vaporized kerosene. CNFs were produced gradually on Fe-deposited CFs along the direction of temperature gradient and promoted the formation of a rough laminar pyrocarbon matrix by further gas infiltration.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characteristics of Carbon Nanofiber‐Reinforced Carbon/Carbon Composites by Fast Catalytic Infiltration Processes

Zhang

Luo

et al. 2009

Chemical Vapor Deposition

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The simultaneous in-situ growth of carbon nanofibers (CNFs) and densification of a CNFs/CF hybrid multiscale felt are accomplished in a single step by thermal gradient chemical vapor infiltration using Fe as the catalyst and vaporized kerosene under atmospheric pressure. A three-dimensional CNF network which could bridge dissimilar components of composites is formed on carbon fibers (CFs). The length of CNFs can reach several micrometers and the diameters are about 80 nm. Smooth and rough surface densified CNFs can be produced after further higher temperature infiltration. CNFs, anchoring to CFs by the adherence of the catalyst nanoparticles, enhance the bonding between CFs and pyrocarbon as well as promoting the formation of a rough laminar pyrocarbon matrix. The deposition mechanisms and physical model are also discussed. This fast catalytic infiltration process can be applied to other ceramic materials and has significant enlargement potential.

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Rapid densification of porous carbon–carbon composites by thermal-gradient chemical vapor infiltration

Cited by 49 publications

References 1 publication

Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

Compression Shear Properties of Adhesively Bonded Single-Lap Joints of C/C Composite Materials at High Temperatures

Modelling of carbon–carbon composite ablation in rocket nozzles

Fabrication and Characteristics of Carbon Nanofiber‐Reinforced Carbon/Carbon Composites by Fast Catalytic Infiltration Processes

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