Fabrication of low-density carbon-bonded carbon fiber composites with an Hf-based coating for high temperature applications

Yang

et al. 2020

Journal of Chemistry

In this paper, lightweight carbon/carbon fiber composite thermal field insulation materials were fabricated by the process method of long carbon fiber airflow netting-needle punching forming felt-resin impregnation-molding curing-high-temperature carbonization and graphitization. The microscopic morphology, conductivity, bending strength, and thermal conductivity of carbon/carbon fiber composites were measured by using the scanning electron microscope (SEM), four probes, electronic universal testing machine, and thermal analyzer. The results show that the long carbon fiber in the carbon/carbon fiber composite forms a three-dimensional structure of X-Y-Z with a density of 0.16 ± 0.02 g/cm3, which makes the composite material have excellent thermal insulation performance at high temperature, and the conductivity is 1452.4 S/m (plane direction) and 182.8 S/m (perpendicular to the plane direction), the compressive strength is 0.2 MPa (plane direction) and 1.31 MPa (perpendicular to the plane direction), the bending strength is 0.24 MPa (plane direction) and 1.1 MPa (perpendicular to the plane direction), and the thermal conductivity is 0.076 W/(mK) (25°C) and 0.17 W/(mK) (1200°C), respectively. The above process methods and test results will provide the application of the carbon/carbon fiber composite in the solar polysilicon furnace, single crystal silicon furnace, semiconductor furnace, sapphire furnace, fiber drawing furnace, and high-end metallurgical heat treatment furnaces, as well as applications in other high-temperature insulation environments, and also provide some suggestions in these insulation applications.

Section: Resultsmentioning

confidence: 99%

Fabrication and Study on Thermal Conductivity, Electrical Properties, and Mechanical Properties of the Lightweight Carbon/Carbon Fiber Composite

Yang

et al. 2020

Journal of Chemistry

“…The surface of the profiled part can also be specially coated, such as graphite coating, silicon carbide coating, Hf-based anti-oxidation coating, and other coatings. 16–24…”

Section: Resultsmentioning

confidence: 99%

“…The surface of the profiled part can also be specially coated, such as graphite coating, silicon carbide coating, Hf-based anti-oxidation coating, and other coatings. [16][17][18][19][20][21][22][23][24] The density of the carbon/carbon fiber composite prepared by the solidification-graphitization of the reticular composite felt is 0.16 ± 0.02 g/cm 3 , which is far lower than that of the high-density carbon/carbon composite insulation material (0.3 g/cm 3 ). This low-density network felt structure gives the material superior thermal insulation properties, which will be described in detail below.…”

Section: Characterizationmentioning

confidence: 99%

Preparation and properties of lightweight carbon/carbon fiber composite thermal field insulation materials for high-temperature furnace

Journal of Engineered Fibers and Fabrics

Hu²,

Lin³

et al. 2019

The main purpose of this work is to make lightweight carbon/carbon fiber composite with low density and low thermal conductivity for high-temperature furnace. Lightweight carbon/carbon fiber composite thermal field insulation materials were prepared by the process method of needle punching—molding curing high-temperature graphitization. The results show that the long carbon fiber in the carbon/carbon fiber composite forms a three-dimensional structure of X-Y-Z with a density of 0.16 ± 0.02 g/cm3, which makes the composite material have excellent thermal insulation performance at high temperature. The thermal conductivity of the carbon/carbon fiber composite at 2000°C is only 0.38 W/(m·K), and the impurity element content is only 19.09 ppm. The method of needle-punching-forming-felt high-temperature graphitization can provide some suggestions for the preparation of the lightweight long carbon fiber composite.

“…1,[13][14][15] Fabricating inorganic material coatings (such as SiOC, SiC, ZrB 2 and their composites) on the surface of carbon fibers are thought to be an effective way to improve the oxidation resistance of CBCF composites. 5,[15][16][17][18][19][20][21][22] Because of the increased density, ceramics coated CBCF composites usually show improved mechanical properties. 15,21 However, to achieve a higher mechanical strength, the density of these modified composites should be further increased, which would result in the reduction of their thermal insulation performance.…”

Section: Introductionmentioning

confidence: 99%

“…Fabricating inorganic material coatings (such as SiOC, SiC, ZrB 2 and their composites) on the surface of carbon fibers are thought to be an effective way to improve the oxidation resistance of CBCF composites . Because of the increased density, ceramics coated CBCF composites usually show improved mechanical properties .…”

Section: Introductionmentioning

confidence: 99%

SiOC modified carbon‐bonded carbon fiber composite with SiC nanowires enhanced interfibrous junctions

et al. 2020

J Am Ceram Soc

Carbon‐bonded carbon fiber (CBCF) composites are promising lightweight and high efficient thermal insulators to be applied in aerospace area, but their practical applications are usually restricted by the low mechanical performance and poor oxidation resistance. To overcome these drawbacks, many efforts have been made in the fabrication of ceramic coated CBCF composites. However, the densities of these modified composites are usually very high, which would result in the reduction in their thermal insulation performance. Herein, we prepared a CBCF composite with SiC nanowires enhanced interfibrous junctions and SiOC ceramic coated carbon fibers (SiCNWs‐SiOC‐CBCF). Similar to CBCF, the SiCNWs‐SiOC‐CBCF exhibits a low density of 0.35 g/cm3 and an anisotropic and highly porous architecture. The SiCNWs‐SiOC‐CBCF possesses a compressive strength of 3.8 MPa and a compression modulus of 195.7 MPa in the X (or Y) direction, ~26.7% and 150% higher than those of CBCF respectively. It can also suffer from an isothermal treatment in air at 900°C for 120 minutes. The combination of these properties makes the SiCNWs‐SiOC‐CBCF a good candidate for thermal insulator to be applied in extreme conditions.