Authors: Joo Sun Kim, H.W. Jun, Huesup Song, Jong Ho Lee, Hai Won Lee
Abstract: High strength reaction-bonded silicon carbide ceramics was successfully produced by reducing the amount of residual silicon and the silicon pocket size with carbon black as an additional carbon source. A prototype of wafer carrier was also produced in near-net dimension by planar contact infiltration of molten silicon into a preform joined with six pieces of simple shape by eliminating process shrinkages. Forming shrinkages were decreased to a negligible level by compression molding, while sintering shrinkage was eliminated by reactive infiltration of molten
silicon.
189
Abstract: A multi-layer coating SiC/ Si - MoSi2 /MoSi2 with good oxidation resistance has been developed by using the slurry-sintering method on the surface of graphite to improve the oxidation resistance performance at 1700 °C for more than 200 h. Microstructure and anti-oxidation property of the as-received coating were investigated. It was found that functionally gradient SiC/ Si - MoSi2 /MoSi2 coating was formed on the surface of the graphite substrate. The coating characterized by excellent thermal shock resistance can effectively protect the graphite from oxidation at 1700 °C for 200 h. The mechanism of the oxidation resistance of the coated graphite is also dicussed, and a dense SiO2 layer was formed on the surface of coating at 1700°C during the isotheral oxidation, which can protect graphite from oxidation at longer time.
1
Authors: Wan Chang Sun, He Jun Li, Qian Gang Fu, Shou Yang Zhang
Abstract: PAN-carbon fibers were pretreated using three methods. 2D-C/C composites were fabricated by a rapid chemical liquid-vaporized infiltration (CLVI) processing. Surface morphologies of carbon fiber pretreated and fracture micrographs of 2D-C/C composites were observed by scanning electron microscopy (SEM) and high resolution transmission electron microscope (HRTEM). The interlaminar shear strength(ILSS) of C/C composites was tested. The influences of carbon fiber surface pretreatments on ILSS and fracture behaviors of C/C composites were analyzed. The experimental results indicated that the C/C composite with carbon fiber coated CVI pyrocarbon possesses both higher flexural strength and interlaminar shear strength than composites with other fiber pretreatments. The fractographes revealed the differences in the mechanical behavior depending on the interface strength of fiber/matrix.
482
Authors: Ying Cao, Li Pan
Abstract: In the present investigation, resin transfer molding has been used to produce high quality carbon fiber epoxy composites and nanotube-reinforced carbon fiber epoxy composites. To study the influence of carbon nanotubes (CNTs) on improving the mechanical properties and fatigue life, the tension-tension fatigue test has been carried out on those two kinds of material in the fiber direction. The damage mechanism in the fiber directions was analyzed by X-ray radiography and electron microscopy. The results show that CNTs pulled out, rapture and bridged cracks during the test, the results also show that CNTs possess an obvious potential on improving the property of carbon fiber epoxy composite, especially for properties that dominated by matrix.
753
Authors: Sai Nan Wei, Rui Zhou Li, Li Chen, Ji Ming Yao
Abstract: Electromagnetic parameters and absorbing properties of fiber absorbents (carbon fiber, SiC fiber and polycrystalline iron fiber) were introduced. The influences of the arrangement, thickness and content of the fibers on radar absorbing property were summarized. New development directions of the fiber absorbents were also indicated.
835