Acid Treatment of Carbon Fiber Surface

The paper describes the modification conducted for the PAN carbon fiber surfaces in the solutions of nitric and sulphuric acids. The authors studied the impact of modification parameters such as temperature, acid concentration, time and ratio of the nitrosulphuric acid on the occurrence of reactive groups on the fiber surface. The authors revealed the presence of carboxylic and ketone reactive groups in the range of 1663-1798 and 1568 cm-1 in the IR spectra of carbon fibers. The use of the nitrosulphuric acid did not identify sulfur-containing functional groups on the carbon fiber IR spectra. Preliminary acid treatment of the carbon fiber surface led to the formation of uniform continuous coating of a SiO2 barrier being 127 ± 30 μm by a sol-gel method

Carbon fiber reinforced magnesium alloy in a Ti-6Al-4V shell

Continuous carbon fiber reinforced magnesium alloy pieces in SMC Ti-6Al-4V shell have been fabricated using pressure infiltration. Similar temperatures (~700°C) for superplastic formation of the shell and melting of the alloy allow this to be done in one step. The quality of infiltration of the molten alloys is found to be proportional to load. A limiting parameter in increasing the infiltration pressure is the strength of the welded bonds. Structure, fracture parameters and mechanical properties are discussed

STRUCTURE AND SUPERCONDUCTING PROPERTIES OF YBa*002Cu*003O*007*00-*00x HOT DEFORMED CERAMICS

The systematic investigation of the mechanical behaviour, microstructural modifications, superconducting properties of polycrystalline ceramics after the hot plastic deformation and thermal treatment is the aim of the paper. As a result microstructural modifications, taking place in a material at the hot deformation have been investigated. The interconnection between structural modifications and superconducting properties has been established. The method of the hot deformation of YBa*002Cu*003O*007*00-*00x extrusion, method making it possible to obtain longitudinal articles with various microstructures, has been developedAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Acid Treatment of Carbon Fiber Surface

The paper describes the modification conducted for the PAN carbon fiber surfaces in the solutions of nitric and sulphuric acids. The authors studied the impact of modification parameters such as temperature, acid concentration, time and ratio of the nitrosulphuric acid on the occurrence of reactive groups on the fiber surface. The authors revealed the presence of carboxylic and ketone reactive groups in the range of 1663-1798 and 1568 cm-1 in the IR spectra of carbon fibers. The use of the nitrosulphuric acid did not identify sulfur-containing functional groups on the carbon fiber IR spectra. Preliminary acid treatment of the carbon fiber surface led to the formation of uniform continuous coating of a SiO2 barrier being 127 ± 30 μm by a sol-gel method

Acid Treatment of Carbon Fiber Surface

The paper describes the modification conducted for the PAN carbon fiber surfaces in the solutions of nitric and sulphuric acids. The authors studied the impact of modification parameters such as temperature, acid concentration, time and ratio of the nitrosulphuric acid on the occurrence of reactive groups on the fiber surface. The authors revealed the presence of carboxylic and ketone reactive groups in the range of 1663-1798 and 1568 cm-1 in the IR spectra of carbon fibers. The use of the nitrosulphuric acid did not identify sulfur-containing functional groups on the carbon fiber IR spectra. Preliminary acid treatment of the carbon fiber surface led to the formation of uniform continuous coating of a SiO2 barrier being 127 ± 30 μm by a sol-gel method

Thermal stability of the carbon fibers with SiO

This paper presents the results of a study of silicon dioxide coating deposited on the surface of carbon fiber by the sol-gel method. The effect of the viscosity of the prepared sol-gel solution and the oxidizing properties at elevated temperatures obtained by SiO2 coatings were studied. It was found that the kinematic viscosity of the sol-gel solution does not change for 72 hours. An increase in viscosity leads to the formation of colloidal particles, which degrades the quality of the coatings.Studies have shown that in the temperature range 600-800 °C, the quality of uncoated fibers degrade, but the SiO2 coating well protects the fiber surface and significantly slows down the rate of destruction

Effect of sol-gel solution parameters on the formation of films on the surface of carbon fibers

In this study to apply an oxide film to the surface of carbon fibers a sol-gel solution was used. Sol-gel solutions were prepared according to the described procedure from tetraethoxysilane (TEOS) and ethanol at various H2O concentrations. The molar ratio H2O/TEOS ratio was changed in the range from 2 to 20. After coating and drying, the surface morphology of carbon fibers was investigated. The relationship between the concentration of sol-gel solutions and the amount of deposited SiO2 on the surface of carbon fibers was analyzed

Effect of sol-gel solution parameters on the formation of films on the surface of carbon fibers

In this study to apply an oxide film to the surface of carbon fibers a sol-gel solution was used. Sol-gel solutions were prepared according to the described procedure from tetraethoxysilane (TEOS) and ethanol at various H2O concentrations. The molar ratio H2O/TEOS ratio was changed in the range from 2 to 20. After coating and drying, the surface morphology of carbon fibers was investigated. The relationship between the concentration of sol-gel solutions and the amount of deposited SiO2 on the surface of carbon fibers was analyzed

Carbon fiber reinforced magnesium alloy in a Ti-6Al-4V shell

Continuous carbon fiber reinforced magnesium alloy pieces in SMC Ti-6Al-4V shell have been fabricated using pressure infiltration. Similar temperatures (~700°C) for superplastic formation of the shell and melting of the alloy allow this to be done in one step. The quality of infiltration of the molten alloys is found to be proportional to load. A limiting parameter in increasing the infiltration pressure is the strength of the welded bonds. Structure, fracture parameters and mechanical properties are discussed