The Influence of Carbon Fiber Heat Treatment Temperature on Carbon-Carbon Brakes Characteristics

Abstract

The effects of heat treatment temperature (HTT) of polyacrylonitrile-based carbon fiber (CF) on the mechanical, thermal, and tribological properties of C/C composites were investigated. It was found that HTT (graphitization) of CF affects the thermal conductivity and mechanical and tribological characteristics of C/C composites. Thermal treatment of fibers at temperatures up to 2800°C led to a decrease of the wear rate and the friction coefficient of C/C composite-based discs from 7.0 to 1.1 μm/stop and from 0.356 to 0.269, respectively. The friction surface morphology and friction mechanism strongly depended on the mechanical properties of the CFs. The relief of the friction surface of composites based on CFs with final graphitization was also modified, compared to that of composites based on initial fibers. This phenomenon could be explained by modification of the abrasive wear resistance of reinforcement fibers and consequently modification of the friction and wearing properties of composites. Correlation of the graphitization temperature with the increased flexural and compressive strength, apparent density, and thermal conductivity of the composites was also demonstrated.

The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments

“…The XRD diffractograms also give insights into the structure of the carbon matrix into which the particles are embedded. The reflex intensity at around 25.9° is characteristic for carbon and, more specifically, graphitic materials based on PAN [30].…”

Are lignin-derived carbon fibers graphitic enough?

“…4, the tensile modulus values for commercial PAN-derived CFs increase with temperature, as one would expect due to the development of graphitic crystallites along the fiber axes. 33,34 Researchers developing lignin-derived CFs use performance metrics of commercial CFs as benchmarks for further research and development. Given that the tensile modulus values of commercial CFs increase during high temperature treatment, one would expect the same from ligninderived CFs; even if lignin-derived CFs have low starting modulus values relative to PAN, their modulus values should still increase at higher temperatures.…”

“…Highly graphitic structure has been claimed to be present in organosolv lignin-derived CFs treated up to 2700°C, as shown 33,34 Lignin Blend: Carbon fibers derived from pyrolysis fuel oil blended with hardwood kraft lignin treated at 800 and 2800°C, 36 Pure Lignin: Carbon fibers derived from softwood kraft lignin treated at 1000-1700°C, 35 Modified Lignin: Carbon fibers derived from acylated softwood lignin treated at 1000-2200°C. 37 by the XRD diffractograms, graphitic crystallite sizes, and decreasing interlayer spacings in Fig.…”

Effect of MoO3 on mechanical interfacial behavior and anti-oxidation of carbon fibers-reinforced composites

“…C/C composites show excellent high-temperature strength and strong resistance to thermal shock because of the negligible effect of the matrix on their mechanical properties. These include corrosion resistance, chemical resistance, thermal conductivity, electrical conductivity, specific strength, inelasticity, and sublimation temperature [1][2][3][4][5][6].…”

“…C/C composites show excellent high-temperature strength and strong resistance to thermal shock because of the negligible effect of the matrix on their mechanical properties. These include corrosion resistance, chemical resistance, thermal conductivity, electrical conductivity, specific strength, inelasticity, and sublimation temperature [1][2][3][4][5][6].Despite these excellent properties, many cracks and pores are formed inside C/C composites, due to the emission of gases by the thermal decomposition of the matrix during carbonization. This results in the deterioration of their thermal and mechanical properties.…”