Role of SiC nanowire coating on oxidation behavior of carbon fibers: Kinetic and thermodynamic study

• Published in: Surface & coatings technology 2014-11, Vol.259, p.637-646
• Main Authors: Prakash, Jyoti, Dasgupta, Kinshuk, Kumar, Brij, Ghosh, Sunil Kumar, Chakravartty, J.K.
• Format: Article
• Language: English
• Subjects: Activation energy; Applied sciences; Carbon fibers; Coating; Corrosion; Corrosion environments; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; High temperature oxidation; Kinetic model; Materials science; Metals. Metallurgy; Nanowire; Nanowires; Oxidation; Physics; Production techniques; Reaction kinetics; Silicon carbide; Surface chemistry; Surface treatment; Surface treatments; Thermodynamic properties
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2014.10.019

The oxidation kinetics of SiC nanowire coated carbon fibers in oxygen atmosphere were studied through isothermal thermo-gravimetric analysis and dynamic thermo-gravimetric analysis. The isothermal weight loss curve showed two activation energies for the oxidation of SiC nanowire coated carbon fibers. The oxidation process was reaction controlled below 923K with an activation energy of 125kJmol−1 and mixed controlled (gas diffusion and reaction) above 923K with an activation energy of 28kJmol−1. Under non-isothermal condition the oxidation mechanism followed three-dimensional diffusion obeying the Zhuravlev–Lesokhin–Tempel'man mechanism with differential form F(α)=1.5(1−a)4/3[(1−a)−1/3−1]−1 and integral form G(α)=[(1−a)−1/3−1]2. The kinetic and thermodynamic parameters were evaluated and correlated with surface induced oxidation mechanism. •The oxidation behavior of SiC nanowire coated carbon fiber was studied using TGA.•Isothermal oxidation occurs through gas diffusion & surface reaction processes.•Non-isothermal oxidation occurs through 3D diffusion and follows ZLT mechanism.•Activation energy is 190.41kJmol−1 and pre-exponential factor is 3.77×108min−1.•SiC nanowire oxidation at around 970K contributes to overall oxidation. [Display omitted]