Tiyuan Wang
Northwestern Polytechnical University
Dissociation (chemistry)Deflection (engineering)Vacancy defectChemical vapor infiltrationIsothermal processTemperature gradientPhysical chemistryAdsorptionCharge densityDensity functional theoryChemical physicsComposite materialMatrix (biology)EpoxyFlexural strengthDopantMaterials scienceResidual strengthElectrophoretic depositionAcetaldehydeQuartzSilicon carbideIndentationCarbon compositesEnergy analysisCarbon atomGrapheneInterface bondingStackingMicromechanicsTexture (crystalline)Chemical engineeringElastic modulusThermal expansionCeramic matrix compositeCarbonCarbon nanotubeMethaneFiberDensity of statesChemical vapor depositionTransition state theoryBasis setPyrolytic carbonReinforced carbon–carbonNanowireAnisotropyArrhenius equationMicrostructureTransition stateReaction rate constantThermal conductivityThermodynamics
9Publications
5H-index
53Citations
Publications 9
Newest
#1Tiyuan WangH-Index: 5
#2Hejun LiH-Index: 68
Last. Shouyang ZhangH-Index: 19
view all 7 authors...
The microstructure of pyrolytic carbon significantly affects the performance of aircraft brake discs. In this study, to explore the effect of precursor on the microstructure of pyrocarbon, two types of pyrocarbon films were grown on the quartz glass substrates by isothermal isobaric chemical vapor infiltration using methane and acetaldehyde as precursors. The microstructures of both the films and their formation mechanisms were investigated and compared. The thicknesses of the pyrocarbon films f...
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#1Tiyuan Wang (NPU: Northwestern Polytechnical University)H-Index: 5
#2Qiang Song (NPU: Northwestern Polytechnical University)H-Index: 26
Last. Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
view all 8 authors...
Abstract Carbon fiber (CF)/epoxy composites with hybrid nanofillers were prepared by electrophoretic deposition (EPD) of silicon carbide nanowires (SiCnws) on CFs, followed by in-situ grafting of graphene via chemical vapor deposition (CVD). The effects of SiC nanowires/graphene hybrid nanofillers on interlaminar shear strength (ILSS), flexural property, and through-thickness thermal conductivity of CF/epoxy composites were investigated. Due to the incorporation of SiCnws and graphene, the inter...
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#1Tiyuan Wang (NPU: Northwestern Polytechnical University)H-Index: 5
#2Shouyang Zhang (NPU: Northwestern Polytechnical University)H-Index: 19
Last. Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
view all 6 authors...
Abstract The present study explored the effect of medium texture (MT) content on flexural properties and thermal expansion coefficients (CTES) of carbon/carbon (C/C) composites with multilayered pyrolytic carbon. The specimen with 39% MT exhibited maximum flexural strength of 221.55 MPa, increasing by 52% compared with pure high texture. While the flexural strength decreased when the MT content exceeded 39%. The excellent strength can be attributed to crack deflection between multilayered textur...
2 CitationsSource
#1Tiyuan Wang (NPU: Northwestern Polytechnical University)H-Index: 5
#2Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
Last. Shouyang Zhang (NPU: Northwestern Polytechnical University)H-Index: 19
view all 7 authors...
Abstract In order to explore the dependence of mechanical properties on the microstructure of high-textured (HT) pyrolytic carbon (PyC), the microstructure and properties of HT PyC specimens prepared by isothermal isobaric chemical vapor infiltration (ICVI) and thermal gradient chemical vapor infiltration (TCVI) processes were investigated. The HT PyC of ICVI was uniform and exhibited a more distinct long-range order compared to that of TCVI. Besides, a spatial gradient in texture existed within...
9 CitationsSource
#1Kun Li (NPU: Northwestern Polytechnical University)H-Index: 5
#2Ni Li (NPU: Northwestern Polytechnical University)H-Index: 1
Last. Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
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Abstract In this paper, the adsorption mechanisms between different species (CH3, CH4, C2H2, C2H4, C2H6, and C6H6) and the carbon-based materials (pristine graphene, N-doped graphene, and vacancy graphene) during the chemical vapor infiltration process were systematically studied using the density functional theory. The optimized adsorption configurations were obtained by using Dmol3 code in Material Studio. The adsorption energies, Mulliken atomic charges, density of states, and charge density ...
10 CitationsSource
#1Tiyuan Wang (NPU: Northwestern Polytechnical University)H-Index: 5
#2Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
Last. W. H. Li (NPU: Northwestern Polytechnical University)H-Index: 1
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Abstract In order to investigate the effect of microstructural evolution on the micromechanical behavior of pyrolytic carbon (PyC), the microstructural parameters and evolution of high texture (HT) and medium texture (MT) PyC after heat treatment from 1600 °C to 2450 °C were studied comparatively. The micro-indentation test was also performed to reveal the micromechanics. In terms of microstructure, after heat treatment, the HT matrix was directly delaminated into many nano-layers accompanied by...
4 CitationsSource
#1Kun Li (NPU: Northwestern Polytechnical University)H-Index: 5
#2Hejun Li (NPU: Northwestern Polytechnical University)H-Index: 68
Last. Qiang Song (NPU: Northwestern Polytechnical University)H-Index: 26
view all 6 authors...
A density functional theory (DFT) study was employed to explore the mechanism of the conversion of methane to benzene in chemical vapor infiltration (CVI) based on the concluded reaction pathways from C1-species to C6-species. The geometry optimization and vibrational frequency analysis of all the chemical species and transition states (TS) were performed with B3LYP along with a basis set of 6–311 +G(d, p), and Gaussian 09 software was used to perform the study. The rate constants were calculate...
1 CitationsSource
#1Qingliang Shen (NPU: Northwestern Polytechnical University)H-Index: 11
#2Qiang Song (NPU: Northwestern Polytechnical University)H-Index: 26
Last. Wei Li (NPU: Northwestern Polytechnical University)H-Index: 206
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Abstract Fatigue strengthening of composites refers to the increase of residual strength after a specific number of loading cycles. This eccentric behavior widely exists in carbon/carbon composites and some ceramic matrix composites while few reasonable mechanisms have been proposed. In the present work, a comparative study of two different types of C/C composites (CNT-C/C with enhanced fiber-matrix interface and SiCNW-C/C composites with strengthened matrix) is performed to probe into the inher...
7 CitationsSource
#1Kun Li (NPU: Northwestern Polytechnical University)H-Index: 4
#1Kun Li (NPU: Northwestern Polytechnical University)H-Index: 5
Last. Zhigang Zhao (NPU: Northwestern Polytechnical University)H-Index: 1
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Abstract To investigate the mechanism of the heterogenous reactions during the Chemical vapor infiltration (CVI) process of carbon/carbon composites, the dissociation of CH4 on graphene was calculated by density functional theory (DFT). Graphene was used as the adsorption surface in the course of the heterogenous reactions. Based on the energy analysis, the preferred adsorption sites of CHx(x = 0–4) and H on graphene were obtained. Then, the stable co-adsorption configurations of CHx/H(x = 0–3) ...
12 CitationsSource