Binding natural graphite with mesophase pitch: A promising route to future carbon blocks

Zhong, Bo; Zhao, Guangbo; Huang, Xiqiang; Liu, J.; Chai, Zhenfei; Tang, Xiaofu; Wen, Guangwu; Wu, Yezhou

doi:10.1016/j.msea.2014.05.038

Cited by 12 publications

(10 citation statements)

References 20 publications

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“…Graphite-mesophase pitch mixtures with graphite to mesophase pitch ratio of 90:10 (designated as GM-I), 80:20 (designated as GM-II) and 70:30 (designated as GM-III) were prepared. The mixtures contain particle with sizes in the range of 4-15 μm [6,7].…”

Section: Related Workmentioning

confidence: 99%

Evaluation of Physico-Chemical, Thermal and Mechanical Properties of Sintered Graphite and Mesophase Formulations

G¹,

Sp²

2016

J Material Sci Eng

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Carbon/graphite materials are widely applied to the areas of seal and friction materials. These applications exploit the exceptional properties of carbon/graphite, such as its excellent mechanical behavior at high temperature and low reactivity. However, Owing to high open porosity, and low strength conventional carbon/graphite materials prepared using pulverized coke as filler and pitch as binder fall across enormous challenge. Therefore, it is necessary to reduce the open porosity and increase in the strength along with thermal conductivity. Using natural graphite as filler instead of coke to prepare carbon blocks can avoid high-temperature graphitization and repeated dipping owing to the high degree of graphitization and high thermal stability of natural graphite; thus it can simplify the working process, save energy and reduce cost. Carbonaceous mesophase has inherent properties, such as a high softening point, high fluidity, high carbon yield, and graphitizability, which make it suitable for the fabrication of polygranular carbon materials. Furthermore, it can be used as a binder. The sintering was performed in a static furnace with argon atmosphere and compared with the same compound sintered in passage furnace with hydrogen and nitrogen atmosphere. The analysis of the properties of the tested material was performed with the aid of metallography using a scanning electron microscope, which verified the particle size distribution, chemical elements and pores present. However, for the graphite powder and zinc stearate, present in smaller percentages were disregarded its influence on the physical properties of the compound generated. Compressibility and compaction are parameters that indicate and describe the behavior of metal powders as they are compressed. The ability of a powder densification is related to compressibility. Already compaction is defined as the stability of the structure of the pressed compacted to a certain working pressure. Therefore, the natural graphite as filler and mesophase pitch as binder can be able to produce high density graphite blocks. The main aim of this work is to produce isotropic graphite material and evaluation of its properties such as high density, high thermal conductivity, high electrical resistivity, low coefficient of thermal expansion, and high compressive strength from natural graphite powder mesophase pitch.

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Section: Related Workmentioning

confidence: 99%

Evaluation of Physico-Chemical, Thermal and Mechanical Properties of Sintered Graphite and Mesophase Formulations

G¹,

Sp²

2016

J Material Sci Eng

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“…Recently, natural graphite (NG) has been used instead of coke filler to prepare carbon blocks owing to its high degree of graphitization and high thermal stability [9][10][11]. The use of NG circumvents high-temperature graphitization; as a result, it could simplify the preparation process, save energy, and reduce costs [12]. Binder pitch must be used for the preparation of artificial graphite, and is composed of a mixture of various molecular weights compounds.…”

Section: Introductionmentioning

confidence: 99%

The Control of Volume Expansion and Porosity in Carbon Block by Carbon Black (CB) Addition for Increasing Thermal Conductivity

et al. 2020

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The graphite block as a phase change materials (PCMs) was manufactured by graphitization of a carbon block. Carbon blocks were prepared by filler (cokes or graphite) and binder (pitch). The binder-coated filler was thermally treated for carbonization. The gases generated from the evaporation of low molecular weight components in the binder pitch during the carbonization process were not released to the outside. Consequently, porosity and volume expansion were increased in artificial graphite, and thereby the thermal conductivity decreased. In this study, to prevent the decrease of thermal conductivity in the artificial graphite due to the disadvantages of binder pitch, the carbon block was prepared by the addition of carbon black, which can absorb low molecular weight compounds and release the generated gas. The properties of the prepared carbon blocks were analyzed by SEM, TGA, and thermal conductivity. The addition of carbon black (CB) decreased the porosity and volume expansion of the carbon blocks by 38.3% and 65.9%, respectively, and increased the thermal conductivity by 57.1%. The CB absorbed the low molecular weight compounds of binder pitch and induced the release of generated gases during the carbonization process to decrease porosity, and the thermal conductivity of the carbon block increased.

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“…However, the thermal conductivity of a typical graphite block using pitch binder and coke powders is as low as 70-150 W m K −1 at room temperature [24,25]. To increase the orientation of the carbon crystallite, efforts have been focused on hot pressing at high temperature (1000-3000 °C) and high pressure (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30). The hydrothermal carbonization method is restrictive, limiting the range of graphite block sizes.…”

Section: Introductionmentioning

confidence: 99%

“…During heat treatment, the graphite crystallites become larger and more perfect, thereby improving the lamellar stacking structure and orientation, which significantly increases the thermal conductivity. Zhong et al [27] achieved the highest bending strength of carbon blocks, i.e., 41.98 MPa and thermal conductivity along the direction parallel to the graphite layers of approximately 55 W m −1 K −1 , using a mesophase pitch content of 25 wt% at 1300 °C. Yuan et al [28] fabricated graphite blocks with thermal conductivity of 522 W m −1 K −1 and flexural strength of 7.7 MPa from NG and mesophase pitch with low-temperature hot pressing at 500 °C.…”

Section: Introductionmentioning

confidence: 99%

Graphite block derived from natural graphite with bimodal particle size distribution

et al. 2020

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This paper presents a novel method for the bimodal design of graphite blocks by optimizing the weight ratio of smallsized natural graphite (NG) particles (mean size of 5 μm) and large-sized NG particles (mean size of 500 μm). Graphite blocks were fabricated by subjecting a mixture containing large NG particles and a well-dispersed pitch/small-sized NG mixture (PSM) to pressure-mold heat treatment. The effect of the PSM contents on the structural, thermal, and mechanical properties of the graphite blocks was investigated. A correlation was found between the amount of small-sized NG particles, the micro-pore structure, and the distribution of large-sized NG particles. In particular, the graphite block, with small-sized NG particle content and pitch binder content of 21 wt% and 9 wt%, respectively, achieved maximum thermal conductivity and flexural strength values of 460 W m K −1 and 14 MPa, respectively, after pressure-mold heat treatment (graphitization) at 2600 °C. Our research advances the development of an eco-friendly solvent-free graphite block fabrication method that produces high-performance graphite blocks of varying size faster and more cost-effectively.

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Binding natural graphite with mesophase pitch: A promising route to future carbon blocks

Cited by 12 publications

References 20 publications

Evaluation of Physico-Chemical, Thermal and Mechanical Properties of Sintered Graphite and Mesophase Formulations

Evaluation of Physico-Chemical, Thermal and Mechanical Properties of Sintered Graphite and Mesophase Formulations

The Control of Volume Expansion and Porosity in Carbon Block by Carbon Black (CB) Addition for Increasing Thermal Conductivity

Graphite block derived from natural graphite with bimodal particle size distribution

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