Changes in Mechanical and Electrical Properties as a Function of Unidirectional Pressure Changes in Preforming While Isostatic Pressing
for Graphite Block Fabrication

Byun, Tae-Sub; Jeon, D.; Lee, Sang-Hye; Lee, Sang‐Woo; Roh, Jae-Seung

doi:10.4150/kpmi.2023.30.1.35

Cited by 2 publications

(3 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For all isotropic carbon blocks, the deviation of density was within 0.02 g/cm 3 , regardless of the applied CIP pressure. According to a study previously conducted by the present authors, for graphite blocks fabricated by unidirectional pressing under 150 MPa, the bulk density was 1.395 g/cm 3 , while the deviation of density was 0.027 g/cm 3 [27]. In this study, CIP-150 exhibited a bulk density of 1.504 g/cm 3 , and the deviation of density was 0.019 g/cm 3 .…”

Section: Bulk Density and Porositysupporting

confidence: 60%

“…The obtained green bodies subsequently underwent carbonization in a tube furnace in which an inert atmosphere was achieved using nitrogen gas. They were heated to 1000 • C and then maintained at that temperature for one hour [2,27]. Each isotropic carbon block was cut into 16 blocks with dimensions of 9 × 9 × 45 mm 3 to measure the bulk density, mechanical properties, and electrical characteristics at different locations and determine their deviation, as shown in Figure 1.…”

Section: Raw Materials and Preparationmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Microstructural Change under Pressure during Isostatic Pressing on Mechanical and Electrical Properties of Isotropic Carbon Blocks

Byun,

Lee,

Kim

et al. 2024

Materials

Self Cite

View full text Add to dashboard Cite

In this study, carbon blocks were fabricated using isotropic coke and coal tar pitch as raw materials, with a variation in pressure during cold isostatic pressing (CIP). The CIP pressure was set to 50, 100, 150, and 200 MPa, and the effect of the CIP pressure on the mechanical and electrical properties of the resulting carbon blocks was analyzed. Microstructural observations confirmed that, after the kneading, the surface of isotropic coke was covered with the pitch components. Subsequently, after the CIP, granules, which were larger than isotropic coke and the kneaded particles, were observed. The formation of these granules was attributed to the coalescence of kneaded particles under the applied pressing pressure. This granule formation was accompanied by the development of pores, some remaining within the granules, while others were extruded, thereby existing externally. The increase in the applied pressing pressure facilitated the formation of granules, and this microstructural development contributed to enhanced mechanical and electrical properties. At a pressing pressure of 100 MPa, the maximum flexural strength was achieved at 33.3 MPa, and the minimum electrical resistivity was reached at 60.1 μΩm. The higher the pressing pressure, the larger the size of the granules. Pores around the granules tended to connect and grow larger, forming crack-like structures. This microstructural change led to degraded mechanical and electrical properties. The isotropic ratio of the carbon blocks obtained in this study was estimated based on the coefficient of thermal expansion (CTE). The results confirmed that all carbon blocks obtained proved to be isotropic. In this study, a specimen type named CIP-100 exhibited the best performance in every aspect as an isotropic carbon block.

show abstract

Section: Bulk Density and Porositysupporting

confidence: 60%

Section: Raw Materials and Preparationmentioning

confidence: 99%

Effect of Microstructural Change under Pressure during Isostatic Pressing on Mechanical and Electrical Properties of Isotropic Carbon Blocks

Byun,

Lee,

Kim

et al. 2024

Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…Zhao et al [12] reported the effect of the average particle size of coke on the microstructure and properties of graphite blocks; An et al [13] reported the relationship between kneading and carbonization temperature and properties during the manufacture of carbon blocks. In previous studies by the authors of the present study, the porosity of bulk graphite fabricated using compression molding, along with the mechanical properties of graphite blocks fabricated with CIP, were examined [14,15]. However, it is difficult to find studies about holding time and pressure during uniaxial pressurization for manufacturing graphite blocks.…”

Section: Introductionmentioning

confidence: 96%

Effect of Pressure and Holding Time during Compression Molding on Mechanical Properties and Microstructure of Coke-Pitch Carbon Blocks

Gwon,

Lee,

Youn

et al. 2024

Applied Sciences

Self Cite

View full text Add to dashboard Cite

In this study, isotropic coke and coal tar pitch were subjected to compression molding while varying the compression pressure and holding time. As a result, carbon blocks were fabricated, and their mechanical properties and microstructure were analyzed, with respect to applied pressure and holding time. The compression pressure was set to 70, 100 and 130 MPa, while the holding time was set to 1, 2 and 3 min. Overall, with an increase in compression pressure, bulk density increased while porosity decreased. Increased compression pressure also led to enhanced mechanical and electrical properties. Microstructural analysis confirmed that, after compression molding granules that were larger than existing kneaded particles appeared. The formation of granules is attributed to the tendency of kneaded particles to connect and coalesce with each other under applied pressure during the compression molding process. As the compression pressure increased, the proportion of granules in the microstructure increased while the size of pores decreased. This phenomenon can be attributed to kneaded particles coming closer to each other under applied pressure. At a compression pressure of 130 MPa, both bulk density and porosity increased with a longer holding time. Some pores existed within granules, while others protruded out of granules, thereby forming long channels of connected pores around them. This microstructural change was considered to result in degraded mechanical and electrical properties.

show abstract

Changes in Mechanical and Electrical Properties as a Function of Unidirectional Pressure Changes in Preforming While Isostatic Pressing for Graphite Block Fabrication

Cited by 2 publications

References 0 publications

Effect of Microstructural Change under Pressure during Isostatic Pressing on Mechanical and Electrical Properties of Isotropic Carbon Blocks

Effect of Microstructural Change under Pressure during Isostatic Pressing on Mechanical and Electrical Properties of Isotropic Carbon Blocks

Effect of Pressure and Holding Time during Compression Molding on Mechanical Properties and Microstructure of Coke-Pitch Carbon Blocks

Contact Info

Product

Resources

About