The Microstructures and Properties of Carbon and Graphite Materials Prepared from Mesocarbon Microbeads by Different Molding Methods

摘要

Mesocarbon microbeads (MCMBs) are the prominent precursors for high-strength and high-density carbon and graphite materials (CGM). The microstructures and properties of CGM prepared by different compaction techniques using raw powders or pelleted powders of MCMBs with low content of p-resins was investigated in the present study. The green blocks by one-step uniaxial compaction at 230MPa were carbonized at 1200°C, forming carbon blocks with density of 1.84g/cm~3 and bending strength of 76.9MPa. After graphitizing at 2700°C the carbon blocks are with density of 1.91g/cm~3 and flexural strength of 70.5MPa. One-step cold isotropic pressing can improve the moldability of green blocks and increase open porosity of graphite blocks to 12.64vol%, with density of 1.87g/cm~3. The green blocks with no cracks prepared by multistep cold isotropic pressing exhibit density of 1.84g/cm~3 and bending strength of 81.7MPa. However, the flexural strength of these carbon and graphite artifacts decreased by 11.6~32.0MPa with comparison to the ones directly prepared from MCMBs.