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URN etd-0904112-183856 Statistics This thesis had been viewed 989 times. Download 0 times. Author Chuan-Hung Huang Author's Email Address No Public. Department Materials Engineering Year 2011 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 91 Title Preparation of Isotropic Graphite Blocks by Mesocarbon Microbeads Keyword MCMB carbonization fracture carbonization fracture MCMB Abstract Mesocarbon microbeads (MCMBs) were used as precursor for high-density isotropic graphites. The cylindrical carbon artifacts, with a diameter of ~21 mm and a height of ~ 60 mm, were prepared using MCMBs by cold isostatic pressing followed by carbonization. The carbonization heat treatment to 1000℃ can be divided into two temperature regions : 200 ~ 600 ℃ and 600 ~ 1000 ℃. Bonding between MCMBs forms during the temperature range 200 ~ 600 ℃, in which slower heating rate is required. However, too slow heating rate will result in the decrease of mechanical properties. Carbonation in the temperature range of 600 ~ 1000 ℃ leads to shrinkage and the heating rate in this temperature range depends on the bonding strength between MCMBs which was formed during 200 ~ 600 ℃. Increase of heating rate in this temperature range will lower the mechanical properties of the carbon blocks. In addition to the heating rate, high cooling rate will also results in the carbonization fracture. For the molding pressure of cold isostatic pressing in the range of 900 ~ 1800 kgf/cm2, the higher the pressure, the better the mechanical properties. Results of elemental analysis and X-ray diffraction indicated that the structure of carbon blocks was not influenced by the molding pressure. The differences of hardness and flexural properties were due to the voids and cracks resulted from the molding pressure. Advisor Committee Shinn-Shyong Tzeng - advisor
Ching-Fang Tu - co-chair
Fu-Sen Liao - co-chair
Files Date of Defense 2012-07-13 Date of Submission 2012-09-04