| Summary: | 碩士 === 國立成功大學 === 資源工程學系碩博士班 === 95 === The study was putting different quantities of Kaolinite into three different kinds of particles of powder will produce the porous SiC ceramics. We used the binder and pore former with the distribution rate of the fixed PVA, which is 5 wt%. The bulk is covered with Al2O3 in the heating furnace while sintering, we heat the temperature by three degrees centigrade per minute to different sintering temperatures and different heating time. We have then produced the porous SiC ceramics successfully within a low constant temperature.
First, we added the Kaolinite and water to make it wet and mixed it with the power of SiC. We then added the binder and pore former PVA. After drying, we ground it into a powder, the powder was uniaxially pressed at 50 Mpa and the result was green bodies. Cover up the green
bodies with Al2O3 powder, burn out the PVA to become pore by 500 degrees centigrade, sinter them and heat the temperature to 1200℃, 1300℃, and 1400 for 1 hour, 3hours and 5 hours. Therefore, the result was different SiC sintered bodies. We used XRD to identify the produced
phases and SEM to observe the fractured surfaces to discover the grain morphology of sintered bodies. By using
the Archimedes, we got the Apparent Density and the open pore. We got the compressive strength by the Material Test System as well.
The research showed that SiC sintered bodies could get the open pore above 21% in three different sintering temperatures for one hour, three hours and five hours individually. Under the condition of sintering at 1300℃ for 3hrs, the open pore and the Apparent Density and the compressive strength are showing that there is a trend in the synchronized variation. They had the same trend in the synchronized variation.The Open pore in 26.318% of the sample of 12S5K is the highest rate, to discover the thermal conductivity in the same condition; we found out
that the sample of 4S5K has the best result. Its Apparent Density is 1.7306 g/cm3 , the Open pore is 22.237 %, the compressive strength is9.11 Mpa, and the thermal conductivity is 10.3 W/m*K.
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