| Summary: | 碩士 === 國立聯合大學 === 材料科學工程學系碩士班 === 96 === The objective of this study is to investigate the structure and electrical resistivity of SiC ceramics that added different amount of boron carbides, sintered at air and CO/CO2 in 1350 ~ 1400℃.
This research shows that optimal mixed ratio of partical size of 1 ~ 10 μm and 40 ~ 60 μm by slip-casting in plaster of Paris and comparison of properties of bulk density, microstructure and electrical resistivity of sintered body was produced by adding amount of 0%、1%、2%、5% of boron carbide and sintering at various temperature in difference atmospheres. According to experiment result, we obtained the optimal condition without plasticizer that particle size of 1 ~ 10μm, 40 ~ 60μm and water of mixed ratio 3:3:4.
We obtained the result that the highest density of sintered SiC by adding 1% boron carbide using Archimedes’ principle. Comparison of the result that the bulk density of sintering in air higher than sintering at CO/CO2 atmosphere due to formation of silica by SiC of oxidation infiltrated between particles. According the analysis result by XRD, generation of β-SiC by sintering at CO/CO2 atmosphere leads to electrical resistivity of sintering body decrease. In addition, we obtained that relative content of β–SiC significantly increased with higher reaction temperature by analysis of XRD and NMR.
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