製作具有竹材結構的多孔碳化矽陶瓷材料

The synthesis of porous SiC using bamboo as biotemplates

邱奕翔(Yi-Hsiang Chiu)

指導教授 ： 林永仁

大同大學/工程學院/材料工程學系所/碩士(2005年)

摘要

本研究的主旨是將竹材製備成多孔碳化矽。利用竹材的多孔性組織構造及成分中含碳元素，在Ar氣氛中經過碳化處理後，使竹材轉化為竹碳，隨後再添加適當的矽源，可成功生成具有竹材結構的多孔性碳化矽陶瓷材料。由實驗結果可知，在反應溫度1400 ℃時，僅在於竹碳表面生成ㄧ層SiC，而反應溫度越高、持溫時間越久時，竹碳轉化為碳化矽的量越多；隨著持溫時間的增加，反應生成碳化矽的深度越深，在1500℃持溫12小時後，軸向的反應層厚度約為3.1 mm，徑向的反應層厚度約為1.35 mm。而具有竹材結構的多孔性碳化矽是由直徑約50 μm、10-20 μm、0.5 μm等三種不同大小的連通孔洞所構成的，而孔隙壁的厚度約為2-3μm。在1500℃持溫4小時合成之多孔性SiC具有低密度(Bulk density : 1.03 g/cm3)、高孔隙率(Open porosity : 66.5 %)，其比表面積為18.5 m2/g，在反應溫度1500℃、持溫8 hr時，軸向抗壓強度約120 MPa，側向抗壓強度約75 MPa，而軸向抗彎強度約12.8 ± 1.7 MPa，側向抗彎強度約42.5 ± 4.5 MPa。

關鍵字

仿生 ； 多孔性碳化矽

並列摘要

The purpose of this research is to fabricate porous silicon carbide from bamboo. The bamboo first transforms into porous charcoal by carbonization in argon atmosphere. Gaseous Si was infiltrated into porous charcoal and reacted with solid charcoal to form SiC. Few SiC was produced on the surface below 1400℃ (the melting point of Si is 1410℃). More SiC was formed with increase of reaction time and temperature. The depth of reaction layer in the axial direction is 3.1 mm and 1.35 mm in the radial direction after reaction for 12 hr at 1500℃. Porous SiC preserves the structure of bamboo and has three distinct pore sizes of about 50 μm, 10-20 μm and 0.5 μm. The strut thickness is 2-3μm and the grain size is 0.5 μm. It has low density (bulk density : 1.03 g/cm3), high porosity (open porosity : 66.5 %) and the specific BET surface area is 18.5 m2/g. The flexural strength of porous SiC synthesized at 1500℃ for 8 hr are 12.8 ± 1.7 MPa in the axial direction and 42.5 ± 4.5 MPa in the radial direction. The compressive strength of porous SiC are 120 MPa in the axial direction and 75 MPa in the radial direction.

並列關鍵字

porosity silicon carbide

參考文獻

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