黏結劑、強化材及含浸對焦炭-碳複合材料之影響

THE EFFECTS OF BINDER, REINFORCEMENT AND INFILTRATION ON THE PROPERTIES OF COKE-CARBON COMPOSITES

王彥鈞(Yan-Giun Wang)

指導教授 ： 林永仁

大同大學/工程學院/材料工程學系所/碩士(2011年)

摘要

本研究分別以煤焦油瀝青和酚醛樹脂作為焦炭的黏結劑，探討不同製程參數處理對材料物性及機械性質影響。兩種黏結劑分別混合焦炭以熱壓成形，再進行碳化。焦炭添加煤焦油瀝青在碳化溫度700℃有最高的密度(1.32 g/cm3)和最佳等向雙軸彎曲強度(12.1 MPa)； 焦炭添加酚醛樹脂則在同參數熱壓成胚後，以熱處理溫度900℃有較相近強度(12.0 MPa)，體密度為1.10 g/cm3。
添加補強材於焦炭-25wt%瀝青各組試片中，以添加5wt%碳纖維其等向雙軸彎曲強度較佳，增加為19MPa，體密度和孔隙率則和未添加之試片差異不大。
另外，以液相含浸法進行焦炭-瀝青試片緻密化，分析含浸材和碳化溫度對材料物理性質和機械強度的影響。結果顯示，試片之孔隙隨含浸次數增加而減少。試片強度因結構中的孔隙等缺陷被填補而增加；當含浸次數超過三次時，填補孔洞效率下降、反覆熱裂解產生裂縫使得試片強度下降。

關鍵字

煤焦油瀝青 ； 酚醛樹脂 ； 呋喃樹脂 ； 焦炭 ； 含浸

並列摘要

Coal tar pitch and phenolic resin are binders of composites. This study is focus on the effects of different processes of manufacture on physical and mechanical properties. Both binders were dry-mixed with coke, hot-pressed and heat-treated to form bulk pellets. The highest density and equi-biaxial (or ring-on-ring) flexural strengths of the coke-25wt% coal tar pitch pellets obtained were 1.32 g/cm3 and 12.1 MPa, respectively, after the pellets were sintered at 700°C. For coke-phenolic resin mixtures, the composites were heat-treated at 600, 700, 800, 900 and 1000℃. When coke-25wt% phenolic resin pellets were sintered at 900°C, their equi-biaxial flexural strengths reached 12.0 MPa and the bulk density was 1.10 g/cm3.
In the other experiment, when 5wt% carbon fiber was added to coke-25wt% coal tar pitch pellets, the equi-biaxial flexural increased to 19.0 MPa. However, the density and the porosity didn’t change significantly. Finally, the coke-pitch pellets were densified by using the process of repeated impregnation- carbonization for different times. This experiment is to investigate the influence of different impregnating precursors and temperature of carbonization on physical and mechanical properties of coke-25wt% phenolic resin pellets. The results indicated that the porosity was reduced by increasing times of impregnation. The flexural strength increased because the pores were filled with impregnating precursors. However, the flexural strength of specimens decreased after three times of the process of impregnation- carbonization owing to cracks and decreased efficiency of impregnation. The thermal cracking has negative effects on mechanical strength of the coke/carbon composites.

並列關鍵字

coke ； coal tar pitch ； phenolic resin ； furan resin ； infiltration

參考文獻

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