二氧化鈦粉末於流體床經由高熱分解轉換合成奈米氮化鈦之研究

Fabrication of nano-TiN powder by pyrolysis conversion of TiO2 in a fluidized bed furnace

邱正瑋(Cheng-wei Chiu)

指導教授 ： 陳繁雄

大同大學/工程學院/材料工程學系所/碩士(2004年)

摘要

經由anatase-TiO2 以及石墨混合作為前驅物,經由高能球磨促使二氧化鈦粉末與石墨產生carbothermic 還原反應,在低壓流體床中與氮氣反應,可生成奈米氮化鈦粉末.高能球磨所造成的晶粒細化,表面積增大以及缺陷濃度的增加以及粉末的內應力提昇皆有助於氮化鈦的形成
由本實驗結果發現,粉末的晶粒會隨著球磨時間的增加而減小並且隨球磨時間的增加所造成的強烈撞擊使得反應的能力提高而大幅降低了反應溫度.未經球磨的粉末由實驗證明無法藉由形成carbothermic 還原反應而形成氮化鈦.
本實驗所產生的奈米氮化鈦粒徑經由穿透式電子顯微鏡的觀察大約為42nm

關鍵字

奈米氮化鈦 ； 流體床法

並列摘要

Nano-structure TiN powders were prepared by using anatase-TiO2 and graphite mixtures as the precursor. Prior to thermal conversion, the mixture of TiO2 and graphite was milled in a high energy attritor to enhance the validity of carbothermic reduction. The nano-TiN powders were thermal converted by introducing N2 into a low pressure circulated fluidized-bed reactor which was previously evacuated to the pressure around 10-1 torr
The formation of TiN compound is greatly enhanced by high-energy milling due to the reduced crystallite size, large grain boundary area, presence of amorphous phases and the increased defect concentration in the powder reactants given by the high-energy milling.
Crystallites size of the powder mixtures decreased as increasing of milling time. The nano-TiN formation can be accomplished at a relatively low reaction temperatures and short reaction time via severe milling of TiO2 + graphite mixtures.
The experiment results evidenced that the carbothermic reduction could not be occurred if the powder mixture of TiO2 + graphite had not been undergone a severe milling

並列關鍵字

Fluidized bed ； nano-TIN

參考文獻

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