流體床滲碳對CP-Ti及Ti-6Al-4V合金之表面改質

Surface Modification of CP-Ti and Ti-6Al-4V Alloy by Fluidized Bed Carburization

吳昶漢(Chan-hang Wu)

指導教授 ： 吳臺一

大同大學/工程學院/材料工程學系所/碩士(2007年)

摘要

本文旨在研發商用純鈦 (commercial purity titanium ; CP-Ti) 及Ti-6Al-4V合金 (Ti-64) 表面改質之流體床滲碳 (fluidized bed carburization; FBC) 製程，已經獲准專利之熔融鹽浴滲碳 (molten salt carburization; MSC) 製程成果亦在文中引用互相比較改質成效。前述兩種滲碳製程處理後皆在材料外表面形成一鑽石、石墨及金紅石之混合膜層。近表面層中主要產物為化學計量低下之缺碳碳化鈦 (carbon deficient titanium carbide, TiC1-x)，該化合物之晶格常數 (ao) 及其化學計量比 (1-x) 分別利用 Nelson-Riley分析及內插計算法獲得。採用 FBC 製程對提升表面硬度有較明顯效益。利用流體床滲碳(fluidized bed carburization ； FBC)於溫度930℃及1000℃下對商用純鈦(commercial purity titanium ； CP-Ti)、Ti-6Al-4V(Ti-64)進行表面改質處理，滲碳量隨處理溫度及處理時間增加而增加。將滲碳試片逐層研磨藉由微光束拉曼光譜術(RMS)、X光繞射儀(XRD)、輝光放電光譜術(GDOS)及維氏微硬度(VHN)觀察試片逐層之含碳量多寡與滲碳深度的影響。

關鍵字

CP-Ti、Ti-6Al-4V、流體床滲碳、熔融鹽浴滲碳、鑽石、石墨、TiC1-x、晶格常數、化學計量比、表面硬度

並列摘要

A fluidized bed carburizing (FBC) process was developed to see the effects on surface modification of commercial purity titanium (CP-Ti) and Ti-6Al-4V (Ti-64) alloy. The performance of a patented molten salt carburizing (MSC) process was also cited in comparison. A mixture of diamond, graphite and rutile were identified to form on the outermost surface for both processes. The major product at the near surface layer for both processes was carbon deficient titanium carbide TiC1-x. The lattice constants (ao) of TiC1-x and the associate stoichiometric ratios (1-x) were obtained by Nelson-Riley approach and interpolation, respectively. The enhancement of surface hardness was more pronounced by employing FBC process.

並列關鍵字

stoichiometric ratio ； CP-Ti ； Ti-6Al-4V ； fluidized bed carburization ； diamond ； graphite ； TiC1-x ； lattice constant ； surface hardness

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