標題: | 鐵-18 at.%鋁-10 at.%鈦合金之相變化 Phase Transformations in an Fe-18 at.%Al-10 at.%Ti Alloy |
作者: | 劉哲郎 劉增豐 朝春光 T. F. Liu C. G. Chao 材料科學與工程學系奈米科技碩博士班 |
關鍵字: | 相變化;鐵鋁鈦合金;phase transformation;Fe-Al-Ti |
公開日期: | 2006 |
摘要: | 我們利用光學顯微鏡(OM)、穿透式電子顯微鏡(TEM)和X光能量散佈分析儀(EDS),研究Fe-18at.%Al-10at.%Ti合金的相變化。
Fe-18at.%Al-10at.%Ti合金在淬火狀態下的顯微結構為(A2+D03)相的混合。其中D03相是經由A2 → B2 → (A2+D03)之連續規律化的過程而產生。當我們將此合金在700℃至1100℃的溫度範圍內施以不同時間的時效處理後發現,此合金隨著溫度的增加其一系列相變化過程為A2+D03→A2+D03+C14→B2+C14→A2+C14→A2;值得ㄧ提的是,這一實驗結果從未被其他學者觀察過。此外,當此合金在800℃作1小時的時效處理後,經過擇區繞射圖我們觀察到基底的(A2+D03)相和C14相會有以下的方向關係(0001)C14//(-1-12)m , (-1100)C14//(-110)m , (11-20)C14//(111)m,這一實驗結果在Fe-Al-Ti合金中也從未被發現過。 Phase transformations in an Fe-20at.%Al-8at.%Ti alloy have been examined by means of optical microscopy (OM), transmission electron microscopy (TEM) and energy-dispersive X-ray spectrometer (EDS). In the as-quenched condition, the microstructure of the Fe - 18at.%Al - 10at.%Ti alloy was a mixture of (A2+D03) phases and the D03 phase was formed by an A2 → B2 → (A2+D03) continuous ordering transition during quenching. When the as-quenched alloy was aged at temperatures ranging from 700℃ to 1100℃, the phase transition sequence as the aging temperature increased was found to be A2+D03→A2+D03+C14→B2+C14→A2+C14→A2. It is noted here that this phase transition has never been observed by other workers in the Fe-Al-Ti alloys before. In addition, when the present alloy was aged at 850℃, the orientation relationship between the C14 precipitate and (A2+D03) matrix was determined to be (0001)C14//(-1-12)m , (-1100)C14//(-110)m , (11-20)C14//(111)m analysed by the above diffraction patterns. This orientation relationship between the C14 precipitate and A2, D03 or B2 matrix has never been reported by other workers in the Fe-Al-Ti alloy systems before. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#GT009452514 http://hdl.handle.net/11536/82021 |
顯示於類別: | 畢業論文 |