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題 名 | 以θ→α-Al[feaf]O[feb0]相轉換的特性製備微粒α-Al[feaf]O[feb0]粉末之研究=Preparation of Nanosized α-Al[feaf]O[feb0]Powders via Characteristics of θ-to α-Al[feaf]O[feb0]Phase Transformation |
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作 者 | 羅慧珊; 溫惠玲; 陳怡堯; 顏富士; | 書刊名 | 陶業學刊 |
卷 期 | 3:1 1999.01[民88.01] |
頁 次 | 頁35-43 |
分類號 | 440.33 |
關鍵詞 | 氧化鋁; 相轉換; 孕核成長; 臨界粒徑; Alumina; Phase transformation; Nucleation and growth; Critical size; |
語 文 | 中文(Chinese) |
中文摘要 | 本文先探討氧化鋁粉末之θ→α-A1�烙�鬲衕鉥囿瑣魖謘A再據此嘗試找出獲得單離且均一相α-A1�烙�健L粉的方法。實驗探用淬冷與持溫二方式,起始原料分別為Boehmite及於900℃/1hr處理之煆燒粉,其結晶相主要為θ-A1�烙�陛C淬冷係將煆燒粉末於900℃至1200℃間作升溫處理後馬上降溫,觀察其變化。持溫則將Boehmite於1050、1100℃做不同時間加熱,再觀察θ與α-A1�烙�陞X現的情形。由Scherrer formula算出α-A1�烙�偌僥|,配合BET法求出的比表面積徑,可推知在θ→α-A1�烙�鬲衕鉥姘L程中,應為單一θ-晶粒對單一α-晶核進行孕核。再由晶核聚合成長至基礎粒徑的α-A1�烙�偃瘣飽A因此欲獲得單離單晶粉末(晶徑為40∼50nm)實為可行。本研究提出三種製作α-A1�烙�健L粒的方法。 |
英文摘要 | Phase transformation behavior of θ→α-A1�烙�� was investigated using quenching and annealing treatments by which the mono-dispersed ultrafine α-A1�烙�� powders can be obtained in this study. Calcined (900℃/1h) boehmite powders were adapted as starting materials for quenching treatment at various temperatures (900∼1200℃) and quenched. Besides, boehmite was heated to 1050 and 1100℃ then annealed with duration of 1 to 100hrs. Studies then performed using X-ray diffraction analysis and BET technique to calculate crystallite and agglomerate size of θ- and α-A1�烙��. It is found that one θ-crystallite nucleated to one α-nucleus during θ→α-A1�烙�� phase transformation and α-nuclei coalesced to form α-A1�烙�� primary particles. There methods of reparing mono-dispersed ultrafine α-A1�烙�� powders (crystallite size = 40∼50nm) were proposed. |
本系統中英文摘要資訊取自各篇刊載內容。