以機械合金化法合成Co-Fe-TM-B(TM=Ti,Zr)之非晶質粉末與其磁特性

Formation of Co-Fe-TM-B (TM=Ti,Zr) Amorphous Powders by Mechanical Alloying and Their Magnetic Properties

李星慶(Hsing-Ching Li)

指導教授 ： 吳新明

大同大學/工程學院/材料工程學系所/碩士(2007年)

摘要

本研究以機械合金化法(Mechanical alloying, MA)之製程來製備Co-Fe-TM-B的非晶質粉末，實際之成分為Co62-XFeXTM8B30，成分元素TM=Ti、Zr，X分別為0、5、10、15、20與25。由X光繞射實驗之結果可知Fe取代量之多寡對以機械合金化法獲得非晶質粉末所需之球磨時間有明顯的影響，取代量愈高，達到非晶化所需球磨的時間亦會愈長。且在相同的取代量下，Co-Fe-Zr-B系統達到非晶化所需之球磨時間會較Co-Fe-Ti-B系統來得短。熱分析的結果則顯示出Co-Fe-Zr-B系統較Co-Fe-Ti-B系統具有較佳之玻璃形成能力。Co-Fe-Zr-B系統之過冷液態區範圍約在46 ℃~58 ℃之間，其中具有最大過冷液態區溫度的Co47Fe15Zr8B30之簡化玻璃轉化溫度(Trg)約為0.50；而Co-Fe-Ti-B系統之過冷液態區範圍約在38 ℃~42 ℃之間，其中具有最大過冷液態區範圍的Co57Fe5Ti8B30之簡化玻璃轉化溫度約為0.43。在磁特性方面，Fe取代量對飽和磁化量亦有明顯的影響。Co-Fe-Ti-B系統與Co-Fe-Zr-B系統之飽和磁化量皆會隨著Fe取代量的增加而提高。在Co-Fe-Ti-B系統中，Fe之取代量每增加1 at%，飽和磁化量約增加1.17 emu/g，而Co-Fe-Zr-B系統之增加量為0.63 emu/g。Co-Fe-Ti-B系統之飽和磁化量實際的範圍在93~124 emu/g之間，本質矯頑磁力則落在68~97 Oe範圍內；而Co-Fe-Zr-B系統之飽和磁化量實際的範圍在92~110 emu/g之間，本質矯頑磁力則落在58~66 Oe範圍內。

關鍵字

非晶質合金 ； 機械合金化法 ； 玻璃形成能力

並列摘要

In this study, amorphous Co-Fe-TM-B powders were synthesized by mechanical alloying (MA). The composition investigated were Co62-XFeXTM8B30 with TM=Ti, Zr and X equal to 0, 5, 10, 15, 20 and 25. The X-ray diffraction results indicate that the amounts of Fe in the powder mixtures significantly affect the time to reach amorphization by MA technique. The higher the Fe content the longer the amorphization. For a fixed amount of Fe, the time to reach amorphization for the Co-Fe-Zr-B system is shorter than that for the Co-Fe-Ti-B system. The thermal analysis results showed that Co-Fe-Zr-B powders have better glass forming ability than the Co-Fe-Ti-B powders. The supercooled liquid regions of the Co-Fe-Zr-B powders vary from 46 to 58℃ and the largest reduced glass transition temperature in these powders (corresponding to Co47Fe15Zr8B30 composition) is 0.50. For the Co-Fe-Ti-B alloys, their supercooled liquid regions vary from 38 to 42℃ and the largest reduced glass transition temperature in these alloys (corresponding to Co57Fe5Zr8B30 composition) is 0.43. For the magnetic property of these alloys, it was found that the amounts of Fe in the powder mixtures affect the saturation magnetization profoundly. The measured saturation magnetization increases with the increase in Fe for both Co-Fe-Ti-B and Co-Fe-Zr-B alloys. It was determined that for each 1 at% increase in Fe substitution for Co, saturation magnetization increase by 1.17 emu/g in Co-Fe-Ti-B alloys and 0.63 emu/g in Co-Fe-Zr-B alloys. The saturation magnetization of Co-Fe-Ti-B alloys and Co-Fe-Zr-B alloys were in the range of 93~124 emu/g and 92~110 emu/g, respectively. The measured intrinsic coercivity of Co-Fe-Ti-B alloys and Co-Fe-Zr-B alloys were in the range of 68~97 Oe and 58~66 Oe, respectively.

並列關鍵字

Amorphous alloy ； Mechanical alloying ； Glass forming ability

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