以延伸X光吸收精細結構探討退火時間對形狀記憶合金Ti48.7Ni51.3 局域結構之影響

Effect of Annealing Tine on the Shape Memory Alloys Ti48.7Ni51.3 Studied by Extended X-ray Absorption Fine Structure

宋佩諭(Pei-Yu Sung)

指導教授 ： 張經霖

淡江大學/理學院/物理學系碩士班/碩士(2017年)

https://doi.org/10.6846/TKU.2017.01055

摘要

我們以X光吸收光譜對不同退火時間（1、3、5、10、25、50 小時）的富鎳之鈦鎳合金Ti48.7Ni51.3進行有系統之研究。從Ti的K-edge譜與Ni的K-edge譜中，前置吸收峰與主吸收峰均無明顯變化。從Ti K-edge EXAFS的傅立葉轉換強度觀察到，在距離約2.56 Å處有第一配位峰，此峰為Ti-Ni鍵結，隨著退火時間的改變有很大的變化。從Ni K-edge EXAFS的傅立葉轉換強度觀察到，在距離約2.56 Å處有第一配位峰，此峰為Ni-Ti鍵結，隨著退火時間的改變有很大的變化。Ti-Ni鍵的配位數均大於Ni-Ti鍵的配位數，與樣品的富鎳性質相符合。當退火時間大於10時，Ti-Ni鍵的Debye-Waller factor與聲子熱導率呈反比關係；當退火時間小於10時，Ni-Ti鍵的Debye-Waller factor與聲子熱導率皆無明顯變化，表示聲子熱導率當退火時間大於10時與Ni亂度有關，當退火時間小於10時與Ti亂度有關。當退火時間大於3時，Ti-Ni鍵的Debye-Waller factor與電阻率呈正比關係； Ni-Ti鍵的Debye-Waller factor與電阻率無明顯關係，表示電阻率當退火時間大於3時與Ni亂度有關。

關鍵字

X光吸收光譜 ； 形狀記憶合金

並列摘要

We studied the nickel-rich Ti-Ni alloy Ti48.7Ni51.3 with different annealing time (1,3,5,10,25,50 hours) in X-ray absorption spectroscopy (XAS). There is no significant change in the pre-absorption peak and the main absorption peak from the K-edge spectrum of Ti and the K-edge spectrum of Ni. From the Fourier transform strength of Ti K-edge EXAFS, there is a first coordination peak at a distance of about 2.56 Å, which is Ti-Ni bond, which greatly changes with the change of annealing time. From the Fourier transform strength of Ni K-edge EXAFS, there is a first coordination peak at a distance of about 2.56 Å, which is Ni-Ti bond, which varies greatly with the change of annealing time. The coordination number of Ti-Ni bond is larger than that of Ni-Ti bond, which is consistent with the nickel-rich nature of the sample. When the annealing time is more than 10 hours, the Debye-Waller factor of Ti-Ni bond is inversely proportional to the lattice thermal conductivity. When the annealing time is less than 10 hours, the Debye-Waller factor and lattice thermal conductivity of Ni-Ti bond are not obvious Change, indicating that the lattice thermal conductivity when the annealing time is greater than 10 hours when the degree of chaos with the Ni, when the annealing time is less than 10 hours when the degree of chaos with the Ti. When the annealing time is more than 3 hours, the Debye-Waller factor of the Ti-Ni bond is proportional to the resistivity. The Debye-Waller factor of the Ni-Ti bond has no obvious relationship with the resistivity, indicating that when the annealing time is greater than 3 hours when the degree of chaos with the Ni.

並列關鍵字

XAS ； XANES ； EXAFS ； Shape Memory Alloys

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