Thermal and Structural Analysis of Mn49.3Ni43.7Sn7.0 Heusler Alloy Ribbons

Entropy

Tarek Bachaga¹  Rakia Daly²  Mohamed Khitouni²  Lluisa Escoda¹  Joan Saurina¹ 

[1] Department of Physics, University of Girona, Campus Montilivi s/n, Girona 17071, Spain; E-Mails:;Laboratory of Inorganic Chemistry, UR 11ES73, University of Sfax, B.P.1171, Sfax 3000, Tunisia; E-Mails:

关键词: entropy;    enthalpy;    X-ray diffraction;    magnetic shape memory;   

DOI  :  10.3390/e17020646

来源: mdpi

【 摘 要 】

The martensitic transformation and the solidification structures of Mn_49.3Ni_43.7Sn_7.0 alloy ribbons prepared by melt-spinning were investigated by means of scanning electron microscopy, X-ray diffraction and differential scanning calorimetry. In those experiments special attention was given to melt spinning processing parameters such as the linear surface speed of the copper wheel rotating, the injection overpressure and the distance between wheel and injection quartz tube. Transformation entropy was found higher when increasing linear surface speed or the distance from injection point to wheel. The resulting samples showed chemical compositions close to the nominal ones and, at room temperature, crystallized in a monoclinic single-phase martensite with 14M modulation (without a significant variation in the cell parameters). Strong dependence of ribbon thickness on processing parameters was found. The average grain size varied between 1.6 and 6.6 μm, while the start temperature of the martensitic temperature varied from 394 to 430 K.

【 授权许可】

CC BY   
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