Martensitic Transformation in Ni-Mn-Sn-Co Heusler Alloys

Metals

Alexandre Deltell¹  Lluisa Escoda¹  Joan Saurina¹  Joan Josep Suñol¹ 

关键词: magnetic shape memory;    martensitic transformation;    DSC;    XRD;    Ni-Mn-Sn-Co;   

DOI  :  10.3390/met5020695

来源: mdpi

【 摘 要 】

Thermal and structural austenite to martensite reversible transition was studied in melt spun ribbons of Ni₅₀Mn₄₀Sn₅Co₅, Ni₅₀Mn_37.5Sn_7.5Co₅ and Ni₅₀Mn₃₅Sn₁₀Co₅ (at. %) alloys. Analysis of X-ray diffraction patterns confirms that all alloys have martensitic structure at room temperature: four layered orthorhombic 4O for Ni₅₀Mn₄₀Sn₅Co₅, four layered orthorhombic 4O and seven-layered monoclinic 14M for Ni₅₀Mn_37.5Sn_7.5Co₅ and seven-layered monoclinic 14M for Ni₅₀Mn₃₅Sn₅Co₅. Analysis of differential scanning calorimetry scans shows that higher enthalpy and entropy changes are obtained for alloy Ni₅₀Mn_37.5Sn_7.5Co₅, whereas transition temperatures increases as increasing valence electron density.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.