Microstructure and Kinetics of Thermal Behavior of Martensitic Transformation in (Mn,Ni)Sn Heusler Alloy

Abstract

In this work, scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry were used to investigate the solidification structure, thermal behavior, and kinetics of the martensitic transformations of the (Mn,Ni)Sn as-spun and annealed ribbons synthesized by melt-spinning. At room temperature, the as-spun and annealed (Mn,Ni)Sn ribbons exhibited a cubic single-phase Heusler L21 structure. The kinetics of the martensitic transformation (MT) was studied, together with their microstructure evolution and cooling rate dependence. The mechanism was also investigated. Additionally, a high dependence between the cooling rates and energy activation (Ea) was detected. A more detailed characterization of MT and account of thermodynamic parameters were examined after annealing.

Keywords

• Heusler alloys
• rapid solidification
• martensitic transition
• thermal analysis
• energy activation
• kinetics