Entropy Change during Martensitic Transformation in Ni50−xCoxMn50−yAly Metamagnetic Shape Memory Alloys

Entropy

Xiao Xu¹  Wataru Ito²  Takeshi Kanomata¹ 

[1] Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; E-Mail:;Department of Materials and Environmental Engineering, Sendai National College of Technology, Natori 981-1239, Japan; E-Mail:

关键词: entropy change;    specific heat;    thermal transformation arrest;    kinetic arrest;    metamagnetic shape memory alloy;    martensitic transformation;    Ni-Co-Mn-Al;   

DOI  :  10.3390/e16031808

来源: mdpi

【 摘 要 】

Specific heat was systematically measured by the heat flow method in Ni_50−xCo_xMn_50−yAl_y metamagnetic shape memory alloys near the martensitic transformation temperatures. Martensitic transformation and ferromagnetic–paramagnetic transition for the parent phase were directly observed via the specific heat measurements. On the basis of the experimental results, the entropy change was estimated and it was found to show an abrupt decrease below the Curie temperature. The results were found to be consistent with those of earlier studies on Ni-Co-Mn-Al alloys.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland