Deformation induced martensite stabilization in Ni45Mn36.7In13.3Co5 microparticles

A Ni45Mn36.7In13.3Co5 alloy has been deformed by hand crushing and ball milling, both in martensite and in austenite, to analyze the effect of the induced plastic deformation on the relative stability between structural phases. A huge martensite stabilization, with shifts on the temperature of the first reverse martensitic transformation of up to 100 K, is observed not only in the deformed martensite but also in the grinding-induced martensite. It is also found that, regardless of the degree of plastic deformation, the stabilized martensite displays a non-modulated tetragonal structure, which accommodates the generated internal stresses better than the thermal induced modulated monoclinic martensite. In all cases, the destabilization process is shown to finish around the Curie temperature of the austenite, which actually represents a high temperature limit for the mechanically-stabilized martensite. This phenomenon is analyzed and explained in terms of the effect of magnetic entropy contribution to the driving force for reverse MT. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Deformation of a Ni45Mn36.7In13.3Co5 alloy was carried out by hand crushing and ball milling in both martensite and austenite states in order to study the effect of induced plastic deformation on the stability between structural phases. It was found that a significant martensite stabilization occurred, resulting in shifts of up to 100 K in the temperature of the first reverse martensitic transformation. The stabilized martensite exhibited a non-modulated tetragonal structure regardless of the degree of plastic deformation, showing better accommodation of internal stresses than the thermally induced modulated monoclinic martensite.