Low-frequency Elastic and Thermomechanical Analysis of Ni-Mn-In(Co) Single Crystals☆

Martensitic transformation (MT) in Ni 45.0 Mn 36.7 In 13.3 Co 5.0 single crystals (SC) has been characterized by DSC and X-ray diffraction. Their elastic and thermomechanical properties have been investigated by a low-frequency dynamic-mechanical analysis in a tensile mode and by static mechanical compression made at different temperatures. The Young's modulus of the order of 10 GPa was measured in tensile tests along crystallographic axis of austenite showing soft behavior in a broad temperature range whereby revealing a lattice instability similar to the classical Ni-Mn-Ga alloys. The compression tests along , and directions have shown that despite a high brittleness the samples exhibit large martensitic plasticity, rubber-like behavior and superelasticity