Microstructure and texture in Ni50Mn29Ga21 deformed by high-pressure torsion

Received 10 December 2009; received in revised form 11 January 2010; accepted 11 January 2010. published online 18 January 2010.

The texture in a polycrystalline Ni50Mn29Ga21 magnetic shape-memory alloy deformed by high-pressure torsion (HPT) at 1173K was investigated with high-energy synchrotron radiation. HPT changed the extrusion texture to a predominant slightly rotated cube {001} 〈100〉 and a weak F {110}〈100〉 component. During HPT the grain structure coarsened. Phase transformations during cooling from the deformation temperature led to coarse and fine sets of martensitic twin variants. The results are discussed with respect to deformation mode, grain growth and phase transformations.

Keywords: NiMnGa, Torsion, Synchrotron radiation, Microstructure, Texture

a Institut für Strukturphysik, Technische Universität Dresden, D-01062 Dresden, Germany

b Fraunhofer-Institut für Werkzeugmaschinen und Umformtechnik, D-01187 Dresden, Germany

c Institut für Werkstoffforschung, GKSS Forschungszentrum Geesthacht, D-21502 Geesthacht, Germany

d Geoforschungszentrum Potsdam, D-14473 Potsdam, Germany

Corresponding author. Tel.: +49 35146334363.

PII: S1359-6462(10)00017-5

doi:10.1016/j.scriptamat.2010.01.016

6 of 26