Development Status of Ni-Mn-Ga Ferromagnetic Shape Memory Polycrystals After Hot Rolling

摘要

In order to obtain magnetic-field-induced strain MFIS in polycrystalline samples, the use of textured samples is most promising. The texture of the polycrystalline Ni_(50)Mn_(30)Ga_(20) magnetic shape memory alloys fabricated by hot rolling has been measured with high-energy synchrotron radiation and neutron diffraction. At room temperature the alloys used are composed of a modulated (7M) and non-modulated (NM) martensitic structure with martensitic twins. With the texture of the hot rolled alloy shows a weak recrystallization texture with {111} and < 112 > aligned parallel to the rolling plane and rolling direction, respectively. The set-up of the MFIS-determination device will be presented. The results are discussed with respect to processing and microstructure.