Formation of texture of Ni48Mn31Ga21 polycrystalline alloy by thermal simulation pack rolling technology
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China; 2. Center of Research and Development of Special Materials, Institute of Shanghai Silicate Research, Chinese Academy of Sciences, Shanghai 200050, China)
Abstract: The hot deformation behavior of Ni48Mn31Ga21 alloy was studied by thermal simulation rolling technology. Microstructure evolution of the alloys under different rolling processes was studied by optical microscopy(OM) and X-ray diffractometry(XRD).The results show that, by thermal simulation pack rolling technology, textures appear in polycrystalline Ni48Mn31Ga21 alloy, and big cracks can be avoided under large deformation ratio. The rolling process with few passes and strong deformation makes Ni48Mn31Ga21 alloy obtain (202), (400) and (323) textures of martensitic variants more easily, especially (400) texture. Besides the interface between package materials and the Ni48Mn31Ga21 alloy is clear, which is beneficial for Ni48Mn31Ga21 alloy to separate from pack.
Key words: Ni-Mn-Ga alloys; magnetic shape memory alloys; thermal simulation; rolling; martensitic transformation; texture