项目名称： 强磁场下MnNi反铁磁多孔合金的多重记忆效应及相关机制的研究

项目编号： No.U1532148

项目类型： 联合基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 万见峰

作者单位： 上海交通大学

项目金额： 50万元

中文摘要： 本课题采用强磁场烧结制备MnNi反铁磁多孔合金，研究强磁场对多孔合金多重记忆效应(包括单/双程温控、磁控形状记忆效应，体积记忆效应以及形状与体积关联效应)的影响规律；实验研究强磁场对MnNi多孔合金中fcc-fct马氏体相变和顺磁-反铁磁相变的影响以及强磁场下微观组织的多重择优取向(晶粒取向、马氏体变体再取向、反铁磁磁畴再取向)及其机制，探寻提高反铁磁材料记忆效应的有效方法；原位观察相变过程中相界和畴界等多种界面迁移的动态过程，建立与强磁场关联的复合界面(马氏体孪晶界与反铁磁畴耦合界面)迁移的动力学模型；基于强磁场，结合马氏体相变、反铁磁相变、微观组织演化特征，建立强磁场下MnNi多孔合金多重记忆效应的微观机制，并建立与强磁场关联的多孔合金可恢复应变理论计算模型。本课题将促进强磁场下材料科学中新现象、新方法、新理论的探究，特别是新材料在极端条件下极限性能的研究，有利于形成强磁场功能材料学。

中文关键词： 强磁场；多重记忆效应；多重择优取向；MnNi反铁磁多孔合金；相变

英文摘要： Antiferromagnetic porous MnNi alloys will be fabricated by using high magnetic field (HMF) sintering. Their multi-memory effects such as single-way, two-way thermal-control shape memory effect（SME）, magnetic field-control SME, volume memory effect and correlation effect between shape and volume will be studied. Phase transition (fcc-fct martensitic transformation and paramagnetic-antiferromagnetic transition) and the multi-preferred orientation (grain alignment, reorientation of martensitic variants, rearrangement of antiferromagnetic domain wall) of microstructures under HMF will be investigated experimentally so as to explore the optimum methods to improve the multi- memory effects. Dynamic model of complex interface (combining martensitic twin interface and antiferromagnetic domain wall) associated with HMF will be build in MnNi alloys based on the in-situ observation. The mechanism of multi-memory effects connected with HMF will be proposed from the analyses of martensitic transformation and magnetic transition as well as micro-structural evolution. The equation of recoverable strain related with HMF will be built in porous alloys. Our project will promote the study of new methods, new phenomena and new theories in material science, especially in the field of ultimate properties of new materials under extreme conditions, and will establish the new research frontier of high-magnetic field functional materials.

英文关键词： high magnetic field;multi-memory effect;multi-preferred orientation;MnNi antiferromagnetic porous alloys;Phase transition