力-磁-热循环载荷作用下Ni-Mn-Ga单晶材料变形理论及机理

Ni-Mn-Ga single crystals have a prosperous application in the fields of aerospace, transportation and automatic, due to their unique magnetic induced shape memory performance. In fact, the deformation theory and microstructure evolution mechanism in coupling fields is one of the focus researches for intelligent material. This topic is an interdisciplinary issue which involves mechanics, magnetism and material science. Under the mechanical-magnetic-thermal cyclic loading, the magnetic properties and microstructure of single crystal will be changed, thereby affecting the driving and sensing. In present work, the Ni-Mn-Ga single crystals (5M) will be investigated by theoretical, numerical, and experimental methods. A general thermodynamic phenomenological model will be proposed for the cyclic loading of mechanical-magnetic-thermal, which can used to describe the hysteretic behavior. The deformation mechanism of single crystal subject to the cyclic loading will be analyzed to reveal the evolution of magnetic properties and microstructure. The new test platforms will be constructed to expand the experimental characterization method. We expect to gain original achievements in the deformation theory, mechanism, and experimental method for the Ni-Mn-Ga single crystals, which can provide the technique and theoretical guidance for its application in practice.

Ni-Mn-Ga单晶材料因其优异的磁致记忆特性，未来在航空航天、轨道交通、机械控制等领域具有广阔的应用前景，其在多场耦合作用下的变形理论及演化机理是智能材料领域研究的热点和难点，研究内容涉及到力学、磁学和材料学等多学科的交叉。力-磁-热循环载荷作用下单晶材料的磁致特性和微观结构会发生变化，进而影响其驱动和传感特性。本项目将以Ni-Mn-Ga单晶材料（5M结构）为研究对象，通过理论分析、数值模拟和实验表征等方法，建立力-磁-热循环载荷作用下单晶材料的广义热动力学宏观唯象变形理论模型，描述材料磁致滞回行为；研究力-磁-热循环载荷作用下单晶材料的变形机理，揭示单晶材料磁化特性和微观结构演化规律；搭建新的实验测试平台，发展单晶材料宏微观实验表征方法。期望在Ni-Mn-Ga单晶材料耦合场循环载荷作用下的变形理论、变形机理和实验表征方法等方面获得原创性成果，为其工程应用提供理论和技术指导。

磁致形状记忆材料因其优异的磁致记忆特性，未来在航空航天、轨道交通、机械控制等领域具有广阔的应用前景，其在多场耦合作用下的变形理论及演化机理是智能材料领域研究的热点和难点，力-磁-热循环载荷作用下单晶材料的磁致特性和微观结构会发生变化，进而影响其驱动和传感特性。本项目以Ni-Mn-Ga单晶材料（5M结构）为研究对象，通过理论分析、数值模拟和实验表征等方法，建立了力-磁-热循环载荷作用下单晶材料的广义热动力学宏观唯象变形理论模型，描述材料磁致滞回行为，并和实验结果进行了对比分析；研究了力-磁-热循环载荷作用下单晶材料的变形机理，揭示单晶材料磁化特性和微观结构的演化规律，结果表明材料的磁化特性随温度升高将大幅衰减，进而影响材料的记忆特性；搭建了新的力-磁-热循环加载和材料微区模量/硬度纳米压痕实验测试平台，发展了单晶材料宏微观实验表征方法。该项目在Ni-Mn-Ga单晶材料耦合场循环载荷作用下的变形理论、变形机理和实验表征方法等方面均获得了一些原创性成果，将为其工程应用提供理论和技术指导。