Multifunctional Ferromagnetic Shape Memory Alloy Transducers with Novel Drive Mechanism

由于当前镍锰镓（Ni-Mn-Ga）器件的低频带宽和低能量密度，这些材料还没有成功地从实验室过渡到商业舞台。这些限制在本提案中通过材料制备和换能器设计中的范式转变来解决，这包括用应力和磁场沿[100]方向共线排列驱动材料，而不是现有的垂直配置。共线结构将实现新型宽带、多功能、紧凑和节能的Ni-Mn-Ga致动器和传感器。应用将包括振动控制、自适应光学、健康监测和水下通信等。虽然现有的马氏体变取向理论不支持这种结构中磁弹性响应的存在，但PI最近进行的测量证明了这种响应，并为这项研究奠定了基础。研究的目的是确定这些意外测量的确切来源，并确定，量化和开发设计和材料加工标准，以实现一类新的铁磁形状记忆致动器和传感器，其中磁场和应力共线对齐。为此，本研究包括三个主要任务：(1)开发共线磁场和应力驱动Ni-Mn-Ga的创新材料和器件模型；(2)进行微观到宏观尺度的实验测试，以确定这些合金的微观组织和宏观行为；(3)构建可改变柔度同时提供力和位移控制的Ni-Mn-Ga致动器和Ni-Mn-Ga多功能传感器。

Abstract 0409512Marcelo DapinoOhio State Univ.Due to the poor frequency bandwidth and low energy density of current nickel manganese gallium (Ni-Mn-Ga) devices, these materials have not made a successful transition from the laboratory to the commercial arena. These limitations are addressed in this proposal by means of a paradigm shift in material preparation and transducer design, which consists of driving the material with the stress and magnetic field aligned collinearly along the [100] direction, as opposed to the existing perpendicular configuration. The collinear configuration will enable a new class of broadband, multifunctional, compact and energy efficient Ni-Mn-Ga actuators and sensors. Applications will include vibration control, adaptive optics, health monitoring and underwater communications, among others. While the existence of magnetoelastic responses in this configuration is not supported by the existing theories for martensitic variant reorientation, recent measurements conducted by the PI demonstrate such responses and lay the groundwork for this research. The objectives of the research are to determine the exact origin of these unexpected measurements and to identify, quantify and develop design and material processing criteria to enable a new class of ferromagnetic shape memory actuators and sensors in which the magnetic field and stress are aligned collinearly. To that end, the research comprises three primary tasks: (1) to develop innovative material and device models for Ni-Mn-Ga driven with a collinear magnetic field and stress; (2) to conduct experimental tests at scales ranging from microscopic to macroscopic aimed at determining the microstructure and macroscopic behaviors of these alloys; and (3) to construct Ni-Mn-Ga actuators which can change their compliance while providing force and displacement control, and Ni-Mn-Ga multifunctional sensors.