Related Articles Condition of the ratchet effect of a magnetic domain wall motion under an asymmetric potential energy J. Appl. Phys. 111, 07D301 (2012) Domain structure and magnetization loss in a toroidal core based on an Fe-based amorphous alloy J. Appl. Phys. 111, 07A302 (2012) Twin-Foucault imaging method Appl. Phys. Lett. 100, 061901 (2012) Temperature-induced martensite in magnetic shape...

The magnetocaloric effect that originates from the martensitic transition in the ferromagnetic Ni-Mn-Ga shape-memory alloy is studied. We show that this effect is controlled by the magnetostructural coupling at both the martensitic variant and magnetic domain length scales. A large entropy change induced by moderate magnetic fields is obtained for alloys in which the magnetic moment of the two ...

Actively controlled shape memory alloy actuators are useful for a variety of applications that require accurate shape control. For shape memory alloy wires, strain is modulated with temperature, usually by an applied voltage difference across the length. Numerical simulation using reinforcement learning has previously been used for determining the temperature strain relationship of a shape memo...

The two-way shape memory effect in a Ti36Ni49Hf15 high temperature shape memory alloy (SMA) has been systematically studied by bending tests. In the TiNiHf alloy, the martensite deformation is an effective method to get two-way shape memory effect even with a small deformation strain. When the TiNiHf alloy is deformed at a full martensite state, the deformation mechanism is the martensite orien...

A process for fabrication of shape memory alloy MEMS actuators on a elastomeric polymer substrate is described. These actuators are designed for use on innovative soft body robots. Patterned shape memory alloy (nitinol) is sputter deposited on a polyimide mesh structure. The mesh substrate acts as a bias spring to de-twin the shape memory alloy in the martensite phase. Significant portions of t...

As a new type of smart material, magnetic shape memory alloy has the advantages of a fast response frequency and outstanding strain capability in the field of microdrive and microposition actuators. The hysteresis nonlinearity in magnetic shape memory alloy actuators, however, limits system performance and further application. Here we propose a feedforward-feedback hybrid control method to impr...

Mechanical anisotropy in an austenitic ferromagnetic shape memory alloy (SMA), Ni50Mn26.25Ga23.75, is investigated along (010), ( 120 ) , ( 121 ) , ( 231 ) and (232) using nanoindentation. While (010) exhibits the highest reduced modulus, Er, and hardness, H, (232) shows the lowest amongst the grain orientations examined in this study. The significant elastic anisotropy measured is attributed t...

-A nonlinear finite element procedure is developed which incorporates a thermodynami~ly derived cons~tutive law for shape. memory alloy material behavior. The constitutive equations include the necessary internal variables to account for the material transfo~ations and are utilized in a onedimensional finite element procedure that captures the unique shape memory alloy responses of pseudoelasti...