Magnetostrictive devices

Technical aspects and potential applications of magnetostrictive materials have been presented by du Tremolet de Lacheisserie (1993). Different kinds of magnetostrictive devices based on Terfenol-D were recently reviewed by Zhu et al. (1997) and Claeyssen et al. (1997). Today, interest is mounting in physical micro-systems of reduced dimensions, typically between 10 and 10 pm. Such systems may satisfy the need to perform functions which are not fulfilled by existing electronic circuits, i.e., sensing... 

Theory of Magnetostriction in Magnetostrictive Devices Constitutive Equations... 

It is interesting to analyse the behavior of linear actuators because most applications are based on such actuators. To simplify the presentation, we can consider an actuator with one end working either free (no load) or against a purely resistive load i ioad (in kg/s) the other end of the actuator is clamped. The vibration against this load produces an output power (either mechanical or acoustic), and its behavior is representative of any magnetostrictive device. Most of them can be analysed as whole systems, including a compliance (at constant field), an effective mass M and a mechanical... 

Nickel is being used ia magnetostrictive transducers ia some ultrasonic devices, eg, solderiag irons and ultrasonic cleaners, because of its moderate magnetostriction and availabiUty. This market, however, is dominated by piezoelectric transducers of lead zirconate—titanate (PZT) (see Ultrasonics). 

Aside from the A effect which is an interesting feature for designing resonant mechanical devices, MSMM show a GMR (AR) effect (Quandt and Ludwig 1999,2000). Thus, as already introduced in section 3.3, the bending of a magnetostrictive bimorph... 

The first practical device to make use of magnetostrictive technology, a sonar system developed by researchers at NSWC, used this property. The system consisted of magnetostrictive materials... 

Linear position Linear motion is typically driven by the use of lead screws, ball screws, or worm drives with ranges from less than a 25 mm to over 6 m. Linear sensors for position feedback in the lower range include LVDTs, magnetic, and optical encoders. For longer strokes, the linear feedback devices include encoders and magnetostrictive position transducers. Optical encoders are practical up to 2 m. Magnetostrictive position transducers can be used up to 20 m. 

Samarium 62 Sm Reactor control and neutron shielding, magnets, luminescent and infra-red absorbing glasses, catalysts, ceramics, electronic devices, magnetostrictive alloys, misch metal... 

Holmium 67 Ho Electronic devices, catalysts, refractories, magnetic materials, magnetostrictive alloys... 

The preceding studies were mainly carried out under free field conditions at high frequencies. Weber and Chon [35] carried out similar measurements at low frequency (21.5 kHz) under restricted field conditions. Their experimental device, similar to that used by Timmerhaus and Fogler [36], is illustrated in Figure 13. The emitter is a magnetostrictive transducer with base area 16 cm2 attached by epoxy to the bottom of a 600 cm3 beaker filled with water as coupling fluid. A tube... 

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