198:), which allows Terfenol-D transducers to reach greater depths for ocean explorations than past transducers. Its low Young's modulus brings some complications due to compression at large depths, which are overcome in transducer designs that may reach 1000 ft in depth and only lose a small amount of accuracy of around 1 dB. Due to its high temperature range, Terfenol-D is also useful in deep hole acoustic transducers where the environment may reach high pressure and temperatures like oil holes. Terfenol-D may also be used for
151:, with a trend of decreasing magnetostriction as the compressive stress increases. There is also a relationship between the magnetic flux and compression in which when the compressive stress increases, the magnetic flux changes less drastically. Terfenol-D is mostly used for its magnetostrictive properties, in which it changes shape when exposed to magnetic fields in a process called
254:, are powder based. These techniques allow for intricate geometry and detail. However, the size is limited to 10mm in diameter and 100mm in length due to the molds used. The resulting microstructures of these powder based methods differ from the solid crystal ones because they do not have a lamellar structure and have a lower
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Terfenol-D has some minor drawbacks which stem from its material properties. Terfenol-D has low ductility and low fracture resistance. To solve this, Terfenol-D has been added to polymers and other metals to create composites. When added to polymers, the stiffness of the resulting composite is low.
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made it easier to induce magnetostrictive responses by making the alloy require a lower level of magnetic fields. When the ratio of Tb and Dy is increased, the resulting alloy's magnetostrictive properties will operate at temperatures as low as −200 °C, and when decreased, it may operate at a
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The increase in use of
Terfenol-D in transducers required new production techniques that increased production rates and quality because the original methods were unreliable and small scale. There are four methods that are used to produce Terfenol-D, which are free stand zone melting, modified
273:. In a study done on processing Terfenol-D alloys, the resulting alloys created using copper and Terfenol-D had increased strength and hardness values, which supports the theory that the composites of ductile metal binders and Terfenol-D result in a stronger and more ductile material.
304:"PRC Espionage leads to 'Terf' war: investigators say China placed students in American universities to gain secret information about an exotic material with valuable industrial and military uses | Insight on the News Newspaper | Find Articles at BNET"
265:(ECG) that results in larger diameter Terfenol-D crystals and increased magnetostrictive performance. The reliability of magnetostrictive properties of the Terfenol-D throughout the life of the material is increased by using ET-Ryma.
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When composites of
Terfenol-D with ductile metal binders are created, the resulting material has increased stiffness and ductility with reduced magnetostrictive properties. These metal composites may be formed by explosion
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of the
Terfenol-D and how the FSZM process has no container to restrict the material. The MB process offers a minimum of 10 mm diameter size and is only restricted due to the wall interfering with the
108:. At its most pure form, it also has low ductility and a low fracture resistance. Terfenol-D is a gray alloy that has different possible ratios of its elemental components that always follow a formula of
230:(MB), are capable of producing Terfenol-D that has high magnetostrictive properties and energy densities. However, FSZM cannot produce a rod larger than 8 mm in diameter due to the
580:
Guruswamy, S.; Loveless, M.R.; Srisukhumbowornchai, N.; McCarter, M.K.; Teter, J.P. (2000). "Processing of
Terfenol-D alloy based magnetostrictive composites by dynamic compaction".
239:. Both methods create solid crystals that require later manufacturing if a geometry other than a right-angle cylinder is needed. The solid crystals produced have a fine
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Verhoeven, J. D.; Ostenson, J. E.; Gibson, E. D.; McMasters, O. D. (1989-07-15). "The effect of composition and magnetic heat treatment on the magnetostriction of Tb
155:. Magnetic heat treatment is shown to improve the magnetostrictive properties of Terfenol-D at low compressive stress for certain ratios of Tb and Dy.
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Due to size restriction, MB is the best process to produce
Terfenol-D, however it is a labor-intensive method. A newer process like MB is ET-Ryma
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96:, up to 0.002 m/m at saturation; it expands and contracts in a magnetic field. Terfenol-D has a large magnetostriction force, high
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drivers due to its high strain and high force properties. Similarly, magnetostrictive actuators have also been considered for use in
414:
Houqing, Zhu; Jianguo, Liu; Xiurong, Wang; Yanhong, Xing; Hongping, Zhang (1997-08-01). "Applications of
Terfenol-D in China".
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Due to its material properties, Terfenol-D is excellent for use in the manufacturing of low frequency, high powered
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in the United States. The technology for manufacturing the material efficiently was developed in the 1980s at
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Snodgrass, Jonathan D.; McMasters, O.D. (1997-08-01). "Optimized TERFENOL-D manufacturing processes".
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maximum of 200 °C. The composition of
Terfenol-D allows it to have a large magnetostriction and
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541:"Fabrication Methods for High-Performance Miniature Disks of Terfenol-D for Energy Harvesting"
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Issindou, Valentin; Viala, B.; Gimeno, L.; Cugat, O.; Rado, C.; Bouat, S. (2017-08-08).
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453:"Active Signal Technologies Terfenol-D Transducer and Actuator Designs"
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Bridgman, sintered powder compact, and polymer matrix composites.
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systems. It sees application in magnetomechanical sensors,
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is applied to it. This case exists for a large range of
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329:"Terfenol-D - ETREMA Products, Inc"
306:. Findarticles.com. Archived from
222:The first two methods, free stand
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302:Wheeler, Scott L. (2002-10-29).
503:Journal of Alloys and Compounds
416:Journal of Alloys and Compounds
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515:10.1016/S0925-8388(97)00067-4
428:10.1016/S0925-8388(97)00068-6
619:http://tdvib.com/terfenol-d/
582:IEEE Journals & Magazine
80:(NOL), and the D comes from
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558:10.3390/proceedings1040579
373:Journal of Applied Physics
371:twinned single crystals".
246:The other two techniques,
252:polymer matrix composites
78:Naval Ordnance Laboratory
62:Naval Ordnance Laboratory
457:www.activesignaltech.com
56: ≈ 0.3), is a
477:"Fuel Injector Patent"
16:Magnetostrictive alloy
226:(FSZM) and modified
165:underwater acoustics
149:compressive stresses
594:2000ITM....36.3219G
385:1989JAP....66..772V
250:powder compact and
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180:transducers
628:Categories
551:(4): 579.
482:2011-02-18
462:2018-12-09
338:2018-12-01
333:TdVib, LLC
314:2010-04-08
289:References
271:compaction
177:ultrasonic
136:dysprosium
82:dysprosium
20:Terfenol-D
567:2504-3900
523:0925-8388
436:0925-8388
401:0021-8979
173:actuators
283:Galfenol
277:See also
248:sintered
228:Bridgman
184:SoundBug
639:Terbium
590:Bibcode
381:Bibcode
256:density
190:). Its
143:when a
70:terbium
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188:FeONIC
100:, low
76:(Fe),
169:sonar
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24:alloy
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