Magnetostrictive Materials

Magnetostrictive Materials

 

soft-magnetic materials that exhibit appreciable magnetostriction.

Magnetostrictive materials are used as converters of electromagnetic energy (for example, into mechanical energy), and for pressure transducers. Magnetostrictive materials include nickel and alloys such as Fe-Al (Alfer), Fe-Ni (Permalloy), Co-Ni, Fe-Co, and Co-Fe-V (Permendur); several ferrites (CoFe2O4 and NiFe2O4); and some rare earths and their alloys and compounds. Nickel has good magnetostrictive, mechanical, and anticorrosion properties. Permendur has large values of saturation magnetostriction Δs and magnetization. The ferrites have high specific electric resistivity and corrosion resistance; they are also the least expensive magnetostrictive materials.

Table 1 shows the initial and reversible magnetic permeability μa and μr, respectively, of magnetostrictive materials; the magnetostriction constant α = ((∂σ/∂β)ε>), which characterizes the dependence of mechanical strain on the magnetic induction B of the specimen under conditions of constant deformation €; the sensitivity β = (∂β/∂σ)h of magnetostrictive materials with respect to strain in a constant magnetic field H\ and the coefficient of gyromagnetic coupling k, which is essential for magnetostrictive ultrasonic emitters (the ratio of the mechanical energy, which was converted by the emitter, to the electromagnetic energy supplied).

Table 1. Main characteristics of most important magnetostrictive materials
 Composition
(% by mass)
μaμrimg0065img0066kλs × 106
Note: 1 dyne/(gauss-cm2) = 103 N/(T-m2); 1 (gauss-cm2)/dyne = 10-3 (T.m2)/ N
Nickel999 Ni2005016610.3035
Co-Ni18 Co, 82 Ni1,000200191270.35-25
Permendur49 Co 2 V; remainder Fe6008011830.3065
Iu14 (Alfer)14 Al, 86 Fe1,0002508650.2450
Ni-Co ferriteNiO0.98Co0.02.Fe2O3707020580.28-25

REFERENCES

Turichin, A. M. Elektricheskie izmereniia neelektricheskikh velichin, 4th ed. Moscow-Leningrad, 1966.
Gershgal, D. A., and V. M. Fridman. Urtrazvukovaia apparatura. Moscow-Leningrad, 1961.
Redkozeme’nye ferromagnetiki i antiferromagnetiki Moscow, 1965.
Table 1. Main characteristics of most important magnetostrictive materials
References in periodicals archive ?
These materials are composed of magnetostrictive materials, which convert magnetism to strain, and piezoelectric materials, which convert strain to voltage converting material.
Chen, Composite Magnetostrictive Materials for Advanced Automotive Magnetomechanical Sensors, Low Temperature Physics, 27, 266 (2001).
Giant magnetostrictive materials (GMM) are widely used in transducer, precision actuator, and active vibration [1-3] because of large magnetostrictive coefficient, excellent dynamic characteristic, and high energy density.
Grunwald, "Design and application of magnetostrictive materials," Materials & Design, vol.
Smart materials could be classified into many types: piezoelectric materials, shape memory alloys, magnetostrictive materials, thermoelectric materials, rheological fluids, and others.
Development has intensified in the past decade in parallel with advances in other smart materials like ionic polymers, magneto/electro-rhological fluids, magnetostrictive materials, and shape memory metallic alloys.
Piezoelectric ceramics such as lead zirconate titanate respond to electricity, shape-memory alloys like nitinol react to heat, while magnetostrictive materials are altered by magnetic fields.
By including, say, piezoelectric materials (which expand or contract in the presence of electric fields) or so-called magnetostrictive materials (which respond similarly but to magnetic fields), they hope to build autonomous space structures that can reconfigure themselves in response to factors such as age, wear or even the continuous thermal cycle of countless orbital treks in and out of sunlight.
Thermal analysis in piezoelectric and magnetostrictive materials using ATILA
MIT collaborated with NASA on the development of actuators based on super-conducting and magnetostrictive materials.
Materials * Piezoelectric materials * Electrostrictive materials * Magnetostrictive materials * Electrorheological materials * Magnetorheological materials * Thermoresponsive materials * pH-Sensitive materials * UV-Sensitive materials * Smart gels(hydrogels) * Smart catalysts * Shape memory alloys * Materials with unusual behaviors
Heat-activated shape memory alloys, such as nitinol, and magnetostrictive materials (Terfenol rare earths) can also be used, though the frequency bandwidths of these materials is limited.