Magnetomechanical properties of epoxy-bonded Terfenol-D composites

Abstract

Eddy-current loss is the principal limitation to the use of Terfenol for high frequency applications. Polymer-bonded Terfenol composites, with reduced eddy current loss, aim to complement conventional Terfenol by broadening the useful range of application into the ultrasonic regime. The dependence of the static magnetomechanical properties of the composite material, on the composition parameters of particle size (Ps) and volume fraction of Terfenol (Vf) are investigated as functions of applied field and stress bias. At zero stress bias magnetisation (M) is independent of Ps and directly proportional to V f It is found that magnetostriction (λ) and differential strain coefficient (d) are both independent of V f and Ps, with saturation strains being higher then the values predicted from the simple dilution model. These higher than expected values are explained by particle connectivity within the microstructure. When stress-bias up to 20 MPa is applied to the material, the average increase in saturation strain is 28%. Normalised plots of λ versus M indicate that the magnetisation process within the material consists of both domain wall motion and rotatio

Effect of the elastic modulus of the matrix on the coupling of magnetostrictive composites

“…Hence (4): (4) Since the matrix phase is nonmagnetic, the permeability varies as a simple dilution function with . Fig.…”

Control of laminated composite plates using magnetostrictive layers

“…Although there have been important research efforts devoted to characterizing the properties of Terfelon-D material, fundamental information about variation in elasto-magnetic material properties is not available. A few studies [12][13][14][15] report experimental evidence for a significant variation in material properties such as Young's modulus and magneto-mechanical coupling coefficients.…”

Dynamic magnetomechanical properties of Terfenol-D/epoxy pseudo 1-3 composites

“…Numerous studies have been conducted on two types of composites: namely, pseudo 1-3 composites ͑i.e., aligning Terfenol-D particles in a polymer matrix͒ and 0-3 composites ͑i.e., dispersing particles in the matrix͒. [1][2][3][4][5][6] In fact the early work undertaken by researchers aimed at maximizing the quasistatic ͑Ͻ10 Hz͒ strains through the optimization of composition parameters and the fabrication process. The dynamic behavior ͑i.e., frequency response data͒ of these materials remained unexplored until the early 2000s even though the critical concern has been to introduce the materials into high-frequency applications.…”