245results about "Magnetostrictive material selection" patented technology

A method for producing an RE-containing alloy represented by formula R(T_1−xA_x)13_−y (wherein R represents Ce, etc.; T represents Fe, etc.; and A represents Al, etc; 0.05≦x≦0.2; and −1≦y≦1) including a melting step of melting alloy raw materials at 1,200 to 1,800° C.; and a solidification step of rapidly quenching the molten metal produced through the above step, to thereby form the first RE-containing alloy, wherein the solidification step is performed at a cooling rate of 10² to 10⁴° C./second, as measured at least within a range of the temperature of the molten metal to 900° C.; and an RE-containing alloy, which is represented by a compositional formula of R_rT_tA_a(wherein R and A represent the same meaning as above, T represents Fe, etc.; 5.0 at. %≦r≦6.8 at. %, 73.8 at. %≦t≦88.7 at. %, and 4.6 at. %≦a≦19.4 at. %) and has an alloy microstructure containing an NaZn_13-type crystal structure in an amount of at least 85 mass % and α-Fe in an amount of 5-15 mass % inclusive.

A positive magnetostrictive material such as a ferromagnetic alloy is subjected to a magnetic field during annealing treatment while being heated for a predetermined period of time at an elevated temperature below its softening temperature followed by cooling resulting in a treated ferromagnetic material having high tensile strength and positive magnetostriction properties for enhancing use thereof under tensile loading conditions. Such treatment of the ferromagnetic alloy may be augmented by application thereto of a compressive stress.

A magnetostrictive element for use in a magneto-mechanical marker has a resonant frequency characteristic that is at a minimum at a bias field level corresponding to the operating point of the magnetomechanical marker. The magnetostrictive element has a magnetomechanical coupling factor k in the range 0.28 to 0.4 at the operating point. The magnetostrictive element is formed by applying cross-field annealing to an iron-rich amorphous metal alloy ribbon (45 to 82 percent iron) which includes a total of from 2 to 17 percent of one or more of Mn, Mo, Nb, Cr, Hf, Zr, Ta, V. Cobalt, nickel, boron, silicon and/or carbon may also be included. The metal alloy may include one early transition element selected from the group consisting of Zr, Hf and Ta, and also a second early transition element selected from the group consisting of Mn, Mo, Nb, Cr, and V.

The present invention is aimed at enabling a spin-transfer magnetization switching in the random access magnetic memory by reducing a switching current density in the spin-transfer magnetization switching to an order smaller than 10 MA/cm² and without causing breakdowns neither in the memory element which uses a TMR film nor in the element selection FET. The memory layer in the magnetoresistance effect element comprises a magnetic film having a value of saturation magnetization in a range from 400 kA/m to 800 kA/m. The memory layer comprises a magnetic film which contains one or more magnetic elements selected from the group of, for example, cobalt, iron and nickel, and which further contains a non-magnetic element. The non-magnetic element is contained at a ratio of, for example, 5 at % or more and less than 50 at %. A memory layer 12 in the memory cell has a dimension less than 200 nmφ.

The invention relates to a FeGa-RE magnetostrictive material and manufacturing technique. The characteristics of magnetostrictive material are that: the ingredient of material consists of Fe, Ga and RE, the content of Ga is 10-40at%, the content of RE is 0.01-20at%, the content of additional intermingle is: C=200-600ppm,N=200-600ppm,O=200-700ppm,other is Fe, the optimal value of Ga is 12-28at%, FeGa-RE magnetostrictive material, the ingredient of material adds one or more kinds of La, Ce, Pr, Nd, Tb, Dy whose content is 0.01-20at%. The manufacturing technique includes the alloy with purified material is cast as the needed round bar, and the alloy bar is crystallized by high temperature gradient flash freezing method and Bridgman method.

A method of making a magnetorestrictive sensor involves the deposition of a magnetorestrictive strip over a substrate, the deposition of an insulating layer over the magnetorestrictive strip, the etching of barber pole windows through the insulating layer, the deposition of a conductive material over the insulating layer and into the barber windows, and the etching away of the conductive material between the barber pole windows so as to form barber poles. In this manner, the formation of the barber poles is controlled by the windows formed in the insulating layer.

A membrane actuator includes a magnetically actuatable membrane and a magnetic trigger. The membrane includes a shape memory alloy (SMA), and the magnetic trigger is configured to induce a martensitic transformation in the SMA, to produce a larger force than would be achievable with non-SMA-based materials. Such a membrane actuator can be beneficially incorporated into a wide variety of devices, including fluid pumps, shock absorbing systems, and synthetic jet producing devices for use in an aircraft. The membrane/diaphragm can be formed from a ferromagnetic SMA, or a ferromagnetic material can be coupled with an SMA such that the SMA and the ferromagnetic material move together. A hybrid magnetic trigger, including a permanent magnet and an electromagnet, is preferably used for the magnetic trigger, as hybrid magnetic triggers are easy to control, and produce larger magnetic gradients than permanent magnets or electromagnets alone.

Textured ceramic compositions having improved piezoelectric characteristics as compared with their random counterparts are provided. Methods of making the compositions and devices using them are also included. More particularly, compositions comprising textured ceramic Na_0.5Bi_0.5TiO₃—BaTiO₃(NBT-BT) materials synthesized from high aspect ratio NBT seeds exhibit improved characteristics, including an increased longitudinal piezoelectric constant (d₃₃) and magnetoelectric coupling coefficient over randomly oriented NBT-BT. Additionally provided are compositions comprising of nanostructured Na_0.5B_0.5TiO₃—BaTiO₃ ferroelectric whiskers having a high aspect ratio. Nanostructured whiskers can be used to improve the piezoelectric properties of the bulk ceramics. The inventive materials are useful in microelectronic devices, with some finding particular application as multilayer actuators and transducers.

[Object] A bulk material which is suitably used as a material for actuator and sensor elements is formed from a Fe—Ga base magnetoresistive alloy and a Ti—Ni base shape memory alloy taking advantage of crystal miniaturization and anisotropy as well as reduction of precipitates (equilibrium state in state diagram) and non-equilibrium phases peculiar to liquid rapidly solidified materials, and the performance of the material is enhanced by a production method thereof which has cost advantage over a melt method.

[Construction] A rapidly solidified material having a particular rapidly solidified texture of a Fe—Ga magnetostrictive alloy or a TiNi-based shape-memory alloy and properties derived therefrom is formed into slices which are laminated to each other in a die, or is formed into a powder or chops which are filled in the die. Subsequently, spark plasma sintering is performed so that bonds between the slices, grains of the powder, or the chops are formed at a high density to form a bulk alloy, followed by annealing whenever necessary, so that the properties of the alloy are improved.

The invention relates to a Fe-Ga group magnetostriction wire and material composition thereof is Fe1-x-yGaxMy, wherein, M is tantalum of transition group except for Fe and one or a plurality of Be, B, Al, In, Si, Ge, Sn, Pb, Sb, Bi, N, S and Se; x is equal to 5-30at percent and y is equal to 0-15at percent and the allowance is Fe; diameter d is 0.1-5mm. A device adopts the Fe-Ga group magnetostriction wire is also disclosed.

A giant-magnetostrictive material is (Tb1-x-yDyxRy)(Fe1-z-pBe2Mp)g, where R is chosen from Ho, Er, Pr and Nd, M is chosen from Ti, V, Cr, Co, Ni, Mn, Si, Ga and Al, x=0.65-0.80, y=0-0.15, and g=1.75-2.55. Its preparing process includes smelting mother alloy in Ar atmosphere in vacuum furnace, growing oriented crystallizing material in vacuum or inert gas, and heat treating in vacuum furnace. Its advantages are high magnetostrictive strain ratio, good low-field performance, and low cost.

A variable inductor type MEMS pressure sensor using a magnetostrictive effect comprises an inductor array unit and a capacitor unit. The inductor array unit includes a coil unit having a plurality of serially connected circular electrodes formed on a first substrate and a magnetostrictive material thin film corresponding one by one to the circular electrode formed on a second substrate opposite to the first substrate at a predetermined distance in parallel to form an inductor which has the magnetostrictive material thin film as a core of the coil unit for inducing change of magnetic permeability of the magnetostrictive thin film depending on external pressure to vary inductance of the inductor. The capacitor unit constitutes a LC resonant circuit with the inductor array unit to convert magnetic energy discharged in the inductor array unit into a voltage. The variable inductor type MEMS pressure sensor has an excellent resolution because it is more sensitive than a conventional piezoresistive or capacitance sensor, and is manufactured using a MEMS process technology exchangeable with a semiconductor process, thereby enabling miniaturization and a mass package process to reduce the cost of production.

The invention discloses a <, a 100>, an axial orientation Fe-Ga magnetostriction material and the preparation method thereof. The material composites are Fe1-x-yGaxAly; wherein, x is between 16 per cent and 21 per cent or 25 per cent and 28 per cent; y is between 0 per cent and 10 per cent; the rest part is iron. The preparation method is that the raw material is melted under the protection of the inert gas, and the improved percy williams bridgman method is adopted to prepare the Fe-Ga magnetostriction material through the directional solidification; The heat treatment conditions are that the material is preserved at 1100 DEG C. to 1200 DEG C. for 0.5 hours to 24 hours, cooled with the furnace till 900 DEG C. to 750 DEG C. for 0.5 hours to 24 hours temperature preservation and then quenched or cooled by air to room temperature; or the material is preserved at 1100 DEG C. to 1200 DEG C. temperature for 0.5 hours to 24 hours and is cooled with the furnace till 500 to 700 DEG C..

The magnetic field heating treatment to improve magnetically driven reversible strain property of polycrystalline Ni2MnGa includes the following steps: preparing Ni2MnGa alloy in nonstoichiometeric ratio with Ni content of 50.3-53.0 at% and Mn/Ga ratio 1.05-1.15; electric arc smelting with high purity element Ni, Mn and Ga material under Ar protection to produce polycrystalline ingot; homogenizing annealing treatment of the polycrystalline ingot at 1100-1200 K for 1-3 days; heat treatment in magnetic field of strength H 0.7T, temperature 240-350 K or 360-460 K for 20-30 min and final air cooling or water quenching. The said process of the present invention raises the magnetically driven reversible strain amount of polycrystalline Ni2MnGa by about 17 %.

The invention relates to a high-performance polycrystalline texture Fe-Ga-based magnetostrictive thin material and a preparation method thereof; the component of the material is Fe100-x-y-zGaxMyNz; M stands for one or more among B, Nb, Cr, VC, TiC, MnS and AlN; N stands for one or more among S, Sb and Sn; wherein, x is equal to 15-25; y is equal to 0.5-3.0; z is equal to 0.01-0.05; and the residual is iron. The method has the following process key points: based on the requirements of the material composition, melting master alloy; casting alloy ingot; hot-forging and cogging; rolling the material into the appropriate thickness; and a variety of follow-up heat treatment. The Fe-Ga-based magnetostrictive thin material has obvious (100)<001>cubic texture or (110) <001> goss texture; and the maximum magnetostriction coefficient (3/2)lambdas is up to 280 multiplying 10<-6>.