114 results about "Magnetic shape-memory alloy" patented technology

In combination with a vehicle and a closure, one or more lockdown regions disposed between the closure and the vehicle body, the one or more lockdown includes a device including an active material disposed in operative communication with the closure and the vehicle body, wherein the active material includes a shape memory alloy, a magnetic shape memory material, a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or combinations comprising at least one of the foregoing active materials; and an activation device coupled to the active material, the activation device being operable to selectively provide an activation signal to the active material and effectuate a change in a dimension, a shape, and / or a flexural modulus property of the active material, wherein the change in the dimension, a shape, and / or flexural modulus of the active material locks down or releases the closure from the vehicle. Such active materials include shape memory alloys, magnetic shape memory alloys, electroactive polymers, shape memory polymers, magnetorheological fluids, magnetorheological elastomers, electrorheological fluids, and piezoelectric materials. Also provided herein are methods for selectively stiffening a closure hingeably attached to a vehicle body.

An active material hood impact mitigation mechanism is activated in response to a signal generated from an impact sensor or pre-impact sensor or manually. The mitigation mechanism is capable of changing either reversibly or irreversibly the stiffness, shape, location, orientation, or displacement force of the hood either globally or locally, before an impact against the hood. The active material mitigation mechanism is held in a device designed to be installed in operative communication with the hood surface. The active material is characterized by a first shape or stiffness and is operative to change to a second shape or stiffness in response to the activation signal. Such active materials include shape memory alloys, electroactive polymers, shape memory polymers, magnetic shape memory alloys, magnetorheological fluids, magnetorheological elastomers, electrorheological fluids, and piezoelectric materials.

An active material hood impact mitigation mechanism is activated in response to a signal generated from an impact sensor or pre-impact sensor or manually. The mitigation mechanism is capable of changing either reversibly or irreversibly the stiffness, shape, location, orientation, or displacement force of the hood either globally or locally, before an impact against the hood. The active material mitigation mechanism is held in a device designed to be installed in operative communication with the hood surface. The active material is characterized by a first shape or stiffness and is operative to change to a second shape or stiffness in response to the activation signal. Such active materials include shape memory alloys, electroactive polymers, shape memory polymers, magnetic shape memory alloys, magnetorheological fluids, magnetorheological elastomers, electrorheological fluids, and piezoelectric materials.

The invention discloses a magnetic shape memory alloy (MSMA) flexible actuator, which comprises a shell, wherein the upper end and the lower end of the shell are connected with an upper end cover and a lower end cover; an MSMA rod is positioned on a central shaft of the shell; magnetic conduction sheets are arranged at the two ends of the MSMA rod; a lower non-magnetic conduction base plate is arranged on the upper side of the lower end cover; an upper non-magnetic conduction base plate is arranged on the lower side of the upper end cover; the upper end of a lead-out rod is extended out of a central hole in the upper end cover; the space between the upper side of a middle step of the lead-out rod and the upper end cover as well as the space between the lower side of the middle step of thelead-out rod and the upper non-magnetic conduction base plate are provided with a disc spring respectively; a coil framework and a permanent magnet are arranged outside the MSMA rod sequentially; andan excitation coil is wound on the coil framework. In the actuator, the disc springs are used for applying prepressing force onto the MSMA rod, the length of the MSMA rod is changed along with the change of a magnetic field generated by the excitation coil and the permanent magnet, and corresponding displacement is output to the outside through the lead-out rod. The actuator has a simple structure, high frequency response, large strain, a wide using frequency band and low driving voltage.

The invention relates to a Ni-Mn-Ge magnetic shape memory alloy of which the chemical formula is NixMnyGezMa, wherein M is a main group element or transition group element; and 51<x<55, 31<y<40, 5<z<20, a<5, x+y+z+a=100, and x, y, z and a represent atomic percents. The alloy is a monocrystalline material or polycrystalline material. The main group element is In, Sn, Sb, As or Si; and the transition group element is Ti, Fe or Co. The magnetic material with magnetic shape memory effect has shape memory effect and ferromagnetic property, and appears the property of entropic change (magnetic card effect) caused by magnetic-field-driven phase change and magnetic order degree change, wherein the change value is up to S=8J / Kkg.

The invention discloses an electro-thermo-magnetic shape memory alloy and magnetorheological fluid composite centrifugal clutch. The clutch comprises a driving shaft, a driven shaft, a left end cover, a right end cover, an outer cylinder and a driven disc, wherein gaps between the driven disc and the left end cover and between the right end cover and the outer cylinder are filled with magnetorheological fluid; an excitation coil is arranged in two coil grooves respectively; a plurality of friction blocks are distributed on the driven disc and are connected with a push rod respectively; a shape memory alloy spring is arranged between the push rod and the bottom of a push rod groove; an electric brush slide ring sleeves the driven shaft; the excitation coil and the shape memory alloy spring pass through a wire hole and a blind hole through a connecting wire respectively and then are connected with the electric brush slide ring. Composite transmission of the shape memory alloy, the magnetorheological fluid and centrifugal force can be realized to improve the transfer torque of the clutch, so that the transfer efficiency of the clutch is improved.

Magnetic materials and methods exhibit large magnetic-field-induced deformation / strain (MFIS) through the magnetic-field-induced motion of crystallographic interfaces. The preferred materials are porous, polycrystalline composite structures of nodes connected by struts wherein the struts may be monocrystalline or polycrystalline. The materials are preferably made from magnetic shape memory alloy, including polycrystalline Ni—Mn—Ga, formed into an open-pore foam, for example, by space-holder technique. Removal of constraints that interfere with MFIS has been accomplished by introducing pores with sizes similar to grains, resulting in MFIS values of 0.12% in polycrystalline Ni—Mn—Ga foams, close to the best commercial magnetostrictive materials. Further removal of constraints has been accomplished by introducing pores smaller than the grain size, dramatically increasing MFIS to 2.0-8.7%. These strains, which remain stable over >200,000 cycles, are much larger than those of any polycrystalline, active material.

A magnetic materials construct and a method to produce the construct are disclosed. The construct exhibits large magnetic-field-induced deformation through the magnetic-field-induced motion of crystallographic interfaces. The construct is a porous, polycrystalline composite structure of nodes connected by struts wherein the struts may be monocrystalline or polycrystalline. If the struts are polycrystalline, they have a “bamboo” microstructure wherein the grain boundaries traverse the entire width of the strut. The material from which the construct is made is preferably a magnetic shape memory alloy, including polycrystalline Ni—Mn—Ga. The construct is preferably an open-pore foam. The foam is preferably produced with a space-holder technique. Space holders may be dissolvable ceramics and salts including NaAlO2.

In combination with a vehicle and a closure, one or more lockdown regions disposed between the closure and the vehicle body, the one or more lockdown regions comprising a device comprising an active material disposed in operative communication with the closure and the vehicle body, wherein the active material comprises a shape memory alloy, a magnetic shape memory material, a shape memory polymer, a magnetorheological fluid, an electroactive polymer, a magnetorheological elastomer, an electrorheological fluid, a piezoelectric material, or combinations comprising at least one of the foregoing active materials; and an activation device coupled to the active material, the activation device being operable to selectively provide an activation signal to the active material and effectuate a change in a dimension, a shape, and / or a flexural modulus property of the active material, wherein the change in the dimension, a shape, and / or flexural modulus of the active material locks down or releases the closure from the vehicle. Such active materials include shape memory alloys, magnetic shape memory alloys, electroactive polymers, shape memory polymers, magnetorheological fluids, magnetorheological elastomers, electrorheological fluids, and piezoelectric materials. Also disclosed herein are methods for selectively stiffening a closure hingeably attached to a vehicle body.

Actuator apparatus having a drive element (26) which can tilt and / or pivot in a predetermined manner in response to electrical activation and which is formed such that it can be contacted by an output partner in order to transmit mechanical drive energy, wherein the drive element, as a connection element, is operatively connected to two expansion units (10, 12; 40, 42), which are formed by means of magnetic shape-memory alloy material, such that the connection element executes a tilting and / or pivoting movement in response to an expansion or contraction movement of one of the expansion units, expansion or contraction movement being produced by the electrical activation and also a magnetic field which is generated by said electrical activation.

A damping and shock absorbing method and apparatus for permanent or non-permanent use in the human body and having a shape memory alloy material cycled through stress-strain hysteresis to dissipate energy for effective damping. A sufficiently high pre-stress is applied to the damping element(s) to ensure that the damping working range is within the superelastic cycle. The damping apparatus can work in tension or compression or both in tension and compression. Moreover, damping elements from a shape memory alloy can also work in flexion and extension as well in rotation. The damping apparatus can have a stroke and force suitable for use in the human body by the design, the structure and the chemical composition of the shape memory alloy and their pre-set properties, such as plateau stresses of the superelastic cycle depend on the ambient temperature, the force of damping elements can also be changed in-situ by changing the temperature of the damping elements. The damping elements made out of a shape memory alloy can be combined with elastic elements made out of other materials to achieve stress-strain behavior more suitable for use in the individual human body.

The invention relates to a magnetic shape memory alloy which comprises, in atomic percent, 45.4 parts of Ni, 41.5 parts of Mn, 11.1 parts of In and 2 parts of Gd. The breaking strength of the alloy is 2201MPa, and the martensite phase transition starting temperature of the alloy is 557 DEG C. The breaking strength of the prepared alloy, which is 2201MPa, is about 1820Mpa higher than that of an existing alloy comprising 45.4 parts of Ni, 41.4 parts of Mn, 13.1 parts of In and 0.1 part of Gd; the martensite phase transition starting temperature of the alloy, which is 557 DEG C, is about 200 DEG C higher than that of the existing alloy comprising 45.4 parts of Ni, 41.4 parts of Mn, 13.1 parts of In and 0.1 part of Gd, and the phase transition lag of the alloy is about 150 DEG C; and the breaking strain of the alloy is improved by 200% as compared with that of the existing alloy comprising 45.4 parts of Ni, 41.4 parts of Mn, 13.1 parts of In and 0.1 part of Gd. The prepared alloy comprising 45.4 parts of Ni, 41.5 parts of Mn, 11.1 parts of In and 2 parts of Gd is high in ductility.

A passive isolator mount capable of dissipating shocks and vibrations as either heat or magnetic energy is presented. The passive isolator includes a pair of L-shaped or C-shaped brackets capable of withstanding repeated deflections and strains, energy dissipating layers disposed along each bracket, and a bond layer. The energy dissipating layers are composed of a rare earth element or alloy, a ferromagnetic shape alloy, a magnetic shape memory alloy, a magnetostrictive alloy, a magneto-mechanical alloy, a super-elastic alloy, or a combination thereof. The bond layer is disposed between and adheres one energy dissipating layer along a first bracket to an energy dissipating layer along a second bracket so that the resultant passive isolator is C-shaped. Energy dissipating and bond layers completely bisect the passive isolator either widthwise through the thickness of the L-shaped brackets or lengthwise through the thickness of the C-shaped brackets.

The invention relates to a preparation method for a magnetic shape memory alloy, in particular to a preparation method for a high strength Ni50Mn34In16 magnetic memory alloy. The high strength Ni50Mn34In16 is prepared according to the following steps of material taking according to the atomic percent, mixing, forming, degreasing and sintering, and then the high strength Ni50Mn34In16 is obtained. The Ni50Mn34In16 alloy prepared by the method has higher fracture strength and fracture strain, the grain size of the magnetic shape memory alloy is tiny so as to drive the threshold value of a magnetic field to be reduced, the excellent magnetic property is achieved, and the train of thought is expanded for application of the high temperature and high plasticity shape memory alloy.

The invention relates to a toughening ferromagnetic shape memory alloy and a preparation method thereof. The toughening ferromagnetic shape memory alloy comprises the following chemical components in part by mol: 50 mol parts of Ni, 30 mol parts of Mn, (20-x) mol parts Ga and x mol parts Cu, wherein x is more than zero and is less than or equal to two; and the breaking strength of the alloy is between 800 and 820 MPa, and the magnetic entropy change Smag is -17.2 J / kg K. The preparation method comprises the following process steps: putting the Ni, the Mn, the Ga and the Cu in a vacuum nonconsumable electrode electric arc furnace in the set mol part ratio; under the protection of inert gases, performing electric arc smelting for 10 to 15 minutes at the temperature of between 1,500 and 1,700 DEG C, and cleaning smelted metal blocks by using acetone; and then putting the metal blocks in a quartz tube of which the vacuum degree is between 10 to 1 Pa for heat preservation for 5 hours at the temperature of 1,000 DEG C, and performing hardening to obtain the alloy. The alloy has the characteristics of high breaking strength, high magnetic entropy change and good toughness.

The invention relates to a preparing method of a magnetic shape memory alloy, in particular to a preparing method for a high-strength and high-plasticity Ni50Mn34In16-xCox magnetic memory alloy. Materials are taken according to the atomic percent, and mixing, forming, degreasing and sintering are carried out to obtain high-strength and high-plasticity Ni50Mn34In16-xCox (x is equal to 2,3,4,5). The prepared magnetic shape memory alloy Ni50Mn34In16-xCox (x is equal to 2,3,4,5) has the beneficial effects of being good in toughness, high in strength, thin and small in texture and the like. The method expands a thought for application of the high-temperature and high-plasticity shape memory alloy.

The invention relates to a method used for preparing Fe-Mn-Si magnetic shape memory alloy film. The invention is characterized in that the Fe-Mn-Si magnetic shape memory alloy film is made by a two-target common sputtering method of magnetron sputtering. The invention has a detailed process that an alloy with a Fe50Mn50 to Fe70Mn30 composition is adopted for preparing an alloy target with a 50 to 60mm diameter and a 1 to 5mm thickness; a single crystal silicon with a 50 to 60mm diameter and a 1mm thickness is selected as a single crystal silicon target; a pure copper sheet or glass is adopted as a substrate; the Fe-Mn alloy target and the single crystal silicon target are arranged to a position which is 50 cm apart from the substrate and forms a 60-degree angle with the substrate; when a sputtering back vacuum degree is less than 10 <-5>Pa, a 0.1 to 1.0Pa of Ar pneumatic pressure is preserved in the sputtering process; the two-target common sputtering method is used for sediment on the substrate to get an applicable Fe-Mn-Si film; when in sputtering, the power of FeMn alloy target is between 50 and 150W while that of the single crystal silicon target is between 20 and 80W.

The invention discloses a toughening magnetic shape memory alloy and a preparation method thereof. The preparation method comprises the following steps: putting 45.4 molar parts of Ni, (41.5-x) molar parts of Mn, 13.1 molar parts of In and x molar parts of Gd (x is more than zero and is less than or equal to two) in a vacuum nonconsumable electrode electric arc furnace performing electric arc smelting under the protection of inert gases at the temperature of between 1,500 and 1,700 DEG C for 10 to 15 minutes, and cleaning smelted metal blocks by using acetone; and then putting the metal blocks in a quartz tube of which the vacuum degree is between 10 to 1 Pa for heat preservation for 12 hours at the temperature of 900 DEG C, and performing hardening to obtain the toughening magnetic shape memory alloy Ni45.4 Mn41.5-xIn 13.1 Gdx. The breaking strength of the alloy is between 370 and 380 MPa; and compared with that of the traditional Ni-Mn-In alloy, the breaking strength of the alloy is improved by about 100 MPa; a driving magnetic field threshold is between 3.2 and 3.8 T, and compared with that of the traditional Ni-Mn-In alloy, the driving magnetic field threshold is reduced by 1.8 to 1.2 T; and the toughness of the alloy is improved obviously.

The invention provides a rare-earth magnetic material with high magnetocrystalline anisotropy and large magnetoelastic strain and a preparation method thereof. The material has high magnetocrystalline anisotropy, and can provide large magnetocrystalline anisotropy under the action of an external magnetic field, so that the material is subjected to twin crystal rearrangement under the martensite state, so as to generate large magnetoelastic strain. The chemical formula of the alloy is CoxNiyAlzErj, wherein x is smaller than or equal to 42 and greater than or equal to 28; y is smaller than or equal to 32 and greater than or equal to 25; z is smaller than or equal to 35 and greater than or equal to 23; j is smaller than or equal to 10 and greater than or equal to 0.5; x+y+z+j is 100; x, y, z and j represent the mole percentage content. Compared with the existing alloy, the high-temperature magnetic shape memory alloy CoxNiyAlzErj disclosed by the invention has high magnetocrystalline anisotropy, high magnetoelastic strain and good mechanical property, and has important application in the fields of an actuator, a magnetosensitive element and a miniature electromechanical system.

A valve for switching of media, such as liquids or gases, is opened, closed or put into an intermediate state by at least one actuator produced from a shape memory alloy. The at least one actuator, as a function of whether electricity is applied to it, acts on at least one valve ball or a valve plunger accommodated in a core element, so that the through-flow of a medium through a fluid part below the core element, with a media-tight membrane interposed between, is opened, interrupted or partially opened in regulated or controlled manner. The core element is produced from a mechanically rigid and thermally well-conductive material, has electrical conductor tracks for electrical connection of the actuator to a supply of electricity on the top side, as well as multiple threaded through-holes for underside connection with the fluid part and the membrane and / or for top-side connection with the actuator.

The present invention discloses a capacitance sensor-based strain test device of magnetic shape memory alloy. According to the device, micro-deformation such as magnetic-field-induced strain of the magnetic shape memory alloy is converted into the change of the area of the parallel polar plate of a parallel plate capacitor probe, and displacement amount is converted to change amount. With the device adopted, the technical problem that a strain existing test device is affected by the surrounding strong magnetic field of the magnetic shape memory alloy can be solved, and therefore, the detection accuracy of the strain test device of the invention can be improved. The capacitance sensor-based strain test device of the magnetic shape memory alloy of the invention includes a capacitance probe, a gear amplifying mechanism (10), an input mechanism (11) an output mechanism (9) and the like.

An actuator adaptable for tunable stiffness control is provided, including a stiffness element including a smart material, and a magnetically actuated biasing element. The biasing element is configured to provide a non-linear or variable bias force on the stiffness element. The smart material may be a shape memory alloy, and the biasing element may be configured to include a permanent magnet, an electromagnet, a magnetic shape memory alloy, or a combination of these. The stiffness element and the biasing element of the actuator may be configured in parallel with each other, or may be configured in series with each other. The bias force may be provided in response to an input defined by one or more of fatigue, functional degradation, aging, shakedown, elongation, and operating environment of the stiffness element of the actuator, or defined by an operating characteristic of the actuator or a device controlled by the actuator.

The invention relates to a high-temperature magnetic shape memory alloy and a preparation method thereof. The memory alloy contains chemical components in ratios of mole fraction as follows: 50 parts of Ga, 25 parts of Mn and 25 parts of Ni; martensite phase transformation temperature is 780K, and Curie temperature is 340K. The preparation method comprises the following steps: taking and putting 50 parts of Ga, 25 parts of Mn and 25 parts of Ni according to mole fraction into a vacuum nonconsumable electrode arc furnace, conducting arc melting for 10 to 15 minutes at the temperature of 1500 to 1700 DEG C under the protection of inert gas, and then using acetone to wash a smelted metal block; subsequently, putting the metal block in a quartz tube with vacuum degree of 10 to 1Pa to conduct heat preservation for 60 hours at the temperature of 650 DEG C, and then conducting hardening, thus obtaining the high-temperature magnetic shape memory alloy Ga2MnNi. Compared with the existing alloy Ni2MnGa, martensite phase transformation temperature of the high-temperature magnetic shape memory alloy is higher by 220K, and Curie temperature thereof is the same.

Actuator device having an expansion unit, which includes a magnetic shape memory alloy material, and a spring unit which interacts therewith in a restoring manner, wherein at least one spring of the spring unit is assigned to the expansion unit, which is designed to perform an expansion movement along an expansion direction, in such a way that the spring can exert a restoring spring force counter to the expansion direction on the expansion unit, and wherein the spring is set up and / or predetermined in its spring characteristic curve properties in such a way that a spring force profile of the spring unit along a stroke range, determined by an expansion force profile of the expansion unit and a restoring spring force profile, of the expansion movement does not form a continuously rising curve, and / or the spring force profile, with respect to a continuously rising curve, extends and / or increases the stroke range.

Apparatus and methods are disclosed that enable writing data on, and reading data of, multi-state elements having greater than two states. The elements may be made of magnetoplastic and / or magnetoelastic materials, including, for example, magnetic shape-memory alloy or other materials that couple magnetic and crystallographic states. The writing process is preferably conducted through the application of a magnetic field and / or a mechanical action. The reading process is preferably conducted through atomic-force microscopy, magnetic-force microscopy, spin-polarized electrons, magneto-optical Kerr effect, optical interferometry or other methods, or other methods / effects. The multifunctionality (crystallographic, magnetic, and shape states each representing a functionality) of the multi-state elements allows for simultaneous operations including read&write, sense&indicate, and sense&control. Embodiments of the invention may be used, for example, for storing, modifying, and accessing data for device, sensor, actuator, logic and memory applications. Embodiments may be particularly effective for non-volatile memory or other read&write, sense&indicate, and / or sense&control functions in computer or other applications; such simultaneous operation of two (or more) of said multiple functionalities open new pathways for miniaturization of devices.

The present invention relates to a method for producing magnetic shape memory alloy wherein the method includes surface treatment of the surface of the alloy. This invention relates also to an MSM device, for example an actuator, sensor or energy harvester including an actuating element produced using the method.

A system may include an actuation member having a first end and a second end. A length of the actuation member is greater than a width of the actuation member. The length extends from the first end to the second end along a longitudinal axis when the actuation member is undeformed. The actuation member may include a magnetic shape memory alloy. The system may further include an anchor retaining the first end of the actuation member. The second end of the actuation member may be free to move laterally to the longitudinal axis in response to a deformation of the actuation member. The system may also include a magnetic field source in proximity to the actuation member. The magnetic field source may be configurable to alter a magnetic field applied to the actuation member to adjust the extent of deformation of the actuation member.

The invention discloses magnesium-series magnetic shape memory alloy. The general formula of the magnesium-series magnetic shape memory alloy is Mg2YZ, Y is Ti or V, and Z is Al or Ga or In. The invention further discloses a method for predicting the structure and the property of the magnesium-series magnetic shape memory alloy. The method basically comprises the steps of A, calculating binding energy of a stoichiometric ratio system, pre-judging the existing probability of materials, and determining an initial cubic austenite structure and magnetic configuration; B, studying probable martensite phase transformation through cubic deformation; C, calculating the elastic constant and the phonon spectrum, and judging the stability. According to the magnesium-series magnetic shape memory alloy, a first-principle calculation method is adopted for studying the structure and the property of the magnesium-series alloy material from the scale of atoms, and the light alloy with the magnetic shape memory effect is discovered on the basis of thoroughly understanding the microcosmic essence of the alloy. The magnesium-series magnetic shape memory alloy has the advantages of being low in cost, short in period, good in repeatability and high in accuracy.