A method for preparing a rare earth anisotropic bonded magnetic powder, comprises the following steps: (1) preparing raw powder with RTBH as the main component, wherein, R is Nd or Pr/Nd, and T is a transition metal containing Fe; (2) adding La/Ce hydride and copper powder to the raw powder to form a mixture; (3) subjecting the mixture to atmosphere diffusion heat treatment to give the rare earth anisotropic bonded magnetic powder. The invention selects high-abundance rare earth elements La, Ce to replace Dy, Tb, Nd, Pr and other medium and heavy rare earth elements, which can achieve the same coercivity improvement effect while also significantly reducing the cost, thereby achieving efficient application of low-cost and high-abundance rare earths.

The invention discloses an anisotropic bonded magnetic powder and a preparation method thereof. The anisotropic bonded magnetic powder has a general formula of R.sub.1R.sub.2TB, wherein R.sub.1 is a rare earth element containing Nd or PrNd, R.sub.2 is one or two of La and Ce, T is a transitional element, and B is boron. The preparation method includes the steps of smelting the master alloy to prepare ingot(s), preparing a rare earth hydride of formula R.sub.1TBH.sub.X, preparing a hydride diffusion source of formula R.sub.1R.sub.2TH.sub.X, mixing, heat treating, and high-vacuum dehydrogenating, to obtain the anisotropic bonded magnetic powder. The invention uses La and Ce hydrides as the diffusion source, can save cost, remove hydrogen from the diffusion source at a lower dehydrogenation temperature, avoid crystal grain growth at a high temperature, and ensure the quality of the product.

The invention discloses a composite rare earth anisotropic bonded magnet and a preparation method thereof. The composite rare earth anisotropic bonded magnet comprises a Nd—Fe—B magnetic powder, a Sm—Fe—N magnetic powder, a binder and an inorganic nano-dispersant. The preparation method comprises steps of preparing a Nd—Fe—B magnetic powder by a HDDR method, preparing a Sm—Fe—N magnetic powder by a powder metallurgy method, mixing the Nd—Fe—B magnetic powder, the Sm—Fe—N magnetic powder, the binder and the inorganic nano-dispersant at a specific ratio to finally obtain the composite rare earth anisotropic bonded magnet. The invention, by adding an inorganic nano-dispersant, enables the full dispersion of the fine Sm—Fe—N powder during the mixing process of the binder, the Nd—Fe—B magnetic powder and the Sm—Fe—N powder, and thus makes the fine Sm—Fe—N powder and the binder evenly coated on the surface of the anisotropic Nd—Fe—B magnetic powder.

The present disclosure provides a method of producing a magnetic powder capable of providing a bonded magnet having a high remanence. The present disclosure relates to a method of producing a magnetic powder, including: 1) mixing an alkyl silicate with an acidic solution; 2) mixing the resultant alkyl silicate mixture with a SmFeLaN anisotropic magnetic powder; and 3) mixing the resultant magnetic powder mixture with an alkali solution.

The present invention relates to an alloy with composition of RE-Fe-M-B as defined herein, wherein said alloy comprises at least 80 vol % RE.sub.2Fe.sub.14B phase, the average crystal grain size of the RE.sub.2Fe.sub.14B phase is in the range of about 20 nm to about 40 nm, and the alloy is an alloy ribbon having a width measured from a left edge to a center portion to a right edge, and the average crystal RE.sub.2Fe.sub.14B grain size difference between the center portion, and left and right edges of said alloy ribbon is less than 20%. The present invention also relates to a method for preparing an alloy ribbon with composition of RE-Fe-M-B as defined herein comprising the steps of: (i) ejecting a melt of the alloy with composition of RE-Fe-M-B onto a rotating wheel at a mass flow rate of about 0.2 kg/min to about 1.0 kg/min; and (ii) quenching the melt using the rotating wheel to obtain said alloy ribbon

An alloy material, a bonded magnet, and a modification method of a rare-earth permanent magnetic powder are provided by the present application. A melting point of the alloy material is lower than 600 C. and a composition of the alloy material by an atomic part is RE.sub.100-x-yM.sub.xN.sub.y, wherein RE is one or more of non-heavy rare-earth Nd, Pr, Sm, La and Ce, M is one or more of Cu, Al, Zn and Mg, N is one or more of Ga, In and Sn, x=10-35 and y=1-15.

A physical unclonable function (PUF) apparatus having magnetic particles is disclosed. The magnetic field data and the image view of the magnetic particles in the PUF apparatus are difficult to counterfeit. A PUF apparatus may be incorporated into a user-replaceable supply item for an imaging device. Further, a PUF reader may be incorporated into an imaging device to read the PUF. Other systems are disclosed.

A method for producing magnet-polymer pellets useful as a feedstock in an additive manufacturing process, comprising: (i) blending thermoplastic polymer and hard magnetic particles; (ii) feeding the blended magnet-polymer mixture into a pre-feed hopper that feeds directly into an inlet of a temperature-controlled barrel extruder; (iii) feeding the blended magnet-polymer mixture into the barrel extruder at a fixed feed rate of 5-20 kg/hour, wherein the temperature at the outlet is at least to no more than 10 C. above a glass transition temperature of the blended magnet-polymer mixture; (iv) feeding the blended magnet-polymer mixture directly into an extruding die; (v) passing the blended magnet-polymer mixture through the extruding die at a fixed speed; and (vi) cutting the magnet-polymer mixture at regular intervals as the mixture exits the extruding die at the fixed speed. The use of the pellets as feed material in an additive manufacturing process is also described.

A responsive material having an elastomeric matrix in which ferromagnetic particles are dispersed so as to have a predetermined magnetization pattern which, when exposed to an external magnetic field, changes the shape of the responsive material from an initial shape to a predetermined transformed shape dictated by the magnetization pattern. An initial shape of the responsive material is formed by direct ink printing while applying magnetic fields to a dispensing nozzle to align the particles and gives rise to the desired magnetization pattern.

A rare earth bonded magnet comprises a rare earth-iron-based magnetic powder and a thermosetting resin composition. The thermosetting resin composition is obtained by blending a dicyclopentadiene type epoxy resin as a base resin and dicyandiamide as a curing agent. The dicyclopentadiene type epoxy resin includes a predetermined structure wherein an average value of a repeating unit n is 1 to 3.