The present invention relates to a method of preparing an anisotropic complex sintered magnet having MnBi, that includes: (a) preparing a non-magnetic phase MnBi-based ribbon by a rapidly solidification process (RSP); (b) heat treating the non-magnetic phase MnBi-based ribbon to convert the non-magnetic phase MnBi-based ribbon into a magnetic phase MnBi-based ribbon; (c) grinding the magnetic phase MnBi-based ribbon to form a MnBi hard magnetic phase powder; (d) mixing the MnBi hard magnetic phase powder with a rare-earth hard magnetic phase powder; (e) magnetic field molding the mixture obtained in step (d) by applying an external magnetic field to form a molded article; and (f) sintering the molded article.

This patent invents a heat-resistant isotropic bonded NdFeB magnet and its preparation technology, belonging to the field of magnetic materials. In present invention, isotropic NdFeB magnetic powders is used as magnetic material, sodium silicate is used as principal binder, and epoxy resin is used as auxiliary binder to prepare heat-resistant isotropic bonded NdFeB magnets. The prepared magnets have greatly increased heat resistance to stand an operating temperature of 200 C., and have advantages of penetration and corrosion resistance. The invented heat-resistant isotropic bonded NdFeB magnets feature good magnetic properties and high operating temperature. During the preparation process, it has the advantage of simple equipment, easy operation, low cost. The technology is easy to large scale production, and has high economic value and huge application prospect in the field of permanent magnetic materials.

Disclosed is an R-T-BGa-based magnet material ahoy where R is at least one element selected from rare earth metals including Y and excluding Gd, Tb, Dy, Ho, Er, TM, Yb, and Lu, and Tis one or more transition metals with Fe being an essential element. The R-T-BGa-based magnet material alloy includes: an R.sub.2T.sub.14B phase 3 which is a principal phase, and an R-rich phase (1 and 2) which is a phase enriched with the R, wherein a non-crystalline phase 1 in the R-rich phase has a Ga content (mass %) that is higher than a Ga content (mass %) of a crystalline phase 2 in the R-rich phase. With this, it is possible to enhance the magnetic properties of rare earth magnets that are manufactured from the alloy and reduce variations in the magnetic properties thereof.

The present invention relates to an RFeB-based magnet in which a treatment (grain boundary diffusion treatment) for diffusing atoms of the heavy rare earth element R.sup.H is performed in a base material including an R.sup.LFeB-based sintered magnet obtained by subjecting crystal grains in a raw-material powder including a powder of an R.sup.LFeB-based alloy containing the light rare earth element R.sup.L, Fe and B to orientation in a magnetic field and then sintering the oriented raw-material powder, or an R.sup.LFeB-based hot-deformed magnet obtained by subjecting the same raw-material powder to hot pressing and then to hot deforming to thereby orient the crystal grains in the raw-material powder, and a method for producing the RFeB-based magnet.

A method for producing a sintered body includes: providing a raw material mixture containing oxide particles containing Ce, Al, Ga, optionally Sc, and a rare earth element R.sup.1 being at least one selected from the group consisting of Y, La, Gd, and Tb to obtain a target composition, wherein a total molar ratio of R.sup.1 and Ce is 3, and a molar ratio of Ce, a total molar ratio of Al, Ga, and Sc, a molar ratio of Al and a molar ratio of the Ga are as described in the disclosure; molding the raw material mixture to obtain a molded body; and calcining the molded body to obtain a sintered body containing a rare earth aluminate crystal phase and 2.7% by volume or more to 57.0% by volume or less of an aluminum oxide phase.

Provided is a surface treatment method of metal powder and surface passivated metal powder. Herein, the surface treatment method uses passivation solution to treat the metal powder, to form a passivation film on the surface of the metal powder; the passivation solution passes through the metal powder by a flowing method; and the average particle size of the metal powder is 0.1?100 ?m. A problem in the prior art that the metal powder is easily oxidized is solved, and it is suitable for the field of metal anti-oxidation.

An article includes a substrate comprising a precipitate-strengthened alloy and a coating disposed over the substrate. The alloy comprises a) a population of gamma-prime precipitates, the population having a multimodal size distribution with at least one mode corresponding to a size of less than about 100 nanometers; or b) a population of gamma-double-prime precipitates having a median size less than about 300 nanometers. The coating comprises at least two elements, and further comprises a plurality of prior particles. At least a portion of the coating is substantially free of rapid solidification artifacts. Methods for fabricating the article and for processing powder useful for fabricating the article are also provided.

The present invention relates to a method of manufacturing a light transmitting yttria member by using hot-press sintering. The present invention provides a method of manufacturing light transmitting yttria by performing hot-press sintering on a molded body made of raw material powder including yttria by using a hot-press sintering apparatus, in which the hot-press sintering is performed in a state in which a spacer is interposed between the molded body and a pressing surface of the molded body, and the spacer is made of heat-resistant metal which is substantially unreactive to the molded body at a sintering temperature. According to the present invention, it is possible to manufacture highly compacted light transmitting yttria having light transmittance of 80% by using a single hot-press sintering process.

A bond magnet molding is provided that contains coated magnetic particles having at least two layers of an oxide layer of 1-20 nm on a surface of magnetic particles and an organic layer of 1-100 nm on an outer side of the oxide layer. The bond magnet molding preferably includes a Zn alloy as a binder. The Zn alloy has a strain rate sensitivity exponent (m value) of not less than 0.3 and an elongation at break of not less than 50%. The magnet particles have a nitrogen compound containing Sm and Fe that are solidified using the binder at a temperature not higher than a molding temperature.

An article includes a substrate comprising a precipitate-strengthened alloy and a coating disposed over the substrate. The alloy comprises a) a population of gamma-prime precipitates, the population having a multimodal size distribution with at least one mode corresponding to a size of less than about 100 nanometers; or b) a population of gamma-double-prime precipitates having a median size less than about 300 nanometers. The coating comprises at least two elements, and further comprises a plurality of prior particles. At least a portion of the coating is substantially free of rapid solidification artifacts. Methods for fabricating the article and for processing powder useful for fabricating the article are also provided.