A method includes depositing a layer of alloy particles including rare earth permanent magnet phase above a substrate, laser scanning the layer while cooling the substrate to melt the particles, selectively initiate crystal nucleation, and promote columnar grain growth in a same direction as an easy axis of the rare earth permanent magnet phase. The method also includes repeating the depositing and scanning to form bulk anisotropic rare earth alloy magnet with aligned columnar grains.

A rare earth sintered magnet is prepared by a method comprising the steps of melting raw materials to form an alloy, pulverizing the alloy into a fine powder, shaping the fine powder into a compact, and sintering the compact. The pulverizing step includes a coarse pulverizing step including hydrogen decrepitation and a fine pulverizing step, and further includes the step of adding a lubricant. The sintering step includes an atmosphere heat treatment including heating the compact at a temperature from the lubricant decomposition temperature to the sintering temperature and holding at the temperature for a time, in an inert gas atmosphere, and a vacuum heat treatment. The sintered magnet has a low impurity concentration and a narrow carbon concentration distribution.

When a slurry s obtained by dispersing a rare-earth-compound powder in a solvent is applied to sintered magnet bodies m, and dried to remove the solvent in the slurry and cause the surfaces of the sintered magnet bodies to be coated with the powder, and the sintered magnet bodies coated with the powder are heat treated to cause the rare-earth element to be absorbed by the sintered magnet bodies, the sintered magnet bodies m are warmed or heated before the slurry s is applied. As a result, the rare-earth-compound powder can be efficiently and uniformly applied to the surfaces of the sintered magnet bodies.

When a slurry s obtained by dispersing a rare-earth-compound powder in a solvent is applied to sintered magnet bodies m, and dried to remove the solvent in the slurry and cause the surfaces of the sintered magnet bodies to be coated with the powder, and the sintered magnet bodies coated with the powder are heat treated to cause the rare-earth element to be absorbed by the sintered magnet bodies, the sintered magnet bodies m are warmed or heated before the slurry s is applied. As a result, the rare-earth-compound powder can be efficiently and uniformly applied to the surfaces of the sintered magnet bodies.

A magnetic polishing slurry for polishing a workpiece includes magnetic particles coated with a modifying material, a liquid carrier, and abrasives. The modifying material has a hardness lower than that of the workpiece.

A magnetic polishing slurry for polishing a workpiece includes magnetic particles coated with a modifying material, a liquid carrier, and abrasives. The modifying material has a hardness lower than that of the workpiece.

The present disclosure relates to a method for preparing high-performance sintered NdFeB magnets. The method comprises the steps of: a) attaching a multi-element alloy powder onto a surface of the sintered NdFeB magnet, wherein the multi-element alloy is of formula (1) Pr.sub.aRH.sub.bGa.sub.cCu.sub.d (1) with RH being at least one element selected from Dy and Tb and a, b, c, and d satisfying the conditions 0.30≤(a+b)/(a+b+c+d)≤0.65, 0.20≤d/(c+d)≤0.50, and 0.23≤b/(a+b)≤0.60; and b) performing a diffusion process.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.

A sintered R.sub.2M.sub.17 magnet is provided that comprises at least 70 Vol % of a Sm.sub.2M.sub.17 phase, wherein R is at least one of the group consisting of Ce, La, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm,

Yt, Lu and Y, and M comprises Co, Fe, Cu and Zr. In an area of the R.sub.2M.sub.17 sintered magnet of 200 by 200 μm viewed in a Kerr micrograph, an areal proportion of demagnetised regions after application of an internal opposing field of 1200 kA/m is less than 5% or less than 2%.

The present disclosure provides a method for manufacturing a multi-main-phase structure magnet having excellent coercive force and a multi-main-phase structure magnet manufactured therefrom.