Disclosed are a stirring process and a stirring system for a neodymium-iron-boron powder and a process for manufacturing a neodymium-iron-boron magnetic steel. The stirring process for the neodymium-iron-boron powder mainly comprises the following aeration, feeding and stirring. Specifically, the aeration refers to filling a mixer with nitrogen and/or an inert gas, with the internal space of the mixer closed; the feeding refers to placing a neodymium-iron-boron powder to be stirred into the mixer and keeping the internal space of the mixer closed; and the stirring refers to introducing the mixer with a pulsed air stream, which is an intermittently jetted air stream formed by nitrogen and/or an inert gas, and by which the neodymium-iron-boron powder can be repeatedly blown up and down to mix and stir the neodymium-iron-boron powder.

Disclosed are a stirring process and a stirring system for a neodymium-iron-boron powder and a process for manufacturing a neodymium-iron-boron magnetic steel. The stirring process for the neodymium-iron-boron powder mainly comprises the following aeration, feeding and stirring. Specifically, the aeration refers to filling a mixer with nitrogen and/or an inert gas, with the internal space of the mixer closed; the feeding refers to placing a neodymium-iron-boron powder to be stirred into the mixer and keeping the internal space of the mixer closed; and the stirring refers to introducing the mixer with a pulsed air stream, which is an intermittently jetted air stream formed by nitrogen and/or an inert gas, and by which the neodymium-iron-boron powder can be repeatedly blown up and down to mix and stir the neodymium-iron-boron powder.

Disclosed are a device and method for continuously performing grain boundary diffusion and heat treatment, characterized in that the alloy workpiece or the metal workpiece are arranged in a relatively independent processing box together with a diffusion source; the device comprises, in successive arrangement, a grain boundary diffusion chamber, a first cooling chamber, a heat treatment chamber, and a second cooling chamber, and a transfer system provided between various chambers for delivering the processing box; each of the first cooling chamber and the second cooling chamber uses an air cooling system, and the cooling air temperature of the first cooling chamber is above 25° C. and at least differs by 550° C. from the grain boundary diffusion temperature of the grain boundary diffusion chamber; the cooling air temperature of the second cooling chamber is above 25° C. and at least differs by 300° C. from the heat treatment temperature of the heat treatment chamber; and the cooling chamber has a pressure of 50 kPa to 100 kPa. The device provided by the present invention can increase the cooling rate and production efficiency, and improve product consistency.

Disclosed are a device and method for continuously performing grain boundary diffusion and heat treatment, characterized in that the alloy workpiece or the metal workpiece are arranged in a relatively independent processing box together with a diffusion source; the device comprises, in successive arrangement, a grain boundary diffusion chamber, a first cooling chamber, a heat treatment chamber, and a second cooling chamber, and a transfer system provided between various chambers for delivering the processing box; each of the first cooling chamber and the second cooling chamber uses an air cooling system, and the cooling air temperature of the first cooling chamber is above 25° C. and at least differs by 550° C. from the grain boundary diffusion temperature of the grain boundary diffusion chamber; the cooling air temperature of the second cooling chamber is above 25° C. and at least differs by 300° C. from the heat treatment temperature of the heat treatment chamber; and the cooling chamber has a pressure of 50 kPa to 100 kPa. The device provided by the present invention can increase the cooling rate and production efficiency, and improve product consistency.

An R-T-B-based permanent magnet which contains R that represents at least one rare earth element essentially including Tb or Dy, T that represents Fe or at least one iron-group element essentially including Fe and Co, and B that represents boron, and further contains Cu. The total content of R is 28.35 to 29.95% by mass, inclusive, the content of Cu is 0.05 to 0.40% by mass, inclusive, and the content of B is 0.93 to 1.00% by mass, inclusive. The distribution of the concentration of Tb or Dy decreases from the outside of the R-T-B-based permanent magnet toward the inside of the R-T-B-based permanent magnet.

Disclosed are a neodymium-iron-boron magnet material, a raw material composition, a preparation method therefor and a use thereof. The raw material composition of the neodymium-iron-boron magnet material comprises the following components by mass percentage: 29.5-32% of R′, wherein R′ is a rare earth element and includes Pr and Nd; and Pr≥17.15%; 0.25-1.05% of Ga; 0.9-1.2% of B; and 64-69% of Fe. Without adding a heavy rare earth element to the neodymium-iron-boron magnet material, the remanence and coercive force of the resulting neodymium-iron-boron magnet material are both relatively high.

A sintered Nd—Fe—B magnet comprising at least one light rare earth element having a weight content between 31 wt. % and 35 wt. %, at least one heavy rare earth element having a weight content of no more than 0.2 wt. %, B having a weight content between 0.95 wt. % and 1.2 wt. %, at least one additive including Ti and having a weight content between 1.31 wt. % and 7.2 wt. %, Fe as a balance, and impurities including C, O, and N. Ti has a weight content between 0.3 wt. % and 1 wt. % and forms a Titanium-Iron-Boron phase with Fe and Boron B and being present in the sintered Nd—Fe—B magnet between 0.86 vol. % and 2.85 vol. %. The C, O, and N satisfy 630 ppm≦1.2C+0.6O+N≦3680 ppm. The sintered Nd—Fe—B magnet has a squareness factor of at least 0.95.

A process for producing R-T-B-based rare earth magnet powder having excellent coercive force and high remanent flux density. A process for producing R-T-B-based rare earth magnet powder by HDDR treatment, in which a raw material alloy for the R-T-B-based rare earth magnet powder includes R (wherein R represents at least one rare earth element including Y), T (wherein T represents Fe, or Fe and Co) and B (wherein B represents boron), and has a composition including R in an amount of between 12.0 atom % and 17.0 atom %, and B in an amount of between 4.5 atom % and 7.5 atom %; the HDDR treatment includes a DR step including a preliminary evacuation step and a complete evacuation step; and a rate of pressure reduction caused by evacuation in the preliminary evacuation step is not less than 1 kPa/min and not more than 30 kPa/min.

The present invention provides a high-strength and high-plasticity titanium matrix composite and a preparation method thereof. The preparation method includes: preparing high-oxygen hydride-dehydride titanium powder using a high-temperature rotary ball grinding treatment process, in which the prepared hydride-dehydride titanium powder has a particle size of 10-40 μm, and has an oxygen content of 0.8-1.5 wt. %; preparing high-purity ultra-fine oxygen adsorbent powder using a wet grinding method of high-energy vibration ball grinding treatment process; in which a purity of the oxygen adsorbent powder is ≥99.9%, and a particle size of the oxygen adsorbent powder is ≤8 μm; mixing the high-oxygen hydride-dehydride titanium powder with the oxygen adsorbent powder in a protective atmosphere, and then press-forming the powder obtained after mixing to obtain a raw material blank; and performing atmosphere protective sintering treatment on the raw material blank to obtain a titanium matrix composite. The method prepares a titanium matrix composite reinforced by in-situ self-generating multi-scale Ca—Ti—O, TiC, TiB particles. The microstructure and grains are effectively refined, and the strength and plasticity of the material are significantly improved.

The present invention provides a high-strength and high-plasticity titanium matrix composite and a preparation method thereof. The preparation method includes: preparing high-oxygen hydride-dehydride titanium powder using a high-temperature rotary ball grinding treatment process, in which the prepared hydride-dehydride titanium powder has a particle size of 10-40 μm, and has an oxygen content of 0.8-1.5 wt. %; preparing high-purity ultra-fine oxygen adsorbent powder using a wet grinding method of high-energy vibration ball grinding treatment process; in which a purity of the oxygen adsorbent powder is ≥99.9%, and a particle size of the oxygen adsorbent powder is ≤8 μm; mixing the high-oxygen hydride-dehydride titanium powder with the oxygen adsorbent powder in a protective atmosphere, and then press-forming the powder obtained after mixing to obtain a raw material blank; and performing atmosphere protective sintering treatment on the raw material blank to obtain a titanium matrix composite. The method prepares a titanium matrix composite reinforced by in-situ self-generating multi-scale Ca—Ti—O, TiC, TiB particles. The microstructure and grains are effectively refined, and the strength and plasticity of the material are significantly improved.