An R-T-B based permanent magnet, in which R is a rare earth element, T is Fe or a combination of Fe and Co, and B is boron, includes main phase grains made of an R.sub.2T.sub.14B crystal phase and grain boundaries formed between the main phase grains. The grain boundaries include an R—O—C—N concentrated part having higher concentrations of R, O, C, and N than that of the main phase grains. The R—O—C—N concentrated part includes a heavy rare earth element. The R—O—C—N concentrated part has a core part and a shell part covering at least part of the core part. A concentration of the heavy rare earth element in the shell part is higher than a concentration of the heavy element in the core part. A covering ratio of the shell part with respect to the core part of the R—O—C—N concentrated part is 45% or more in average.

A method of preparing magnetic powder includes preparing iron powder by a reduction reaction of iron oxide; preparing magnetic powder by heat-treating a molded article prepared by pressure-molding a mixture containing the iron powder, neodymium oxide, boron and calcium at a pressure of 22 MPa or more; and coating an organic fluoride on a surface of the magnetic powder.

A method of preparing magnetic powder includes preparing iron powder by a reduction reaction of iron oxide; preparing magnetic powder by heat-treating a molded article prepared by pressure-molding a mixture containing the iron powder, neodymium oxide, boron and calcium at a pressure of 22 MPa or more; and coating an organic fluoride on a surface of the magnetic powder.

A hybrid method of surface hardening metallic components using a combination of chemical modification achieved through additive manufacturing and/or diffusion-based processing with transformation-based processing using a high energy density heat source. The hybrid process results in increased surface hardness and/or increased average case hardness and/or increased case depth compared to either treatment individually.

The disclosure relates to the technical field of sintered type NdFeB permanent magnets, in particular to a low-cost rare earth magnet and manufacturing method. There is provided a method of preparing a high-coercivity, sintered NdFeB magnet including cerium comprising the following steps:

(S1) Providing alloy flakes composed of R.sub.xT.sub.(1-x-y-z)B.sub.yM.sub.z;

(S2) Mixing the alloy flakes, a low melting point powder, and a lubricant, then subjecting the mixture to a hydrogen embrittlement process followed in this order by pulverizing the process product to an alloy powder by jet milling, magnetic field orientation molding of the alloy powder to obtain a blank, sintering and aging treatment the blank;

(S3) Coating a film composed of a diffusion source of formula R1.sub.xR2.sub.yH.sub.zM.sub.1-x-y-z on the sintered NdFeB magnet; and

(S4) Performing a diffusion heat treatment, followed by aging the sintered NdFeB magnet to obtain the low-cost rare earth magnet.

The disclosure relates to a method of preparing a low-heavy rare earth magnet comprising the following steps: S1, smelting and strip casting of the raw materials of a NdFeB alloy to obtain a NdFeB alloy sheets, and mechanically crushing the NdFeB alloy sheets into flaky alloy sheets; S2, mechanically mixing the flaky alloy sheets, a low melting point powder and a lubricant to obtain a mixture, followed by hydrogen absorption and dehydrogenation treatment of the mixture and jet milling of the product to obtain a NdFeB magnet powder; S3, pressing, forming and sintering the NdFeB magnet powder to obtain a sintered NdFeB magnet; S4, mechanically processing the sintered NdFeB magnet to a desired shape, and then forming a diffusion source film on the surface of the sintered NdFeB magnet; and S5, performing a diffusion process and aging to obtain the low-heavy rare earth magnet.

A cutting tool includes a substrate of cemented carbide including hard constituents in a metallic binder. The hard constituents includes WC and the WC content in the cemented carbide is 80-96 wt%. The cemented carbide has a Ni content of 2.5-13 wt%, a weight ratio of Fe / Ni < 1.5 and a weight ratio of Co / Ni < 0.825. The cutting tool includes a rake face, a flank face and a cutting edge there between, wherein the hardness H is measured with Vickers indentation and the crack resistance W is the ratio of the load to the total crack lengths of the cracks in the corners of said Vickers indentation. The product of the hardness at the rake face H(rake) and the crack resistance at the rake face W(rake) for the cutting tool is H(rake)*W(rake) > 2000 HV100*N/.Math.m.

A cutting tool includes a substrate of cemented carbide including hard constituents in a metallic binder. The hard constituents includes WC and the WC content in the cemented carbide is 80-96 wt%. The cemented carbide has a Ni content of 2.5-13 wt%, a weight ratio of Fe / Ni < 1.5 and a weight ratio of Co / Ni < 0.825. The cutting tool includes a rake face, a flank face and a cutting edge there between, wherein the hardness H is measured with Vickers indentation and the crack resistance W is the ratio of the load to the total crack lengths of the cracks in the corners of said Vickers indentation. The product of the hardness at the rake face H(rake) and the crack resistance at the rake face W(rake) for the cutting tool is H(rake)*W(rake) > 2000 HV100*N/.Math.m.

A coil component includes a body that is made of a composite material containing a resin material and metal powder, a coil conductor which is provided in the body and an end portion of which is exposed on an end face of the body, and a metal film that is provided on an outer surface of the body and that is electrically connected to the coil conductor on the end face in the outer surface. The outer surface of the body has a contact area that is in contact with the metal film. Multiple particles of the metal powder escape from the resin material and are in contact with each other in the contact area of the body.

A coil component includes a body that is made of a composite material containing a resin material and metal powder, a coil conductor which is provided in the body and an end portion of which is exposed on an end face of the body, and a metal film that is provided on an outer surface of the body and that is electrically connected to the coil conductor on the end face in the outer surface. The outer surface of the body has a contact area that is in contact with the metal film. Multiple particles of the metal powder escape from the resin material and are in contact with each other in the contact area of the body.