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R-t-b-based sintered magnet

A R-T-B, sintered magnet technology, applied in the direction of magnetic objects, magnetic materials, inorganic materials, etc., can solve the problems of price fluctuation and supply instability

Active Publication Date: 2015-11-18
HITACHI METALS LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Because Dy is restricted by the place of production and other reasons, there are problems such as unstable supply and price fluctuations.

Method used

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Examples

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Embodiment

[0072] The present invention will be described in more detail through examples, but the present invention is not limited thereto.

[0073] Using Nd with a purity of more than 99.5% by mass, electrolytic iron, electrolytic Co, Al, Cu, Ga, and iron-boron alloys, the composition of the sintered magnet is formulated according to the components shown in Table 1, the above raw materials are smelted, and according to the belt The casting method is used for casting to obtain a flake-shaped alloy with a thickness of 0.2-0.4 mm. The obtained flaky alloy was subjected to hydrogen embrittlement in a hydrogen pressurized atmosphere, and then subjected to a dehydrogenation treatment in which it was heated to 550° C. in a vacuum and cooled to obtain a coarsely pulverized powder. Next, 0.04% by mass of zinc stearate as a lubricant was added to the obtained coarsely pulverized powder with respect to 100% by mass of the coarsely pulverized powder, and after mixing, the powder was crushed in a s...

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Abstract

The present invention provides an R-T-B-based sintered magnet that is high in Br and HcJ without using Dy. The R-T-B-based sintered magnet has a Nd2Fe14B-type compound as a main phase, and includes the main phase, a first grain boundary present between two main phases, and a second grain boundary present between three or more main phases, the R-T-B-based sintered magnet comprising 29.0 to 31.5 mass% R, 0.86 to 0.90 mass% B, 0.4 to 0.6 mass% Ga, and 0.5 mass% or less of Al (including 0 mass%), the balance being made up of T and unavoidable impurities.

Description

technical field [0001] The present invention relates to R-T-B series sintered magnets. Background technique [0002] As the magnet with the highest performance among permanent magnets, it is known that Nd 2 Fe 14 R-T-B system sintered magnets (R is at least one of the rare earth elements, and must contain Nd; T is a transition metal element, and must contain Fe) in which the B-type compound is the main phase, which is used for hybrid vehicles and electric vehicles. Various generators for home appliances, etc. [0003] However, under high temperature conditions, the coercivity H of the R-T-B sintered magnet cJ (Hereinafter, it is sometimes abbreviated as "H cJ ”) is reduced, resulting in irreversible thermal demagnetization. Therefore, especially when it is used in generators for hybrid vehicles and electric vehicles, it is required to maintain a high H at high temperature cJ . [0004] All along, in order to improve the H cJ , a large amount of heavy rare earth elemen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/08C22C38/00H01F1/057H01F41/02B22F9/04C22C33/02
CPCC22C38/00C22C33/02C22C38/002C22C38/005C22C38/06C22C38/10C22C38/16C22C2202/02H01F1/0577H01F1/086
Inventor 国吉太石井伦太郎西内武司川田常宏
Owner HITACHI METALS LTD