Alloy material, bonded magnet, and modification method of rare-earth permanent magnetic powder

Patent metadata

Field	Value
Publication number	US-10811175-B2
Application number	US-201715796153-A
Country	US
Kind code	B2
Filing date	Oct 27, 2017
Priority date	Dec 22, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

An alloy material, a bonded magnet, and a modification method of a rare-earth permanent magnetic powder are provided by the present application. A melting point of the alloy material is lower than 600° C. and a composition of the alloy material by an atomic part is RE100-x-yMxNy, wherein RE is one or more of non-heavy rare-earth Nd, Pr, Sm, La and Ce, M is one or more of Cu, Al, Zn and Mg, N is one or more of Ga, In and Sn, x=10-35 and y=1-15.

First claim

What is claimed is:

1. A modification method of a rare-earth permanent magnetic powder, wherein the modification method comprising:
step S1, mixing an alloy material with a rare-earth permanent magnetic powder to obtain a mixed powder, wherein a mass proportion of the alloy material in the mixed powder is 1-10%, a melting point of the alloy material is lower than 600° C. and a composition of the alloy material by an atomic part is RE100-x-yMxNy, wherein RE is one or more of non-heavy rare-earth Nd, Pr, Sm, La and Ce, M is one or more of Cu, Al, Zn and Mg, N is one or more of Ga, In and Sn, x=10-35 and y=1-15, the alloy material is an alloy powder; and
step S2, in a first inert atmosphere or a vacuum state, performing a heat treatment on the mixed powder to obtain a modified rare-earth permanent magnetic powder
the step S2 comprises:
step S21, in the first inert atmosphere or the vacuum state, heating the mixed powder for 5-30 min at 675-900° C. to obtain a pretreated powder; and
step S22, heating the pretreated powder for 2-12 h at 500-600° C. to obtain the modified rare-earth permanent magnetic powder, before the step S21, the step S2 further comprises: heating at a heating rate not less than 15° C./min to 675-900° C.

2. The modification method as claimed in claim 1 , wherein the alloy material is an alloy powder whose granularity is 160-40 μm.

3. The modification method as claimed in claim 1 , wherein the vacuum degree of the vacuum state is 10 −2 -10 −4 Pa.

4. The modification method as claimed in claim 1 , wherein after the step S21 and before the step S22, the step S2 further comprises: cooling at a cooling rate not less than 15° C./min to 500-600° C.

5. The modification method as claimed in claim 1 , wherein a magnetic main phase of the rare-earth permanent magnetic powder is provided with a RE′ 2 Fe 14 B structure; wherein, RE′ is Nd and/or Pr and parts of the Nd or the Pr therein may be substituted by Dy, Tb, La and/or Ce; a total atomic ratio of rare earths in the rare-earth permanent magnetic powder is 9-12.0%.

6. The modification method as claimed in claim 1 , wherein the modification method further comprises a preparation method of the alloy material; the preparation method comprises:
weighing each raw material according to the composition of the alloy material, and preparing the each raw material into a master alloy by employing induction smelting or electric arc smelting;
preparing the master alloy into alloy sheets by employing a strip casting sheet casting method or a melt quenching method; and
crushing the alloy sheets into the alloy powder by employing mechanical crushing or hydrogen crushing in a second inert atmosphere, the granularity of the alloy powder being 160-40 μm.

7. The modification method as claimed in claim 1 , wherein the mass proportion of the alloy material in the mixed powder is 2-5%.

8. The modification method as claimed in claim 1 , wherein a granularity of the rare-earth permanent magnetic powder is 400-50 μm.

9. The modification method as claimed in claim 1 , wherein the first inert atmosphere is an argon atmosphere.

10. The modification method as claimed in claim 6 , wherein the second inert atmosphere is an argon atmosphere.

Assignees

• Grirem Advanced Mat Co Ltd

Inventors

• Luo Yang
• Yuan Chao
• Men Kuo
• Quan Ningtao
• Zhang Hongbin
• Yan Wenlong
• Yu Dunbo
• Yang Yuanfei

Classifications

• B22F1/142

  Thermal or thermo-mechanical treatment · CPC title

• B22F1/105

  containing inorganic lubricating or binding agents, e.g. metal salts · CPC title

• H01F41/0293 Primary

  diffusion of rare earth elements, e.g. Tb, Dy or Ho, into permanent magnets · CPC title

• H01F1/0577

  sintered · CPC title

• C22F1/16

  of other metals or alloys based thereon · CPC title