Rare-earth sintered magnet
US-2020005973-A1 · Jan 2, 2020 · US
Permanent magnet and permanent magnet powder
US11205532B2 · US · B2
| Field | Value |
|---|---|
| Publication number | US-11205532-B2 |
| Application number | US-201716465397-A |
| Country | US |
| Kind code | B2 |
| Filing date | Nov 30, 2017 |
| Priority date | Nov 30, 2016 |
| Publication date | Dec 21, 2021 |
| Grant date | Dec 21, 2021 |
How to read this patent
A practical reading order for non-experts. Skip the full description unless you need deep technical detail.
- Title
What the patent document calls the invention.
- Abstract
A short plain-language summary of the technical disclosure.
- Assignees and inventors
Who owns or filed the patent and who is credited as inventor.
- Key dates
Filing, priority, publication, and grant dates set the timeline.
- First independent claim
The legal scope of protection — read this for what is actually claimed.
- CPC / IPC classifications
Technology tags used to group this patent with similar filings.
- Citations and related patents
Prior art links and similar publications in this corpus.
Abstract
Official abstract text for this publication.
A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount. Main phase grains included in the permanent magnet have an Nd5Fe17 type crystal structure. An average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm. A number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%.
First claim
Opening claim text (preview).
What is claimed is: 1. A permanent magnet comprising R and T, R being essentially Sm or being at least one selected from rare earth elements in addition to Sm, and T being essentially Fe or a combination of Fe and Co or being at least one selected from transition metal elements in addition to Fe or the combination of Fe and Co, wherein a composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less, a remaining part is substantially only T, or only T and C, T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount, main phase grains included in the permanent magnet have an Nd 5 Fe 17 type crystal structure, an average crystal grain size of the main phase grains of the permanent magnet is greater than 1 μm, and a number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%, and C amount is 0 at % or more and 15.4 at % or less. 2. The permanent magnet according to claim 1 , wherein C amount is more than 0 at % and 15 at % or less. 3. The permanent magnet according to claim 1 , wherein the average crystal grain size of the main phase grains is greater than 1 μm and less than 10 μm. 4. A permanent magnet powder comprising R and T, R being essentially Sm or being at least one selected from rare earth elements in addition to Sm, and T being essentially Fe or a combination of Fe and Co or being at least one selected from transition metal elements in addition to Fe or the combination of Fe and Co, wherein a composition ratio of R in the permanent magnet powder is 20 at % or more and 40 at % or less, a remaining part is substantially only T, or only T and C, T amount is more than 1.5 times of R amount and less than 4.0 times of the R amount, main phase grains included in the permanent magnet powder have an Nd 5 Fe 17 type crystal structure, an average crystal grain size of the main phase grains of the permanent magnet powder is more than 1 μm, and a number ratio of main phase grains having a crystal grain size of less than 0.4 μm is less than 20%, and C amount is 0 at % or more and 15.4 at % or less. 5. The permanent magnet powder according to claim 4 , wherein C amount is more than 0 at % and 15 at % or less. 6. The permanent magnet according to claim 4 , wherein the average crystal grain size of the main phase grains is greater than 1 μm and less than 10 μm. 7. An anisotropic bond magnet, including: the permanent magnet powder according to claim 4 ; and a resin. 8. An anisotropic sintered magnet comprising the permanent magnet powder according to claim 4 .
Assignees
Inventors
Classifications
Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title
Thermal or thermo-mechanical treatment · CPC title
- C22C38/005Primary
containing rare earths, i.e. Sc, Y, Lanthanides · CPC title
Magnetic · CPC title
Aspects linked to processes or compositions used in powder metallurgy · CPC title
Patent family
Related publications grouped by family.
External sources
Frequently asked questions
Answers are generated from the same data shown on this page.
- What does patent US11205532B2 cover?
- A permanent magnet includes R and T (R essentially includes Sm one or more of rare earth elements in addition to Sm, and T essentially includes Fe, or Fe and Co, one or more of transition metal elements in addition to Fe, or Fe and Co). A composition ratio of R in the permanent magnet is 20 at % or more and 40 at % or less. A remaining part is substantially only T, or only T and C. T amount is …
- Who is the assignee on this patent?
- Tdk Corp
- What technology area does this patent fall under?
- Primary CPC classification C22C38/005. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Tue Dec 21 2021 00:00:00 GMT+0000 (Coordinated Universal Time) (B2). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 2 related publications on this page (citations in our corpus or others sharing the same primary CPC).