Optimized R-T-B Permanent Magnet for Enhanced Magnetic Properties
Here’s PatSnap Eureka !
Summary
Problems
Existing rare earth permanent magnets with R-T-B composition face challenges in achieving high residual magnetic flux density (Br) and coercive force (HcJ) while maintaining corrosion resistance and production stability.
Innovation solutions
An R-T-B based permanent magnet with specific elemental compositions and concentration distributions, including Tb, Fe, Cu, Co, Ga, and B, optimized within certain mass percentage ranges, and incorporating grain boundary diffusion techniques to enhance magnetic properties and stability.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If rare earth permanent magnet with R-T-B composition is used to achieve high residual magnetic flux density and coercive force, then magnetic properties are improved, but production stability deteriorates
Why choose this principle:
The patent applies parameter changes by precisely controlling the compositional parameters within specific ranges: Tb content at 0.05-5.0 mass%, Cu at 0.04-0.50 mass%, Co at 0.5-3.0 mass%, Ga at 0.08-0.30 mass%, and B at 0.85-0.95 mass%. These defined parameter ranges ensure reproducible manufacturing while achieving superior magnetic properties. The total rare earth content is controlled at 28.05-30.60 mass%, providing a narrow but optimized composition window for consistent production.
Principle concept:
If Tb concentration is increased to improve coercive force, then magnetic properties are improved, but manufacturing complexity increases
Why choose this principle:
The patent implements local quality through a controlled concentration gradient of Tb element, where the surface region contains higher Tb content than the center. This gradient structure can be achieved through directional solidification or diffusion processes during manufacturing, allowing the material to self-organize the desired composition distribution without requiring complex post-processing or multiple assembly steps.
Application Domain
Data Source
AI summary:
An R-T-B based permanent magnet with specific elemental compositions and concentration distributions, including Tb, Fe, Cu, Co, Ga, and B, optimized within certain mass percentage ranges, and incorporating grain boundary diffusion techniques to enhance magnetic properties and stability.
Abstract
An object of the present invention is to provide an R-T-B based permanent magnet showing high residual magnetic flux density Br and coercive force HcJ. Provided is an R-T-B based permanent magnet in which, R is a rare earth element, T is an element other than the rare earth element, B, C, O or N, and B is boron. R at least includes Tb and T at least includes Fe, Cu, Co and Ga, and a total of R content is 28.05 to 30.60 mass %, Cu content is 0.04 to 0.50 mass %, Co content is 0.5 to 3.0 mass %, Ga content is 0.08 to 0.30 mass %, and B content is 0.85 to 0.95 mass %, relative to 100 mass % of a total mass of R, T and B, and Tb concentration reduces from outside to inside of the R-T-B based permanent magnet.