Rare Earth Magnet Composition Stabilizing 1-5 Phase
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Solution Overview
Problem
Rare earth magnets with a binary system of rare earth and transition metal elements face instability issues when Ce is used for part of the rare earth element and Co is replaced with Fe, leading to a decrease in 1-5 phase content and reduced saturation magnetization and anisotropy field.
Innovation Solution
A rare earth magnet composition of (Ce x La (1-x-w) R' w ) v (Co y Fe (1-y) ) (100-v-z) M z is developed, where R' is a rare earth element other than Ce and La, and M represents transition metal elements or impurities, with specific molar ratios and quenching processes to stabilize the 1-5 phase.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If Ce is used to replace Sm and Co is replaced with Fe, then cost is reduced and saturation magnetization is improved, but 1-5 phase stability deteriorates and anisotropy field is reduced
Solution Approach 1:
The patent applies parameter changes by precisely controlling the composition ratios within the formula (Ce x La (1-x-w) R' w ) v (Co y Fe (1-y) ) (100-v-z) M z, where x, y, v, and z are optimized to maintain 1-5 phase stability while incorporating Fe. The specific constraint y ≤ -1.25x + 1.25 represents a parameter relationship that balances Fe content with Ce content to prevent 1-5 phase decomposition
Solution Approach 2:
The patent creates a composite material system combining multiple rare earth elements (Ce, La, R') and transition metal elements (Co, Fe, M) in specific proportions. This composite approach allows the benefits of Fe (higher saturation magnetization) and Ce (lower cost) while using La and other elements to stabilize the 1-5 phase structure that would otherwise decompose
2Quantity of substance
If Co is replaced with Fe, then saturation magnetization is improved, but anisotropy field is reduced and phase stability is reduced
Solution Approach 1:
The patent uses parameter changes by optimizing the Fe content parameter y within the constraint y ≤ -1.25x + 1.25, where x represents Ce content. This parameter relationship ensures that Fe is incorporated to improve saturation magnetization while the combined effect of Ce and La stabilization prevents excessive loss of anisotropy field and maintains 1-5 phase stability
Data Source
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AI summary
[PROBLEM TO BE SOLVED] To provide a rare earth magnet in which 1-5 phase is stabilized even when Ce is used for at least part of the rare earth element and part of Co is replaced with Fe, and a production method thereof. [MEANS TO SOLVE THE PROBLEM] A rare earth magnet having a composition represented by the formula: (CexLa(1-x-w)R'w)v(CoyFe(1-y))(100-v-z)Mz, wherein R' is one or more rare earth elements other than Ce and La, M represents one or more members selected from the group consisting of a transition metal element other than Co and Fe, Ga, Al, Zn, and In, and an unavoidable impurity element, 0<x<1.0, 0<y<1.0, 0≤w≤0.1, 7.1≤v≤20.9, and 0≤z≤8.0, and satisfying, in the formula, the relationship of y≥-3x+1.7, and a production method thereof.