ThMn12 Magnetic Material Dual-Phase Structure for Coercive Force
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Solution Overview
Problem
Current high-performance permanent magnets face challenges in achieving both high saturation magnetization and coercive force, particularly in reducing size while maintaining magnetic properties, especially in applications like rotary electrical machines and vehicles.
Innovation Solution
A magnetic material composition incorporating a ThMn12 crystal phase with a rare-earth element, Fe or Fe and Co, and non-magnetic elements like Cu and Sn, forming sub phases to enhance coercive force and saturation magnetization, stabilized by elements such as Yttrium and Ti, with controlled elemental ratios and heat treatment to optimize crystal structure and properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If rare-earth elements (Nd, Sm) are used to increase magnetic anisotropy and coercive force, then coercive force is improved, but saturation magnetization is limited
Solution Approach 1:
The patent applies local quality by creating a dual-phase structure where the ThMn12 phase provides high saturation magnetization in specific regions while the (R,T)2Fe17 phase provides high coercive force in other regions. This spatial differentiation of magnetic properties allows the material to achieve both high saturation magnetization and high coercive force simultaneously, resolving the contradiction between these two parameters.
Solution Approach 2:
The patent uses composite materials by combining two distinct intermetallic phases (ThMn12 and (R,T)2Fe17) in a controlled microstructure. The ThMn12 phase contributes high saturation magnetization while the (R,T)2Fe17 phase contributes high coercive force. This composite approach at the phase level enables the material to overcome the limitations of single-phase rare-earth magnets and achieve superior overall magnetic performance.
2Quantity of substance
If Fe and Co are increased to enhance saturation magnetization, then saturation magnetization is improved, but coercive force decreases
Solution Approach 1:
The patent applies local quality by concentrating Fe and Co in the ThMn12 phase where they contribute to high saturation magnetization, while concentrating rare-earth elements (R) and Ti in the (R,T)2Fe17 phase where they provide high coercive force. This spatial separation of elemental functions allows each phase to optimize its contribution without compromising the other property.
Solution Approach 2:
The patent uses composite materials to resolve this contradiction by creating a two-phase system where the ThMn12 phase (rich in Fe, Co, and non-magnetic elements) provides high saturation magnetization and the (R,T)2Fe17 phase (rich in rare-earth elements and Ti) provides high coercive force. The synergistic combination of these phases achieves both high saturation magnetization and high coercive force.
3Volume of moving object
If product size is reduced for miniaturization, then device size is improved, but magnetic performance is degraded
Solution Approach 1:
The patent applies parameter changes by precisely controlling the composition parameters (ratios of R, Fe, Co, Ti, and non-magnetic elements) and microstructural parameters (phase distribution, grain size) to achieve optimal magnetic performance in miniaturized products. The specific composition formula (R1-xYx)aMbTcDd with controlled ranges of a, b, c, d, and x allows tuning of magnetic properties to maintain performance despite size reduction.
Solution Approach 2:
The patent uses composite materials with a specifically designed dual-phase microstructure that maintains high magnetic performance even in miniaturized forms. The ThMn12 phase provides high saturation magnetization while the (R,T)2Fe17 phase provides high coercive force, and their controlled distribution ensures that even small volumes of material achieve the required magnetic performance for miniaturized rotary electrical machines and vehicles.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The magnetic material achieves improved coercive force and saturation magnetization, enabling high-performance permanent magnets suitable for miniaturized rotary electrical machines and vehicles with enhanced efficiency and cost reduction.
Implementation Method 1
these magnets contain rare-earth elements such as Nd and Sm, which bring about a large magnetic anisotropy which is derived from a behavior of 4f electrons of the rare-earth elements in a crystal field
Implementation Method 2
a large magnetic anisotropy which is derived from a behavior of 4f electrons of the rare-earth elements in a crystal field
Implementation Method 3
Fe and Co contribute to increase in saturation magnetization
Data Source
AI summary
A magnetic material is expressed by a composition formula 1: (R1-xYx)aMbTcDd. The magnetic material includes: a main phase having a ThMn12 crystal phase, and a sub phase having a phase containing the element D.