Iron Nitride Magnet Composition With Grain Size Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current permanent magnets rely on rare earth elements, which are scarce, expensive, and environmentally detrimental, with manufacturing processes being costly and environmentally harmful, while iron nitride magnets with high magnetic anisotropy and saturation magnetization are difficult to manufacture effectively.
Innovation Solution
Developing alloy compositions with iron nitride phases and controlling grain sizes between 20 nm and 100 nm to enhance coercivity, using techniques like quenching, annealing, doping, and nitriding to create bulk permanent magnets with magnetic properties comparable to rare earth magnets without using rare earth elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rare earth elements are used in permanent magnets, then high energy product and magnetic performance are achieved, but supply availability, cost, and environmental impact deteriorate
Solution Approach 1:
The patent replaces expensive rare earth elements with inexpensive iron and nitrogen to form Fe16N2 permanent magnets. This substitution principle directly addresses the supply availability and cost issues by using abundant, cheap materials (iron and nitrogen) instead of scarce rare earth elements, while maintaining magnetic performance through controlled grain size and phase structure
Solution Approach 2:
The patent changes the material composition parameters from rare earth-based to iron-nitride-based systems. By adjusting the grain size to 20-100 nm and controlling the Fe16N2 phase formation through nitriding processes, the patent achieves high magnetic performance without rare earth elements, resolving the contradiction between material availability and magnetic performance
2Reliability
If rare earth elements are used in permanent magnets, then high energy product is achieved, but manufacturing cost increases
Solution Approach 1:
The patent substitutes expensive rare earth materials with cheap iron and nitrogen. The Fe16N2 phase can be produced through relatively simple nitriding processes of iron-based alloys, avoiding the complex and expensive sintering processes required for rare earth magnets, thereby reducing manufacturing cost while maintaining energy product
Solution Approach 2:
The patent changes the manufacturing approach from high-temperature sintering of rare earth alloys to nitriding of iron-based materials. By controlling grain size (20-100 nm) and nitrogen content during nitriding, the patent achieves high energy product at lower manufacturing cost
3Reliability
If rare earth elements are used in permanent magnets, then high magnetic performance is achieved, but environmental deterioration worsens
Solution Approach 1:
The patent replaces rare earth elements, whose mining causes severe environmental deterioration, with iron and nitrogen. The nitriding process used to create Fe16N2 magnets is environmentally friendly compared to rare earth mining and processing, thus reducing environmental impact while maintaining magnetic performance
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 approach results in bulk permanent magnets with high coercivity and energy product, comparable to or exceeding those of rare earth magnets, while utilizing abundant and inexpensive iron and nitrogen, thus addressing supply and environmental concerns.
Implementation Method 1
treating an alloy composition including a plurality of grains including an iron-based phase to control an average grain size of the plurality of grains to between about 20 nm and about 100 nm
Implementation Method 2
nitriding the plurality of grains to form or grow an iron nitride phase
Implementation Method 3
using techniques like quenching, annealing, doping, and nitriding to create bulk permanent magnets
Data Source
AI summary
An example composition may include a plurality of grains including an iron nitride phase. The plurality of grains may have an average grain size between about 10 nm and about 200 nm. An example technique may include treating a composition including a plurality of grains including an iron-based phase to adjust an average grain size of the plurality of grains to between about 20 nm and about 100 nm. The example technique may include nitriding the plurality of grains to form or grow an iron nitride phase.