Sm-Fe-N Magnet Compaction Without Sintering via Oriented Rolling
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Solution Overview
Problem
Manufacturing bulk Sm—Fe—N magnets without sintering is challenging due to their pyrolysis at high temperatures, and existing rolling methods do not adequately enhance magnetic properties.
Innovation Solution
A method involving a sealing step, magnetic field application, preliminary rolling, and pressurizing step is employed, including tapping and vibration to fill the metal sheath, aligning magnetic orientation, and applying controlled rolling pressures to improve magnetic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sintering at high temperatures is used to manufacture Sm-Fe-N magnets, then magnetic properties can be improved, but the Sm-Fe-N compounds pyrolyze and cannot be sintered
Solution Approach 1:
The patent changes the temperature parameter from high-temperature sintering to room temperature or low-temperature pressurizing, making the process compatible with the pyrolysis characteristics of Sm-Fe-N compounds while still achieving desired magnetic properties through alternative mechanisms
Solution Approach 2:
The patent replaces the thermal sintering process with a mechanical pressurizing process, substituting heat treatment with cold isostatic pressing or uniaxial pressing to achieve densification without triggering pyrolysis
2Ease of manufacture
If rolling is used to manufacture Sm-Fe-N magnets without sintering, then the manufacturing process is simplified, but magnetic properties are insufficient
Solution Approach 1:
The patent applies a preliminary magnetic field treatment to the magnet powder before pressurizing, which orients the magnetic moments in advance and enhances the final magnetic properties when combined with the mechanical pressing process
Solution Approach 2:
The patent creates a composite structure by combining Sm-Fe-N magnet powder with a binder material, forming a composite that maintains the magnetic properties of the Sm-Fe-N compound while allowing for flexible processing and improved overall magnet 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 method results in Sm—Fe—N magnets with improved magnetic characteristics, achieving relative densities of 52% to 88% and magnetic orientation of 0.72 to 0.87, suitable for applications in motors and generators.
Implementation Method 1
a magnetic field applying step of applying a magnetic field to the magnet powder sealed in the metal sheath and magnetizing the magnet powder by magnetically orienting the magnet powder
Implementation Method 2
magnetizing the magnet powder by magnetically orienting the magnet powder and aligning a direction of magnetic orientation in one direction
Implementation Method 3
a pressurizing step of pressurizing the green compact sealed in the metal sheath and densifying the green compact to form a magnet body
Implementation Method 4
a preliminary rolling step of preliminarily rolling the magnetically oriented magnet powder sealed in the metal sheath to make the magnetically oriented magnet powder into a green compact
Data Source
AI summary
A method of manufacturing an Sm—Fe—N magnet includes filling a metal sheath with a magnet powder including an Sm—Fe—N compound as a main component and sealing the metal sheath, applying a magnetic field to the magnet powder sealed in the metal sheath, and magnetizing the magnet powder by magnetically orienting the magnet powder and aligning a direction of magnetic orientation in one direction, preliminarily rolling the magnetically oriented magnet powder sealed in the metal sheath to make the magnetically oriented magnet powder into a green compact, and pressurizing the green compact sealed in the metal sheath and densifying the green compact to form a magnet body, wherein the preliminary rolling is performed by lightly rolling the magnetically oriented magnet powder sealed in the metal sheath with a pressure smaller than a pressure for pressurizing the green compact.