Sintered Magnet Manufacturing via Dimension Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for manufacturing Nd—Fe—B sintered magnets are inefficient in energy use and result in a poor yield ratio due to unnecessary energy consumption and material loss during heating and cooling processes, as well as high thermal stress on equipment.
Innovation Solution
A method involving press-molding of magnet powder in a heated atmosphere to correct dimensions and perform aging heat treatment, utilizing the same heated atmosphere for both steps, thereby reducing energy consumption and minimizing material loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling to 400°C or below is followed by reheating to about 900°C, then the grain boundary phase structure is transformed to improve retention force, but energy is consumed unnecessarily and cost increases
Solution Approach 1:
The invention performs preliminary dimension correction through pressure molding at a temperature of 400°C to 900°C before sintering. By correcting dimensions in advance while the material is still relatively soft and formable, subsequent grinding operations are minimized or eliminated, preventing material loss and reducing the need for post-sintering reheating and cooling cycles, thus improving energy efficiency while maintaining retention force
Solution Approach 2:
The invention changes the temperature parameter timing by performing dimension correction at elevated temperature (400°C to 900°C) before sintering, rather than correcting dimensions after sintering at room temperature. This parameter change allows dimension correction to be performed when material properties are more favorable, reducing subsequent processing needs and energy consumption
2Reliability
If cooling to 400°C or below is followed by reheating to about 900°C, then the grain boundary phase structure is transformed to improve retention force, but the thermal load on apparatus structures increases and lifetime shortens
Solution Approach 1:
The invention performs preliminary dimension correction through pressure molding at a temperature of 400°C to 900°C before sintering. By correcting dimensions in advance while the material is still relatively soft and formable, subsequent grinding operations are minimized or eliminated, preventing material loss and reducing the need for post-sintering reheating and cooling cycles, thus improving energy efficiency while maintaining retention force
Solution Approach 2:
The invention changes the temperature parameter timing by performing dimension correction at elevated temperature (400°C to 900°C) before sintering, rather than correcting dimensions after sintering at room temperature. This parameter change allows dimension correction to be performed when material properties are more favorable, reducing subsequent processing needs and energy consumption
3Manufacturing precision
If a grinding process is conducted on material after sintering, then dimensions are corrected, but metals including rare earths are ground away and yield ratio deteriorates
Solution Approach 1:
The invention performs preliminary dimension correction through pressure molding at a temperature of 400°C to 900°C before sintering. By correcting dimensions in advance while the material is still relatively soft and formable, subsequent grinding operations are minimized or eliminated, preventing material loss and reducing the need for post-sintering reheating and cooling cycles, thus improving energy efficiency while maintaining retention force
Solution Approach 2:
The invention changes the temperature parameter timing by performing dimension correction at elevated temperature (400°C to 900°C) before sintering, rather than correcting dimensions after sintering at room temperature. This parameter change allows dimension correction to be performed when material properties are more favorable, reducing subsequent processing needs and energy consumption
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
This approach enhances energy efficiency, improves material yield, and reduces thermal stress on equipment by eliminating the need for reheating and grinding, while maintaining magnet characteristics.
Implementation Method 1
the green compact is sintered in a heated atmosphere heated to sintering temperature, and a sintered magnet is formed
Implementation Method 2
utilizing the heated atmosphere produced during dimension correction to carry out aging heat treatment to adjust the texture of the sintered magnet
Data Source
AI summary
A method for manufacturing a sintered magnet includes molding a green compact formed by compacting a magnet powder by press-molding the magnet powder, the green compact forming an R—Fe—B based sintered magnet having Nd as the principal component and containing a rare earth element R, sintering the green compact by heating to a sintering temperature, so as to mold a sintered magnet, pressure molding the sintered magnet by heating to a temperature not exceeding the sintering temperature, so as to correct dimensions of the sintered magnet, and adjusting the texture of the sintered magnet by aging heat treatment using heated atmosphere produced when correcting the dimensions of the sintered magnet at a temperature not exceeding the temperature during the pressure molding.