Permanent Magnet Sintering Die for Controlled Density Patterns
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Solution Overview
Problem
Conventional methods for manufacturing permanent magnets, such as rare earth magnets, are inefficient and costly due to the need for machining, which reduces manufacturing output and increases expenses.
Innovation Solution
A die assembly with conductive and non-conductive surface portions is used for field-assisted sintering, allowing for the creation of permanent magnets with varying densities and resistivities through controlled electrical current application, enabling the formation of high-density and low-density portions with precise patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional machining methods are used to manufacture permanent magnets, then manufacturing precision can be achieved, but productivity decreases and manufacturing costs increase
Solution Approach 1:
The patent replaces conventional mechanical machining processes with field-assisted sintering that uses electrical fields and magnetic fields to directly form magnets with precise dimensions. The electrical current applied through conductive die portions and the magnetic field work together to sinter the magnetic powder mixture into the desired shape without subsequent machining operations, thereby eliminating the trade-off between precision and productivity.
Solution Approach 2:
The patent changes the physical and chemical parameters of the magnetic powder mixture during sintering by controlling electrical current density, temperature, and magnetic field strength. By adjusting these parameters, the process achieves both high dimensional precision and high productivity, as the material transforms directly into the final magnet shape through controlled sintering rather than mechanical removal.
2Manufacturing precision
If conventional machining methods are used to manufacture permanent magnets, then manufacturing precision can be achieved, but manufacturing costs increase
Solution Approach 1:
The patent replaces expensive mechanical machining operations with a field-assisted sintering process that uses electrical and magnetic fields to directly form precise magnet geometries. This substitution eliminates the need for multiple machining steps, tooling, and associated costs, achieving both precision and cost-effectiveness simultaneously.
Solution Approach 2:
The patent controls the sintering process by adjusting electrical current, temperature, and magnetic field parameters to achieve precise dimensional control directly during formation. This eliminates the need for costly post-machining operations while maintaining high precision, thereby reducing overall manufacturing costs.
3Device complexity
If uniform electrical current is applied during sintering, then simple processing is achieved, but the ability to create complex density patterns is limited
Solution Approach 1:
The patent divides the die surface into multiple portions with different electrical conductivity properties (conductive and non-conductive areas). This segmentation allows different regions of the magnetic powder mixture to experience different current densities during sintering, enabling the creation of complex density patterns and gradients within the final magnet without requiring complex processing equipment.
Solution Approach 2:
The patent applies local quality by creating specific conductivity characteristics in different regions of the die surface. The conductive portions generate higher current density for high-density magnet regions, while non-conductive portions generate lower current density for low-density regions. This local variation in electrical properties enables precise control over the density distribution pattern in the final magnet product.
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 method enhances manufacturing efficiency, reduces costs, and allows for the production of magnets with complex shapes by utilizing field-assisted sintering, achieving superior magnetic, electric, and mechanical properties.
Implementation Method 1
applying an electrical current to the magnetic powder
Implementation Method 2
field assisted sintering
Data Source
AI summary
Magnets having various portions of different densities and resistivities are disclosed. In a refinement, the various portions may have the same composition but different physical structures. Unique dies may be used to during processing, such as during sintering to manufacture the magnets. The die may include conductive and non-conductive surfaces that contact the green magnetic powder mixture during sintering such that the electrical current applied to the magnetic powder mixture is managed by the conductive and non-conductive surfaces to provide unique and complex magnets. Methods of manufacturing the magnets with the dies such as field assisted sintering, i.e., spark plasma sintering, are also disclosed.