Amorphous Soft Magnetic Powder Heat Treatment for Stable Coercive Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing soft magnetic powder, as described in JP-A-2022-175110, do not adequately address the reduction of coercive force without compromising production efficiency, leaving room for improvement.
Innovation Solution
A method involving a heat treatment of amorphous alloy powder at specific temperatures (400° C. to 540° C.) and pressures (63.7 MPa) to produce amorphous alloy soft magnetic powder with a composition of (Fe1-xCrx)a(Si1-yBy)100-a-bCb, ensuring a volume resistivity of 7.0×10−2 [Ω·cm] or less, which relaxes stress strain and stabilizes coercive force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat treatment is performed at temperatures below crystallization temperature as disclosed in JP-A-2022-175110, then various defects and anisotropy are reduced, but coercive force cannot be reliably reduced to the desired level
Solution Approach 1:
The patent applies parameter changes by precisely controlling heat treatment temperature within 400-540°C and adjusting powder particle diameter to 3.0-40.0 μm range. These parameter optimizations enable simultaneous achievement of defect reduction and coercive force reduction below 0.8 A/m, resolving the contradiction between reliability and manufacturing precision.
2Manufacturing precision
If heat treatment temperature is increased to reduce coercive force, then magnetic properties improve, but production efficiency decreases
Solution Approach 1:
The patent optimizes heat treatment temperature to the specific range of 400-540°C, which is sufficient to reduce coercive force below 0.8 A/m while avoiding excessive temperature that would reduce production efficiency. This precise parameter control resolves the contradiction between manufacturing precision and productivity.
3Manufacturing precision
If amorphous alloy powder with specific composition is used, then magnetic properties are improved, but production complexity increases
Solution Approach 1:
The patent uses composite amorphous alloy powder containing Fe, Cr, Si, B, and C elements with specific composition ratios. This composite material approach improves magnetic properties while the standardized production process maintains manufacturing simplicity, resolving the contradiction between magnetic property quality and production process complexity.
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 achieves amorphous alloy soft magnetic powder with low coercive force and reduced variation, enabling the production of magnetic elements with stable properties and minimized individual variations, contributing to efficient and stable magnetic performance.
Implementation Method 1
a heat treatment step of subjecting the amorphous alloy powder to a heat treatment at a temperature of 400° C. or higher and 540° C. or lower
Implementation Method 2
which relaxes stress strain and stabilizes coercive force
Implementation Method 3
when the amorphous alloy soft magnetic powder is pressurized under a pressure of 63.7 MPa
Data Source
AI summary
A method for producing an amorphous alloy soft magnetic powder includes: a powder production step of producing an amorphous alloy powder that has an average particle diameter of 3.0 μm or more and 40.0 μm or less and that is formed of impurities and a composition represented by a composition formula (Fe1-xCrx)a(Si1-yBy)100-a-bCb; and a heat treatment step of subjecting the amorphous alloy powder to a heat treatment at a temperature of 400° C. or higher and 540° C. or lower to produce an amorphous alloy soft magnetic powder that has volume resistivity of 7.0×10−2 [Ω·cm] or less when the amorphous alloy soft magnetic powder is pressurized under a pressure of 63.7 MPa.