Mn-Al Magnetic Particles via One-Step τ-Phase Calorizing

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Solution Overview

Problem

The existing production process for magnetic particles of a manganese-aluminum alloy containing a τ phase is complex and requires multiple steps, including melt spraying, pulverization, and aging treatment.

Innovation Solution

A method involving mixing manganese particles, an aluminum source, a halide-containing activator, and an anti-sintering agent, followed by heating to a temperature between 1,000 °C to 1,235 °C to form magnetic particles with a manganese-aluminum alloy containing a τ phase, and then removing the anti-sintering agent to recover the magnetic particles.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the conventional production process (melt spraying, pulverization, aging treatment) is used, then magnetic particles containing τ phase can be produced, but the production process becomes complicated and time-consuming

Engineering Contradiction:
Improveproduction of magnetic particles containing τ phaseVSAvoidproduction process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention combines multiple conventional steps (melt spraying, pulverization, and aging treatment) into a single calorizing treatment step. By mixing manganese particles with aluminum powder and performing one-step heating treatment, the process achieves the same result of producing magnetic particles containing τ phase while dramatically simplifying the production流程

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention performs preliminary mixing of manganese particles with aluminum powder and other additives before the calorizing treatment. This preliminary preparation ensures proper composition and distribution, enabling the subsequent single-step heating to successfully produce the desired magnetic particles with τ phase

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the conventional production process is used, then magnetic particles containing τ phase can be produced, but the production time is extended due to multiple processing steps

Engineering Contradiction:
Improveproduction of magnetic particles containing τ phaseVSAvoidproduction time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The invention merges the multi-step conventional process into a single calorizing treatment step. By combining melt spraying, pulverization, and aging treatment into one simultaneous heating operation, the production time is significantly reduced while maintaining the reliability of producing magnetic particles with τ phase

Inventive Principle:
Principle #5Merging (Combining)

3Stability of the object's composition

If the anti-sintering agent is used during calorizing treatment, then particle aggregation is prevented, but additional separation steps are required

Engineering Contradiction:
Improveparticle dispersion during heatingVSAvoidseparation process complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The invention uses an anti-sintering agent during the calorizing treatment to prevent particle aggregation and ensure proper alloy formation. After the treatment, the anti-sintering agent is removed through separation processes, allowing the magnetic particles to be recovered in their desired dispersed state. This approach temporarily introduces the agent for process control, then removes it to achieve the final product quality

Inventive Principle:
Principle #34Discarding and recovering

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 simplifies the production of magnetic particles containing a manganese-aluminum alloy with a τ phase, allowing for easier separation and recovery of the magnetic particles, thereby reducing the complexity and increasing the efficiency of the process.

Implementation Method 1

heating the mixed powder to a temperature in a range from 1,000 °C to 1,235 °C to calorize the manganese particles

Methodology Applied
Scientific EffectCalorizing: Heating

Implementation Method 2

by utilizing gaps between particles of the anti-sintering agent formed by the anti-sintering agent

Methodology Applied
Scientific EffectAnti-sintering:

Data Source

PatentEP4534221A1Method for manufacturing magnetic particles, magnetic particles, and permanent magnet using same
Publication Date: 2025.04.09 AGC INC
  • EP4534221A1 patent drawingFigure 1
  • EP4534221A1 patent drawingFigure 2
  • EP4534221A1 patent drawingFigure 3

AI summary

A method for producing magnetic particles containing a manganese-aluminum alloy includes: mixing manganese particles, an aluminum source, an activator containing a halide, and an anti-sintering agent to obtain a mixed powder; heating the mixed powder to calorize the manganese particles by utilizing gaps between particles of the anti-sintering agent formed by the anti-sintering agent, to obtain a treated mixture containing magnetic particles containing a manganese-aluminum alloy, wherein a mass ratio of aluminum to manganese (Al/Mn) in the manganese-aluminum alloy is in a range from 25/75 to 35/65; removing the anti-sintering agent from the treated mixture to recover the magnetic particles containing the manganese-aluminum alloy.