Grooved Single-Crystal Magnetostrictive Member for Stable Field Tuning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetostrictive vibration power generation devices face variations in optimum magnetic field strength due to inconsistent magnetostrictive characteristics, necessitating individual magnet strength adjustments, which reduces productivity.

Innovation Solution

A magnetostrictive member with grooves extending in the long-side direction and subjected to heat treatment, ensuring a standard deviation of optimum magnetic field strength of 0.2 or less, achieved through electromechanical equivalent circuit analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If magnetostrictive members are manufactured by cutting from Fe-Ga polycrystal, then manufacturing process is simple, but magnetostrictive characteristics show large variation

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidmagnetostrictive characteristics consistency
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention changes the material parameter from polycrystalline to single crystal structure, and controls the crystal orientation parameter to be <100>. This fundamental parameter change ensures that all magnetostrictive members cut from the single crystal exhibit consistent <100> orientation, thereby achieving uniform magnetostrictive characteristics while maintaining manufacturing simplicity through standardized cutting processes.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies local quality by ensuring that the entire magnetostrictive member possesses uniform <100> crystal orientation throughout its structure. This uniformity in local crystal structure guarantees consistent magnetostrictive properties across different members, eliminating the variation problem associated with polycrystalline materials where grain orientations differ.

Inventive Principle:
Principle #3Local quality

2Reliability

If individual magnet strength adjustments are made for each device, then device output consistency is improved, but productivity decreases

Engineering Contradiction:
Improvedevice output consistencyVSAvoidmanufacturing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention performs preliminary action by pre-establishing uniform <100> crystal orientation in all magnetostrictive members during the manufacturing stage. This preliminary control of crystal structure ensures that all members inherently possess consistent magnetostrictive characteristics, eliminating the need for subsequent individual magnet strength adjustments and thereby maintaining high productivity while achieving device output consistency.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If Fe-Ga alloy with Ga concentration of 18-19 at% or 27-28 at% is used, then magnetostriction constant is maximized, but manufacturing complexity increases

Engineering Contradiction:
Improvemagnetostriction constantVSAvoidalloy composition control
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the alloy composition parameter to Fe-Ga with Ga concentration of 18-19 at%, which maximizes the magnetostriction constant. This specific composition parameter change, combined with single crystal growth and <100> orientation control, achieves optimal magnetostrictive performance while the standardized process reduces overall manufacturing complexity.

Inventive Principle:
Principle #35Parameter changes

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 solution provides consistent high parallel magnetostriction and force coefficient, reducing variations in magnetic field strength and enhancing device output consistency.

Implementation Method 1

Magnetostrictive materials are attracting attention as functional materials. For example, Fe-Ga alloys, which are iron-based alloys, are materials exhibiting the magnetostrictive effect and the inverse magnetostrictive effect, showing a large magnetostriction of about 100 to 350 ppm.

Methodology Applied
Scientific EffectMagnetostriction: Magnetostriction

Implementation Method 2

A magnetostrictive member with grooves extending in the long-side direction and subjected to heat treatment, ensuring a standard deviation of optimum magnetic field strength of 0.2 or less

Methodology Applied
Scientific EffectHeat treatment: Heat Treatment

Data Source

PatentEP4680000A1Magnetostrictive member and production method for magnetostrictive member
Publication Date: 2026.01.14 SUMITOMO METAL MINING CO LTD
  • EP4680000A1 patent drawingFigure 1
  • EP4680000A1 patent drawingFigure 2
  • EP4680000A1 patent drawingFigure 3

AI summary

[Problem] Provided is a magnetostrictive member that provides large device output and reduce a variation in optimum magnetic field strength in device characteristics when the magnetostrictive member with a large parallel magnetostriction amount and a small variation in the parallel magnetostriction amount among members is incorporated into a magnetostrictive vibration power generation device. [Solution] A magnetostrictive member includes a plurality of magnetostrictive members obtained from the same crystal, the magnetostrictive member being formed of a crystal of an iron-based alloy having magnetostrictive characteristics, being a plate-shaped body having a long-side direction and a short-side direction, and having a plurality of grooves extending in the long-side direction on at least one surface of a front surface and a back surface of the plate-shaped body, and the magnetostrictive members having a ratio (standard deviation/average value) of a standard deviation of optimum magnetic field strength to an average value of the optimum magnetic field strength determined by electromechanical equivalent circuit analysis of 0.2 or less.