Grooved Fe-Ga Magnetostrictive Member for Stable Parallel Magnetostriction

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Solution Overview

Problem

Magnetostrictive members manufactured from Fe-Ga alloys exhibit variations in magnetostriction constant and parallel magnetostriction amount, affecting device characteristics despite uniform Ga concentration and crystal orientation.

Innovation Solution

Forming grooves on the surface of magnetostrictive members to align lattice constants in a specific direction, specifically making the lattice constant in the short-side direction larger than in the long-side direction, thereby stabilizing the parallel magnetostriction amount and reducing variations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a magnetostrictive wire is repeatedly drawn to reduce diameter, then the diameter is reduced, but the material structure becomes coarse and performance deteriorates

Engineering Contradiction:

ImprovediameterVSAvoidmaterial structure uniformity

Core Design Contradiction:

Volume of moving objectVSManufacturing precision

Solution Approach 1:

The wire drawing process is divided into multiple stages with intermediate annealing treatments. The wire is drawn to partial reduction, then annealed to reset the material structure, and this cycle is repeated. This segmentation prevents coarse structure formation while achieving the target diameter reduction.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Annealing treatments are performed at predetermined intervals during the drawing process to preemptively prevent material structure degradation. By applying heat treatment before the structure becomes coarse, the patent maintains material uniformity throughout the drawing process.

Inventive Principle:

Principle #10Preliminary action

2Volume of moving object

If the magnetostrictive wire diameter is reduced, then the coil size is reduced, but the coil impedance increases

Engineering Contradiction:

Improvecoil sizeVSAvoidcoil impedance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent changes the material parameters of the magnetostrictive wire by controlling its composition (Fe-Ni-Al alloy with specific ratios) and heat treatment conditions. These parameter changes enable the wire to maintain suitable impedance characteristics even at reduced diameters, thus allowing smaller coil sizes without compromising reliability.

Inventive Principle:

Principle #35Parameter changes

3Volume of moving object

If the magnetostrictive wire diameter is reduced, then the actuator size is reduced, but the driving capability deteriorates

Engineering Contradiction:

Improveactuator sizeVSAvoiddriving capability

Core Design Contradiction:

Volume of moving objectVSForce

Solution Approach 1:

The patent uses a composite Fe-Ni-Al alloy material that combines the advantages of different elements. This composite material structure enables the wire to maintain high magnetostrictive properties and driving capability even when the diameter is reduced, thus allowing compact actuator design without sacrificing force output.

Inventive Principle:

Principle #40Composite materials

4Ease of manufacture

If conventional drawing process is used, then the manufacturing process is simple, but the material structure becomes coarse and performance is insufficient

Engineering Contradiction:

Improvemanufacturing process complexityVSAvoidmaterial structure uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent changes the material parameters by controlling composition and heat treatment conditions, enabling the material to maintain fine structure and high performance even after multiple drawing passes, thus improving manufacturing precision without significantly increasing process 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 method achieves a high magnetostriction constant and parallel magnetostriction amount with minimal variations among members, enhancing device performance by maintaining the parallel magnetostriction amount at a high level and reducing variations to within 10%.

Implementation Method 1

a magnetostrictive member which has a magnetostrictive property and includes a magnetostrictive wire

Methodology Applied

Scientific EffectMagnetostriction: Magnetostriction

Data Source

PatentEP4293145B1Magnetostrictive member and method for manufacturing magnetostrictive member

Publication Date: 2026.05.06 SUMITOMO METAL MINING CO LTD

Figure 1(A)~1(B)
Figure 2
Figure 3(A)~3(B)

AI summary

Provided are a magnetostrictive member having a high magnetostriction constant and a high parallel magnetostriction amount and small variations in the magnetostriction constant and the parallel magnetostriction amount among members and a method for manufacturing such a magnetostrictive member. The magnetostrictive member is formed of a single crystal of an iron-based alloy having magnetostrictive characteristics, is a plate-like body having a long-side direction and a short-side direction, and has a lattice constant of a <100> orientation in the short-side direction larger than a lattice constant of a <100> orientation in the long-side direction.