Fe-Co Alloy Bar Grain Orientation for Stable Magnetic Properties

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing Fe—Co-based alloy bars do not reliably achieve the level of magnetic properties required for advanced applications due to insufficient crystal grain orientation and size distribution.

Innovation Solution

The Fe—Co-based alloy bar is formulated to have an area ratio of crystal grains with a grain orientation spread (GOS) value of 0.5° or more exceeding 80%, with a difference in area ratios between cross sections within 10%, and an average crystal grain size of 6.0 to 8.5, enhancing magnetic properties through controlled processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional hot-rolling processing is used to manufacture Fe-Co-based alloy bars, then production efficiency is maintained, but magnetic properties are insufficient due to poor crystal grain orientation

Engineering Contradiction:
Improvemagnetic propertiesVSAvoidcrystal grain orientation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by performing specific hot-rolling processing conditions before final product completion. The alloy is hot-rolled at 950-1100°C with controlled reduction ratios (total reduction 60-80%, with intermediate annealing) to pre-establish the desired crystal grain orientation and structure before final product formation, ensuring excellent magnetic properties are achieved during subsequent processing

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies parameter changes by optimizing specific processing parameters: hot-rolling temperature (950-1100°C), reduction ratio (60-80% total), and intermediate annealing conditions. These parameter adjustments transform the crystal grain structure to achieve the required orientation and size distribution, directly improving magnetic properties while maintaining manufacturing feasibility

Inventive Principle:
Principle #35Parameter changes

2Reliability

If crystal grain size is reduced to improve magnetic properties, then magnetic permeability increases, but manufacturing complexity increases due to tighter process control requirements

Engineering Contradiction:
Improvemagnetic permeabilityVSAvoidprocess control complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent controls average crystal grain size at 6.0-8.5 by optimizing hot-rolling temperature (950-1100°C) and reduction ratio (60-80%), followed by controlled cooling. This parameter optimization achieves the target grain size range that ensures excellent magnetic permeability while maintaining manageable process control requirements through well-defined processing windows

Inventive Principle:
Principle #35Parameter changes

3Reliability

If uniform crystal grain distribution is achieved to ensure consistent magnetic properties across the bar, then magnetic property reliability improves, but manufacturing time increases due to additional processing steps

Engineering Contradiction:
Improvemagnetic property consistencyVSAvoidmanufacturing cycle time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by implementing intermediate annealing during the hot-rolling process. After initial hot-rolling, the alloy undergoes annealing at 700-900°C for 0.5-2 hours, then continues with remaining hot-rolling passes. This intermediate treatment pre-establishes uniform crystal grain distribution throughout the material, ensuring consistent magnetic properties across the entire bar while completing the process within efficient timeframes

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies periodic action through intermediate annealing cycles during continuous hot-rolling. The process alternates between hot-rolling passes and annealing treatments, creating periodic thermal-mechanical cycles that progressively refine crystal grain structure and ensure uniform distribution throughout the alloy bar, achieving both consistency and manufacturing efficiency

Inventive Principle:
Principle #19Periodic action

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 results in an Fe—Co-based alloy bar with superior magnetic properties, including higher magnetic permeability and lower coercive force, ensuring consistent performance across different cross-sectional orientations.

Implementation Method 1

an area ratio of crystal grains having a grain orientation spread (GOS) value of 0.5° or more exceeds 80%

Methodology Applied
Scientific EffectGrain orientation spread (GOS):

Data Source

PatentUS12522900B2Fe-Co-based alloy bar
Publication Date: 2026.01.13 PROTERIAL LTD

AI summary

The present invention provides an Fe—Co-based alloy bar which enables excellent magnetic properties to be reliably obtained. In the Fe—Co-based alloy bar, an area ratio of crystal grains having a grain orientation spread (GOS) value of 0.5° or more exceeds 80%, and the difference between an area ratio of crystal grains having a GOS value of 0.5° or more observed in a cross section in a direction perpendicular to an axis of the bar and an area ratio of crystal grains having a GOS value of 0.5° or more observed in a cross section in an axial direction of the bar is within 10%. Preferably, the average crystal grain size number is 6.0 or more and 8.5 or less.