Aluminum Alloy Bus Bar Composition for Bendable High-Strength Conductors

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Solution Overview

Problem

Existing aluminum alloys used in bus bars, such as A6101-T6, exhibit poor bending workability and electrical connection stability, leading to increased manufacturing costs and material loss due to sharp corners and stress concentration, while industrial pure aluminum lacks sufficient strength for automotive applications.

Innovation Solution

An aluminum alloy bus bar with a controlled texture state, containing 0.35 to 0.8% magnesium and 0.3 to 0.7% silicon, dispersed with Mg-Si system acicular particles of specific length and density, enhancing yield stress and suppressing stress relaxation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If A6101 alloy is used to increase strength, then tensile strength and yield stress are improved, but bending workability deteriorates

Engineering Contradiction:
Improvetensile strengthVSAvoidbending workability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The invention changes the microstructural parameters of the aluminum alloy by controlling the size and distribution of Mg-Si precipitates. By reducing the precipitate size to 67.1-378.4 nm and optimizing their number density, the material achieves both high strength and improved bending workability without requiring heating during forming operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite microstructure within the aluminum alloy by dispersing Mg-Si acicular particles throughout the aluminum matrix. This composite structure at the microscale provides both the strength enhancement from precipitates and the ductility needed for good bending workability.

Inventive Principle:
Principle #40Composite materials

2Strength

If A6101 alloy is used to increase strength, then yield stress is improved, but electrical connection stability deteriorates

Engineering Contradiction:
Improveyield stressVSAvoidelectrical connection stability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The invention optimizes the size parameter of Mg-Si precipitates to a specific range (67.1-378.4 nm) that simultaneously provides yield stress enhancement and maintains electrical connection stability. The controlled number density of precipitates ensures adequate strength while preventing excessive stress relaxation that would compromise electrical connections.

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If heating is applied during edgewise bending to improve bending workability, then bending workability is improved, but strength decreases due to quality change

Engineering Contradiction:
Improvebending workabilityVSAvoidstrength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The invention performs preliminary action by controlling the precipitate formation and texture state during manufacturing, before the bending operation. By pre-establishing the optimal microstructure with fine Mg-Si precipitates, the material achieves good bending workability at room temperature without requiring subsequent heating that would compromise strength.

Inventive Principle:
Principle #10Preliminary action

4Ease of manufacture

If heating is applied during edgewise bending to improve bending workability, then bending workability is improved, but manufacturing costs increase

Engineering Contradiction:
Improvebending workabilityVSAvoidmanufacturing costs
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The invention changes the material parameters during manufacturing to achieve room-temperature formability. By controlling the Mg-Si precipitate characteristics, the bus bar can be bent without heating equipment, eliminating the additional manufacturing steps and costs associated with thermal processing while maintaining adequate bending workability.

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

Improves bending workability and electrical connection stability, reducing material loss and stress concentration, while maintaining high conductivity and strength for automotive environments.

Implementation Method 1

A plurality of Mg-Si system acicular particles containing magnesium and silicon are dispersed in the aluminum alloy. A6101 alloy has fine magnesium-silicon precipitates in an aluminum matrix and achieves high strength by the Orowan mechanism.

Methodology Applied
Scientific EffectPrecipitation hardening: Precipitation Hardening

Implementation Method 2

An aluminum alloy bus bar that is improved in bending workability and electrical connection stability by controlling the texture state of the material... suppressing stress relaxation

Methodology Applied
Scientific EffectStress relaxation: Stress Relaxation

Data Source

PatentEP4682277A1Aluminum alloy bus bar
Publication Date: 2026.01.21 YAZAKI CORP
  • EP4682277A1 patent drawingFigure 1
  • EP4682277A1 patent drawingFigure 2~3
  • EP4682277A1 patent drawingFigure 4~5

AI summary

An aluminum alloy bus bar (1) includes a flat electric conductor (10) made of an aluminum alloy containing 0.35 to 0.8% by mass of magnesium and 0.3 to 0.7% by mass of silicon, with the remainder consisting of aluminum and unavoidable impurities. A plurality of Mg-Si system acicular particles (16) containing magnesium and silicon are dispersed in the aluminum alloy. An average length of the Mg-Si system acicular particles (16) is 67.1 nm to 378.4 nm, and number density of the Mg-Si system acicular particles (16) in the aluminum alloy is 4.5×1020/m3 to 6.8×1021/m3.