Al Alloy Wire for Engine Wiring Harnesses

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Solution Overview

Problem

There is a need for an aluminum alloy wire with a wire diameter of 0.5 mm or less that has high strength, high electrical conductivity, sufficient elongation, and superior impact resistance, as well as high-temperature strength and heat resistance, to be used in dynamic and high-temperature locations such as vehicle engines.

Innovation Solution

The aluminum alloy wire is fabricated using an Al-Mg-Si alloy with specific ranges of elements like Zr, Mn, Ti, and B to refine the crystal structure, achieving a fine grain size and improved mechanical properties, including high tensile strength and electrical conductivity, even at elevated temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If pure aluminum is used as the conductor material, then the weight is reduced, but the impact resistance and flexing characteristics deteriorate

Engineering Contradiction:
Improveweight of electrical wireVSAvoidimpact resistance and flexing characteristics
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent applies composite materials by developing an aluminum alloy wire comprising Al-Mg-Si base alloy and specific additive elements (Ti, B, Zr, Mn, Cr, Cu, Fe) in controlled amounts. This composite alloy structure combines the lightweight property of aluminum with enhanced mechanical strength and ductility, resolving the contradiction between weight reduction and impact resistance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs parameter changes by precisely controlling the compositional parameters of the aluminum alloy (Mg: 0.2-1.5%, Si: 0.1-2.0%, Ti: 0.003-0.06%, B: 0.0003-0.006%, etc.) and processing parameters (elongation ratio: 30-80%, solution treatment temperature: 400-650°C, aging treatment temperature: 100-300°C) to achieve optimal balance between weight, strength, and ductility.

Inventive Principle:
Principle #35Parameter changes

2Weight of moving object

If the wire diameter is reduced to 0.5 mm or less, then the weight is reduced, but the strength and elongation deteriorate

Engineering Contradiction:
Improveweight of wireVSAvoidtensile strength and elongation
Core Design Contradiction:
Weight of moving objectVSStrength

Solution Approach 1:

The patent applies parameter changes by optimizing the alloy composition parameters and heat treatment parameters to achieve high strength and elongation in extra fine wires with diameter of 0.5 mm or less. The specific compositional parameters and processing parameters are controlled to ensure the wire maintains sufficient mechanical properties despite the reduced diameter.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials with multiple alloying elements (Al-Mg-Si base with Ti, B, Zr, Mn, Cr, Cu, Fe additives) to enhance the mechanical strength of extra fine wires, allowing the wire to maintain high strength despite the reduced diameter that would normally weaken the structure.

Inventive Principle:
Principle #40Composite materials

3Strength

If the tensile strength is increased through alloying, then the high-temperature strength is improved, but the electrical conductivity deteriorates

Engineering Contradiction:
Improvehigh-temperature strengthVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the compositional parameters of alloying elements to achieve the optimal balance between high-temperature strength and electrical conductivity. The specific ranges of Mg (0.2-1.5%), Si (0.1-2.0%), and additive elements are optimized to minimize the impact on electrical conductivity while maximizing high-temperature strength.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs local quality by having different elements perform specific functions: Mg and Si provide strength enhancement, while Ti, B, Zr, Mn, Cr, Cu, and Fe are added in small amounts to refine grain structure and improve high-temperature properties with minimal impact on overall electrical conductivity, creating a multi-functional composite alloy system.

Inventive Principle:
Principle #3Local quality

4Strength

If the wire is subjected to solution treatment and aging treatment to increase strength, then the high-temperature strength is improved, but the elongation deteriorates

Engineering Contradiction:
Improvehigh-temperature strengthVSAvoidelongation
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent applies parameter changes by optimizing the solution treatment parameters (temperature: 400-650°C, time: 0.5-5 hours) and aging treatment parameters (temperature: 100-300°C, time: 1-24 hours) to achieve the desired balance between high-temperature strength and elongation. The compositional parameters of the alloy are also optimized to respond favorably to these heat treatments.

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 resulting aluminum alloy wire exhibits high strength, high electrical conductivity, and excellent elongation, making it suitable for dynamic and high-temperature applications, with the ability to maintain strength and conductivity over time, even in harsh environments.

Implementation Method 1

high electrical conductivity

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

superior in elongation

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 3

superior in elongation

Methodology Applied
Scientific EffectPlastic deformation: Plasticity

Data Source

PatentEP2987880B1Aluminum alloy wire and aluminum alloy twisted wire, covered electric wire, and wire harness using the same
Publication Date: 2018.10.24 SUMITOMO ELECTRIC INDUSTRIES LTD
  • EP2987880B1 patent drawingFigure 1(A)~1(D)

AI summary

An aluminum (Al) alloy wire, which is an extra fine wire having a wire diameter of 0.5 mm or less, contains, in mass%, Mg at 0.03% to 1.5%, Si at 0.02% to 2.0%, at least one element selected from Cu, Fe, Cr, Mn and Zr at a total of 0.1% to 1.0% and the balance being Al and impurities, and has an electrical conductivity of 40% IACS or more, a tensile strength of 150 MPa or more, and an elongation of 5% or more. By producing the extra fine wire from an Al alloy of a specific composition containing Zr, Mn and other specific elements, though the extra fine wire is extra fine, it has a fine structure with a maximum grain size of 50 µm or less and is superior in elongation. A tensile strength after being retained for 1000 hours at an arbitrary temperature selected from 80°C to 150°C is 150 MPa or more, which is superior in heat resistance. Thereby, there is provided an Al alloy wire which is extra fine and superior in elongation while having a high strength and a high electrical conductivity, an Al alloy twisted wire, a covered electrical wire including the Al alloy wire or the Al alloy twisted wire, and a wire harness including the covered electrical wire.