Copper Alloy Composition for Strength and Conductivity

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Solution Overview

Problem

Copper alloys with higher strength tend to have reduced electrical conductivity, limiting their application due to increased resistance, and there is a need for materials that balance strength and conductivity while avoiding hazardous elements like cadmium.

Innovation Solution

Development of copper base alloys with specific compositions of chromium, silver, and magnesium or tin, processed through methods like casting, extruding, and heat treating to achieve a balance of tensile strength and electrical conductivity, suitable for various forms such as wires, strands, and cables.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If copper alloys with higher strength are used, then tensile strength is improved, but electrical conductivity deteriorates

Engineering Contradiction:
Improvetensile strengthVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the composition ranges of alloying elements (Cr: 0.3-1.5%, Ag: 0.02-0.2%, Sn: 0.05-0.15%, Mg: 0.05-0.15%) and applying specific heat treatment parameters (aging temperature 150-500°C, annealing temperature 650-950°F for 1-5 hours) to achieve the optimal balance between strength and conductivity that cannot be obtained by simple alloying alone

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite copper alloy system combining multiple elements (Cr, Ag, Sn, Mg) with copper base metal, where each element contributes specific properties: Cr for strength, Ag for conductivity enhancement, Sn and Mg for synergistic strengthening. This multi-element composite approach achieves superior strength-conductivity balance compared to single-element alloys

Inventive Principle:
Principle #40Composite materials

2Strength

If cadmium-containing alloys are used to increase strength, then tensile strength is improved, but safety and environmental compatibility deteriorate

Engineering Contradiction:
Improvetensile strengthVSAvoidhazardous nature of cadmium
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and eliminates the harmful cadmium element from the alloy composition while maintaining the desired strength properties through substitution with safer elements like chromium, silver, tin, and magnesium that provide equivalent or superior mechanical properties without the toxic effects of cadmium

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses abundant, non-toxic, and environmentally friendly elements (Cr, Ag, Sn, Mg) that are safer and more sustainable than cadmium, replacing hazardous materials with cheaper, non-harmful alternatives that achieve the same functional goals

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If beryllium copper alloy is used to increase strength, then tensile strength is improved, but electrical conductivity deteriorates further

Engineering Contradiction:
Improvetensile strengthVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent changes the alloying parameters by using smaller, more controlled amounts of strengthening elements (Cr: 0.3-1.5% compared to higher Be content in C17510) and optimizing heat treatment parameters to achieve strength levels comparable to or exceeding C17510 while maintaining superior electrical conductivity through the copper-rich matrix and beneficial Ag addition

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional processing methods are used, then ease of manufacture is maintained, but achieving high strength and high conductivity simultaneously becomes difficult

Engineering Contradiction:
Improveease of processingVSAvoidcombination of strength and conductivity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies preliminary action through controlled aging heat treatment (150-500°C) applied before final drawing and annealing operations, which pre-establishes the optimal precipitation hardening structure in the alloy, enabling subsequent conventional processing to maintain both high strength and high conductivity without requiring specialized equipment or complex process sequences

Inventive Principle:
Principle #10Preliminary 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 alloys achieve a superior combination of electrical conductivity and tensile strength, exceeding industry standards with enhanced flexure life and resistance to softening, making them suitable for demanding applications.

Implementation Method 1

heat treating (aging)

Methodology Applied
Scientific EffectAging: Heat Treatment

Implementation Method 2

The alloys achieve a superior combination of electrical conductivity and tensile strength, exceeding industry standards with enhanced flexure life and resistance to softening

Methodology Applied
Scientific EffectPrecipitation hardening: Precipitation Hardening

Implementation Method 3

final heat treating (annealing) usually within a range of 650-950°F for 1 to 5 hours

Methodology Applied
Scientific EffectAnnealing: Annealing

Data Source

PatentEP2646586B1High strength, high conductivity copper alloys and electrical conductors made therefrom
Publication Date: 2019.06.05 FISK ALLOY
  • EP2646586B1 patent drawingFigure 1~2
  • EP2646586B1 patent drawingFigure 3~4
  • EP2646586B1 patent drawingFigure 5~6

AI summary

A copper base alloy achieves a breakthrough electrical conductor product of strength, flexure and conductivity of minimal inverse in relationship of at least 85 % IACS electrical conductivity while providing an 80 to 85 ksi tensile strength, an increase of at least 33% in strength compared to prior art and is made from an alloy consisting essentially of 0.2-0.5 w/o chromium,.02-.20 w/o silver and.04-.16 w/o of a third metallic component selected from the group consisting of tin, magnesium and tin/magnesium together.