Zirconium Copper Alloy Wire Grain Refinement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Copper alloy wires containing zirconium face challenges in improving bendability without compromising electrical conductivity, as existing methods to enhance mechanical strength often decrease electrical conductivity.
Innovation Solution
A manufacturing method involving solid-solution treatment, thermal treatment, and wire drawing steps to create a copper alloy wire with a copper crystal grain diameter of 1 μm or smaller, dispersing zirconium precipitates, and performing thermal treatments at 350 to 400°C to maintain high electrical conductivity and tensile strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If thermal treatment is performed to deposit zirconium precipitates to improve tensile strength, then bendability deteriorates due to increased brittleness
Solution Approach 1:
The patent applies parameter changes by precisely controlling the thermal treatment temperature range (350-400°C) and duration to achieve optimal precipitate distribution. This temperature control allows zirconium precipitates to form uniformly without excessive growth, improving tensile strength while maintaining sufficient ductility for bending operations.
Solution Approach 2:
The patent creates a composite microstructure within the copper alloy wire by distributing zirconium precipitates throughout the copper matrix. This composite structure at the micro-scale provides both the strength from precipitate reinforcement and the ductility from the copper matrix, resolving the contradiction between tensile strength and bendability.
2Strength
If zirconium content is increased to improve tensile strength, then electrical conductivity decreases due to impurity scattering
Solution Approach 1:
The patent optimizes the zirconium content parameter within a specific range (200-2000 ppm) to achieve the desired balance. By controlling the concentration of zirconium atoms, the patent ensures sufficient precipitate formation for strength enhancement while limiting the overall impurity content to maintain electrical conductivity above 87% IACS.
Solution Approach 2:
The patent applies local quality by concentrating zirconium atoms specifically as discrete precipitates at controlled locations within the copper matrix, rather than uniform distribution. This localized precipitation provides strengthening where needed while leaving the bulk copper matrix relatively pure for maintaining electrical conductivity.
3Strength
If copper crystal grain diameter is reduced to improve tensile strength, then manufacturing complexity increases due to additional processing steps
Solution Approach 1:
The patent merges the grain refinement function into the existing thermal treatment step by selecting appropriate temperature and duration parameters. The same thermal treatment that deposits zirconium precipitates also promotes copper grain boundary migration and refinement, achieving both strengthening mechanisms through a single integrated process rather than separate operations.
Solution Approach 2:
The patent uses parameter changes in the thermal treatment process (temperature of 350-400°C and controlled duration) to simultaneously achieve precipitate deposition and grain refinement. By optimizing these parameters, the patent accomplishes multiple microstructural improvements without adding separate processing steps, thereby reducing manufacturing complexity.
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 effectively improves bendability and tensile strength of copper alloy wires while maintaining electrical conductivity above 87% IACS and tensile strength above 545 MPa, enhancing their durability against repeat bending.
Implementation Method 1
a step of performing a solid-solution treatment to a copper material having a state in which zirconium is solid-solved in copper to from the copper material having a supersaturated solid-solution state
Implementation Method 2
a step of performing a thermal treatment to the second wire material at 350 to 400° C. to deposit a precipitate containing zirconium in the second copper alloy wire
Implementation Method 3
a step of elongating the copper material having the supersaturated solid-solution state to form a first wire material
Data Source
AI summary
Bendability of a copper alloy wire is improved without decrease in an electrical conductivity of the copper alloy wire made of copper alloy containing zirconium. A cable includes: a two-core stranded wire formed by intertwining two electrical wires made of a conductor and an insulating layer covering the conductor; a filler formed around the two-core stranded wire; and a sheath formed around the filler and the electrical wire. The conductor is a copper alloy wire in which a precipitate containing the zirconium disperses, and has a crystal gain diameter that is equal to or smaller than 1 μm, an electrical conductivity that is equal to or higher than 87% IACS, and a tensile stress that is equal to or larger than 545 MPa.