Aluminum Base Wire Segmented Copper Coating for Bending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aluminum base wires with conventional copper plating layers crack upon bending, leading to galvanic corrosion due to exposure of the core wire, as copper has low ductility and poor adhesion with tin-based materials.
Innovation Solution
The aluminum base wire design features a core wire with scattered copper-based coating pieces and a multilayer coating structure, including a copper-tin first layer and a tin-based second layer, which improves adhesion and flexibility, preventing cracking and peeling even under bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional copper plating layer is used on the aluminum base wire, then electrical conductivity is improved, but the coating layer cracks upon bending due to low ductility of copper
Solution Approach 1:
The copper coating is segmented into discrete coating pieces rather than a continuous layer. This segmentation allows the coating to accommodate bending deformation without cracking, as the discrete pieces can shift and deform independently while maintaining electrical conductivity through the scattered distribution of conductive elements.
Solution Approach 2:
The invention uses a composite coating structure combining copper-based coating pieces with a tin-based coating layer. The copper pieces provide electrical conductivity while the tin-based matrix provides ductility and flexibility, creating a composite material that exhibits both high conductivity and good bendability.
2Reliability
If a thick copper plating layer is applied to ensure adequate conductivity, then electrical performance is improved, but adhesion with tin-based materials deteriorates
Solution Approach 1:
The copper is distributed locally as scattered coating pieces rather than applied as a uniform thick layer. This local quality approach maintains adequate conductivity through the presence of conductive copper regions while avoiding the adhesion problems associated with thick continuous copper layers, as the tin-based coating can properly adhere to the aluminum base wire in the non-copper regions.
3Productivity
If wire drawing is performed on a base member with conventional coating layers, then manufacturing efficiency is improved, but the coating layer cracks and peels during the drawing process
Solution Approach 1:
The segmented copper coating pieces allow the coating structure to accommodate the deformation stresses of wire drawing without cracking. The discrete pieces can deform and reposition during the drawing process, maintaining coating integrity while enabling efficient manufacturing through continuous wire drawing operations.
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 effectively suppresses coating layer cracking and corrosion of the core wire, allowing for easy twisting of stranded wires and improved manufacturing processes with high bendability and corrosion resistance.
Implementation Method 1
a step of heating the base member
Data Source
AI summary
An aluminum base wire includes a core wire composed of pure aluminum or an aluminum alloy; a plurality of coating pieces provided so as to be scattered on an outer periphery of the core wire; and a coating layer provided on the outer periphery of the core wire and an outer periphery of each of the plurality of coating pieces. The coating layer includes a first layer that is provided continuously on the outer periphery of the core wire between adjacent coating pieces and the outer periphery of each of the plurality of coating pieces, and a second layer provided on an outer periphery of the first layer. The plurality of coating pieces are each composed of copper or a copper alloy, the first layer is composed of metals that include copper and tin, and the second layer is composed of tin or a tin alloy.