Aluminum Coated Copper Wire Bonding Process
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Solution Overview
Problem
Conventional methods for applying aluminum cladding to copper core rods and wires are limited by the need for expensive intermediate metals, elaborate surface preparation, and restricted wire length, as well as complex and costly heat treatment processes.
Innovation Solution
Methods involving the application of aluminum powder or tubes with brazing alloys, where the aluminum powder is compacted and heated to form a metallurgical bond with the copper core, or using a thermal spray deposition process to coat the copper rod with aluminum, allowing for continuous production of long aluminum clad copper wires without expensive intermediates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional methods use intermediate metal cladding (silver) to bond aluminum to copper, then metallurgical bond strength is improved, but manufacturing cost increases significantly
Solution Approach 1:
The invention extracts and eliminates the expensive intermediate metal layer (silver) from the conventional three-layer structure, reducing the bonding system to a simple two-layer aluminum-copper structure while maintaining bond strength through direct aluminum-to-copper bonding achieved by the patent's specific heating and rolling process
Solution Approach 2:
The invention replaces expensive silver intermediate layer with inexpensive aluminum powder or foil that can be directly applied to copper, using a cost-effective materials combination that achieves the same bonding function without the high cost of precious metals
2Ease of manufacture
If conventional methods apply aluminum strips to copper wire by high pressure compression, then aluminum cladding is achieved, but elaborate surface cleaning and preparation is required
Solution Approach 1:
The invention performs preliminary action by applying aluminum powder or foil to the copper surface before final bonding, allowing the aluminum to be positioned and prepared in advance, then activated through heating and rolling to create the metallurgical bond without requiring extensive surface cleaning
Solution Approach 2:
The invention changes the physical parameters of the aluminum material from solid strips to powder or thin foil form, and changes the bonding mechanism from cold high-pressure compression to thermally-activated bonding, thereby reducing surface preparation requirements while achieving strong adhesion
3Device complexity
If conventional methods use fixed-length copper rods for cladding, then bonding process is simplified, but final product length is severely limited
Solution Approach 1:
The invention enables continuous production by allowing the cladding process to operate continuously on copper wire fed from reels, with the aluminum powder/foil and copper wire moving through the heating and rolling zones in a continuous manner, producing long lengths of clad wire without interruption
Solution Approach 2:
The invention transitions from static fixed-length rod processing to dynamic continuous wire processing, where materials move continuously through the bonding zone, enabling production of much longer final products limited only by reel capacity rather than rod length
4Strength
If conventional methods apply aluminum cladding through multiple heat treatment steps, then metallurgical bond is achieved, but processing time and energy consumption increase
Solution Approach 1:
The invention merges the heating and bonding operations into a single integrated process step, where aluminum powder/foil is applied to copper and then both are heated together in one zone to achieve metallurgical bonding, eliminating the need for separate heat treatment steps required in conventional methods
Solution Approach 2:
The invention utilizes phase transition (melting) of aluminum at relatively low temperature to achieve bonding, where the aluminum powder or foil melts and bonds to the copper surface in a single heating step, avoiding the need for multiple heat treatment cycles at different temperature stages
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
These methods enable the efficient and cost-effective manufacturing of long aluminum clad copper wires with a firm metallurgical bond between the copper and aluminum layers, eliminating the need for expensive intermediate metals and simplifying the heat treatment process, while avoiding elaborate surface preparation and complex atmosphere treatments.
Implementation Method 1
passing the rod through a first set of compression rolls thereby forcing the aluminum powder into a compacted preform around the rod
Implementation Method 2
heating the rod covered by the preform to a temperature between 550° C. and 620° C.
Implementation Method 3
heating the rod covered by the preform to a temperature between 550° C. and 620° C. The heated preform coated rod is then passed through a second set of compression rolls thereby obtaining an aluminum coated copper rod
Implementation Method 4
the heated preform coated rod is then passed through a second set of compression rolls thereby obtaining an aluminum coated copper rod
Implementation Method 5
heating the composite tube-rod to a first temperature. The above process causes the inner layer of the brazing aluminum alloy to melt and fuse to the copper rod
Implementation Method 6
The aluminum tube includes an inner layer formed of a brazing aluminum alloy
Implementation Method 7
using a thermal spray deposition process to coat the copper rod with aluminum
Data Source
AI summary
Methods of applying aluminum coating layers over copper wires are disclosed. A first method may include applying aluminum powder to the surface of a rod, passing the rod through a first set of compression rolls thereby forcing the aluminum powder into a compacted preform around the rod, and heating the rod covered by the preform at 550° C. to 620° C. Further, the heated preform coated rod is passed through a second set of compression rolls thereby obtaining an aluminum coated copper rod. A second method includes disposing a copper rod inside an aluminum tube having an inner layer formed of brazing aluminum alloy, reducing the diameter of the tube's inner surface to match the copper rod, and heating the composite tube-rod such that the inner layer of the brazing alloy fuses to the rod. Another method includes passing the copper rod through a spray of metallic aluminum.