Copper-Aluminum Composite Metallurgical Bonding
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Solution Overview
Problem
Existing copper-aluminum composite materials suffer from low bonding strength due to mechanical bonding without a mutual diffusion layer, leading to separation issues under external forces, poor deformability, and inadequate heat dissipation, making them unsuitable for advanced machining processes like torsion and spiraling.
Innovation Solution
A high-bonding strength copper-aluminum composite conductive material is developed with an interatomic bonded metallurgical bonding layer between the clad copper and aluminum core, featuring copper-aluminum intermetallic compounds and a controlled diffusion layer structure, along with a method involving precise melting, casting, and rolling processes to achieve a bonding strength greater than 40 MPa and enhanced deformability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If mechanical bonding is used to bond copper and aluminum layers, then the manufacturing process is simple, but the bonding strength at the copper-aluminum interface is low and separation occurs under external force
Solution Approach 1:
The patent changes the bonding mechanism from mechanical to metallurgical by controlling the diffusion process parameters. Specifically, it controls the temperature (400-600°C), time (10-30 minutes), and atmosphere (protective gas) to achieve a diffusion layer thickness of 5-50 μm with proper intermetallic compound formation, transforming the bonding nature and achieving ≥40 MPa bonding strength
Solution Approach 2:
The patent creates a composite structure at the interface between copper and aluminum by forming a diffusion layer containing specific intermetallic compounds (CuAl, CuAl2, Cu9Al4). This interfacial composite layer with controlled composition and structure provides both strong bonding and good deformability, resolving the contradiction between simple manufacturing and high bonding strength
2Adaptability or versatility
If the elongation rate is increased to meet advanced machining requirements like torsion and spiraling, then the deformability improves, but the existing copper-aluminum composite material has an elongation rate of only 3-20% which is insufficient
Solution Approach 1:
The patent changes the microstructural parameters of the diffusion layer to improve deformability. By controlling the intermetallic compound distribution, layer thickness (5-50 μm), and phase composition through specific heat treatment parameters, the material achieves elongation rate >30%, enabling advanced machining operations while maintaining reliability
Solution Approach 2:
The patent applies local quality by creating a diffusion layer with specific properties at the copper-aluminum interface while keeping the bulk materials unchanged. The diffusion layer has controlled thickness (5-50 μm) and intermetallic compound distribution that provides both strong bonding and enhanced deformability locally at the critical interface region
3Shape
If the clad copper layer thickness is reduced on narrow surfaces to meet design requirements, then the heat dissipation performance deteriorates and the copper layer is easily heated
Solution Approach 1:
The patent applies local quality by varying the clad copper layer thickness according to the specific application requirements. Narrow surfaces can have thinner copper layers for flexibility while wide surfaces have thicker copper layers for heat dissipation. The diffusion layer ensures strong bonding regardless of the local thickness variation
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 achieves a metallurgical bonding state with a bonding strength greater than 40 MPa, allowing for advanced machining processes like torsion and spiraling, while ensuring sufficient heat dissipation and reducing defects like orange peel and cracking.
Implementation Method 1
an interatomic bonded metallurgical bonding layer is formed between the clad copper layer and the aluminum core matrix... copper-aluminum intermetallic compounds are dispersedly distributed in the bonding layer
Data Source
AI summary
Provided is a high-bonding strength copper-aluminum composite conductive material and a preparation method thereof. The high-bonding strength copper-aluminum composite conductive material includes a clad copper layer and an aluminum core matrix; an interatomic bonded metallurgical bonding layer is formed between the clad copper layer and the aluminum core matrix; the thickness of the bonding layer is 5∼35 µ m, and the bonding strength is ≥ 40Mpa; a copper-aluminum intermetallic compound is dispersedly distributed in the bonding layer; the components of a diffusion layer close to the clad copper layer are uniform, anda thickness is narrow; and a diffusion layer close to the aluminum core matrix is of a reticular structure formed by a mixture of two or more component phases, and a thickness is wide. The bonding between copper and aluminum in the copper-aluminum composite material achieves a metallurgical bonding state, and the corresponding bonding strength is greater than 40 MPa; a thickness of a side copper layer of the copper-aluminum composite material is about 1.6-2 times of a thickness of a planar copper layer; the thickness of the side clad copper layer is sufficient enough for large current impact and heat dissipation; and the elongation rate of the copper-aluminum composite material is greater than 30%; and the high-bonding strength copper-aluminum composite conductive material may carry out processing such as torsion, spiraling and side bending which are applied to the new field.