Dual-Metal Adapter Structure for Low-Current Brazed Joining
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing metal joining techniques, such as resistive brazing/soldering and spot welding, face issues with electrode wear due to indirect heating, where most heat is generated in the electrodes, causing them to become hotter than the parts being joined, leading to inefficient energy use and reduced lifespan.
Innovation Solution
A dual metal adapter system comprising an inner tube of lower resistivity metal and an outer tube of higher resistivity metal, where the outer tube generates heat that conducts inwardly to melt a filler metal, directly bonding the inner tube to the parts, reducing the need for high current and minimizing electrode temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high current is used to generate heat in electrodes for joining metal parts, then the joining process can be achieved, but the electrodes become excessively hot and wear out quickly
Solution Approach 1:
The adapter uses two different metals with different resistivities in specific locations: the inner tube uses low resistivity metal to conduct current with minimal heat generation, while the outer tube uses high resistivity metal to generate heat locally for brazing. This local differentiation of material properties allows heat generation exactly where needed without overheating the electrodes or other components.
Solution Approach 2:
The adapter is constructed as a composite structure combining two metal tubes with different electrical and thermal properties. The inner low-resistivity metal tube and outer high-resistivity metal tube work together to achieve both efficient current conduction and localized heat generation, resolving the contradiction between power delivery and component durability.
2Power
If most heat is generated in the electrodes to indirectly heat the parts, then the joining process works, but energy efficiency is reduced and electrodes wear
Solution Approach 1:
The outer tube of high-resistivity metal serves itself by generating the heat needed for brazing through its own electrical resistance. This eliminates the need for electrodes to generate excessive heat, as the heat is produced directly in the adapter component that requires heating, significantly improving energy efficiency.
Solution Approach 2:
The invention changes the resistivity parameter of the adapter material from uniform (electrode material) to graduated (inner low-resistivity tube and outer high-resistivity tube). This parameter change shifts the heat generation location from the electrodes to the outer tube, improving energy efficiency by reducing unnecessary heat generation in other components.
3Temperature
If electrodes are made hotter than the parts to be joined to enable heat flow, then joining can occur, but the electrodes suffer from thermal stress and wear
Solution Approach 1:
The heat generation function is extracted from the electrodes and transferred to the outer tube of the adapter. The electrodes only need to heat the outer tube to brazing temperature, not exceed it significantly. This extraction of the heat generation role from the electrodes reduces their thermal stress and improves reliability.
4Ease of manufacture
If uniform metal is used in the adapter, then manufacturing is simple, but heat generation cannot be controlled to the specific location needed for brazing
Solution Approach 1:
The adapter employs local quality by using different metals in different locations: the inner tube uses low-resistivity metal for current conduction while the outer tube uses high-resistivity metal for localized heat generation. This spatial differentiation of material properties enables precise control of heat generation location while maintaining manufacturing feasibility through a relatively simple two-layer construction.
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
This solution allows for efficient direct heating of the inner tube and filler metal, reducing the current required for bonding and prolonging electrode lifespan, while enabling the use of lower resistivity components like copper, and simplifying the assembly process without moving parts.
Implementation Method 1
The outer tube is formed from a second metal having a second resistivity greater than the first resistivity... efficient direct heating of the inner tube and filler metal
Implementation Method 2
heat conducts inwardly to melt a filler metal
Implementation Method 3
The first ends of the first and second members are metallurgically bonded to the inner tube by the filler metal in response to heat applied to the assembly
Data Source
AI summary
An assembly includes at least one member having first and second ends. A dual metal adapter for connecting to the at least one member includes an inner tube for receiving and contacting the first end of the at least one member and being formed from a first metal having a first resistivity. An outer tube extends over the inner tube and is secured thereto. The outer tube is formed from a second metal having a second resistivity greater than the first resistivity. The first end of the at least one member is metallurgically bonded to the inner tube.