Diffusion-Bonded Copper Alloy Body for Thermal Shock Resistance
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Solution Overview
Problem
Existing diffusion bonding methods for copper alloys struggle to achieve high bonding strength and texture, particularly when subjected to severe thermal shock or dimensional fluctuations during solution annealing and aging treatments.
Innovation Solution
Selectively using an age-hardenable copper alloy with a beryllium content of 0.7% by weight or less, ensuring a flat and oxide-free bonding surface, and performing diffusion bonding followed by homogenization treatment, solution annealing, and aging treatment to reduce inclusion ratios and enhance bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If diffusion bonding is performed on copper alloy in a similar step to stainless steel, then bonding is achieved, but bonding strength and texture are insufficient and the bonded body breaks under thermal shock
Solution Approach 1:
The patent changes the bonding parameters specifically for copper alloy by controlling the temperature increase rate (5-20°C/min) and holding time (30-180 minutes) at bonding temperature, which differs from the stainless steel bonding process. This parameter optimization prevents oxide film formation while achieving strong bonding that withstands thermal shock.
Solution Approach 2:
The patent performs preliminary oxide film removal from the copper alloy bonding surfaces before diffusion bonding, similar to the stainless steel process. This preliminary action ensures clean bonding surfaces that will not form oxides during the controlled heating process, enabling strong and reliable bonds.
2Ease of manufacture
If copper alloy bonding surfaces are heated under high vacuum, then bonding is facilitated, but oxide film forms again on the bonding surface
Solution Approach 1:
The patent removes oxide films from copper alloy bonding surfaces before diffusion bonding, creating a clean surface that is less prone to re-oxidation during the controlled heating process in high vacuum.
Solution Approach 2:
The patent controls the temperature increase rate (5-20°C/min) and holds the bonding temperature for a specific duration (30-180 minutes) to minimize oxide film formation on the bonding surfaces during the diffusion bonding process in high vacuum.
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 approach results in a copper alloy bonded body with an extremely high bonding strength, capable of withstanding severe thermal and dimensional changes without breaking at the bonding part.
Implementation Method 1
members diffusion-bonded to one another
Implementation Method 2
temperature increase rate is 5° C./min or more and 20° C./min or less
Implementation Method 3
solution annealing and an aging treatment
Implementation Method 4
solution annealing and an aging treatment
Data Source
AI summary
There is provided a copper alloy bonded body composed of members made of an age-hardenable copper alloy, diffusion-bonded to one another. In the bonded body, a bonding interface between the members remains, and (i) the age-hardenable copper alloy is a beryllium copper alloy of which the beryllium content is 0.7% by weight or less, and an area ratio of inclusions composed of an oxide, a carbide, and/or an intermetallic compound in a HAADF-STEM image of a rectangular section of a size of 800 nm×400 nm including the bonding interface is 7.5% or less, or (ii) the age-hardenable copper alloy is a copper alloy free from beryllium, and an area ratio of inclusions composed of an oxide, a carbide, and/or an intermetallic compound in a HAADF-STEM image of a rectangular section of a size of 800 nm×400 nm including the bonding interface is 30% or less.