Copper Heat Exchanger LMD Joining Without an Intermediate Nickel Layer
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Solution Overview
Problem
The existing heat exchanger designs for rocket engines and other applications require a nickel layer between the copper heat transfer body and the LMD layer to facilitate laser metal deposition, increasing costs and complexity.
Innovation Solution
A method to directly form the LMD layer on the outer surface of a copper or copper alloy heat transfer body using laser metal deposition, eliminating the need for a nickel layer by setting the energy density of the laser light to melt both the metal material and the heat transfer body, thereby achieving a strong bond without the intermediate layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nickel layer is provided between the copper heat transfer body and the LMD layer, then the LMD treatment can be performed successfully due to lower laser light reflectivity, but the manufacturing cost and process complexity increase
Solution Approach 1:
The patent removes the nickel intermediate layer from the structure, extracting the problematic component that caused increased complexity and cost. By directly applying the LMD layer to the copper heat transfer body, the solution eliminates the unnecessary intermediate layer while maintaining bond strength through optimized laser parameters
Solution Approach 2:
The patent changes the laser treatment parameters, specifically using laser light with a wavelength of 1070 nm and controlling the energy density to overcome the high reflectivity of copper. This parameter change enables direct LMD treatment on copper without requiring a nickel intermediate layer, thus reducing complexity while maintaining reliability
2Reliability
If a nickel layer is provided between the copper heat transfer body and the LMD layer, then the LMD treatment can be performed, but the manufacturing cost increases
Solution Approach 1:
The patent removes the nickel intermediate layer, eliminating the additional material cost and processing steps associated with depositing and treating this layer. The direct LMD approach reduces manufacturing cost while maintaining bond strength through optimized laser parameters
Solution Approach 2:
The patent adopts a simpler, more economical approach by using direct LMD on copper without the expensive nickel intermediate layer. The optimized laser parameters ensure successful bonding despite copper's high reflectivity, making the process both cheaper and more efficient
3Device complexity
If laser metal deposition is performed directly on copper, then the manufacturing process is simplified, but the high reflectivity of copper makes the treatment difficult
Solution Approach 1:
The patent changes the laser wavelength to 1070 nm and optimizes the energy density parameters to overcome copper's high reflectivity. This parameter optimization enables direct LMD treatment on copper, simplifying the structure while making the treatment feasible
Solution Approach 2:
The patent applies preliminary surface treatment or preparation to the copper heat transfer body before LMD, such as creating a roughened surface or applying a primer layer, to reduce laser reflectivity and facilitate direct LMD treatment without requiring a nickel intermediate layer
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 approach allows for a high bond strength between the heat transfer body and the LMD layer, eliminating the need for a low-reflectivity nickel layer and reducing manufacturing steps, while preventing oxide formation and ensuring uniform density of the LMD layer.
Implementation Method 1
irradiating the supply position with laser light, and thereby, the LMD treatment melts both the metal material and the outer circumferential surface
Implementation Method 2
the LMD treatment melts both the metal material and the outer circumferential surface formed of the material including the pure copper or the copper alloy
Data Source
AI summary
A heat transfer body 3 is prepared. The heat transfer body 3 forms an inner space 7 for existence of one of a higher-temperature fluid or a lower-temperature fluid. The heat transfer body 3 constitutes a heat exchanger, and is formed of a copper material as a wall surrounding the inner space 7. In the wall, a flow path through which the other of the higher-temperature fluid and the lower-temperature fluid flows is formed. By LMD treatment, an LMD layer is formed directly on an outer circumferential surface 3a of the heat transfer body 3. In the LMD treatment, a metal material is supplied to a supply position on the outer circumferential surface 3a, and the supply position is irradiated with laser light to form an LMD layer 5. An energy density of the laser light is set to melt both the metal material and the outer circumferential surface 3a.