Multi-Nozzle Cold Spray Apparatus with Laser Heating
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Solution Overview
Problem
Existing cold spray technologies face challenges in achieving uniform coatings on large substrates with varying surface areas, as they require complex tool path optimization and can result in defects and imperfections, especially when coating circular or conical objects, due to limitations in nozzle design and particle distribution.
Innovation Solution
A multi-nozzle cold spray apparatus with a common exit and integrated laser beams that heat particles and substrates, optimizing particle distribution and energy absorption, and allowing for differential coating mass to achieve conformal coatings without complex tool path optimization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a single cold spray nozzle is used to coat large substrates by raster scanning, then the substrate can be covered, but coating uniformity deteriorates due to defects developing between tracks and varying surface area
Solution Approach 1:
The single nozzle is divided into multiple nozzles (e.g., 5 nozzles) arranged in an array, with each nozzle having its own inner passage terminating at a common exit. This segmentation allows simultaneous coating of multiple tracks, covering large areas while maintaining uniform coating quality by eliminating the defect propagation issue between sequential tracks.
Solution Approach 2:
Multiple nozzles are merged into a single apparatus with a common exit, allowing simultaneous particle delivery to multiple locations on the substrate. This combining approach enables large area coating in a single pass while maintaining manufacturing precision through uniform particle distribution from all nozzles.
2Area of stationary object
If the nozzle cross section area is increased to coat larger substrates, then coating area increases, but gas dynamics and particle velocity distribution deteriorate
Solution Approach 1:
Instead of increasing the cross section of a single nozzle, the system segments the coating function across multiple nozzles, each maintaining its own optimized inner passage geometry. This allows each nozzle to preserve proper gas dynamics and particle velocity while collectively covering a larger substrate area through the array configuration.
3Manufacturing precision
If complex tool path optimization is implemented to achieve uniform coating on large substrates, then coating uniformity improves, but device complexity and process time increase
Solution Approach 1:
The coating function is segmented across multiple nozzles that simultaneously deposit material across the substrate width. This eliminates the need for complex raster scanning tool paths, reducing device complexity while achieving uniform coating through the parallel architecture of multiple nozzles with optimized particle distribution.
4Productivity
If thicker coating layers are deposited in a single pass to reduce passes, then productivity increases, but defect growth and coating quality deteriorate
Solution Approach 1:
Multiple nozzles are combined to deliver particles simultaneously across the substrate, enabling thick coating layers to be deposited in a single pass without defect growth. The parallel particle delivery from all nozzles ensures uniform deposition throughout the thickness, maintaining coating quality while achieving high productivity.
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 enables high-accuracy and efficient coating of complex substrates with reduced defect growth and eliminates the need for extensive finish machining, achieving uniformity and conformality across large areas.
Implementation Method 1
each nozzle includes a laser beam that is transmitted through the inner passage and exits via the common nozzle exit toward the substrate. The laser heats at least one of the particles within the inner passage and the substrate to promote coating of the substrate with the particles
Implementation Method 2
a stream of solid particles is accelerated to high speeds by a carrier gas through a nozzle toward a substrate. The particles have enough kinetic energy such that upon impact with the substrate, they deform plastically and bond metallurgical-ly/mechanically to the substrate
Implementation Method 3
It is hypothesized that the particles adhere to the substrate when their kinetic energy is converted to a sufficient level of thermal and strain (mechanical) energy leading to a phenomenon known in art as 'adiabatic shear instability'
Data Source
Figure 1~2
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AI summary
A cold spray apparatus for applying a coating of particles to a substrate includes a nozzle assembly having a plurality of inner passages terminating at a common exit. The nozzle assembly includes a particle supply members in communication with the inner passages. The particle supply members supply the particles to flow and accelerate through the inner passages and out of the nozzle assembly via the common exit toward the substrate to be coated thereon. Furthermore, each inner passage includes a laser that emits a laser beam that is transmitted through the inner passage. The laser heats at least one of the particles and the substrate to promote coating of the substrate with the particles.