Cold Spray Deposition Using Supercritical Fluid Jet
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cold spray method faces limitations in deposition efficiency, particularly for alloy powders and ceramic particles, with narrow windows for method parameters and powder sizes, high gas consumption, and limited sprayable materials, including issues with larger particles not being accelerated to sufficient velocities and ceramic particles not adhering to substrates due to hardness.
Innovation Solution
A system and method utilizing high-pressure and high-velocity superheated or supercritical fluids to accelerate particles, with a fluid jet unit producing jets up to 1200 m/s and pressures between 150 and 620 MPa, and a nozzle configuration that mixes and projects the fluid and powder onto a substrate, enabling acceleration of particles above critical velocity and deposition of larger diameter particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional cold spray method uses high velocity propelling gas to accelerate particles, then particles can be deposited on substrate, but deposition efficiency is low for alloy powders and ceramic particles
Solution Approach 1:
The invention changes the propellant from conventional high velocity gas to high pressure liquid (water), representing a fundamental parameter change in the cold spray process. This parameter change enables significantly higher particle acceleration velocities and improves deposition efficiency for alloy powders and ceramic particles that previously exhibited low deposition efficiency with conventional gas propellants
2Productivity
If conventional cold spray uses particles within limited size range, then particles can be accelerated to sufficient velocity, but larger particles (greater than 40 μm) are not accelerated at sufficient high velocity
Solution Approach 1:
The invention changes the propellant state from gas to high pressure liquid, which fundamentally alters the acceleration mechanism. This parameter change enables the system to accelerate larger particles (greater than 40 μm) to sufficient velocities for effective deposition, thereby expanding the sprayable particle size range while maintaining deposition efficiency
3Productivity
If conventional cold spray method is used, then coating can be deposited, but ceramic particles do not stick on substrates due to their high hardness
Solution Approach 1:
The invention changes the propellant from gas to high pressure liquid, which enables higher acceleration velocities and more effective particle-substrate impact. This parameter change overcomes the adhesion problem for hard ceramic particles by delivering sufficient impact energy to enable bonding, thereby improving both deposition efficiency and adhesion strength for ceramic coatings
4Productivity
If conventional cold spray uses high velocity propelling gas, then particles can be accelerated, but gas consumption is high
Solution Approach 1:
The invention transitions from using high velocity propelling gas (pneumatic approach) to high pressure liquid (hydraulic approach). This principle change exploits the higher density and energy density of liquid propellant, enabling effective particle acceleration with significantly reduced propellant consumption compared to conventional gas-based cold spray methods
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 enhances deposition efficiency, allows for the use of larger particle sizes, and improves adhesion, reducing defects and material waste, while being cost-effective and environmentally friendly, suitable for diverse materials and applications like 3D manufacturing and component repair.
Implementation Method 1
the heating unit controlling a temperature of the fluid and outputting one of: a superheated and a supercritical fluid
Implementation Method 2
the nozzle being configured for acceleration of the fluid, mixing the fluid and the feedstock powder particles, and projecting the mixture onto the substrate
Data Source
AI summary
A method and a system for cold spray deposition of a solid material on a substrate, the system comprising a fluid jet unit; a heating unit; a nozzle, and a powder feeder; the fluid jet unit providing a fluid of a speed up to 1200 m/s and a pressure in a range between 150 and 620 MPa to the heating unit, the heating unit controlling a temperature of the fluid and outputting one of: a superheated and a supercritical fluid; the powder feeder injecting feedstock powder particles into a mixing chamber of the nozzle, the feedstock powder particles being accelerated to a speed above a critical velocity of the feedstock powder particles by the fluid within the nozzle, the nozzle being configured for acceleration of the fluid, mixing the fluid and the feedstock powder particles, and projecting the mixture onto the substrate.