EP-4735183-A2 - NOZZLE DESIGN FOR HIGH-VELOCITY DEPOSITION OF PARTICLES

Abstract

In accordance with embodiments of the present disclosure, a nozzle may include a housing, a bore centrally disposed through the housing, the bore comprising an inlet and a main outlet; and one or more pressure relief outlets formed in the housing, each of the one or more pressure relief outlets extending from the bore and through a wall of the housing.

Inventors

• BIERSCHENK, Stephen G.
• KOVAR, DESIDERIO

Assignees

• Board of Regents, The University of Texas System

Dates

Publication Date

20260506

Application Date

20240620

Claims (20)

1. 1. A nozzle comprising: a housing; a bore centrally disposed through the housing, the bore comprising an inlet and a main outlet; and one or more pressure relief outlets formed in the housing, each of the one or more pressure relief outlets extending from the bore and through a wall of the housing.
2. 2. The nozzle of Claim 1 , wherein an angle between the bore and at least one of the one or more pressure relief outlets is less than 135°, wherein the angle is defined by a first axis defined as a line including a center of an inlet for the one pressure relief outlet and a center of an outlet for the one pressure relief outlet and a second axis defined as a line including a center of the main outlet and a center of the inlet, and wherein such angle includes the center of the outlet for the one pressure relief outlet and the center of the main outlet.
3. 3. The nozzle of Claim 1, wherein the housing comprises a polymer material.
4. 4. The nozzle of Claim 1 , wherein the housing comprises metal.
5. 5. The nozzle of Claim 1, wherein the housing comprises ceramic.
6. 6. The nozzle of Claim 1, wherein the one or more pressure relief outlets are formed in the housing at the same lateral distance from the main outlet.
7. 7. The nozzle of Claim 1 , wherein at least two of the one or more pressure relief outlets are formed in the housing at different lateral distances from the main outlet.
8. 8. The nozzle of Claim 1, wherein the bore comprises: a converging portion extending from the inlet of the bore and decreasing in a cross-sectional area from the inlet; and a diverging portion, the diverging portion fhiidically coupled to the converging portion at a throat of the bore at which a cross-sectional area of the bore is at its minimum, and the diverging portion extending from the throat to the main outlet of the bore and increasing in a cross-sectional area from the throat to the main outlet.
9. 9. The nozzle of Claim 8, wherein each of the one or more pressure relief outlets extend from the diverging portion of the bore and through a wall of the housing.
10. 10. A method for forming a nozzle comprising: centrally disposing a bore through a housing, the bore comprising an inlet and a main outlet; and forming one or more pressure relief outlets in the housing, each of the one or more pressure relief outlets extending from the bore and through a wall of the housing.
11. 11. The method of Claim 10, further comprising forming the nozzle such that an angle between the bore and at least one of the one or more pressure relief outlets is less than 135°, wherein the angle is defined by a first axis defined as a line including a center of an inlet for the one pressure relief outlet and a center of an outlet for the one pressure relief outlet and a second axis defined as a line including a center of the main outlet and a center of the inlet, and wherein such angle includes the center of the outlet for the one pressure relief outlet and the center of the main outlet.
12. 12. The method of Claim 10, comprising forming the nozzle using one or more of casting, machining, and additive manufacturing.
13. 13. The method of Claim 10, further comprising forming the one or more pressure relief outlets by creating one or more openings in the housing.
14. 14. The method of Claim 13, further comprising creating one or more openings in the housing by drilling the one or more openings through the housing.
15. 15. The method of Claim 13, further comprising creating one or more openings in the housing by cutting the one or more openings through the housing using a blade.
16. 16. The method of Claim 10, comprising forming the nozzle with a polymer material.
17. 17. The method of Claim 10, comprising forming the nozzle with a metal material.
18. 18. The method of Claim 10, comprising forming the nozzle with a ceramic material.
19. 19. The method of Claim 10, comprising forming the one or more pressure relief outlets in the housing at the same lateral distance from the main outlet.
20. 20. The method of Claim 10, comprising forming at least two of the one or more pressure relief outlets in the housing at different lateral distances from the main outlet.

Description

NOZZLE DESIGN FOR HIGH-VELOCITY DEPOSITION OF PARTICLES RELATED APPLICATION The present disclosure claims priority to United States Provisional Application Serial No. 63/510397 filed June 27, 2023, which is incorporated by reference herein in its entirety. FIELD OF DISCLOSURE The present disclosure relates in general to methods and systems for the high- velocity deposition of particles, including micro-scale and nano-scale particles of metal, ceramic, or other material, using a nozzle. BACKGROUND Cold spray and micro-cold spray are techniques that may be used to produce thick (e.g., 1-100 pm), nearly full density metal and ceramic films using a feedstock of dry particles, typically 200 nm to 5 pm in diameter in micro-cold spray and typically 1 pm to 75 pm in diameter for cold spray, using known approaches. Micro-cold spray techniques may also be referred to as aerosol deposition, low pressure cold spray, vacuum cold spray, or vacuum kinetic spraying. In micro-cold spray, particles may be aerosolized in a low pressure carrier gas and then accelerated through a nozzle into a vacuum chamber. In cold spray, particles may be aerosolized in a high pressure carrier gas and then accelerated through a nozzle into an ambient pressure chamber. For both micro-cold spray and cold spray, the particles may impact onto a substrate at a high enough velocity where particles may deform and adhere to the substrate. Using existing techniques, deposition efficiencies for particles may often be less than 10%, due to a variety of causes such as material loss due to fracture of the particles, deflection of smaller particles due to the presence of a bow shock in the supersonic gas, and erosion due to high kinetic energy impacts of larger particles. As is known in the field of aerodynamics, a bow shock, also called a detached shock or bowed normal shock, is a curved propagating disturbance wave characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density. A bow shock may occur when a supersonic flow encounters a body, around which the necessary deviation angle of the flow is higher than the maximum achievable deviation angle for an attached oblique shock. Then, the oblique shock transforms into a curved detached shock wave. As bow shocks occur for high flow deflection angles, they are often seen forming around blunt bodies, because of the high deflection angle that the body imposes to the flow around it. Supersonic spray nozzles result in a bow shock that the particles travel through before impacting the substrate being coated. A stagnation region may form downstream of the bow shock where the gas is stagnant or nearly stagnant and compressed to a high density, which slows or deflects particles that are small or have a low material density (typical of ceramics). Consequently, smaller particles may not deposit at the high velocities required to produce high quality, dense films. Numerical studies of particle velocity have indicated the slowing of small particles is strongly dependent on both the density and thickness of the stagnant gas region upstream of the substrate surface (i.e., the stagnation region). The density within the stagnation region has also been shown to be linearly dependent on the nozzle inlet pressure. Experimentally, a reduction in pressure downstream of the shock wave results in increased film thickness, indicating that, by minimizing the effects of the stagnation region, film deposition rate and efficiency can be improved. For small particles to maintain sufficient impact velocity while passing through the stagnation region, the pressure within the stagnation region must be low enough that minimal particle deceleration occurs while, al the same time, a high gas velocity is maintained to sufficiently accelerate particles through the nozzle. Accordingly, systems and methods that enable minimizing pressure downstream of the bow shock and in the stagnation region may be desired. SUMMARY In accordance with the teachings of the present disclosure, the disadvantages and problems associated with existing approaches for depositing particles using cold spray and micro-cold spray techniques may be reduced or eliminated. In accordance with embodiments of the present disclosure, a nozzle may include a housing, a bore centrally disposed through the housing, the bore comprising an inlet and an outlet, and one or more pressure relief outlets formed in the housing, each of the one or more pressure relief outlets extending from the bore and through a wall of the housing. In accordance with these and other embodiments of the present disclosure, a method for forming a nozzle may comprise centrally disposing a bore through a housing, the bore comprising an inlet and a main outlet and forming one or more pressure relief outlets in the housing, each of the one or more pressure relief outlets extending from the bore and through a wall of the housing. In accordance with these and other embodiments