Low-energy method of manufacturing bulk metallic structures with submicron grain sizes
View Patent ↗Three dimensionally large metallic structures comprised of submicron grain sizes are produced by a process which includes directing a supersonic powder jet against a substrate such that the powder adheres to the substrate and to itself to form a dense cohesive deposit. The powder jet may be comprised of refractory metal powders. The powder may be deposited by a supersonic jet and may be extruded by Equi channel angular extrusion.
1. A process for producing three dimensionally large metallic structures having submicron grain sizes, the process comprising:
using a cold spray system, accelerating a metal powder having a grain size larger than 5 microns with a heated gas, thereby forming a supersonic metal powder jet; and
directing the supersonic metal powder jet against a substrate,
the powder adhering to the substrate and to itself to form a dense cohesive deposit having a submicron grain structure and a thickness larger than 0.5 mm, thereby forming the three dimensionally large metallic structure, the three dimensionally large metallic structure being a product selected from the group consisting of explosively formed projectiles and kinetic energy penetrators and hydrogen membranes.
2. The process of claim 1 wherein the powder jet comprises at least one refractory metal powder.
3. The process of claim 2 , wherein the three dimensionally large metallic structure produced is a refractory metal structure.
4. A process for producing three dimensionally large metallic structures having submicron grain sizes, the process comprising:
using a cold spray system, accelerating a metal powder having a grain size larger than 5 microns with a heated gas, thereby forming a supersonic metal powder jet;
directing the supersonic metal powder jet against a substrate,
the powder adhering to the substrate and to itself to form a dense cohesive deposit having a submicron grain structure and a thickness larger than 0.5 mm, thereby forming the three dimensionally large metallic structure; and
extruding the deposit by Equi channel angular extrusion.
5. The process of claim 1 wherein after the deposit is formed, it is maintained attached to the substrate.
6. The process of claim 1 further comprising separating the substrate and the deposit from each other.
7. The process of claim 1 further comprising annealing the deposit to at least one of increase interparticle bonding, increase ductility, or decrease work hardening.
8. The process of claim 1 wherein the powder is selected from the group consisting of tantalum, niobium, and molybdenum.
9. The process of claim 1 wherein the deposit has a grain size less than 500 nanometers.
10. The process of claim 1 wherein the deposit has a grain size less than 400 nanometers.
11. The process of claim 1 wherein the heated gas comprises nitrogen at a temperature between 500° C. and 800° C.
12. The process of claim 1 wherein the thickness of the deposit is larger than approximately 1 cm.
13. The process of claim 4 wherein the metal powder comprises at least one refractory metal powder.
14. The process of claim 4 wherein after the deposit is formed, it is maintained attached to the substrate.
15. The process of claim 4 further comprising separating the substrate and the deposit from each other.
16. The process of claim 4 wherein the three dimensionally large metallic structure produced is a product selected from the group consisting of explosively formed projectiles and kinetic energy penetrators and hydrogen membranes.
17. The process of claim 4 further comprising annealing the deposit to at least one of increase interparticle bonding, increase ductility, or decrease work hardening.
18. The process of claim 4 wherein the powder is selected from the group consisting of tantalum, niobium, and molybdenum.
19. The process of claim 4 wherein the deposit has a grain size less than 500 nanometers.
20. The process of claim 4 wherein the deposit has a grain size less than 400 nanometers.
21. The process of claim 4 wherein the heated gas comprises nitrogen at a temperature between 500° C. and 800° C.