Fabrication of transparent ceramics using nanoparticles
View Patent ↗A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.
1. A method of making a transparent ceramic, comprising the steps of:
providing metal salts,
dissolving said metal salts to produce an aqueous salt solution,
adding an organic chelating agent to produce a complexed-metal sol,
heating said complexed-metal sol to produce a gel,
drying said gel to produce a powder,
synthesizing nanoparticles by combusting said powder to produce said nano-particles,
calcining said nano-particles to produce oxide nano-particles,
forming said oxide nano-particles into a green body, and
sintering said green body to produce the transparent ceramic.
2. The method of claim 1 wherein said step of providing metal salts comprises providing nitrate, chloride, acetate, acetylacetonate, or carbonate metal salts or a combination thereof.
3. The method of claim 1 wherein said step of adding an organic chelating agent to produce a complexed-metal the chelating agent is a tri-dentate organic species.
4. The method of claim 1 wherein said step of adding an organic chelating agent to produce a complexed-metal sol comprises adding oxalic, malic, polygalacturonic, tannic, fulvic, tartaric, succinic, pyruvic or other tri-dentate organic species organic chelating agent.
5. The method of claim 1 wherein said step of adding an organic chelating agent to produce a complexed-metal sol comprises adding citric acid as an organic chelating agent to produce a complexed-metal sol.
6. The method of claim 1 wherein said step of drying said gel to produce a powder comprises drying said gel in a vacuum to produce a powder.
7. The method of claim 1 wherein said step of combusting said powder to produce nano-particles comprises heating said powder in air at 300-600° C.
8. The method of claim 1 wherein said step of calcining said nano-particles to produce oxide nano-particles comprises combusting said powder by heating said nano-particles in air at 600-1200° C. to produce oxide nano-particles.
9. The method of claim 1 wherein said step of forming said oxide nano-particles into a green body comprises uniaxial pressing, cold isostatic pressing, or slip casting said oxide nano-particles to form a green body.
10. The method of claim 1 wherein said step of sintering said green body to produce the transparent ceramic comprises vacuum sintering, controlled atmosphere sintering, pulsed-electric current sintering, plasma sintering, microwave sintering, laser sintering, radio-frequency sintering, or hot-pressing said green body to produce the transparent ceramic.
11. The method of fabricating a transparent ceramic of claim 1 wherein said step of sintering said green body to produce the transparent ceramic comprises vacuum sintering said green body for 2-12 hours at 1700-1900° C. to produce the transparent ceramic.
12. The method of claim 1 wherein said steps of forming said oxide nano-particles into a green body and sintering said green body comprise:
(a) green body formation via uniaxial pressing, cold isostatic pressing, or slip casting,
(b) followed by consolidation via vacuum sintering, controlled atmosphere sintering, pulsed-electric current sintering, plasma sintering, microwave sintering, laser sintering, radio-frequency sintering, or hot-pressing, and
(c) subsequent hot isostatic pressing to improve clarity, or any combination thereof.
13. The method of fabricating a transparent ceramic of claim 1 wherein the transparent ceramic has a cubic garnet structure including Lu 3 Al 5 O 12 , Y 3 Al 5 O 12 , Gd 3 Al 5 O 12 and related materials, (A 1-x , B x , etc.) 3 (C 1-y , D y , etc.) 5 O 12 where first site (A, B, etc.) can contain any mixture of the following that results in the garnet structure: Y, Gd, Lu, La, Tb, Pr; and the second site (C, D, etc.) site can contain any mixture of the following that results in the garnet structure: Al, Ga, Sc.
14. The method of fabricating a transparent ceramic of claim 1 wherein said step of dissolving said metal salts to produce an aqueous salt solution includes stirring said metal salts to produce an aqueous salt solution.
15. The method of fabricating a transparent ceramic of claim 1 wherein said step of heating said complexed-metal sol to produce a gel includes stirring said complexed-metal sol to produce a gel.
16. A method of fabricating a transparent ceramic, comprising the steps of:
providing metal salts,
dissolve and stir said metal salts to produce an aqueous salt solution,
add an organic chelating agent to produce a complexed-metal sol,
heat and stir said complexed-metal sol to produce a gel,
dry said gel to produce a powder,
synthesize nanoparticles by combusting combust said powder in air to produce said nano-particles,
calcine said nano-particles in air to produce oxide nanoparticles,
form said oxide nano-particles in to a green body, and
sinter said green body to produce the transparent ceramic.
17. The method of fabricating a transparent ceramic of claim 16 wherein said step of providing metal salts is providing nitrate, chloride, or nitrate and chloride metal salts.
18. The method of fabricating a transparent ceramic of claim 16 wherein said organic chelating agent is citrate.
19. The method of fabricating a transparent ceramic of claim 16 wherein said organic chelating agent is citric acid.
20. The method of fabricating a transparent ceramic of claim 16 wherein said organic chelating agent is the oxalic, malic, polygalacturonic, tannic, fulvic, tartaric, succinic, pyruvic, or other tri-dentate organic species.
21. The method of fabricating a transparent ceramic of claim 16 wherein said step of combusting said powder in air comprises heating said powder in air at 300-600° C.
22. The method of fabricating a transparent ceramic of claim 16 wherein said step of calcine said powder in air to produce oxide nano-particles comprises calcine said powder in air at 600-1200° C. to produce said oxide nano-particles.
23. The method of fabricating a transparent ceramic of claim 16 wherein said step of sinter comprises vacuum sintering for 2-12 hours at 1700-1900° C. to produce a transparent ceramic.
24. The method of fabricating a transparent ceramic of claim 16 wherein said steps of forming a green body and sintering said green body comprise:
(a) green body formation via uniaxial pressing, cold isostatic pressing, or slip casting,
(b) followed by consolidation via vacuum sintering, controlled atmosphere sintering, pulsed-electric current sintering, plasma sintering, microwave sintering, laser sintering, radio-frequency sintering, or hot-pressing, and
(c) subsequent hot isostatic pressing to improve clarity, or any combination thereof.
25. A method of fabricating a transparent oxide ceramic scintillator, comprising the steps of:
providing metal salts,
dissolve and stir said metal salts to produce an aqueous salt solution,
add an organic chelating agent to produce a complexed-metal sol,
heat and stir said complexed-metal sol to produce a gel,
dry said gel to produce a powder,
synthesize nanoparticles by combusting said powder in air to produce said nano-particles,
calcine said nano-particles in air to produce oxide nanoparticles,
form said oxide nano-particles in to a green body, and
sinter said green body to produce the transparent oxide ceramic scintillator.
26. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of providing metal salts comprises providing nitrate, chloride, acetate, acetylacetonate, or carbonate metal salts or a combination thereof.
27. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein in said step of adding an organic chelating agent to produce a complexed-metal, the chelating agent is a tri-dentate organic species such as oxalic, malic, polygalacturonic, tannic, fulvic, tartaric, succinic, pyruvic, or other organic species.
28. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of adding an organic chelating agent to produce a complexed-metal the chelating agent is oxalic, malic, polygalacturonic, tannic, fulvic, tartaric, succinic, pyruvic or other tri-dentate organic species.
29. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of adding an organic chelating agent to produce a complexed-metal sol comprises adding citric acid to produce a complexed-metal sol.
30. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of drying said gel to produce a powder comprises drying said gel in a vacuum to produce a powder.
31. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of combusting said powder to produce nano-particles comprises heating said powder in air at 300-600° C.
32. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of calcining said nano-particles to produce oxide nano-particles comprises heating said nano-particles in air at 600-1200° C. to produce oxide nano-particles.
33. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of forming said oxide nano-particles into a green body comprises uniaxial pressing, cold isostatic pressing, or slip casting said oxide nano-particles to form a green body.
34. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of sintering said green body to produce the transparent ceramic comprises vacuum sintering, controlled atmosphere sintering, pulsed-electric current sintering, plasma sintering, microwave sintering, laser sintering, radio-frequency sintering, or hot-pressing said green body to produce the transparent ceramic.
35. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said step of sintering said green body to produce the transparent ceramic comprises vacuum sintering for 2-12 hours at 1700-1900° C. to produce the transparent ceramic.
36. The method of fabricating a transparent oxide ceramic scintillator of claim 25 wherein said steps of forming said oxide nano-particles into a green body and sintering said green body comprise:
(a) green body formation via uniaxial pressing, cold isostatic pressing, or slip casting,
(b) followed by consolidation via vacuum sintering, controlled atmosphere sintering, pulsed-electric current sintering, plasma sintering, microwave sintering, laser sintering, radio-frequency sintering, or hot-pressing, and
(c) subsequent hot isostatic pressing to improve clarity, or any combination thereof.
37. The method of fabricating a transparent oxide ceramic scintillator of claim 25 , including the step of: activating said transparent oxide ceramic scintillator using Ce or Pr.
38. The method of fabricating a transparent oxide ceramic scintillator of claim 25 , including the step of: activating said transparent oxide ceramic scintillator using Bi, Eu, Tb, Gd, Sm, Er, Nd.