Ceramic insulator and methods of use and manufacture thereof
View Patent ↗One embodiment of the present disclosure is directed to an insulator comprising a ceramic composition, wherein the ceramic composition comprises about 25-60% SiO 2 ; 15-35% R 2 O 3 , wherein the R 2 O 3 is 3-15% B 2 O 3 and 5-25% Al 2 O 3 ; 4-25% MgO+0-7% Li 2 O, wherein the total of MgO+Li 2 O is between about 6-25%; 2-20% R 2 O, wherein the R 2 O is 0-15% Na 2 O, 0-15% K 2 O, 0-15% Rb 2 O; 0-15% Rb 2 O; 0-20% Cs 2 O; and 4-20% F; crystalline grains, wherein the crystalline grains are substantially oriented to extend in a first direction to provide improved insulating properties in a direction perpendicular to the first direction, wherein the first direction is circumferential and the direction perpendicular to the first direction is radial; and a first zone and a second zone, wherein the first zone is in compression and the second zone is in tension.
1. An insulator comprising:
a ceramic composition,
wherein the ceramic composition comprises crystalline grains and wherein the crystalline grains are substantially oriented to extend in a first direction to provide improved insulating properties in a direction perpendicular to the first direction, wherein the ceramic composition comprises: about 25-60% SiO 2 ;
15-35% R 2 O 3 , wherein the R 2 O 3 is 3-15% B 2 O 3 and 5-25% Al 2 O 3 ;
4-25% MgO+0-7% Li 2 O, wherein the total of MgO+Li 2 O is between about 6-25%;
2-20% R 2 O, wherein the R 2 O is 0-15% Na 2 O, 0-15% K 2 O, 0-15% Rb 2 O;
0-15% Rb 2 O;
0-20% Cs 2 O; and
4-20% F,
wherein the first direction is circumferential and the direction perpendicular to the first direction is radial.
2. The insulator of claim 1 further comprising a first zone and a second zone wherein the first zone is in compression and the second zone is in tension.
3. The insulator of claim 2 wherein the first zone is adjacent an outer surface of the insulator.
4. The insulator of claim 3 wherein the first zone comprises more crystal grains per volume that the second zone.
5. The insulator of claim 3 wherein the crystal grains of the first zone have a packing efficiency less than the crystal grains of the second zone.
6. The insulator of claim 3 wherein the first zone comprises diffused ions, sputtered surfaces, or a dopant.
7. The insulator of claim 2 wherein the insulator has a dielectric strength of greater than about 1.2 KV/0.001″ at a temperature from about −30° C. to 450° C.
8. The insulator of claim 2 wherein the insulator has a dielectric strength of greater than about 1.9 KV/0.001″ at a temperature from about −30° C. to 450° C.
9. The insulator of claim 2 wherein the insulator has a dielectric strength of greater than about 2.5 KV/0.001″ at a temperature from about −30° C. to 450° C.
10. The insulator of claim 2 wherein the insulator has a dielectric strength of greater than about 3 KV/0.001″ at a temperature from about −30° C. to 450° C.
11. A fuel injector-igniter comprising the insulator of claim 2 .
12. An insulator comprising:
a ceramic composition, wherein the ceramic composition comprises:
about 25-60% SiO 2 ; 15-35% R 2 O 3 , wherein the R 2 O 3 is 3-15% B 2 O 3 and 5-25% Al 2 O 3 ; 4-25% MgO+0-7% Li 2 O, wherein the total of MgO+Li 2 O is between about 6-25%; 2-20% R 2 O, wherein the R 2 O is 0-15% Na 2 O, 0-15% K 2 O, 0-15% Rb 2 O; 0-15% Rb 2 O; 0-20% Cs 2 O; and 4-20% F;
crystalline grains, wherein the crystalline grains are substantially oriented to extend in a first direction to provide improved insulating properties in a direction perpendicular to the first direction, wherein the first direction is circumferential and the direction perpendicular to the first direction is radial; and
a first zone and a second zone, wherein the first zone is in compression and the second zone is in tension.