Glass compositions and fibers made therefrom
Embodiments of the present invention relate to glass compositions, glass fibers formed from such compositions, and related products. In one embodiment, a glass composition comprises 58-62 weight percent SiO 2 , 14-17 weight percent Al 2 O 3 , 14-17.5 weight percent CaO, and 6-9 weight percent MgO, wherein the amount of Na 2 O is 0.09 weight percent or less.
1. A glass composition comprising:
60-62 weight percent SiO 2 ;
14-17 weight percent Al 2 O 3 ;
14-17.5 weight percent CaO;
6-<8.75 weight percent MgO; and
0-1 weight percent TiO 2 ;
wherein the amount of Na 2 O is 0.09 weight percent or less, the CaO/MgO ratio on a weight percent basis is greater than 2.0, and the glass composition is substantially free of B 2 O 3 .
2. The glass composition of claim 1 , wherein the glass composition is substantially free of Na 2 O.
3. The glass composition of claim 1 , wherein the (MgO+CaO) content is greater than 21.5 weight percent.
4. The glass composition of claim 1 , further comprising 0-1 weight percent K 2 O and 0-2 weight percent Li 2 O.
5. The glass composition of claim 4 , wherein the (Na 2 O+K 2 O+Li 2 O) content is less than 1 weight percent.
6. The glass composition of claim 1 , wherein the glass composition is fiberizable, has a liquidus temperature of less than 1250° C., and has a forming temperature of less than 1300° C., wherein the difference between the forming temperature and the liquidus temperature is at least 50° C.
7. The glass composition of claim 1 , further comprising at least one rare earth oxide in an amount between about 0.1 and 3.0 weight percent.
8. A glass fiber formed from the glass composition of claim 1 .
9. The glass fiber of claim 8 , wherein the glass fiber has a Young's modulus greater than 80 GPa.
10. The glass fiber of claim 8 , wherein the glass fiber has a Young's modulus greater than 85 GPa.
11. The glass fiber of claim 8 , wherein the glass fiber has a Young's modulus greater than 87 GPa.
12. A glass composition comprising:
60-62 weight percent SiO 2 ;
14.5-16 weight percent Al 2 O 3 ;
14.5-17.5 weight percent CaO;
6-7.5 weight percent MgO; and
0-1 weight percent TiO 2 ;
wherein the amount of Na 2 O is 0.09 weight percent or less, the CaO/MgO ratio on a weight percent basis is greater than 2.0, and the glass composition is substantially free of B 2 O 3 .
13. The glass composition of claim 12 , wherein the glass composition is substantially free of Na 2 O.
14. The glass composition of claim 12 , wherein the (MgO+CaO) content is greater than 21.5 weight percent.
15. The glass composition of claim 12 , further comprising 0-1 weight percent K 2 O and 0-2 weight percent Li 2 O, and wherein the (Na 2 O+K 2 O+Li 2 O) content is less than 1 weight percent.
16. The glass composition of claim 12 , wherein the glass composition is fiberizable, has a liquidus temperature of less than 1250° C., has a forming temperature of less than 1300° C., and wherein the difference between the forming temperature and the liquidus temperature is at least 50° C.
17. The glass composition of claim 12 , further comprising at least one rare earth oxide in an amount between about 0.1 and 3.0 weight percent.
18. A glass fiber formed from the glass composition of claim 12 .
19. The glass fiber of claim 18 , wherein the glass fiber has a Young's modulus greater than 80 GPa.