Machinable and chemically toughenable fluorine glass-ceramic

• US 10,766,807 B2
• Filed: 08/28/2017
• Issued: 09/08/2020
• Est. Priority Date: 02/28/2015
• Status: Active Grant

• Current Assignee: Schott Glass Technologies Suzhou Co Ltd
• Original Assignee: Schott Glass Technologies Suzhou Co Ltd
• Inventors: Fan, Huiyan, Xue, Junming, Zimmer, Jose, Wang, Chong, Ping, Wenliang
• Primary Examiner(s): Le, Hoa (Holly)
• Application Number:
  US15/688,258
• Publication Number:
  US 20180044225A1
• Time in Patent Office: 1,107 Days
• Field of Search: 501 55, 501 57, 501 58, 501 59, 501 63, 501 66, 501 69, 501 70
• CPC Class Codes: C03B 27/03 the liquid being a molten metal or a molten salt
• CPC Class Codes: C03C 10/0045 containing SiO2, Al2O3 and MgO as main constituents
• CPC Class Codes: C03C 10/0054 containing PbO, SnO2, B2O3
• CPC Class Codes: C03C 10/16 Halogen containing crystalline phase
• CPC Class Codes: C03C 21/002 to perform ion-exchange between alkali ions C03C21/005 takes precedence
• CPC Class Codes: C03C 21/005 to introduce in the glass such metals or metallic ions as Ag, Cu
• CPC Class Codes: C03C 2204/02 Antibacterial glass, glaze or enamel
• CPC Class Codes: C03C 3/112 containing fluorine
• CPC Class Codes: C03C 4/18 for ion-sensitive glass

Abstract

The present invention is directed to a kind of machinable glass ceramic which can be chemically toughened. The machinable and chemically toughenable glass ceramic, which comprises, as represented by weight percentage based on the following compositions, 25-75 wt % of SiO₂, 6-30 wt % of Al₂O₃, 0.1-30 wt % of Na₂O, 0-15 wt % of K₂O, 0-30 wt % of B₂O₃, 4-35 wt % of MgO, 0-4 wt % of CaO, 1-20 wt % of F, 0-10 wt % of ZrO₂, 0.1-10 wt % of P₂O₅, 0-1 wt % of CeO₂ and 0-1 wt % of SnO₂, wherein P₂O₅+Na₂O>3 wt %, and Al₂O₃+Na₂O+P₂O₅>17 wt %. Mica crystalline phase can be formed in the glass ceramic and the glass ceramic can be chemically toughened by one step, two steps or multiple steps with depth of K-ion layer of at least 15 μm and surface compress stress of at least 300 MPa. The profile on depth of the ion exchange layer follows the complementary error function. Hardness can be improved by at least 20% after chemical toughening. The dimension deviation ratio is less than 0.06% by ion-exchanging.

Claims

1. A fluorine mica glass-ceramic, comprising:

SiO₂;

25-75 wt %;

Al₂O₃;

6-30 wt %;

Na₂O;

3-30 wt %;

K₂O;

0-15 wt %;

B₂O₃;

0.1-30 wt %;

MgO;

4-35 wt %;

CaO;

0-4 wt %;

F;

1-20 wt %;

ZrO₂;

0-10 wt %;

P₂O₅;

1-10 wt %;

CeO₂;

0-1 wt %;

SnO₂;

0-1 wt %,

wherein P₂O₅+Na₂O>

5 wt %, and Al₂O₃+Na₂O+P₂O₅>

17 wt %, and,

wherein the glass ceramic has a microstructure comprising;

1). a glass matrix, and

2) at least one crystalline phase with the formula of (K,Na)<sub>1−

x</sub>Mg₃(Al,B,P)<sub>1−

x</sub>Si_3+xO₁₀F₂, where x is 0 to 1,the glass ceramic is machinable and can be ion exchanged to achieve compress stress CS >

300 MPa, and Dol >

15 μ

m.

2. The fluorine mica glass-ceramic according to claim 1, comprising the following composition, as calculated from batches based on oxides:

SiO₂;

30-70 wt %;

Al₂O₃;

7-29 wt %;

Na₂O;

3-15 wt %;

K₂O;

0.5-12 wt %;

B₂O₃;

0.1-20 wt %;

MgO;

4-25 wt %;

CaO;

0-2 wt %;

F;

1-15 wt %;

P₂O₅;

1-9 wt %;

ZrO₂;

0-8 wt %;

CeO₂;

0-0.5 wt %;

SnO₂;

0-0.5 wt %.

3. The fluorine mica glass-ceramic according to claim 1, comprising the following composition, as calculated from batches based on oxides:

SiO₂;

35-65 wt %;

Al₂O₃;

8-27 wt %;

Na₂O;

3-15 wt %;

K₂O;

1-11 wt %;

B₂O₃;

1-20 wt %;

MgO;

4-20 wt %;

CaO;

0-1.5 wt %;

F;

2-12 wt %;

P₂O₅;

1-8 wt %;

ZrO₂;

0-6 wt %;

CeO₂;

0-0.3 wt %;

SnO₂;

0-0.3 wt %.

4. The fluorine mica glass-ceramic according to claim 1, comprising the following compositions, as calculated from batches based on oxides:

SiO₂;

40-65 wt %;

Al₂O₃;

8-26 wt %;

Na₂O;

3-14 wt %;

K₂O;

2-10 wt %;

B₂O₃;

1-17 wt %;

MgO;

4-17 wt %;

CaO;

0-1 wt %;

F;

5-10 wt %;

P₂O₅;

1-7 wt %;

ZrO₂;

0-6 wt %;

CeO₂;

0-0.2 wt %;

SnO₂;

0-0.2 wt %.

5. The fluorine mica glass-ceramic according to claim 1, wherein the fluorine mica glass-ceramic has a porosity of 0%, has greater than 40 Vol. % of crystalline phase and interlock crystallization structure can be formed, wherein the mica crystalline size is 5-100 μ

m, with an aspect ratio of <

0.5.

6. The fluorine mica glass-ceramic according to claim 1, having a CTE <

20 ppm/K in the temperature range of 20−

300°

C. and a Poisson'"'"'s ratio of <

0.3.

7. The fluorine mica glass-ceramic according to claim 1, having a maximum thermal shock resistance Δ

T>

300°

C., thermal conductivity lower than 1.8 W/m°

C. and maximum usage temperature higher than 800°

C.

8. The fluorine mica glass-ceramic according to claim 1, having the thermal shock resistance parameter R of higher than 180 W/m².

9. The fluorine mica glass-ceramic according to claim 1, having a compress stress higher than 300 MPa, a mechanical strength higher than 350 MPa, fracture modulus higher than 100 MPa, Young'"'"'s modulus higher than 65 GPa, and bending strength higher than 94 MPa.

10. The fluorine mica glass-ceramic according to claim 1, having a dielectric constant in the range of 5.5-9 at 25°

C. and 1 KHZ, and a loss tangent of <

0.002 at 25°

C. and 1 MHz.

11. The fluorine mica glass-ceramic according to claim 1, wherein the fluorine mica glass-ceramic exhibits an Hv hardness higher than 200 kg/mm².

12. The fluorine mica glass-ceramic according to claim 1, having a chemical toughening temperature from 300°

C.^˜

500°

C., a chemical toughening time of 0.1<sup>˜

16</sup>h in a pure KNO₃ salt bath.

13. The fluorine mica glass-ceramic according to claim 1, with a depth of K ion layer >

15 μ

m, and a compress stress >

300 MPa.

14. The fluorine mica glass-ceramic according to claim 1, wherein the hardness of chemically toughened machinable glass ceramic can be improved by higher than 20% after chemical toughening.

15. The fluorine mica glass-ceramic according to claim 1, having a dimension deviation ratio of the fluorine mica glass ceramic that is less than 0.06%, which is caused by chemical toughening.

16. The fluorine mica glass-ceramic according to claim 1, having widths and depths of scratches that are reduced by higher than 10% after chemical toughening.

17. The fluorine mica glass-ceramic according to claim 1, that is chemically toughened by three steps.

18. The fluorine mica glass-ceramic according to claim 17, wherein the first step produces a Dol₁, and the Dol₁ varies according to a first function;

the second step produces a Dole, and the Dole varies according to a second function, and wherein the first function is different from the second function; and

the third step produces Dol₃, and the Dol₃ varies according to a third function, and wherein the third function is different from the first function and the second function.

19. The fluorine mica glass-ceramic according to claim 18, wherein the first function is a first complementary error function.

20. The fluorine mica glass-ceramic according to claim 18, wherein the second function is a second complementary error function.

21. The fluorine mica glass-ceramic according to claim 18, wherein for the first step, a chemical toughening temperature is 300°

C.^˜

500°

C., a chemical toughening time is 0.1^˜

16h in a pure KNO₃ salt bath.

22. The fluorine mica glass-ceramic according to claim 18, wherein for the second step, a heat treatment temperature is 200^˜

600°

C. and a treatment time is 0.1^˜

10h.

23. The fluorine mica glass-ceramic according to claim 18, wherein for the third step, a chemical toughening temperature is 300°

C.^˜

500°

C., a chemical toughening time is 0.01^˜

16h in a pure KNO₃ salt bath.

24. The fluorine mica glass-ceramic according to claim 1, wherein the fluorine mica glass-ceramic can be chemically toughened by multiple steps, to achieve a depth of K ion layer >

40 μ

m, and a compress stress >

300 MPa.

25. The fluorine mica glass-ceramic according to claim 1, wherein the hardness of machinable glass ceramic can be improved by higher than 30% after multiple chemical toughening steps.

26. The fluorine mica glass-ceramic according to claim 1, wherein the dimension deviation ratio of the machinable glass ceramic is less than 0.06% after multiple chemical toughening steps.

27. The fluorine mica glass-ceramic according to claim 1, wherein the widths and depths of scratches can be reduced by higher than 15% after multiple chemical toughening steps.

28. The fluorine mica glass-ceramic according to claim 1, which can be chemical toughened by AgNO₃ to get the antimicrobial properties and can be colorized by kinds of coloring ions (e.g. Cu²⁺, Fe²⁺, Co³⁺, Ni⁴⁺ and Cr³⁺).

29. The fluorine mica glass-ceramic according to claim 1, wherein the fluorine mica glass-ceramic, which can be chemically toughened, can be used for providing insulation and tighten performance in high-end equipment, holders in the equipment, or a backside cover/frame on electronic products.

30. A fluorine mica glass-ceramic, comprising:

SiO₂;

25-75 wt %;

Al₂O₃;

6-30 wt %;

Na₂O;

3-30 wt %;

K₂O;

0-15 wt %;

B₂O₃;

0.1-30 wt %;

MgO;

4-35 wt %;

CaO;

0-4 wt %;

F;

1-20 wt %;

ZrO₂;

0-10 wt %;

P₂O₅;

0.1-10 wt %;

CeO₂;

0-1 wt %;

SnO₂;

0-1 wt %,

wherein P₂O₅+Na₂O>

3 wt %, and Al₂O₃+Na₂O+P₂O₅>

17 wt %,

wherein the fluorine mica glass-ceramic has a porosity of 0%, has greater than 40 Vol. % of crystalline phase and interlock crystallization structure can be formed, wherein the mica crystalline size is 5-100 μ

m, with an aspect ratio of <

0.5, and

wherein the glass ceramic has a microstructure comprising;

1). a glass matrix, and

2) at least one crystalline phase with the formula of (K,Na)<sub>1−

x</sub>Mg₃(Al,B,P)<sub>1−

x</sub>Si_3+xO₁₀F₂, where x is 0 to 1,the glass ceramic is machinable and can be ion exchanged to achieve compress stress CS >

300 MPa, and Dol >

15 μ

m.

31. A fluorine mica glass-ceramic, comprising:

SiO₂;

25-75 wt %;

Al₂O₃;

6-30 wt %;

Na₂O;

3-30 wt %;

K₂O;

0-15 wt %;

B₂O₃;

0.1-30 wt %;

MgO;

4-35 wt %;

CaO;

0-4 wt %;

F;

1-20 wt %;

ZrO₂;

0-10 wt %;

P₂O₅;

0.1-10 wt %

CeO₂;

0-1 wt %;

SnO₂;

0-1 wt %,

wherein P₂O₅+Na₂O>

5 wt %, and Al₂O₃+Na₂O+P₂O₅>

17 wt %, and,

wherein the glass ceramic has a microstructure comprising;

1). a glass matrix, and

2) at least one crystalline phase with the formula of (K,Na)<sub>1−

x</sub> Mg₃(Al,B,P)<sub>1−

x</sub>Si_3+xO₁₀F₂, where x is 0 to 1,the glass ceramic is machinable and can be ion exchanged to achieve compress stress CS >

300 MPa, and Dol >

15 μ

m,

wherein the fluorine mica glass-ceramic exhibits an Hv hardness higher than 200 kg/mm².