Transparent strengthened glass ceramic having high stress depth, preparation method therefor and application thereof
View Patent ↗Disclosed is a transparent strengthened glass ceramic having high stress depth. The crystal phase of the strengthened glass ceramic comprises spinel crystals and zirconium oxide crystals, and does not contain Li-containing crystals; the strengthened glass ceramic has a compressive stress region extending from the surface thereof to a compression depth, the depth of a compressive stress layer, DOL_0, of the strengthened glass ceramic is greater than or equal to 14% the thickness of the strengthened glass ceramic, and the tensile stress line density of the strengthened glass ceramic is greater than or equal to 25,000 MPa/mm. More Li ions and Na ions are introduced into a spinel glass ceramic component, so that a prepared transparent spinel glass ceramic can be chemically strengthened to obtain a transparent strengthened glass ceramic having high CS, DOL_0, CT_AV and CT_LD, and the strengthened glass ceramic shows excellent anti-dropping performance.
1 . A transparent strengthened glass ceramic having high stress depth, wherein, a crystal phase of the strengthened glass ceramic comprises spinel crystal and zirconium oxide crystal, and does not comprise a Li-containing crystal; and
the strengthened glass ceramic has a compressive stress zone extending from a surface of the strengthened glass ceramic to a compressive depth, the depth of compressive stress layer DOL_0 of the strengthened glass ceramic is greater than or equal to 14% of the thickness of the strengthened glass ceramic, and the linear density of center tension CT_LD of the strengthened glass ceramic is 25,000 to 40.000 MPa/mm;
the strengthened glass ceramic comprises a compressive stress layer on the surface and a tensile stress layer inside, and in molar percentage of oxides, the tensile stress layer of the strengthened glass ceramic comprises:
Li 2 O: 3.50 to 6.00 mol %,
Na 2 O: 2.00 to 4.00 mol %,
SiO 2 : 50.00 to 65.00 mol %,
Al 2 O 3 : 14.50 to 25.00 mol %,
MgO: 3.50 to 8.00 mol %,
ZnO: 8.00 to 16.00 mol %,
BaO: 0 to 2.00 mol %, and
TiO 2 +ZrO 2 : 3.00 to 5.50 mol %; and
in molar percentage of oxides, the tensile stress layer of the strengthened glass ceramic satisfies:
0.4
≤
(
Al
2
O
3
+
ZnO
+
M
g
O
+
Z
r
O
2
+
T
i
O
2
)
/
(
Li
2
O
+
Na
2
O
+
S
i
O
2
+
B
a
O
)
≤
0
.
7
0.
2 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the crystal phase of the strengthened glass ceramic does not comprise quartz and a solid solution of quartz.
3 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the surface compressive stress CS of the strengthened glass ceramic is greater than or equal to 650 MPa.
4 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the average center tension CT_AV of the strengthened glass ceramic is greater than or equal to 35.0 MPa.
5 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the Vickers hardness of the strengthened glass ceramic is greater than or equal to 740HV0.3.
6 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the fracture toughness of the strengthened glass ceramic is greater than or equal to 1.500 MPa·m 1/2 .
7 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the spinel crystal comprises a zinc spinel and a magnesium spinel.
8 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the transmittance of the strengthened glass ceramic with a thickness of 0.7 mm is greater than 85.00% at a light having a wavelength of 550 nm.
9 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the strengthened glass ceramic has a crystallinity of at least 30.00 wt. %; and/or
wherein, the average crystal size in the strengthened glass ceramic is less than or equal to 15.0 nm.
10 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the transparent strengthened glass ceramic having high stress depth is prepared by a method comprising:
(1) batching and mixing raw materials to prepare a glass precursor;
(2) subjecting the prepared glass precursor to nucleation and crystallization successively to prepare a transparent spinel glass ceramic; and
(3) subjecting the transparent spinel glass ceramic obtained in step (2) to a one-step or multi-step ion exchange process in a salt bath to obtain the strengthened glass ceramic;
in step (2), during the crystallization, the temperature is raised at a heating rate of greater than 20° C./min to reach the crystallization temperature.
11 . The transparent strengthened glass ceramic having high stress depth according to claim 10 , wherein, in step (2),
the nucleation is performed at a nucleation temperature of 700 to 800° C. for a nucleation time of 30 to 1440 min; and
the crystallization is performed at a crystallization temperature of 900 to 1000° C. for a crystallization time of 5 to 1440 min.
12 . The transparent strengthened glass ceramic having high stress depth according to claim 11 , wherein, in step (2),
during the nucleation, the temperature is raised at a heating rate of 5 to 20° C./min to reach the nucleation temperature.
13 . The transparent strengthened glass ceramic having high stress depth according to claim 10 , wherein, in step (3), during the one-step ion exchange, the salt bath comprises 50 to 100 wt. % NaNO 3 +0 to 50 wt. % KNO 3 , and the ion exchange is performed at a temperature of 400 to 500° C. for a time period of 0.5 to 48 hours; or
in step (3), during a two-step ion exchange:
in the first step, the salt bath comprises 90 to 100 wt. % NaNO 3 +0 to 10 wt. % KNO 3 , and the ion exchange is performed at a temperature of 400 to 500° C. for a time period of 0.5 to 48 hours; and
in the second step, the salt bath comprises 0 to 10 wt. % NaNO 3 +90 to 100 wt. % KNO 3 , and the ion exchange is performed at a temperature of 400 to 500° C. for a time period of 0.5 to 48 hours.
14 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein the transparent strengthened glass ceramic having high stress depth is used in watches, transparent armors, guided missile windows, fairings, substrate materials, new lamps and lanterns, observation windows for equipment used in high-temperature, high-pressure and corrosive environments, automobiles, trains, aircrafts, marine vehicles, building materials, or portable intelligent electronic devices.
15 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein the transparent strengthened glass ceramic having high stress depth is comprised in an electronic terminal, and wherein the electronic terminal comprises:
a housing, comprising a front surface, a back surface, and a side surface; and
an electronic assembly partially located in the housing, comprising a display device located on or adjacent to the front surface of the housing; wherein the front surface and/or the back surface and/or the side surface comprises the strengthened glass ceramic material; and
a covering product configured to cover the front surface of the housing or dispose on the display device, wherein the covering product comprises the strengthened glass ceramic material; and
wherein the electronic terminal includes mobile phones, tablet computers, or photovoltaic devices.
16 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, in molar percentage of oxides, the tensile stress layer of the strengthened glass ceramic satisfies:
0.035
≤
Na
2
O
/
(
Li
2
O
+
Na
2
O
+
S
i
O
2
+
B
a
O
)
≤
0.07
;
and
/
or
0.054
≤
L
i
2
O
/
(
Li
2
O
+
Na
2
O
+
S
i
O
2
+
B
a
O
)
≤
0.09
;
and
/
or
0.43
⩽
(
Al
2
O
3
+
Z
n
O
+
M
g
O
+
Z
r
O
2
+
T
i
O
2
)
/
(
Li
2
O
+
Na
2
O
+
S
i
O
2
+
B
a
O
)
≤
0.68
.
17 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, in molar percentage of oxides, the tensile stress layer of the strengthened glass ceramic comprises:
SiO 2 : 50.00 to 63.00 mol %, and/or
Al 2 O 3 : 14.50 to 20.00 mol %, and/or
MgO: 3.90 to 7.60 mol %, and/or
ZnO: 8.00 to 15.50 mol %, and/or
BaO: 0 to 1.50 mol %, and/or
LizO: 3.50 to 5.00 mol %, and/or
Na 2 O: 2.30 to 3.60 mol %, and/or
TiO 2 : 0 to 2.00 mol %, and/or
ZrO 2 : 2.50 to 5.00 mol %.
18 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, in molar percentage of oxides, the tensile stress layer of the strengthened glass ceramic comprises:
SiO 2 : 50.00 to 57.00 mol %, and/or
Al 2 O 3 : 15.00 to 19.00 mol %, and/or
MgO: 4.00 to 7.50 mol %, and/or
ZnO: 9.00 to 15.20 mol %, and/or
BaO: 1.00 to 1.35 mol %, and/or
Li 2 O: 4.00 to 5.00 mol %, and/or
Na 2 O: 3.00 to 3.60 mol %, and/or
TiO 2 : 0.30 to 1.30 mol %, and/or
ZrO 2 : 2.90 to 4.20 mol %.
19 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the linear density of center tension CT_LD of the strengthened glass ceramic is 27,000 to 40,000 MPa/mm; and/or
the surface compressive stress CS of the strengthened glass ceramic is 650 to 1000 MPa; and/or
the average center tension CT_AV of the strengthened glass ceramic is 35.0 to 70.0 MPa; and/or
the fracture toughness of the strengthened glass ceramic is 1.500 to 1.7000 MPa·m 1/2 .
20 . The transparent strengthened glass ceramic having high stress depth according to claim 1 , wherein, the strengthened glass ceramic has a crystallinity of 30.00 to 50.00 wt. %; and/or
the average crystal size in the strengthened glass ceramic is 3.0 to 15.0 nm.