Red zirconium-oxide sintered body, preparation method and use

Abstract

A red zirconium-oxide sintered body includes oxide of cerium, auxiliary metal oxide and oxide of zirconium, wherein the auxiliary metal oxide includes any one or a combination of at least two of oxide of yttrium, oxide of magnesium, oxide of calcium and oxide of ytterbium; the red zirconium-oxide sintered body satisfies conditions that the oxide of cerium has a content of 0.2˜1.5 mol %; the oxide of cerium comprises trivalent cerium oxide; a sum of contents of the oxide of cerium and the auxiliary metal oxide is 1.1˜2.5 mol %; and the sintered body has fracture toughness≥8 MPa.Math.m.sup.1/2. The zirconium-oxide sintered body has red appearance and toughness more than 8 MPa.Math.m.sup.1/2, and can be used for products such as mobile phone backboards, ornaments and dial plates.

Claims

1. A red zirconium-oxide sintered body, comprising an oxide of cerium, an auxiliary metal oxide and an oxide of zirconium, wherein the auxiliary metal oxide comprises any one of an oxide of yttrium, an oxide of magnesium, an oxide of calcium and an oxide of ytterbium, or a combination of at least two therefrom; and the red zirconium-oxide sintered body satisfies conditions (1)-(4): (1) the oxide of cerium has a content of 0.2 to 1.5 mol %; (2) the oxide of cerium comprises a trivalent cerium oxide, wherein in the oxide of cerium, trivalent cerium, calculated based on cerium atom, has a mole percentage≥60%; (3) a sum of the oxide of cerium and the auxiliary metal oxide in content is 1.1 to 2.2 mol %; and (4) the sintered body has fracture toughness≥8 MPa.Math.m.sup.1/2, wherein the oxide of cerium is calculated based on CeO.sub.2, and the oxide of yttrium is calculated based on Y.sub.2O.sub.3.

2. The red zirconium-oxide sintered body according to claim 1, wherein the sintered body has a three-point bending strength≥1000 MPa.

3. The red zirconium-oxide sintered body according to claim 1, wherein the sintered body has an average grain size≤500 nm.

4. The red zirconium-oxide sintered body according to claim 1, wherein a particle size distribution of the grain size of the sintered body is 150 to 400 nm.

5. The red zirconium-oxide sintered body according to claim 1, wherein the auxiliary metal oxide is the oxide of yttrium.

6. The red zirconium-oxide sintered body according to claim 1, wherein the red zirconium-oxide sintered body further contains an oxide of aluminum.

7. The red zirconium-oxide sintered body according to claim 6, wherein the oxide of aluminum in the red zirconium-oxide sintered body, calculated based on Al.sub.2O.sub.3, has a mole percentage≤2.5 mol %.

8. The red zirconium-oxide sintered body according to claim 1, wherein in a Lab color system, the red zirconium-oxide sintered body has a value a≥25, wherein a ratio of the value a to a value b is ≥0.9, and a value L≥20.

9. A method for preparing the red zirconium-oxide sintered body according to claim 1, wherein the method comprises following steps: (I) mixing an oxide of cerium, an auxiliary metal oxide and a zirconium oxide according to a molar ratio of conditions (a)-(c), to obtain a mixture to be sintered, wherein the condition (a) is that the oxide of cerium has a content of 0.2 to 1.5 mol %; wherein the oxide of cerium comprises a trivalent cerium oxide, wherein in the trivalent cerium, calculated based on cerium atom, has a mole percentage≥60%; the condition (b) is that a sum of the oxide of cerium and the auxiliary metal oxide in content is 1.1 to 2.2 mol %; and the condition (c) is that a balance is the zirconium oxide; and the auxiliary metal oxide comprises any one of an oxide of yttrium, an oxide of magnesium, an oxide of calcium and an oxide of ytterbium, or a combination of at least two therefrom; and (II) firstly carrying out a primary sintering on the mixture obtained in the step (I) under a normal pressure, and then carrying out a secondary sintering on the mixture under a reducing atmosphere, to obtain the red zirconium-oxide sintered body having a fracture toughness≥8 MPa.Math.m.sup.1/2.

10. The method according to claim 9, wherein the mixture to be sintered in the step (I) further contains an oxide of aluminum less than 2.5 mol %.

11. The method according to claim 9, wherein the zirconium-oxide sintered body has a crystal particle size≤500 nm.

12. The method according to claim 9, wherein the zirconium oxide is prepared by a hydrothermal method.

13. The method according to claim 9, wherein the primary sintering is carried out at a temperature of 1300 to 1600° C. for 1˜5 h.

14. The method according to claim 9, wherein the secondary sintering is carried out at a temperature of 1300˜1600° C. for 1 to 5 h.

15. The method according to claim 9, wherein the reducing atmosphere is a mixed gas of hydrogen and nitrogen, wherein a volume proportion of hydrogen in the mixed gas is 3 to 7 v %.

16. A red zirconium-oxide article, wherein the red zirconium-oxide article is obtained by treating the red zirconium-oxide sintered body according to claim 1.

17. The red zirconium-oxide article according to claim 16, wherein the article comprises any one of a mobile phone backboard, a watch case, a watch chain, a watch hand, and an ornament.

18. A red zirconium-oxide sintered body, wherein the red zirconium-oxide sintered body comprises, in mole percentage, following components: 0.2 to 1.4 mol % of an oxide of cerium, 0.8 to 2.0 mol % of an oxide of yttrium, 0 to 2.5 mol % of an oxide of aluminum and a balance being zirconium oxide, wherein a sum of the oxide of cerium and the oxide of yttrium in content is 1.1 to 2.2 mol %, the oxide of cerium comprises a trivalent cerium oxide, wherein in the oxide of cerium, trivalent cerium, calculated based on cerium atom, has a mole percentage>60%, the sintered body has fracture toughness≥8 MPa.Math.m.sup.1/2 and the oxide of cerium is calculated based on CeO.sub.2, and the oxide of yttrium is calculated based on Y.sub.2O.sub.3.

Description

DETAILED DESCRIPTION OF EMBODIMENTS

(1) In order to facilitate understanding the present disclosure, examples listed in the present disclosure are as follows. Those skilled in the art should know that the examples are merely to help understand the present disclosure, but should not be considered as specific limitation on the present disclosure.

Examples 1˜17 and Comparative Examples 1˜11

(2) A method for preparing a red zirconium-oxide sintered body included following steps: (1) mixing oxide of cerium (CeO.sub.2), oxide of yttrium (Y.sub.2O.sub.3), zirconium oxide (ZrO.sub.2) and oxide of aluminum (Al.sub.2O.sub.3) to obtain a mixture to be sintered, wherein the mixture to be sintered was mixed according to mole percentages shown in Table 1-1; and (2) firstly carrying out primary sintering on the mixture obtained in the step (1) at 1500° C. under normal pressure for 3 h, and then carrying out secondary sintering on the mixture at 1500° C. in an atmosphere of the mixed gas of hydrogen and nitrogen for 3 h.

(3) TABLE-US-00001 TABLE 1-1 Powder Al.sub.2O.sub.3/ Ce.sub.2O.sub.3/ Y.sub.2O.sub.3/ Ce.sub.2O.sub.3 + Y.sub.2O.sub.3/ Average Example mol % mol % mol % mol % Grain/nm Example 1 0 0.4 1 1.4 220 Comparative 0 0.4 0.6 1.0 220 Example 1 Comparative 0 0.1 1 1.1 220 Example 2 Example 2 0 0.8 1 1.8 220 Example 3 0 1.2 1 2.2 220 Example 4 0 0.8 0.8 1.6 220 Comparative 0 1.6 0.8 2.4 220 Example 3 Comparative 0 0.1 0.8 0.9 220 Example 4 Example 5 0 0.8 1 1.8 220 Example 6 0 0.8 1.2 2.0 220 Example 7 0.6 0.8 1.2 2.0 220 Comparative 0.6 0.8 2.5 3.3 220 Example 5 Comparative 0.6 0.8 3.0 3.8 220 Example 6 Comparative 0.6 2.0 1.2 2.2 220 Example 7 Comparative 0.6 3.0 1.2 4.2 220 Example 8 Example 8 1.2 0.8 1.2 2.0 220 Example 9 0 0.8 1.2 2.0 150 Example 10 0 0.8 1.2 2.0 385 Example 11 0 0.8 1.2 2.0 460 Example 12 0.6 0.8 1.2 2.0 460 Comparative 0.6 0.8 1.2 4.2 650 Example 9 Comparative 0.6 0.8 1.2 4.2 835 Example 10 Comparative 0.6 0.8 1.2 4.2 1050 Example 11 Example 13 2.5 0.2 0.9 1.1 500 Example 14 0 1.5 0.5 2.0 120 Example 15 0 0.5 2.0 2.5 220 Example 16 2.6 0.8 1.2 2.0 220 Example 17 3.5 0.8 1.2 2.0 220
Performance Test 1:

(4) The sintered bodies obtained in Examples 1˜17 and Comparative Examples 1˜11 were subjected to the following performance tests: (1) three-point bending strength: the test method was GB-T 6569-2006; (2) toughness: the test method was ISO 24370-2005; and (3) Lab color: the test method was as follows: selecting a ceramic chip with the thickness of 1 mm, and polishing two surfaces of the ceramic chip until the smoothness Ra was less than 0.04; and placing the processed ceramic chip in a Konica Minolta device CM-3700A-U for detection, and testing the ceramic chip by adopting an SCE mode with a D65 illuminant as device illuminant.

(5) See Table 1-2 for test results.

(6) TABLE-US-00002 TABLE 1-2 Three-point Bending Toughness/ Example Strength/MPa MPa .Math. m.sup.1/2 L a b Example 1 1128 13.5 30.25 40.15 36.38 Comparative 789 4.38 33.58 40.13 38.99 Example 1 Comparative 658 3.99 45.18 12.33 20.38 Example 2 Example 2 1185 12.8 29.52 40.28 38.65 Example 3 1209 12.7 28.4 43.21 41.05 Example 4 1255 13.2 29.35 40.28 39.65 Comparative 1154 7.68 37.33 39.88 37.66 Example 3 Comparative 678 4.89 45.23 5.89 15.88 Example 4 Example 5 1189 11.8 29.33 41.25 40.23 Example 6 1267 9.5 28.12 43.2 39.89 Example 7 1308 11.63 31.05 42.88 40.25 Comparative 1109 4.65 31.25 41.26 39.22 Example 5 Comparative 1087 4.25 32.55 43.12 41.89 Example 6 Comparative 1106 4.89 26.78 41.25 40.36 Example 7 Comparative 1165 3.93 22.33 39.25 36.78 Example 8 Example 8 1337 10.94 32.76 43.16 42.49 Example 9 1319 10.55 27.35 42.55 39.55 Example 10 1165 9.68 29.54 41.89 40.22 Example 11 1086 9.12 27.89 42.11 38.45 Example 12 1255 10.56 29.88 41.78 40.89 Comparative 1089 4.76 30.88 39.31 37.55 Example 9 Comparative 986 4.25 32.35 38.99 37.64 Example 10 Comparative 897 3.66 33.55 37.64 37.89 Example 11 Example 13 646 5.67 50.24 15.23 28.46 Example 14 1050 7.62 33.28 40.15 39.48 Example 15 1083 7.59 32.35 39.84 36.52 Example 16 1105 9.54 40.55 35.89 49.87 Example 17 1089 8.99 42.55 34.88 55.23

(7) As can be seen from Table 1-2, for all of the zirconium-oxide sintered bodies satisfying the conditions that the oxide of cerium (trivalent cerium oxide) has a content of 0.2˜1.5 mol % and that the sum of the contents of the oxide of cerium and the oxide of yttrium is 1.1˜2.5 mol % (Examples 1˜15), the toughness is 8 MPa.Math.m.sup.1/2 or higher, the three-point bending strength is 1000 MPa or higher, and a red color is presented.

(8) It can be seen from comparison between Comparative Example 1 and Example 1 that when the content of the oxide of cerium is unchanged and the content of the oxide of yttrium is reduced, if the content of the oxide of yttrium and the oxide of cerium are less than 1.1 mol %, the sintered body cannot be stable at room temperature, and the ceramic will crack; and it can be seen from comparison between Comparative Example 2 and Example 1 that when the content of the oxide of yttrium is unchanged and the content of the oxide of cerium is reduced, if the content of the oxide of yttrium and the oxide of cerium are less than 1.1 mol %, the sintered body cannot be stable at room temperature, the ceramic will crack, and the bright red appearance cannot be obtained.

(9) It can be seen from comparison between Comparative Example 3 and Example 4 that when the content of the oxide of yttrium is unchanged and the content of the oxide of cerium is greater than 1.5 mol %, the toughness will be reduced; and it can be seen from comparison between Comparative Example 4 and Example 4 that when the content of the oxide of yttrium is unchanged, and the content of the oxide of cerium is less than 0.2 mol %, the red appearance cannot be presented.

(10) It can be seen from comparison among Comparative Example 5, Comparative Example 6 and Example 7 that when the content of the oxide of cerium is unchanged, and the content of the oxide of yttrium is increased, it is not the case that a higher content of the oxide of yttrium is better, and if the content of the oxide of yttrium and the oxide of cerium exceed 2.5 mol %, the toughness will be significantly reduced. It can be seen from comparison among Comparative Example 7, Comparative Example 8 and Example 7 that when the content of the oxide of cerium is increased so that the content of the oxide of yttrium and the oxide of cerium exceed 2.5 mol %, the toughness also will be significantly reduced. Therefore, either the increase of the content of the oxide of yttrium or the increase of the content of the oxide of cerium will result in significant reduction in toughness.

(11) It can be seen from Example 16 and Example 17 that the red zirconium-oxide of the present disclosure has good compatibility with other metal oxides, and can render the desired color by adding other elements, for example, orange-colored zirconium oxide is obtained by adding aluminum oxide.

Examples 18˜20

(12) The only difference from Example 8 is that the oxide of yttrium was replaced by oxide of magnesium MgO.sub.2 (Example 18), oxide of calcium CaO (Example 19) and oxide of ytterbium Yb.sub.2O.sub.3 (Example 20) in an equimolar amount.

(13) Performance Test 2:

(14) The performance test was performed on Examples 18˜20 according to the method for performance test 1, and test results are shown in Table 2.

(15) TABLE-US-00003 TABLE 2 Three-point Bending Toughness/ Example Strength/MPa MPa .Math. m.sup.1/2 L a b Example 18 1052 9.32 33.65 42.18 40.28 Example 19 1023 9.13 32.69 42.89 40.12 Example 20 1235 11.87 33.99 42.68 41.53

(16) It can be seen from Table 2 that when the yttrium oxide was replaced by other oxides in an equimolar amount, the red sintered body having toughness≥8 MPa.Math.m.sup.1/2 still could be obtained, but the three-point bending strength and toughness were not exhibited as well as those of the red zirconium oxide obtained by adding yttrium oxide in an equimolar amount.

(17) The applicant states that the present disclosure illustrates the detailed process equipment and process flow of the present disclosure through the above examples, but the present disclosure is not limited to the above detailed process equipment and process flow, which means that the present disclosure must be implemented relying upon the detailed process equipment and process flow above. Those skilled in the art should know that any improvement on the present disclosure, equivalent substitutions of raw materials and addition of auxiliary components of products of the present disclosure, selection of specific modes, etc., are included in the scope of protection and the scope of disclosure of the present disclosure.

INDUSTRIAL APPLICABILITY

(18) (1) The zirconium-oxide sintered body provided in the present disclosure has red appearance and toughness more than 8 MPa.Math.m.sup.1/2, and the three-point bending strength of the sintered body is ≥1000 MPa; with an expanded application scene thereof, the zirconium-oxide sintered body can be used for products such as mobile phone backboards, ornaments and dial plates, moreover, the resistance to falling of ceramic members is improved due to the high toughness of the zirconium-oxide sintered body; and (2) the preparation method provided in the present disclosure is simple, and can be used to prepare the high-toughness zirconium-oxide sintered body with red appearance.