CN116425530A

CN116425530A - Color zirconia and preparation method thereof

Info

Publication number: CN116425530A
Application number: CN202310208042.3A
Authority: CN
Inventors: 刘杰鹏; 李钢; 邱基华
Original assignee: Chaozhou Three Circle Group Co Ltd
Current assignee: Chaozhou Three Circle Group Co Ltd
Priority date: 2023-03-06
Filing date: 2023-03-06
Publication date: 2023-07-14

Abstract

The invention discloses a color zirconia and a preparation method thereof. A color zirconia, comprising the following elemental components in percentage by mass: 65 to 81.5 weight percent of Zr+Hf element, 1.3 to 6.3 weight percent of Y element and 0.25 to 1.3 weight percent of sol element; the sol element comprises at least one of Fe, mn and Cr; the sol element is coated on the surface of zirconia. The colored zirconia of the invention can not achieve the purposes of low-temperature sintering and grain strengthening when the components (sol elements) enriched on the grain boundary are insufficient, and the strength of the zirconia after porcelain formation is poor; when the enrichment component is excessive on the grain boundary, the zirconia grains grow abnormally under the sintering promotion effect of sol elements, so that the zirconia strength is seriously attenuated.

Description

Color zirconia and preparation method thereof

Technical Field

The invention relates to the field of ceramic materials, in particular to a colored zirconia and a preparation method thereof.

Background

Zirconia ceramics have excellent mechanical properties, such as high strength, high hardness, wear resistance, metallic luster after polishing, no anaphylactic effect on human body and the like, and are gradually becoming new pets for high-grade decorative materials such as artificial precious stones, watch cases, watch chains, mobile phone shells and the like in recent years. The traditional zirconia ceramics are white after sintering, and as the demands of people for ornaments are continuously improved, the single color is difficult to meet the increasing demands of people for zirconia ceramic decorative materials. Therefore, the research and development of the color zirconia ceramics have wide market prospect.

The traditional color ceramic is prepared by mechanically mixing the coloring material directly with the zirconia powder, and then molding and sintering, wherein the color zirconia prepared by the process has poor uniformity of the coloring material, so that the product is non-uniform in color, and the added coloring material has a large influence on the strength of the zirconia.

Disclosure of Invention

In order to solve the problems that the color of a product is uneven due to poor uniformity of pigment in the prior color zirconia, the added pigment has great influence on the strength of the zirconia, and the like, the first aspect of the invention provides a color zirconia, and the second aspect of the invention provides a preparation method of the color zirconia.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

the first aspect of the invention provides a colored zirconia, which comprises the following element components in percentage by mass:

65 to 81.5 weight percent of Zr+Hf element, 1.3 to 6.3 weight percent of Y element and 0.25 to 1.3 weight percent of sol element;

the sol element comprises at least one of Fe, mn and Cr; the sol element is coated on the surface of zirconia.

Preferably, the color zirconia comprises the following element components in percentage by mass:

70 to 76.5 weight percent of Zr+Hf element, 2.8 to 4.8 weight percent of Y element and 0.4 to 1.0 weight percent of sol element.

The second aspect of the present invention provides a method for preparing the above-mentioned colored zirconia, comprising the steps of:

(1) Mixing the acetate solution with organic acid, heating and stirring to obtain sol A;

(2) Mixing part of yttrium-containing zirconia powder, water and a dispersing agent, and grinding to obtain ceramic slurry B;

(3) Mixing the sol A and the ceramic slurry B, and then spraying and granulating to obtain sol-coated zirconia ceramic powder;

(4) Mixing the ceramic powder of the sol-coated zirconia with the rest yttrium-containing zirconia powder, grinding to obtain ceramic slurry C, adding a binder into the ceramic slurry C, spraying and granulating, and forming to obtain a zirconia blank;

(5) Calcining the zirconia blank to obtain the colored zirconia.

Adsorbing at least one hydroxide or oxide sol of Fe, mn and Cr on the surface of yttrium-containing zirconia (Y-TZP) powder, mixing the obtained sol with zirconia slurry, spraying and granulating to obtain ceramic powder with zirconia coated by pigment sol, mixing the zirconia ceramic powder coated by sol with the rest yttrium-containing zirconia powder to form a ceramic green body, and sintering to obtain the zirconia ceramic with a specific microstructure.

The sol oxide or hydroxide uniformly coated on the surface of the zirconia particles can be uniformly distributed in each area of the whole sintered body in the sintering process, and has stronger color development capability and color development uniformity than spinel pigment. The fine coloring agent has higher activity and higher color forming capability, and meanwhile, the powder can form a glass phase after being sintered to about 1200 ℃ and can be rapidly diffused and wrapped on a zirconia grain boundary. The formation of the glass phase plays a role in promoting sintering densification in the solid phase sintering process of zirconia, so that the binding force between zirconia grain boundaries is improved, and the strength of a ceramic product is improved. Meanwhile, as the fine sol is added, the growth of zirconia grains can be inhibited, and the zirconia grains are reinforced, so that the strength of the zirconia ceramic is improved.

In the ceramic sintering process, the sol powder coated on the surface of the zirconia powder has small particles at about 900-1000 ℃ to lead zirconia particles to be rearranged and the pores of the biscuit to be discharged, thereby reducing the sintering temperature of the zirconia, inhibiting the growth of crystal grains, strengthening the strength of the crystal grains, improving the strength of the zirconia, and being beneficial to improving the color-forming capability of pigment elements due to the coating and enrichment of colloid components on the crystal boundary. Therefore, when the components (sol elements) enriched on the grain boundary are insufficient, the purposes of low-temperature sintering and grain strengthening cannot be achieved, and the strength of the zirconia after porcelain formation is poor; when the enrichment component is excessive on the grain boundary, the zirconia grains grow up abnormally under the sintering promotion effect of sol elements, so that the zirconia strength is seriously attenuated.

Preferably, in the preparation method, in the step (1), the concentration of the acetate solution is 0.1-0.5 mol/L; further preferably, the concentration of the acetate solution is 0.2 to 0.4mol/L.

Preferably, in the preparation method, in the step (1), the acetate solution comprises at least one of ferric acetate, manganese acetate and chromium acetate solution.

Preferably, in the preparation method, in the step (1), the concentration of the organic acid is 0.25-1.5 mol/L; more preferably, the concentration of the organic acid is 0.4 to 1.0mol/L.

Preferably, in the preparation method, the mass ratio of the acetate solution to the organic acid in the step (1) is 1: (1.5-4).

Preferably, in the preparation method, in the step (1), the organic acid comprises at least one of citric acid, malic acid, tartaric acid and salicylic acid.

Preferably, in the preparation method, in the step (1), the temperature of heating and stirring is 70-100 ℃; further preferably, the temperature of heating and stirring is 70-90 ℃; still more preferably, the temperature of the heating and stirring is 75-85 ℃; the heating and stirring are carried out under water bath conditions.

Preferably, in the preparation method, in the step (1), heating and stirring are carried out for 10-25 hours; further preferably, the heating and stirring time is 10-20 hours; still more preferably, the heating and stirring time is 12 to 18 hours.

Preferably, in the preparation method, in the step (2), the mass ratio of part of yttrium-containing zirconia powder, water and dispersing agent is 100: (90-120): (0.5-1.5); further preferably, the mass ratio of the yttrium-containing zirconia powder to the water to the dispersant is 100: (100-115): (0.8-1.3).

Preferably, in the preparation method, in the step (2), ball milling is adopted, the rotation speed of the ball milling is 20-60 rpm, and the ball milling time is 5-15 h.

Preferably, in the preparation method, in the step (2), the dispersing agent comprises at least one of ammonium polyacrylate, sodium tripolyphosphate, sodium hexametaphosphate, ammonia polymethacrylate and polyethylene glycol.

Preferably, in the preparation method, in the step (3), the mass ratio of the sol A to the ceramic slurry B is (1-10): (90-99).

Preferably, in the preparation method, in the step (4), the binder comprises at least one of polyvinyl alcohol, gelatin and sodium alginate.

Preferably, in the preparation method, in the step (4), the mass ratio of the ceramic powder of sol-coated zirconia to the rest yttrium-containing zirconia powder is (1-20): (80-99).

Preferably, in the preparation method, in the step (4), the mass ratio of the binder to the ceramic slurry C is (2-5): 100.

preferably, in the preparation method, in the step (4), the forming adopts at least one of dry pressing, injection and casting; in some embodiments of the invention, dry pressing and isostatic pressing are used for molding.

Further preferably, the dry pressure is 3 to 6MPa; still more preferably, the dry pressure is 4 to 6MPa; still more preferably, the dry pressure is 4.5 to 5.5MPa.

Further preferably, the isostatic pressure is 150-300 MPa; still more preferably, the isostatic pressure is 150-250 MPa; still more preferably, the isostatic pressure is 180-220 MPa.

Preferably, in the preparation method, in the step (5), the calcining temperature is 1300-1400 ℃; further preferably, the calcination temperature is 1320 to 1380 ℃; still more preferably, the calcination temperature is 1340-1360 ℃.

Preferably, in the preparation method, in the step (5), the calcination time is 2-5 hours; further preferably, the calcination time is 2 to 4 hours; still more preferably, the calcination time is 2.5 to 3.5 hours.

Preferably, in the preparation method, in the step (5), the zirconia blank is calcined, and then the surface is ground and polished to obtain the colored zirconia.

The beneficial effects of the invention are as follows:

when the components (sol elements) enriched on the grain boundary are insufficient, the color zirconia cannot achieve the purpose of grain strengthening, and the strength of the zirconia after porcelain formation is poor; when the enrichment component is excessive on the grain boundary, the zirconia grains grow abnormally under the sintering promotion effect of sol elements, so that the zirconia strength is seriously attenuated.

Drawings

Fig. 1 is a TEM image of the colored zirconia ceramic of example 1.

FIG. 2 is a TEM image of the colored zirconia ceramic of comparative example 6.

Detailed Description

The present invention will be described in further detail with reference to specific examples. The starting materials, reagents or apparatus used in the examples and comparative examples were either commercially available from conventional sources or may be obtained by prior art methods unless specifically indicated. Unless otherwise indicated, assays or testing methods are routine in the art.

The "parts" in the following examples and comparative examples each refer to "parts by mass".

Example 1

The present example provides a colored zirconia ceramic, the contents of the elements are shown in table 1 below:

the preparation method of the color zirconia ceramics of the embodiment is as follows:

(1) Preparing oxide sol to be added: 30 parts of 0.3mol/L acetate solution (chromium acetate and ferric acetate) and 70 parts of 0.5mol/L citric acid solution are mixed, stirred in a water bath and heated at 80 ℃ for 15 hours to obtain sol A;

(2) To 100 parts of yttrium-containing zirconia powder, 100 parts of pure water and 1.0 part of dispersant ammonium polyacrylate are added, and the mixture is ball-milled for 10 hours at 50rpm to obtain ceramic slurry B.

(3) Mixing 5 parts of the sol A obtained in the step (1) with 95 parts of the ceramic slurry B obtained in the step (2), and then spraying and granulating to obtain ceramic powder with zirconia coated by the pigment sol;

(4) Mixing 15 parts of ceramic powder with zirconia coated by the pigment sol and 85 parts of yttrium-containing zirconia powder, performing ball milling and sand milling to obtain ceramic slurry C, adding 3 parts of binder polyvinyl alcohol into the ceramic slurry C for spray granulation based on 100 parts of the ceramic slurry C, and forming to obtain zirconia blanks;

(5) Calcining the zirconia blank, grinding the surface of the zirconia blank, and polishing to obtain zirconia ceramic;

the dry pressure in the step (4) is 5MPa, and the isostatic pressure is 200MPa; the calcination temperature in the step (5) is 1350 ℃, and the calcination time is 3 hours.

Example 2

The present example provides a colored zirconia ceramic, the contents of the elements are shown in table 2 below:

TABLE 2

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 2	76.5	5.14	0.25	Fe

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and that acetate was replaced with iron acetate and the amount thereof was adjusted.

Example 3

The present example provides a colored zirconia ceramic, the contents of the elements are shown in table 3 below:

TABLE 3 Table 3

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 3	65	6.3	1.3	Fe

Example 4

This example provides a colored zirconia ceramic having the following contents of the elements shown in table 4:

TABLE 4 Table 4

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 4	81.5	1.3	0.4	Mn

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and acetate was replaced with manganese acetate and the amount thereof was adjusted.

Example 5

This example provides a colored zirconia ceramic having the following contents of the elements shown in table 5:

TABLE 5

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 5	70	4.8	1.0	Cr

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and acetate was replaced with chromium acetate and the amount thereof was adjusted.

Example 6

The present example provides a colored zirconia ceramic, the contents of the elements are shown in table 6 below:

TABLE 6

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 6	74.14	2.98	0.74	Fe、Cr、Mn

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and acetate was replaced with chromium acetate, iron acetate and manganese acetate and the amount thereof was adjusted.

Example 7

This example provides a colored zirconia ceramic having the following contents of the elements shown in table 7:

TABLE 7

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 7	78.33	2.8	0.47	Cr、Mn

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and acetate was replaced with chromium acetate and manganese acetate and the amount thereof was adjusted.

Example 8

The present example provides a colored zirconia ceramic, the contents of the elements are shown in the following table 8:

TABLE 8

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Example 8	67.5	5.34	0.36	Fe、Mn

The method for producing the colored zirconia ceramics of this example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and that acetate was replaced with iron acetate and manganese acetate and the amount thereof was adjusted.

Comparative example 1

This comparative example provides a colored zirconia ceramic having the following contents of the elements as shown in table 9:

TABLE 9

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Comparative example 1	75.5	6.5	0	Without any means for

The method for producing the colored zirconia ceramics of this comparative example was the same as in example 1, except that the yttrium-containing zirconia powder and the amount of the yttrium-containing zirconia powder were adjusted without adding acetate.

Comparative example 2

This comparative example provides a colored zirconia ceramic having the following contents of the elements as shown in table 10:

table 10

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Comparative example 2	76.98	7.35	0.1	Fe

The method for producing the colored zirconia ceramics of this comparative example was the same as in example 1, except that yttrium-containing zirconia powder and the amount thereof were adjusted, and that acetate was replaced with iron acetate and the amount thereof was adjusted.

Comparative example 3

This comparative example provides a colored zirconia ceramic having the following contents of the elements as shown in table 11:

TABLE 11

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Comparative example 3	63.21	3.84	1.43	Fe

Comparative example 4

This comparative example provides a colored zirconia ceramic having the following contents of the elements as shown in table 12:

table 12

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition
					Comparative example 4	62.81	3.99	1.72	Fe

Comparative example 5

This comparative example provides a colored zirconia ceramic having the following contents of the elements as shown in table 13:

TABLE 13

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition	Oxide colorant/wt%
						Comparative example 5	76.5	5.14	/	/	0.28/Fe ₂ O ₃

The preparation method of the color zirconia ceramics of the comparative example is as follows:

(1) To 99 parts of yttrium-containing zirconia powder, 1 part of Fe is added ₂ O ₃ Is prepared from yttrium-containing zirconia powder and Fe ₂ O ₃ 100 parts of pure water and 1.0 part of dispersant ammonium polyacrylate are added, and ball milling is carried out for 10 hours at 50rpm to obtain ceramic slurry B.

(2) Adding 2.0 parts of binder polyvinyl alcohol into 100 parts of ceramic slurry B by weight, and then spraying and granulating to obtain ceramic powder with pigment coated with zirconia.

(3) Carrying out dry pressing and isostatic compaction on the ceramic powder of which the zirconium oxide is coated with the pigment to obtain a zirconium oxide blank;

(4) Calcining the zirconia blank, grinding the surface of the zirconia blank, and polishing to obtain the zirconia ceramic.

The dry pressure in the step (3) is 5MPa, and the isostatic pressure is 200MPa; the calcination temperature in the step (4) is 1350 ℃, and the calcination time is 3 hours.

Comparative example 6

This comparative example provides a colored zirconia ceramic having the following contents of the elements shown in table 14:

TABLE 14

Numbering device	Zr+Hf/wt％	Y/wt％	Sol element/wt%	Sol element composition	Oxide colorant/wt%
						Comparative example 6	81.5	1.55	/	/	0.55/MnO

The method for producing the colored zirconia ceramics of this comparative example was the same as that of comparative example 5, except that the yttrium-containing zirconia powder and the amount thereof were adjusted, and that Fe was added ₂ O ₃ Replaced by MnO, and the dosage is adjusted.

The color zirconia ceramics prepared in the examples and the comparative examples are subjected to four-point bending strength and chromaticity SCI test, and the four-point bending strength is tested according to the national standard GBT 4741-1999 "ceramic material bending strength test method Standard"; chromaticity SCI: coloring with a SPECTROPHOTOMETER CM-2600d colorimeter, measuring the thickness of a polishing sheet (0.4+/-0.03) mm, testing 10pcs in each batch, and calculating an average value; the test results are shown in table 15 below.

TABLE 15

The TEM image of the colored zirconia ceramic of example 1 is shown in fig. 1, and the element distribution at the grain boundaries of the selected regions is analyzed, and as shown in the figure, the element distribution of Cr and Fe is present at the grain boundaries of the zirconia and the zirconia grains are wrapped. As shown in Table 15, the strength of the colored zirconia ceramics of this example was high.

As shown in FIG. 2, the TEM image of the colored zirconia ceramic of comparative example 6 shows that the manganese pigment directly added in the form of oxide does not form a coating at the zirconia grain boundary, and as a result of the chromaticity and strength of comparative example 4, the chromaticity fluctuation of comparative example 6 is large and the strength is significantly lower.

As can be seen from the data of examples and comparative examples in the tables, the sol-coated Y-ZrO ₂ With Y-ZrO ₂ The mixed zirconia ceramics have smaller SCI chromaticity value fluctuation and even color development compared with the traditional mode, and the ceramic after ceramic sintering is formed within the element content range of the zirconia ceramic sintering body defined by the inventionHigh strength and difficult deformation.

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments of the present invention should be included in the scope of the present invention.

Claims

1. A colored zirconia, characterized in that the colored zirconia comprises the following elemental components in mass percent:

2. The colored zirconia of claim 1, wherein the colored zirconia comprises the following elemental components in mass percent:

3. A method for producing the colored zirconia according to claim 1 or 2, comprising the steps of:

(5) Calcining the zirconia blank to obtain the colored zirconia.

4. The method according to claim 3, wherein in the step (1), the concentration of the acetate solution is 0.1 to 0.5mol/L; the concentration of the organic acid is 0.25-1.5 mol/L.

5. The method according to claim 3, wherein in the step (1), the organic acid comprises at least one of citric acid, malic acid, tartaric acid, and salicylic acid.

6. The method according to claim 4, wherein in the step (1), the temperature of the heating and stirring is 70 to 100℃for 10 to 25 hours.

7. The method according to claim 3, wherein in the step (2), the mass ratio of the yttrium-containing zirconia powder, water and dispersant is 100: (90-120): (0.5-1.5).

8. The method according to claim 3, wherein in the step (3), the mass ratio of the sol A to the ceramic slurry B is (1 to 10): (90-99).

9. The method according to claim 3, wherein in the step (4), the mass ratio of the sol-coated zirconia ceramic powder to the remaining yttrium-containing zirconia powder is (1 to 20): (80-99).

10. A method according to claim 3, wherein in step (5), the calcination is carried out at a temperature of 1300 to 1400 ℃ for a time of 2 to 5 hours.