A zirconium hafnium oxide ceramic powder and a preparation method thereof

Abstract

The present invention discloses a zirconium hafnium oxide ceramic powder and a preparation method thereof. The preparation method of the zirconium hafnium oxide ceramic powder comprises the following steps: heating and stirring a zirconium source, a hafnium source, yttrium oxide and water, then cooling to room temperature, filtering, and collecting the filtrate; adding γ-aminobutyric acid to the filtrate and performing stirring treatment to obtain a mixed solution; evaporating the mixed solution to dryness, performing high-temperature sintering, grinding and sieving to obtain the zirconium hafnium oxide powder. The zirconium hafnium oxide ceramic powder of the present invention has excellent high-temperature resistance through specific raw materials and preparation processes. Among them, through the addition of γ-aminobutyric acid, cation chelation can be realized, the dispersion performance and molecular distance of each raw material can be improved, so that the finally prepared ceramic powder has better crystallinity and purity. Specifically, the phase transition temperature of the ceramic powder can reach up to more than 1582 °C, thereby expanding the application fields and better meeting the market demand.

Description

Technical Field

[0001] The present invention relates to the technical field of zirconium hafnium ceramic materials, and particularly relates to a zirconium hafnium oxide ceramic powder and a preparation method thereof. Background Art

[0002] The proven zirconium resources in the world are about 19 million tons. Zirconia is usually obtained by purifying zircon ore. Under normal pressure, pure ZrO2 has three crystal forms: monoclinic zirconia (m-ZrO2), tetragonal zirconia (t-ZrO2), and cubic zirconia (c-ZrO2). The above three crystal forms exist in different temperature ranges and can be transformed into each other. The transformation temperatures are as follows: monoclinic zirconia (m-ZrO2) < 950 °C; tetragonal zirconia (t-ZrO2) is 1200 - 2370 °C; and cubic zirconia (c-ZrO2) > 2370 °C. The above three crystal forms have different physical and chemical properties. In actual applications, to obtain the required crystal form and performance, different types of stabilizers are usually added to make different types of zirconia ceramics, such as partially stabilized zirconia (PSZ). When the stabilizer is CaO, MgO, Y2O3, they are respectively represented as Ca-PSZ, Mg-PSZ, Y-PSZ, etc.

[0003] At present, the phase transformation temperature of zirconia ceramics is lower than 1200 °C, which affects their scope of use.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a zirconium hafnium oxide ceramic powder and a preparation method thereof. The zirconium hafnium oxide ceramic powder of the present invention has excellent high-temperature resistance through specific raw materials and preparation processes, and the specific phase transformation temperature is as high as above 1450 °C.

[0006] In order to achieve the above object of the present invention, the following technical solutions are specifically adopted:

[0007] The first aspect of the present invention provides a preparation method of a zirconium hafnium oxide ceramic powder. The preparation method of the zirconium hafnium oxide ceramic powder includes the following steps:

[0008] (a) Heating and stirring zirconium source, hafnium source, yttrium oxide and water, then cooling to room temperature and filtering to collect the filtrate;

[0009] (b) Adding γ-aminobutyric acid to the filtrate and performing stirring treatment to obtain a mixed solution;

[0010] (c) Evaporate the mixed solution to dryness, sinter at high temperature, grind and sieve to obtain the zirconium hafnium oxide powder.

[0011] Preferably, the zirconium source is zirconium nitrate.

[0012] Preferably, the hafnium source is hafnium nitrate.

[0013] Preferably, the molar ratio of the zirconium source to the hafnium source is 1:(0.5 - 1).

[0014] Preferably, the molar ratio of yttrium oxide to the zirconium source is (2 - 3):50.

[0015] Preferably, the heating and stirring temperature is 75 - 90 °C and the time is 1.5 - 2.5 h.

[0016] Preferably, the molar ratio of γ-aminobutyric acid to the zirconium source is (8 - 10):1.

[0017] Preferably, the stirring treatment time is 1 - 2 h.

[0018] Preferably, the high-temperature sintering includes: heating at a heating rate of 1 - 2 °C / s to 240 - 260 °C and holding for 15 - 20 min, then heating at 4 - 6 °C / s to 1250 - 1400 °C and holding for 4 - 5 h.

[0019] The second aspect of the present invention provides a zirconium hafnium oxide ceramic powder prepared by the above preparation method.

[0020] Compared with the prior art, the beneficial effects of the present invention at least include:

[0021] The zirconium hafnium oxide ceramic powder of the present invention has excellent high-temperature resistance through specific raw materials and preparation processes. Among them, through the addition of γ-aminobutyric acid, cation chelation can be achieved, the dispersion performance and molecular distance of each raw material can be improved, so that the finally prepared ceramic powder has better crystallinity and purity. Specifically, the phase transition temperature of the ceramic powder can reach up to above 1582 °C, thereby expanding the application field and better meeting the market demand. Detailed Embodiments

[0022] The embodiments of the technical solutions of the present invention will be described in detail below with reference to the embodiments. The following embodiments are only used to illustrate the technical solutions of the present invention more clearly, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0023] It should be noted that unless otherwise specified, the technical terms or scientific terms used in this application should have the ordinary meaning understood by those skilled in the art to which the present invention belongs.

[0024] An embodiment of the present invention provides a method for preparing zirconium hafnium oxide ceramic powder, and the method for preparing the zirconium hafnium oxide ceramic powder includes the following steps:

[0025] (a) Heating and stirring zirconium source, hafnium source, yttrium oxide and water, then cooling to room temperature and filtering to collect the filtrate;

[0026] (b) Adding γ-aminobutyric acid to the filtrate and performing stirring treatment to obtain a mixed solution;

[0027] (c) Evaporating the mixed solution to dryness, performing high-temperature sintering, grinding and sieving to obtain the zirconium hafnium oxide powder.

[0028] The zirconium hafnium oxide ceramic powder of the present invention has excellent high-temperature resistance through specific raw materials and preparation processes. Among them, by adding γ-aminobutyric acid, chelation of cations can be achieved, the dispersion performance and molecular distance of each raw material can be improved, so that the finally prepared ceramic powder has better crystallinity and purity. Specifically, the phase transition temperature of the ceramic powder can reach up to 1582 °C or higher, thereby expanding the application fields and better meeting the market demand.

[0029] In one embodiment, the zirconium source is zirconium nitrate.

[0030] In one embodiment, the hafnium source is hafnium nitrate.

[0031] In one embodiment, the molar ratio of the zirconium source to the hafnium source can be 1:(0.5 - 1), specifically 1:0.5 or 1:1.

[0032] In one embodiment, the molar ratio of yttrium oxide to the zirconium source can be (2 - 3):50, specifically 1:25 or 3:50.

[0033] In one embodiment, the heating and stirring temperature can be 75 - 90 °C, and the time can be 1.5 - 2.5 h.

[0034] In one embodiment, the molar ratio of γ-aminobutyric acid to the zirconium source can be any value in (8 - 10):1.

[0035] In one embodiment, the stirring treatment time can be 1 - 2 h.

[0036] In one embodiment, the high-temperature sintering includes: heating to 240 - 260 °C at a heating rate of 1 - 2 °C / s and holding for 15 - 20 min, and then heating to 1250 - 1400 °C at a heating rate of 4 - 6 °C / s and holding for 4 - 5 h.

[0037] Another embodiment of the present invention provides a zirconium hafnium oxide ceramic powder prepared by the above preparation method.

[0038] The technical solution of the present invention will be further described in detail below through specific embodiments.

[0039] Example 1

[0040] This example is a preparation method of zirconium hafnium oxide ceramic powder. The preparation method of the zirconium hafnium oxide ceramic powder includes the following steps:

[0041] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 75 °C, stir for 2.5 h, then cool to room temperature, filter, and collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:0.5; the molar ratio of yttrium oxide to zirconium nitrate is 2:50;

[0042] (b) Add γ-aminobutyric acid to the filtrate and stir for 1 h to obtain a mixed solution. Among them, the molar ratio of γ-aminobutyric acid to zirconium nitrate is 10:1;

[0043] (c) Evaporate the mixed solution to dryness, heat it to 240 °C at a heating rate of 1 °C / s and keep it warm for 20 min, then heat it to 1250 °C at a heating rate of 4 °C / s and keep it warm for 5 h, and grind and sieve it to obtain the zirconium hafnium oxide powder.

[0044] Example 2

[0045] This example is a preparation method of zirconium hafnium oxide ceramic powder. The preparation method of the zirconium hafnium oxide ceramic powder includes the following steps:

[0046] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 90 °C, stir for 1.5 h, then cool to room temperature, filter, and collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:1; the molar ratio of yttrium oxide to zirconium nitrate is 3:50;

[0047] (b) Add γ-aminobutyric acid to the filtrate and stir for 2 h to obtain a mixed solution. Among them, the molar ratio of γ-aminobutyric acid to zirconium nitrate is 8:1;

[0048] (c) Evaporate the mixed solution to dryness, heat it to 260 °C at a heating rate of 2 °C / s and keep it warm for 15 min, then heat it to 1400 °C at a heating rate of 6 °C / s and keep it warm for 4 h, and grind and sieve it to obtain the zirconium hafnium oxide powder.

[0049] Example 3

[0050] This example is a preparation method of zirconium hafnium oxide ceramic powder. The preparation method of the zirconium hafnium oxide ceramic powder includes the following steps:

[0051] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 85 °C and stir for 2 h, then cool to room temperature, filter, and collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:0.8; the molar ratio of yttrium oxide to zirconium nitrate is 2.5:50;

[0052] (b) Add γ-aminobutyric acid to the filtrate and stir for 1.5 h to obtain a mixed solution. Among them, the molar ratio of γ-aminobutyric acid to zirconium nitrate is 9:1;

[0053] (c) Evaporate the mixed solution to dryness, heat it to 250 °C at a heating rate of 2 °C / s and hold for 20 min, then heat it to 1350 °C at a heating rate of 5 °C / s and hold for 5 h, grind and screen to obtain the zirconium hafnium oxide powder.

[0054] Example 4

[0055] This example is a method for preparing zirconium hafnium oxide ceramic powder. The method for preparing zirconium hafnium oxide ceramic powder includes the following steps:

[0056] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 85 °C and stir for 2 h, then cool to room temperature, filter, and collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:0.8; the molar ratio of yttrium oxide to zirconium nitrate is 2.5:50;

[0057] (b) Add γ-aminobutyric acid to the filtrate and stir for 1.5 h to obtain a mixed solution. Among them, the molar ratio of γ-aminobutyric acid to zirconium nitrate is 9:1;

[0058] (c) Evaporate the mixed solution to dryness, heat it to 1350 °C at a heating rate of 5 °C / s and hold for 5 h, grind and screen to obtain the zirconium hafnium oxide powder.

[0059] Example 5

[0060] This example is a method for preparing zirconium hafnium oxide ceramic powder. The method for preparing zirconium hafnium oxide ceramic powder includes the following steps:

[0061] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 85 °C and stir for 2 h, then cool to room temperature, filter, and collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:0.8; the molar ratio of yttrium oxide to zirconium nitrate is 2.5:50;

[0062] (b) Add γ-aminobutyric acid to the filtrate and stir for 1.5 h to obtain a mixed solution. Among them, the molar ratio of γ-aminobutyric acid to zirconium nitrate is 9:1;

[0063] (c) Evaporate the mixed solution to dryness, heat it at a heating rate of 5 °C / s to 250 °C and hold for 20 min, then heat it at 5 °C / s to 1350 °C and hold for 5 h, and grind and sieve it to obtain the zirconium hafnium oxide powder.

[0064] Comparative Example 1

[0065] This comparative example is a method for preparing zirconium hafnium oxide ceramic powder. The method for preparing the zirconium hafnium oxide ceramic powder includes the following steps:

[0066] (a) Heat zirconium nitrate, hafnium nitrate, yttrium oxide and water to 85 °C and stir for 2 h, then cool to room temperature and filter to collect the filtrate. Among them, the molar ratio of zirconium nitrate to hafnium nitrate is 1:0.8; the molar ratio of yttrium oxide to zirconium nitrate is 2.5:50;

[0067] (b) Evaporate the filtrate to dryness, heat it at a heating rate of 2 °C / s to 250 °C and hold for 20 min, then heat it at 5 °C / s to 1350 °C and hold for 5 h, and grind and sieve it to obtain the zirconium hafnium oxide powder.

[0068] Experimental Example

[0069] Respectively obtain the zirconium hafnium oxide powders prepared in Examples 1 to 5 and Comparative Example 1;

[0070] Detect the phase transition temperatures of the zirconium hafnium oxide powders prepared in Examples 1 to 5 and Comparative Example 1. The detection results are shown in Table 1;

[0071] Table 1

[0072] Group Phase transition temperature (°C) Example 1 1468 Example 2 1582 Example 3 1559 Example 4 1415 Example 5 1471 Comparative Example 1 1346

[0073] As can be seen from Table 1:

[0074] Compared with the comparative example, the zirconium hafnium oxide ceramic powder prepared in the examples of the present application has better heat resistance temperature and a wider application field.

[0075] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A method for preparing zirconium hafnium oxide ceramic powder, characterized in that, The preparation method of the zirconium hafnium oxide ceramic powder comprises the following steps: (a) Heating and stirring zirconium source, hafnium source, yttrium oxide and water, then cooling to room temperature, filtering, and collecting the filtrate; (b) Adding γ-aminobutyric acid to the filtrate and carrying out stirring treatment to obtain a mixed solution; (c) Drying the mixed solution by evaporation, performing high-temperature sintering, grinding and sieving to obtain the zirconium hafnium oxide ceramic powder; The zirconium source is zirconium nitrate; the hafnium source is hafnium nitrate; the molar ratio of the zirconium source to the hafnium source is 1∶(0.5 - 1); the molar ratio of yttrium oxide to the zirconium source is (2 - 3)∶50; the heating and stirring temperature is 75 - 90 °C, and the time is 1.5 - 2.5 h; the molar ratio of γ-aminobutyric acid to the zirconium source is (8 - 10)∶1; The stirring treatment time is 1 - 2 h; the high-temperature sintering includes: heating to 240 - 260 °C at a heating rate of 1 - 2 °C / s and holding for 15 - 20 min, and then heating to 1250 - 1400 °C at a heating rate of 4 - 6 °C / s and holding for 4 - 5 h.