阅读说明：本技术 一种高稳定氧化锆及其生产工艺 (High-stability zirconia and production process thereof ) 是由 王洋 于 2020-07-25 设计创作，主要内容包括：本申请公开了一种高稳定氧化锆及其生产工艺,属于氧化锆材料技术领域。本申请的高稳定氧化锆的生产工艺包括如下步骤：1)将制备原料混合均匀,在2600-2800℃下保温1-3h,制得熔融液；所述制备原料包括如下重量份数的组分：氧化锆88-92份、氧化钇6-9份、氧化铈0.5-1.2份、氧化钙0.8-1.5份、氧化镁0.2-0.3份；2)将步骤1)得到的熔融液采用压缩空气进行喷吹,将喷吹出的颗粒冷却。本申请的高稳定氧化锆生产工艺中原料包括氧化钇和氧化铈,提高了氧化锆的高温传质作用,制得的氧化锆材料稳定性非常高,而且本申请的高稳定氧化锆的生产工艺中,烧结温度高,原料充分熔融,制得的材料结构非常均匀。(The application discloses high-stability zirconia and a production process thereof, and belongs to the technical field of zirconia materials. The production process of the high-stability zirconia comprises the following steps: 1) uniformly mixing the preparation raw materials, and preserving heat for 1-3h at the temperature of 2600-; the preparation raw materials comprise the following components in parts by weight: 88-92 parts of zirconium oxide, 6-9 parts of yttrium oxide, 0.5-1.2 parts of cerium oxide, 0.8-1.5 parts of calcium oxide and 0.2-0.3 part of magnesium oxide; 2) blowing the molten liquid obtained in the step 1) by adopting compressed air, and cooling the blown particles. The high stable zirconia production technology of this application raw materials includes yttrium oxide and cerium oxide, has improved the high temperature mass transfer effect of zirconia, and the zirconia material stability of making is very high, and in the high stable zirconia's of this application production technology, sintering temperature is high moreover, and the raw materials is fully molten, and the material structure of making is very even.)

1. A production process of high-stability zirconia is characterized by comprising the following steps: the method comprises the following steps:

1) uniformly mixing the preparation raw materials, and preserving heat for 1-3h at the temperature of 2600-; the preparation raw materials comprise the following components in parts by weight: 88-92 parts of zirconium oxide, 6-9 parts of yttrium oxide, 0.5-1.2 parts of cerium oxide, 0.8-1.5 parts of calcium oxide and 0.2-0.3 part of magnesium oxide;

2) blowing the molten liquid obtained in the step 1) by using compressed gas, and cooling the blown particles.

2. The process for producing highly stable zirconia according to claim 1, wherein: the preparation raw materials also comprise 0.2 to 0.3 weight part of alumina and 0.3 to 0.5 weight part of cosolvent.

3. The process for producing highly stable zirconia according to claim 2, wherein: the cosolvent is silicon dioxide or potassium chloride.

4. The process for producing highly stable zirconia according to claim 1, wherein: the preparation raw material also comprises 0.1-0.2 weight part of indium oxide.

5. The process for producing highly stable zirconia according to claim 1, wherein: in the step 1), the temperature is raised to 1600-.

6. The process for producing highly stable zirconia according to claim 1, wherein: in the step 1), water is also added when the preparation raw materials are uniformly mixed.

7. The process for producing highly stable zirconia according to any one of claims 1 to 6, wherein: and 2) cooling to obtain hollow spheres, soaking the hollow spheres in a zirconium salt solution for 2-3h, and sintering at the temperature of 1500-.

8. The process for producing highly stable zirconia according to claim 7, wherein: the zirconium salt solution is obtained by uniformly mixing zirconium salt, a dispersing agent and a solvent; the dispersant is any one of polyethylene glycol, triethanolamine and hexadecyl trimethyl ammonium bromide.

9. The process for producing highly stable zirconia according to claim 7, wherein: after soaking, solid-liquid separation is carried out before sintering at the temperature of 1500-1700 ℃, and then drying is carried out for 15-20min at the temperature of 45-55 ℃.

10. The highly stabilized zirconia obtained by the production process according to claim 1, wherein: the high-stability zirconia is spherical or approximately spherical particles, and the spherical or approximately spherical particles comprise spherical shells which enclose an inner cavity.

Technical Field

The application relates to the technical field of zirconia materials, in particular to high-stability zirconia and a production process thereof.

Background

Zirconia belongs to novel ceramics, has very excellent physical and chemical properties, and is widely applied to industrial production. For example, the present invention has been widely used in various fields such as refractory materials, electronic materials, and structural materials. Compared with other metal oxide ceramic materials, zirconia has good high-temperature thermal stability and excellent heat insulation performance, and is widely used as a ceramic coating and a high-temperature refractory product in the field of refractory materials. Zirconia has also become important in its particular crystal structureThe electronic material of (1). In addition, the strength and fracture toughness of the zirconia material can be as high as 1.5GPa and l5MPa/m²The alloy has good hardness, wear resistance and chemical corrosion resistance, and is often applied to bearings, sealing elements, engine piston tops, valve cams and the like.

As the application range of the zirconia material is wider and wider, the large-scale production process of the zirconia material is more and more emphasized. Currently, the preparation method of pure zirconia mostly adopts a chemical method or an electric melting method, wherein the electric melting method is adopted on a large scale due to the characteristic of simple process. The stability of high-purity zirconia is influenced by the crystal form and the particle size of the high-purity zirconia, and zirconia materials used in many application fields are zirconia composite materials added with stabilizers. However, many zirconia composite materials have a low firing temperature during production, and thus the stabilizer and zirconia are not sufficiently fused together, and the mechanical properties of the zirconia composite materials are reduced.

The Chinese patent application with publication number CN1524828A discloses an improved partially stabilized zirconia, the main improvement is in the use of CaO or MgO partially stabilized ZrO₂In which 0.1-5 wt% of barium-containing compound and 0.1-5 wt% of TiO are added₂Thereby improving ZrO₂Firing performance and thermal shock stability of the ceramic. The sintering temperature is 1500-1580 ℃, the sintering temperature is low, and the cost of the zirconia material in preparation can be reduced. However, the zirconia material is stabilized by only calcium oxide and magnesium oxide, and the stability of the zirconia material still needs to be improved.

Disclosure of Invention

In view of the defects in the prior art, the first objective of the present application is to provide a production process of high-stability zirconia, and the obtained zirconia material has very high stability.

A second object of the present application is to provide a highly stable zirconia obtained by the above method.

In order to achieve the first object, the present application provides the following technical solutions:

a production process of high-stability zirconia comprises the following steps:

1) uniformly mixing the preparation raw materials, and preserving heat for 1-3h at the temperature of 2600-; the preparation raw materials comprise the following components in parts by weight: 88-92 parts of zirconium oxide, 6-9 parts of yttrium oxide, 0.5-1.2 parts of cerium oxide, 0.8-1.5 parts of calcium oxide and 0.2-0.3 part of magnesium oxide;

2) blowing the molten liquid obtained in the step 1) by using compressed gas, and cooling the blown particles.

By adopting the technical scheme, the raw materials such as zirconia, yttria and the like are sintered at a high temperature, so that all the raw materials of the oxides are melted and fully fused to generate a substance with a complex composition but a very uniform structure, the stability of the finally prepared material is improved, and the material structure is not easily damaged due to the influence of external force in the using process. Cerium oxide is also added into the preparation raw materials, and has a very high stabilizing effect on cubic-phase zirconium oxide. Because the atomic radius of cerium is very close to that of zirconium, cerium oxide has very high solid solubility in zirconium oxide, and the sintering mass transfer effect during the sintering of zirconium oxide can be promoted. On the basis of adding zirconia and yttria, calcium oxide and magnesium oxide are also added, so that the phase change stability of zirconia is improved, and the prepared material has better comprehensive mechanical properties. The hollow spherical ceramic particles can be obtained by adopting compressed gas for blowing, the density is lower, the comprehensive performance is higher, and the compressed gas can adopt compressed air or compressed nitrogen.

The application is further configured to: the preparation raw materials also comprise 0.2 to 0.3 weight part of alumina and 0.3 to 0.5 weight part of cosolvent.

By adopting the technical scheme, the alumina is added into the preparation raw materials, the hardness of the alumina is higher, and the hardness and the compressive strength of the composite material can be improved. The alumina and the zirconia can form solid solution in the high-temperature sintering process, and the stability of the zirconium crystal phase is further improved. The melting of the oxide can be accelerated by adding the cosolvent, so that the raw materials are contacted more fully, and the generated phase is more uniform and stable.

The application is further configured to: the cosolvent is silicon dioxide or potassium chloride.

By adopting the technical scheme, the silica is used as the cosolvent, so that the eutectic temperature of oxides in the raw materials can be reduced, the melting efficiency is improved, and the added silica can form a silicic acid compound with other elements, thereby playing a good bonding role in the microstructure of the finally prepared material. When the potassium chloride is used as a cosolvent, the cosolvent temperature of each oxide in the raw materials can be reduced, and the transformation of zirconia crystal phases can be promoted, so that the control of the zirconia crystal phases is facilitated.

The application is further configured to: the preparation raw material also comprises 0.1-0.2 weight part of indium oxide.

By adopting the technical scheme, the addition of the indium oxide is beneficial to exerting the surface effect, further refining the crystal grains and promoting the generated crystal phase to be more uniform. The addition of indium oxide can also optimize the conductive capability of the zirconia material and improve the electrical performance of the zirconia material.

The application is further configured to: in the step 1), the temperature is raised to 1600-.

By adopting the technical scheme, the melting points of various oxides are different due to more kinds of the oxides in the raw materials for preparation. In the heating process, three-stage heating is adopted, oxides with lower melting points are firstly melted at the temperature of about 1600 ℃, and melted liquid can be immersed among unmelted material particles, so that the contact is more sufficient. And further heating to 2050-.

The application is further configured to: in the step 1), water is also added when the preparation raw materials are uniformly mixed.

By adopting the technical scheme, because the raw materials contain calcium oxide, after water is added, the calcium oxide can generate calcium hydroxide and form solution, so that the raw materials are bonded together when being mixed, and further, the heat transfer is faster and the reaction efficiency is higher during later sintering.

The application is further configured to: and 2) cooling to obtain hollow spheres, soaking the hollow spheres in a zirconium salt solution for 2-3h, and sintering at the temperature of 1500-.

By adopting the technical scheme, after the prepared hollow sphere is soaked in the zirconium salt solution, the zirconium salt solution can be attached to the surface of the hollow sphere, and the zirconium salt is decomposed and forms a coating layer on the surface of the ceramic hollow sphere in the sintering process, so that the mechanical property of the hollow sphere is enhanced, the hollow sphere can be protected, and the probability of cracks on the surface of the hollow sphere in the using process is reduced.

The application is further configured to: the zirconium salt solution is obtained by uniformly mixing zirconium salt, a dispersing agent and a solvent; the dispersant is any one of polyethylene glycol, triethanolamine and hexadecyl trimethyl ammonium bromide.

By adopting the technical scheme, the hollow spheres are soaked in the zirconium salt solution, so that the zirconium salt solution can be attached to the surfaces of the ceramic hollow spheres to form a liquid film. After the dispersing agent is added into the zirconium salt solution, the solution is favorably distributed more uniformly on the surface of the ceramic hollow sphere to form a thin liquid film, and the thin liquid film is more firmly combined on the surface of the hollow sphere, so that the discontinuous condition of the liquid film is reduced, and the continuity and the uniformity of a finally generated coating layer are further ensured.

The application is further configured to: after soaking, solid-liquid separation is carried out before sintering at the temperature of 1500-1700 ℃, and then drying is carried out for 15-20min at the temperature of 45-55 ℃.

By adopting the technical scheme, the hollow spheres are dried after being soaked, so that the solvent in the solution can be quickly volatilized, only the zirconium salt is left to be attached to the surfaces of the ceramic hollow spheres, and the phenomenon that the liquid films on the surfaces of the ceramic hollow spheres are damaged due to the action of external force in the process of transferring the hollow spheres to a sintering furnace at the later stage is avoided.

In order to achieve the second object, the present application provides the following technical solutions:

the high-stability zirconia prepared by the production process is spherical or approximately spherical particles, and the spherical or approximately spherical particles comprise spherical shells, and the spherical shells surround an inner cavity.

By adopting the technical scheme, the zirconia material particles prepared by the production process have a hollow structure, very low overall density, obvious light weight characteristic and good application prospect. The raw materials for preparation adopt various oxides such as yttrium oxide, cerium oxide and the like, and the prepared zirconium oxide composite material has very high stability, is not easily damaged by external force in the later application process, and has longer service life.

In summary, the present application has the following beneficial effects:

1. in the production process of the high-stability zirconia, the raw materials comprise yttrium oxide and cerium oxide, the solid solubility of the raw materials in the zirconia is very high, the mass transfer effect of the zirconia during high-temperature sintering can be improved, and the stability of the prepared zirconia material is greatly improved. In addition, the sintering temperature in the production process of the high-stability zirconia is very high, all raw materials can be fully melted, the structural uniformity of the material is improved, and the stability of the material is further improved.

2. The production process of the high-stability zirconia adopts a three-section heating mode when sintering and heating, and the three-section heating mode is adopted to respectively keep the temperature for a period of time at different temperatures, so that different types of oxides are melted at different stages, the dispersion uniformity among the raw materials is improved, the raw materials are promoted to fully react when being sintered at high temperature, and the structural uniformity of the finally prepared material is improved.

3. In the production technology of high stable zirconia of this application, after making ceramic hollow ball, soak ceramic hollow ball in zirconium salt solution, at ceramic hollow ball surface adhesion one deck liquid film, then through the sintering, make the decomposition of cladded zirconium salt, generate the oxide coating, can play good guard action to ceramic hollow ball.

Drawings

FIG. 1 is a topographical view of highly stable zirconia prepared in example 2 of the present application.

Detailed Description

The technical solution of the present application is further described in detail below.

The production process of the high-stability zirconia comprises the following steps:

1) uniformly mixing the preparation raw materials, and preserving heat for 1-3h at the temperature of 2600-; the preparation raw materials comprise the following components in parts by weight: 88-92 parts of zirconium oxide, 6-9 parts of yttrium oxide, 0.5-1.2 parts of cerium oxide, 0.8-1.5 parts of calcium oxide and 0.2-0.3 part of magnesium oxide;

2) blowing the molten liquid obtained in the step 1) by using compressed gas, and cooling the blown particles.

The zirconia in the step 1) is fused zirconia. In the fused zirconia, ZrO₂Not less than 99.5% by mass, Fe₂O₃Is not more than 0.01 percent, TiO₂Is not more than 0.005% by mass, SiO₂Is not more than 0.01 percent. Preferably, the fused zirconia is fused zirconia produced by Shandong hong Yuan New Material science and technology Limited. The preparation raw materials also comprise 0.2 to 0.3 weight part of alumina and 0.3 to 0.5 weight part of cosolvent. Preferably, 0.25 weight parts of alumina and 0.4 weight parts of cosolvent are included. Preferably, the average particle size of the alumina is 1 to 1.5 μm. More preferably, the average particle size of the alumina is 1 μm. The alumina is alpha alumina.

The calcium oxide powder has a particle size of 325 meshes and a purity of 85-98%. Preferably, the purity of the calcium oxide is 95%. The purity of the magnesium oxide is 95-98%. Preferably, the magnesium oxide is 98% pure. The bulk density of the magnesium oxide was 0.4g/cm³。

The step 1) of uniformly mixing the preparation raw materials is ball milling for 3-10h at the rotating speed of 300-1800 rpm. The ball milling adopts chemical zirconia ceramic balls as milling balls.

Step 1), adding a carbon material when uniformly mixing the preparation raw materials; the carbon material is at least one of activated carbon, graphite, Ketjen black and graphene. The mass ratio of the carbon material to the zirconia is 0.5-1: 88-92. Further preferably, the carbon material is formed by mixing at least one of activated carbon, graphite and graphene with ketjen black in a mass ratio of 3-5: 1.

In the step 1), water is also added when the preparation raw materials are uniformly mixed. The mass ratio of the water to the zirconia is 2.5-5: 88-92.

In the step 1), the temperature is raised to 1600-.

The fused zirconia is dried, crushed and sieved before mixing. The drying is carried out at 40-50 deg.C for 30-50 min. The crushing is carried out by ball milling at the rotating speed of 300 and 400rpm for 10-20 min. The screening is 400-2500 mesh. Preferably, the sieving is 400-800 mesh. Preferably, the screening is to pass through a 400-DEG C900-mesh sieve, then pass the undersize through a 1100-DEG C1600-mesh sieve, and take the oversize; or firstly screening the mixture through 900-1600-mesh sieve, then screening the undersize product through 1800-2500-mesh sieve, and taking the oversize product.

Further preferably, the screening is followed by electromagnetic iron removal. The magnetic flux density in the case of removing iron by electromagnetic induction was 1.5T, and the exciting current was 14A. The electromagnetic iron removal adopts a QM250 type electromagnetic iron remover, and is produced by ceramic equipment Limited of Hangshan.

In the step 2), the blowing is to blow the molten liquid into the air by adopting compressed air or compressed nitrogen. And rapidly cooling the blown particles in the falling process in the air to obtain hollow spherical particles, namely the ceramic hollow spheres. The pressure of compressed air or compressed nitrogen gas adopted in the blowing process is 7-9kg/cm². Further, the blown particles are cooled by nitrogen at 50-70 ℃.

The ceramic hollow spheres obtained after cooling in the step 2) are placed in a zirconium salt solution for soaking for 2-3h, and then sintered for 2-3h at the temperature of 1500-. More preferably, after soaking, drying at 45-55 deg.C for 15-20 min. Sintering at 1500-1700 ℃ for 2-3h, and cooling to room temperature. The cooling may be air cooling.

The ratio of said zirconium salt to the solvent in the solution of zirconium salt is between 0.8 and 1L of solvent per 25 and 35g of zirconium salt. Preferably, the zirconium salt solution is obtained by uniformly mixing a zirconium salt, a dispersing agent and a solvent. The zirconium salt is at least one of zirconium acetate, zirconium oxalate and zirconium nitrate. The dispersant is any one of polyethylene glycol, triethanolamine and cetyl trimethyl ammonium bromide. The solvent is water or ethanol water solution. The ethanol water solution is formed by mixing ethanol and water according to the volume ratio of 1: 3-5. Preferably, the mass ratio of the ethanol to the zirconium salt to the dispersant is 25-35: 5-10.