CN102603272A - Ceramic material and preparation method thereof - Google Patents

Abstract

The invention discloses a ceramic material and a preparation method thereof, which belong to the technical field of ceramic materials. The ceramic material is made of, by weight, 89.2-93.6% of alumina powder, 6-10% of zirconia powder and 0.4-0.8% of yttria powder. By adding the yttria into the ceramic material, dynamic performance of the ceramic material is improved, voidage of the ceramic material is decreased, and high fatigue limit can be achieved in stress alternative circulation. Further, owning to adding of the zirconia, the alumina ceramic material is reinforced, the fracture way of the ceramic material turns to be transcrystalline rupture with no crystalline grain pulled out, and accordingly abrasive wear is reduced, the ceramic material which is high in wear resistance, high in toughness and low in friction is obtained, and application range of the ceramic material in engineering is widened.

Description

Ceramic material and its preparation method

technical field

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

Background technique

Ceramic materials are a kind of inorganic non-metallic materials made of natural or synthetic compounds after forming and high-temperature sintering. The ceramic materials manufactured by utilizing the special functions of ceramics on sound, light, electricity, magnetism, heat and other physical properties are called functional ceramics. There are many types of functional ceramics with different uses. Among them, alumina ceramics have become one of the most popular ceramic materials due to their excellent physical and mechanical properties, such as high hardness, high melting point, and good wear resistance, and are widely used in cutting tools, wear-resistant parts, high-temperature parts, etc. . the

However, the friction coefficient of alumina ceramics in the prior art is relatively high, and the capacity loss in engineering applications is relatively large, which affects the quality of products and limits the further application of alumina ceramic materials. the

Contents of the invention

In order to reduce the friction coefficient of alumina ceramics and increase the application range of alumina ceramics, an embodiment of the present invention provides a ceramic material and a preparation method thereof. Described technical scheme is as follows:

On the one hand, the embodiment of the present invention provides a kind of ceramic material, and the formula of described ceramic material is made up of the raw material of following percentage by weight:

Aluminum oxide powder 89.2-93.6%;

Zirconia powder 6-10%;

Yttrium oxide powder 0.4-0.8%. the

Preferably, the formula of described ceramic material comprises the raw material of following percentage by weight:

Alumina powder 92.4-92.6%; zirconia powder 7%; yttrium oxide powder 0.4-0.6%. the

Preferably, the alumina powder has an average particle diameter of 0.20-0.26 μm and a purity of 99.8%. the

On the other hand, the embodiment of the present invention also provides a kind of preparation method of ceramic material, and described method comprises:

Mix, grind and granulate alumina powder, zirconia powder and yttrium oxide powder to make ceramic powder;

Making the ceramic powder into a green body through a molding process;

The body is sintered to obtain a ceramic material. the

Specifically, the alumina powder, zirconia powder and yttrium oxide powder are mixed, ground and granulated to make ceramic powder, which specifically includes:

Put the alumina powder, zirconia powder, yttrium oxide powder and binder solution into the ball mill jar, and ball mill for 12 hours;

The solution after ball milling is vacuum-dried to form a block, and the block is ground into powder;

Water was sprayed on the powder so that the powder was granulated and sieved with a sieve. the

Specifically, the amount of water added is such that 80% of the powder forms granules, and no water flows in the powder after adding water. the

Preferably, the binder solution is a polyvinyl alcohol solution with a concentration of 7%, and the quality of the binder solution added is 16.6%-20% of the raw material of the ceramic material. Since polyvinyl alcohol can be dissolved in hot water, there is a strong attraction between the polar molecules of water, and it has good viscosity and fluidity, so the polyvinyl alcohol solution is used as the binder to make the ceramic powder Has good plasticity. the

Specifically, the polyvinyl alcohol solution can be prepared by the following methods:

Mix the polyvinyl alcohol powder and water in proportion, put it into a constant temperature water bath and heat it at 100°C, and keep it warm for 8 hours. the

Preferably, the sieves are 100-mesh and 220-mesh sieves. The powder that does not form powder particles is removed through two sieves, and the molding strength is maintained. the

Specifically, the ceramic powder is made into a green body through a molding process, which specifically includes:

Compression molding and cold isostatic pressing were performed on the ceramic powder to obtain a green body, wherein the pressure of the compression molding was 20 MPa, the pressure of the cold isostatic pressing was 200 MPa, and the pressure was maintained for 10 minutes. The ceramic powder is molded first, and after a period of cold isostatic pressing, the uneven distribution of density and stress inside the ceramic powder is eliminated, and a uniform and dense ceramic powder is obtained. the

Specifically, the described green body is sintered to obtain a ceramic material, which specifically includes:

The green body was sintered under the condition of normal pressure of 1600° C. and kept for 2 hours. In this step, the sintering method with the lowest requirement is adopted, which simplifies the production process. the

The beneficial effects brought by the technical scheme provided by the embodiments of the present invention are:

By adding yttrium oxide to the ceramic material, the mechanical properties of the ceramic material are improved, so that the porosity of the ceramic material is small, and in the stress alternating cycle, a higher fatigue limit is obtained. At the same time, due to the addition of zirconia, the strength and toughness Alumina ceramic materials are used, so that the fracture mode of ceramic materials is transgranular fracture, and no crystal grains are pulled out, thereby reducing abrasive wear, and then obtaining ceramic materials with high wear resistance, high toughness, and low friction. The scope of application of ceramic materials in engineering has been increased. the

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the implementation manners of the present invention will be further described in detail below. the

Example 1

Weigh raw materials according to the following formula: (kg)

Aluminum oxide powder 93.6, zirconia powder 6, yttrium oxide powder 0.4. the

Preparation:

(1) Accurately weigh the alumina powder, zirconia powder, and yttrium oxide powder according to the above formula for later use. Among them, the alumina powder had an average particle diameter of 0.26 μm and a purity of 99.8%. And a binder solution is configured, and the binder solution is a polyvinyl alcohol solution with a concentration of 7%. Among them, the following method can be used to prepare the polyvinyl alcohol solution: mix the polyvinyl alcohol powder and water in proportion, put it into a constant temperature water bath and heat it, the heating temperature is 100°C, and the holding time is 8 hours. the

(2) Put the weighed powder and binder solution in a ball mill jar, and mill for 12 hours to obtain a uniformly mixed solution; wherein, the quality of the added binder solution is 20. the

(3) Put the solution obtained in the step (2) into a hollow drying oven to dry to form a block, and put the block into a mill and grind it into powder. the

(4) Spread the powder obtained in step (3), and sprinkle water on the powder, so that the powder forms granules, and sieve through 100 mesh and 220 mesh sieves, remove the powder that does not form granules, and obtain ceramic powder , wherein the amount of water added is such that 80% of the powder forms granules, and there is no flow of water in the powder after adding water. the

(5) The ceramic powder obtained in step (4) is first molded into a green body with a pressure of 20 MPa, and then the green body is subjected to cold isostatic pressing at a pressure of 200 MPa, and the pressure is maintained for 10 minutes to eliminate the internal pressure of the green body. The density and stress distribution are uneven, and a uniform and dense ceramic body is obtained. the

(6) Sinter the ceramic green body obtained in step (5) using the sintering method with the lowest requirement: sintering at 1600° C. under normal pressure and holding for 2 hours. the

Example 2

Weigh raw materials according to the following formula: (kg)

Aluminum oxide powder 89.2, zirconia powder 10, yttrium oxide powder 0.8. the

The preparation method is as in Example 1. the

Example 3

Weigh raw materials according to the following formula: (kg)

Aluminum oxide powder 92.4, zirconia powder 7, yttrium oxide powder 0.6. the

The preparation method is as in Example 1. the

Example 4

Weigh raw materials according to the following formula: (kg)

Aluminum oxide powder 91.4, zirconia powder 8, yttrium oxide powder 0.6. the

The preparation method is as in Example 1. the

Product experiment:

The embodiments of the present invention test the performance of the existing alumina ceramics and the ceramics provided by the present invention, and the specific detection contents are as follows:

1. Test content: friction coefficient, fracture toughness, flexural strength, sintering conditions. the

2. The test results are as follows:

the Coefficient of friction Fracture toughness Bending strength Sintering conditions current technology μ＝0.347 4.3Mpa m ^1/2 297MPa Vacuum hot pressing this invention μ＝0.136 7.05Mpa m ^1/2 576.5MPa Atmospheric pressure

It should be noted that the performance values in the above table are the average values of multiple tests. the

It can be seen from the above table that the friction coefficient of the ceramic material provided by the present invention is smaller than that of the prior art ceramic material, and the fracture toughness and bending strength are significantly higher than the prior art ceramic material. In addition, from the above table, it can be seen that the ceramic material of the present invention can adopt the lowest sintering conditions, which reduces the complexity of the preparation process. The ceramic material made from the ceramic material formula of the invention has the characteristics of low friction and high wear resistance, and can be widely used in engineering. the

The embodiments described above are only one of the more preferred specific implementations of the present invention, and the usual changes and substitutions performed by those skilled in the art within the scope of the technical solutions of the present invention should be included in the scope of the present invention. the

Claims (9)

1. A ceramic material, characterized in that, the formula of said ceramic material is made from the following raw materials in percentage by weight: Aluminum oxide powder 89.2-93.6%; Zirconia powder 6-10%; Yttrium oxide powder 0.4-0.8%. 2. material as claimed in claim 1, is characterized in that, the prescription of described ceramic material comprises the raw material of following percentage by weight: Alumina powder 92.4-92.6%; zirconia powder 7%; yttrium oxide powder 0.4-0.6%. 3. The material according to claim 1, characterized in that the alumina powder has an average particle size of 0.2-0.26 μm and a purity of 99.8%. 4. a preparation method of the ceramic material described in any one of claims 1-3, is characterized in that, described method comprises: Mix, grind and granulate alumina powder, zirconia powder and yttrium oxide powder to make ceramic powder; Making the ceramic powder into a green body through a molding process; The body is sintered to obtain a ceramic material. 5. The method according to claim 4, wherein said alumina powder, zirconia powder and yttrium oxide powder are mixed, ground and granulated to make ceramic powder, specifically comprising: Put alumina powder, zirconia powder, yttrium oxide powder and binder solution into a ball mill jar, and ball mill for 12 hours; vacuum drying the milled solution to form a block, and grinding the block into powder; Water was sprayed on the powder so that the powder was granulated and sieved with a sieve. 6. The method according to claim 5, wherein the binder solution is a polyvinyl alcohol solution with a concentration of 7%, and the quality of the binder solution added is 16.6% of the raw material of the ceramic material. %-20%. 7. The method of claim 5, wherein the sieves are 100-mesh and 220-mesh sieves. 8. The method according to claim 4, wherein said making the ceramic powder into a green body through a molding process specifically comprises: Compression molding and cold isostatic pressing were performed on the ceramic powder to obtain a green body, wherein the pressure of the compression molding was 20 MPa, the pressure of the cold isostatic pressing was 200 MPa, and the pressure was maintained for 10 minutes. 9. The method according to claim 4, wherein the sintering of the green body to obtain a ceramic material specifically comprises: The green body was sintered under the condition of normal pressure of 1600° C. and kept for 2 hours.