Wear-resistant special ceramic material and preparation method thereof

Abstract

The invention discloses a wear-resistant special ceramic material and a preparation method thereof, and belongs to the technical field of special ceramic preparation. The wear-resistant special ceramic material comprises the following raw materials: zirconium silicate, zirconium oxide whiskers, titanium carbonitride, zinc oxide whiskers, magnesium oxide, petalite, cerium oxide, nickel-based alloy powder and the balance of aluminum oxide. The zirconium silicate, the zirconium oxide whisker, the titanium carbonitride, the zinc oxide whisker and the nickel-based alloy powder are used as combined additives, so that composite synergistic reinforcement and toughening of multiple phases are realized; compared with conventional aluminum oxide ceramics, the prepared wear-resistant aluminum oxide ceramic material has the advantages that the wear resistance, the fracture toughness and the thermal shock resistance are remarkably improved, and the performance requirements of more severe working environments can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of special ceramic preparation, and particularly relates to a wear-resistant special ceramic material and a preparation method thereof. Background Art

[0002] With the development of industrial technology, rigid requirements for various properties of materials in core fields such as energy, metallurgy, and chemical industry have become increasingly demanding. Alumina ceramics are special corundum ceramics mainly made of alumina as the main raw material and sintered at high temperature after forming. Due to the good wear resistance, acid and alkali corrosion resistance, high temperature resistance, etc. of alumina ceramics, they can meet the needs of different industries and are suitable for a variety of different working environments, thus becoming an indispensable important material in modern industrial production.

[0003] Currently, there is an imbalance between hardness and toughness in alumina ceramics. Their fracture toughness is low, and their impact resistance and thermal shock resistance are poor. Under high temperature and high pressure, high-speed or high-load working conditions, cracks are easily generated due to stress concentration, even leading to brittle fracture. In response to this, the existing process mainly prepares composite ceramics by adding reinforcing and toughening phases to improve the comprehensive performance of alumina ceramics, such as adding a certain proportion of yttria-stabilized nano-zirconia, carbides, nitrides, borides, etc. However, although the added reinforcing and toughening phases can improve some properties of alumina ceramics, they generally have the disadvantages of uneven dispersion and high cost. Poor compatibility and weak interfacial bonding force between the additives and the alumina matrix will cause problems such as overburning, residual internal stress or interfacial cracks, ultimately resulting in a significant attenuation of the performance of the prepared ceramic products.

[0004] In view of this, in order to ensure the service life and reliability of alumina ceramics and expand their application range, it is necessary to develop a high-performance composite alumina ceramic material that can be applied to more working conditions. Summary of the Invention

[0005] Aiming at the problems mentioned in the background art, the purpose of the present invention is to provide a wear-resistant special ceramic material and a preparation method thereof. The present invention uses zirconium silicate, zirconia whiskers, titanium carbonitride, zinc oxide whiskers and nickel-based alloy powder as additives to achieve the composite synergistic strengthening and toughening of multiple phases; finally, a high-strength and high-toughness wear-resistant alumina ceramic material is prepared by controlling the sintering process. Compared with conventional alumina ceramics, the performance is significantly improved, and it can meet the performance requirements of more harsh working environments.

[0006] The present invention provides a wear-resistant special ceramic material, which includes the following component raw materials by mass percentage: Zirconium-containing compound 1.0% - 4.5%, Titanium carbonitride 0.2% - 0.6%, Zinc oxide whiskers 0.8% - 1.5%, Magnesium oxide 0.1% - 0.3%, Petalite 0.15% - 0.4%, Cerium oxide 0.1% - 0.15%, Nickel - based alloy powder 0.7% - 1.2%, The balance is alumina; The zirconium - containing compound includes zirconium silicate and zirconia whiskers.

[0007] Furthermore, the raw materials of the special ceramic material include by mass percentage: Zirconium - containing compound 3%, Titanium carbonitride 0.5%, Zinc oxide whiskers 1.2%, Magnesium oxide 0.2%, Petalite 0.25%, Cerium oxide 0.14%, Nickel - based alloy powder 1%, The balance is alumina.

[0008] Furthermore, the zirconium - containing compound is composed of zirconium silicate and zirconia whiskers in a mass ratio of (2 - 5):1; the length of the zirconia whiskers is 50 - 100 μm and the aspect ratio is 20 - 50.

[0009] Furthermore, the particle size of the titanium carbonitride is 15 - 45 μm; the zinc oxide whiskers are four - needle - shaped, with a length of 20 - 50 μm and an aspect ratio of 5 - 20.

[0010] Furthermore, the composition of the nickel - based alloy powder by mass percentage is: Cr 6.9% - 8.8%, B 2.8% - 4.5%, Si 1.7% - 3.0%, Mn 0.8% - 1.7%, Co 0.06% - 0.3%, C 1.0% - 2.2%, and the balance is Ni.

[0011] In view of the problems of low fracture toughness, poor impact resistance and thermal shock resistance of current alumina ceramics, as well as the uneven dispersion of reinforcement and toughening phases and poor compatibility with the alumina matrix in composite alumina ceramics, the present invention adds zirconium silicate, zirconia whiskers, titanium carbonitride, zinc oxide whiskers and nickel-based alloy powder to prepare a multi-component composite phase alumina ceramic: Zirconium silicate is distributed at the alumina grain boundaries, which can inhibit abnormal grain growth and refine grains. The active silica decomposed at high temperature can also promote sintering and strengthen grain boundaries; at the same time, the similar thermal expansion coefficients of zirconium silicate and alumina are helpful to reduce the interfacial thermal stress and improve the thermal shock resistance. In addition to the toughening mechanism of phase transformation to improve toughness and thermal shock resistance, zirconia whiskers can further improve the fracture toughness through whisker bridging. Titanium carbonitride is a ternary solid solution, which combines the advantages of titanium carbide and titanium nitride, and has characteristics such as high hardness, wear resistance, oxidation resistance and corrosion resistance, and can improve the hardness and wear resistance of ceramics. The four-needle structure of zinc oxide whiskers can inhibit crack propagation from multiple angles and has the effect of multi-directional toughening, which is more suitable for dynamic high-load environments. By appropriately adjusting the component content of nickel-based alloy powder, it is helpful to improve the compatibility with other reinforcement and toughening phases during the sintering process and enhance the interfacial bonding; and the selected nickel-based alloy powder can further absorb energy, hinder crack propagation and improve seismic resistance. In addition, magnesium oxide, petalite and cerium oxide are used as sintering aids. The combination of the three can not only reduce the sintering temperature and promote densification, but also inhibit grain boundary migration and abnormal grain growth. Through the combination of the above-mentioned various additives and aids, and their balance, complementarity and synergistic effects, the present invention effectively improves the wear resistance, toughness and thermal shock resistance of the prepared alumina ceramics, and makes up for the deficiencies of traditional alumina ceramics.

[0012] The present invention also provides a preparation method of the above-mentioned wear-resistant special ceramic material, which includes the following steps: Step 1: Take each raw material according to the formula for standby. Add the raw materials other than zirconia whiskers and zinc oxide whiskers to a solvent for ultrasonic dispersion to obtain a dispersion for standby; Step 2: After ball-milling the obtained dispersion, add zirconia whiskers and zinc oxide whiskers, and continue ball-milling to obtain a slurry mixture; Step 3: Dry and press the slurry mixture into a mold, and finally perform high-temperature sintering. After cooling with the furnace, the ceramic product is obtained.

[0013] Further, the solvent in Step 1 is a mixed solution of polyethylene glycol and absolute ethanol; the solid-liquid ratio of the raw material to the solvent is 1:(10-20).

[0014] Further, the ball-to-material ratio in Step 2 is (10-20):1.

[0015] Further, the high-temperature sintering in Step 3 is as follows: First, the formed ceramic green body is heated to 900 - 1000 °C for pre-sintering for 1 - 2 h, and then continuously heated to 1300 - 1450 °C for final sintering for 2 - 4 h.

[0016] Further, the heating rate of the pre-sintering is 5 - 10 °C / min, and the heating rate of the final sintering is 1 - 5 °C / min.

[0017] After the alumina base material is mixed with various additives and auxiliaries and pressed into shape, the present invention performs segmented high-temperature sintering: First, pre-sintering in an inert atmosphere liquefies the nickel-based alloy powder, enabling it to fully penetrate and diffuse in the alumina ceramic green body, effectively promoting the uniform dispersion between the composite phases. In addition, the present invention also reduces the sintering temperature of the alumina ceramic. After pre-sintering, the ceramic material can be fired at only 1300 - 1450 °C, effectively reducing the process energy consumption.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: Aiming at the defects of the existing composite alumina ceramics, according to the effect characteristics of different phases, zirconium silicate, zirconia whiskers, titanium carbonitride, zinc oxide whiskers and nickel-based alloy powder are combined and the dosage is adjusted as additives. They can be uniformly dispersed and have a strong interfacial bond with alumina, and can realize the composite synergistic strengthening and toughening of multiple phases. The high-strength and high-toughness wear-resistant alumina ceramic material prepared by the present invention has significantly improved wear resistance, fracture toughness and thermal shock resistance compared with conventional alumina ceramics, and can meet the performance requirements of more harsh working environments. Specific Embodiments

[0019] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Those not specified in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field of the present invention. The terms used in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0021] Example 1 A wear-resistant special ceramic material, and the preparation method includes: 1. Weigh zirconium silicate 2.4%, zirconia whiskers 0.6%, titanium carbonitride 0.5%, zinc oxide whiskers 1.2%, magnesium oxide 0.2%, petalite 0.25%, cerium oxide 0.14%, nickel-based alloy powder (composition: Cr 7.6%, B 3.4%, Si 4.3%, Mn 1.4%, Co 0.16%, C 1.7%, the balance is Ni) 1% by mass percentage, and the balance is alumina.

[0022] 2. Mix alumina, zirconium silicate, titanium carbonitride, magnesium oxide, petalite, cerium oxide, and nickel-based alloy powder and add them to a solvent with a mass 15 times that of theirs (composed of PEG-4000 and absolute ethanol in equal volume ratio), disperse evenly by ultrasonic for 30 min, then add cemented carbide balls (ball-to-material ratio is 20:1) and ball mill for 30 h, and then add zirconia whiskers and zinc oxide whiskers and continue to ball mill for 10 h to obtain a slurry mixture; nitrogen is filled for protection during the whole ball milling process.

[0023] 3. Dry the slurry mixture to obtain a mixed powder, pour it into a mold and press it into a ceramic green body; then transfer it to a tube furnace and first heat it to 960 °C at a rate of 10 °C / min and hold for 2 h for pre-sintering, and then continue to heat it to 1400 °C at a rate of 4 °C / min and hold for 3.5 h for final sintering to obtain a ceramic product.

[0024] Example 2 A wear-resistant special ceramic material, the preparation method includes: 1. Weigh zirconium silicate 1.5%, zirconia whiskers 0.3%, titanium carbonitride 0.4%, zinc oxide whiskers 0.8%, magnesium oxide 0.2%, petalite 0.25%, cerium oxide 0.12%, nickel-based alloy powder (composition: Cr 7.6%, B 3.4%, Si 4.3%, Mn 1.4%, Co 0.16%, C 1.7%, the balance is Ni) 1.2% by mass percentage, and the balance is alumina.

[0025] 2. Mix alumina, zirconium silicate, titanium carbonitride, magnesium oxide, petalite, cerium oxide, and nickel-based alloy powder and add them to a solvent with a mass 15 times that of theirs (composed of PEG-4000 and absolute ethanol in equal volume ratio), disperse evenly by ultrasonic for 30 min, then add cemented carbide balls (ball-to-material ratio is 20:1) and ball mill for 30 h, and then add zirconia whiskers and zinc oxide whiskers and continue to ball mill for 10 h to obtain a slurry mixture; nitrogen is filled for protection during the whole ball milling process.

[0026] 3. Dry the slurry mixture to obtain a mixed powder, pour it into a mold and press it into a ceramic green body; then transfer it to a tube furnace and first heat it to 1000 °C at a rate of 10 °C / min and hold for 1 h for pre-sintering, and then continue to heat it to 1450 °C at a rate of 5 °C / min and hold for 2 h for final sintering to obtain a ceramic product.

[0027] Example 3 A wear-resistant special ceramic material, and the preparation method includes: 1. Weigh 2% zirconium silicate, 1% zirconia whiskers, 0.5% titanium carbonitride, 1.5% zinc oxide whiskers, 0.2% magnesium oxide, 0.25% petalite, 0.14% cerium oxide, 0.7% nickel-based alloy powder (the composition is Cr 7.6%, B 3.4%, Si 4.3%, Mn 1.4%, Co 0.16%, C 1.7%, and the balance is Ni) by mass percentage, and the balance is alumina.

[0028] 2. Mix alumina, zirconium silicate, titanium carbonitride, magnesium oxide, petalite, cerium oxide, and nickel-based alloy powder and add them to a solvent (composed of PEG-4000 and absolute ethanol in an equal volume ratio) with a mass 15 times that of the mixture, and disperse evenly by ultrasonic for 30 min. Then add cemented carbide balls (the ball-to-material ratio is 20:1) and ball mill for 30 h. Subsequently, add zirconia whiskers and zinc oxide whiskers and continue to ball mill for 10 h to obtain a slurry mixture; nitrogen is filled for protection during the whole ball milling process.

[0029] 3. Dry the slurry mixture to obtain a mixed powder, pour it into a mold and press it into a ceramic green body; then transfer it to a tube furnace and first heat it to 900 °C at a rate of 5 °C / min and hold for 1.5 h for pre-sintering, and then continue to heat it to 1300 °C at a rate of 4 °C / min and hold for 4 h for final sintering to obtain a ceramic product.

[0030] Comparative Example 1 Referring to the step parameters of Example 1, the difference is that zirconia whiskers are not added to the ceramic component raw materials (the total addition amount of zirconium-containing compounds remains unchanged), that is, the formula is: 3% zirconium silicate, 0.5% titanium carbonitride, 1.2% zinc oxide whiskers, 0.2% magnesium oxide, 0.25% petalite, 0.14% cerium oxide, 1% nickel-based alloy powder, and the balance is alumina.

[0031] Comparative Example 2 Referring to the step parameters of Example 1, the difference is that zirconium silicate is not added to the ceramic component raw materials (the total addition amount of zirconium-containing compounds remains unchanged), that is, the formula is: 3% zirconia whiskers, 0.5% titanium carbonitride, 1.2% zinc oxide whiskers, 0.2% magnesium oxide, 0.25% petalite, 0.14% cerium oxide, 1% nickel-based alloy powder, and the balance is alumina.

[0032] Comparative Example 3 Referring to the step parameters of Example 1, the difference is that titanium carbonitride is not added to the ceramic component raw materials.

[0033] Comparative Example 4 Referring to the step parameters of Example 1, the difference is that zinc oxide whiskers are not added to the ceramic component raw materials.

[0034] Comparative Example 5 Referring to the step parameters of Example 1, the difference is that nickel-based alloy powder is not added to the raw materials of the ceramic components.

[0035] Comparative Example 6 Referring to the step parameters of Example 1, the difference is that in step 3, the sintering is directly heated to 1400 °C at a rate of 4 °C / min and held for 3.5 h for final sintering.

[0036] Test Example Performance tests were carried out on the ceramic samples prepared in the above examples and comparative examples (hardness test refers to GB / T 16534-2009, wear resistance test refers to GB / T 18301-2012, fracture toughness test refers to GB / T 23806-2009, flexural strength test refers to ASTM C1499, thermal shock resistance test refers to GB / T 3298-2022), and the results are shown in Table 1.

[0037] Table 1 Performance test results of ceramic samples

[0038] According to the above test results, it can be seen that the ceramic samples prepared in Examples 1-3 of the present invention have high hardness, high flexural strength and excellent thermal shock resistance. At the same time, the wear loss is less than 0.2 g / kg·h, and the fracture toughness reaches 6.5 MPa·m 1 / 2 As mentioned above, it can be seen that the alumina ceramic material prepared by the present invention effectively solves the defects of low fracture toughness and poor thermal shock resistance of traditional alumina ceramics. It can better adapt to harsh working conditions such as high temperature and high pressure, high speed or high load, with stable performance and significantly extended service life. Comparing the test data of Comparative Example 1 and Comparative Example 2 of the present invention, it can be seen that the single toughening and strengthening of zirconium silicate or zirconia whiskers has limited improvement in the wear resistance, fracture toughness or thermal shock resistance of alumina ceramics. Comparing the test data of Comparative Example 3 and Comparative Example 4 of the present invention, it can be seen that titanium carbonitride can significantly improve the hardness and wear resistance of ceramics, while the multi-directional toughening effect of zinc oxide whiskers has a significant impact on the fracture toughness of ceramics. Comparing the test data of Comparative Example 5 and Comparative Example 6 of the present invention, it can be seen that through the nickel-based alloy powder and the segmented sintering process, the present invention fully disperses and combines the selected various additives, and finally prepares a wear-resistant alumina ceramic material with high strength, high toughness and excellent thermal shock resistance through their mutual balance, complementarity and cooperative interaction. The present invention overcomes the defects of existing composite alumina ceramics, can better adapt to harsh working conditions such as high temperature and high pressure, high speed or high load, expands the application range of alumina ceramics, and has good market competitiveness.

[0039] The embodiments described above merely represent several preferred embodiments of the present invention. The description thereof is relatively specific and detailed, but it is not intended to limit the present invention. It should be noted that for those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the concept and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wear-resistant special ceramic material, characterized in that: The raw materials include the following components by mass percentage: Containing zirconium compounds 1.0%-4.5%, Titanium carbonitride 0.2%-0.6%, Zinc oxide whisker 0.8%-1.5%, Magnesium oxide 0.1%-0.3%, Petalite 0.15%-0.4%, Cerium oxide 0.1%-0.15%, Nickel-based alloy powder 0.7%-1.2%, The balance is aluminum oxide; The zirconium-containing compound includes zirconium silicate and zirconium oxide whisker.

2. The wear-resistant special ceramic material according to claim 1, characterized in that: The raw materials of the special ceramic material include, by mass percentage: Contains 3% zirconium compound, Titanium carbonitride 0.5%, Zinc oxide whisker 1.2%, Magnesium oxide 0.2%, Petalite 0.25%, Cerium oxide 0.14%, Nickel-based alloy powder 1%, The balance is alumina.

3. The wear-resistant special ceramic material according to claim 1, characterized in that: The zirconium-containing compound is composed of zirconium silicate and zirconium oxide whiskers in a mass ratio of (2-5):1; the length of the zirconium oxide whiskers is 50-100 μm and the aspect ratio is 20-50.

4. The wear-resistant special ceramic material according to claim 1, characterized in that: The particle size of the titanium carbonitride is 15-45 μm; the zinc oxide whisker is four-needle-shaped, with a length of 20-50 μm and an aspect ratio of 5-20.

5. The wear-resistant special ceramic material according to claim 1, characterized in that: The components of the nickel-based alloy powder are as follows by mass percentage: Cr 6.9%-8.8%, B 2.8%-4.5%, Si 1.7%-3.0%, Mn 0.8%-1.7%, Co 0.06%-0.3%, C 1.0%-2.2%, and the balance is Ni.

6. The method for preparing the wear-resistant special ceramic material according to any one of claims 1 to 5, characterized in that: The steps include: Step 1, taking all raw materials according to the formula and setting aside, adding raw materials other than zirconium oxide whiskers and zinc oxide whiskers into a solvent for ultrasonic dispersion, and obtaining a dispersion for setting aside; Step 2: After ball milling the obtained dispersion, zirconium oxide whiskers and zinc oxide whiskers are added, and the ball milling is continued to obtain a slurry mixture; Step 3: Dry the slurry mixture, press it into shape, and finally sinter it at high temperature. After cooling in the furnace, the finished ceramic product is obtained.

7. The method for preparing the wear-resistant special ceramic material according to claim 6, characterized in that: The solvent in step 1 is a mixture of polyethylene glycol and anhydrous ethanol; the solid-liquid ratio of the raw material to the solvent is 1:(10-20).

8. The method for preparing the wear-resistant special ceramic material according to claim 6, characterized in that: The ball-to-material ratio of ball milling in step 2 is (10-20):

1.

9. The method for preparing the wear-resistant special ceramic material according to claim 6, characterized in that: The high temperature sintering in step 3 is as follows: firstly, the formed ceramic body is heated to 900-1000°C for pre-firing for 1-2 h, and then the temperature is further raised to 1300-1450°C for final sintering for 2-4 h.

10. The method for preparing the wear-resistant special ceramic material according to claim 9, characterized in that: The heating rate of the pre-firing is 5-10°C / min, and the heating rate of the final firing is 1-5°C / min.

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