Ti-nb-zr multi-principal element-based max phase ceramic material, preparation method and application thereof

Abstract

This invention discloses a Ti-Nb-Zr multi-principal-element MAX phase ceramic material, its preparation method, and its application. 0.5 x Nb 0.5 x Zr 2x )2AlC2, where x The concentration is 0.05–0.15. This invention utilizes Zr to equimolarly replace Ti and Nb, dissolving Zr into multi-principal MAX phase ceramic materials. The amount of Zr added is limited to a specific range. The introduction of Zr, with its low electronegativity, not only preserves the original crystal structure of the MAX phase ceramic with almost no impact on its mechanical properties, but also promotes the formation of amorphous carbon at moderate temperatures, giving the material a low coefficient of friction and excellent lubrication performance at room temperature to 400 °C. Within the Zr addition range, the lubrication performance is greatly improved with increasing Zr addition.

Description

Technical Field

[0001] This invention relates to the field of MAX phase ceramics technology, specifically to a MAX phase ceramic material based on Ti-Nb-Zr multi-principal elements, its preparation method, and its application. Background Technology

[0002] Traditional ceramic materials, due to their strong internal covalent bonds, typically possess high hardness and wear resistance, making them valuable for solid lubrication applications in high-vacuum, highly corrosive environments such as bearings. However, precisely because of this hard structure, traditional ceramics are prone to fatigue failure and the formation of hard wear debris during contact, especially in the intermediate temperature range of room temperature to 400 °C, where it is difficult to form a stable friction film and maintain lubrication. While layered van der Waals materials, represented by graphite, possess low shear strength and film-forming ability, exhibiting excellent solid lubrication performance in the intermediate temperature range, their extremely poor mechanical strength and high interfacial inertia make it difficult to form sufficiently strong composites with traditional ceramics, thus limiting their direct application. Max phase ceramics, as a class of ceramics with good ductility and toughness, can partially overcome the fatigue resistance of traditional ceramics. However, they still face the challenges of high friction film shear strength and a relatively high coefficient of friction in the intermediate temperature range. Therefore, introducing friction-reducing media that can function effectively in the intermediate temperature range while maintaining the excellent mechanical properties of Max phase ceramics is a key issue that needs to be addressed in constructing self-lubricating ceramic materials for the intermediate temperature range.

[0003] Existing MAX phase ceramic materials, such as those disclosed in CN119100795A (which presents a high-entropy MAX phase material, its preparation method, and applications) and CN11699204A (which discloses a method for preparing MAX phase ceramics), both employ the idea of ​​using high-entropy elemental composition to improve the stability of MAX phase materials. However, neither has effectively improved the friction-reducing properties of the materials. In existing methods for preparing MAX phase ceramic materials, transition metal carbides and elemental powders are used as raw materials, inevitably introducing impurities and making it difficult to meet the high purity requirements of the materials, thus affecting their wear-resistant and friction-reducing properties. Summary of the Invention

[0004] This invention addresses the problems existing in the prior art by providing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material, its preparation method, and its application.

[0005] The technical solution adopted in this invention is: a Ti-Nb-Zr multi-principal-element MAX phase ceramic material, wherein the MAX phase ceramic material is: (Ti 0.5 x Nb 0.5 x Zr2x )2AlC2, where x It ranges from 0.05 to 0.15.

[0006] A method for preparing Ti-Nb-Zr multi-principal-component MAX phase ceramic materials includes the following steps: The desired MAX phase ceramic material can be obtained by mixing powders of Ti2AlC, Nb2AlC, Zr, Al and C, ball milling, and then performing discharge plasma sintering under a protective atmosphere. Al was added in excess.

[0007] Furthermore, both Ti2AlC and Nb2AlC have a 211-phase MAX structure.

[0008] Furthermore, the Al powder is added in excess at a chemical dosage ratio of 1.1.

[0009] Furthermore, the ball milling is an intermittent ball milling, and the number of milling cycles is N, where N≥2.

[0010] Furthermore, during the ball milling process, each milling session lasts for 30 minutes, followed by a 30-minute interval before the next milling session begins.

[0011] Furthermore, the discharge plasma sintering temperature is 1500 ℃ and the sintering time is 15 min.

[0012] Furthermore, during the discharge plasma sintering process, a pressure of 50 MPa is applied, and the heating and cooling rates are both 100 ℃ / min.

[0013] An application of a Ti-Nb-Zr multi-principal-element MAX phase ceramic material, wherein the MAX phase ceramic material is used as a lubricating material.

[0014] Furthermore, the lubricating material is used under conditions of room temperature to 400°C.

[0015] The beneficial effects of this invention are: This invention utilizes Zr to equimolarly replace Ti and Nb, dissolving Zr into multi-principal MAX phase ceramic materials. The amount of Zr added is limited to a specific range. The introduction of Zr, with its low electronegativity, not only preserves the original crystal structure of the MAX phase ceramic but also ensures that its mechanical properties are almost unaffected. It can also promote the formation of amorphous carbon at moderate temperatures, enabling the material to possess a low coefficient of friction and excellent lubrication performance at room temperature to 400 °C.

[0016] Using 211 phase Ti2AlC, Nb2AlC and elemental metal powder as reaction raw materials helps to maintain the mechanical properties of MAX materials unchanged. The solid solution of Zr does not affect the nanohardness and folded modulus of the material, which remain basically unchanged. Attached Figure Description

[0017] Figure 1 The X-ray diffraction patterns are those of the ceramic materials obtained in Examples 1-3 and the material obtained in Comparative Example 1 of the present invention.

[0018] Figure 2 The crystal axis parameters of the ceramic materials obtained in Examples 1-3 and Comparative Example 1 of this invention are shown. a shaft and c Curve showing the change of axis with Zr content.

[0019] Figure 3 The images shown are scanning electron microscope backscattering (SEM) images and EDS elemental distribution maps of the ceramic materials obtained in Examples 1 to 3 of this invention. a represents the result of Example 1, b represents the result of Example 2, and c represents the result of Example 3.

[0020] Figure 4 The results show the comparison of the mechanical properties of the ceramic materials obtained in Examples 1-3 of this invention and the material obtained in Comparative Example 1.

[0021] Figure 5 The results show the comparison of the average friction coefficients of the ceramic materials obtained in Examples 1-3 of this invention and the material obtained in Comparative Example 1 under the conditions of room temperature to 400 °C.

[0022] Figure 6 The images shown are scanning electron microscope (SEM) images and EDS elemental distribution maps of the ceramic material obtained in Example 3 of this invention after friction tests at different temperatures. a represents the result at 25 ℃, b represents the result at 200 ℃, and c represents the result at 400 ℃. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] A Ti-Nb-Zr multi-principal-element MAX phase ceramic material, wherein the MAX phase ceramic material is: (Ti 0.5 x Nb 0.5 x Zr 2x )2AlC2, where x It ranges from 0.05 to 0.15.

[0025] A method for preparing Ti-Nb-Zr multi-principal-component MAX phase ceramic materials includes the following steps: Powders of Ti2AlC, Nb2AlC, Zr, Al, and C are mixed, ball-milled, and then subjected to discharge plasma sintering under a protective atmosphere to obtain the desired MAX phase ceramic material; both Ti2AlC and Nb2AlC have a 211 phase MAX structure.

[0026] The ball milling is intermittent, with N milling cycles, where N≥2. Each milling cycle lasts 30 minutes, followed by a 30-minute interval before the next milling cycle begins.

[0027] The discharge plasma sintering temperature is 1500 ℃, the sintering time is 15 min, and a pressure of 50 MPa is applied during the sintering process. The heating and cooling rates are both 100 ℃ / min.

[0028] Al was added in excess, by a factor of 1.1.

[0029] This invention utilizes spark plasma sintering to replace Ti and Nb elements in equimolar proportions with Zr, dissolving Zr into the original MAX phase ceramic material without altering its structure. The resulting material exhibits superior lubrication properties in atmospheric environments ranging from room temperature to 400 °C.

[0030] Example 1 A Ti-Nb-Zr multi-principal-component MAX phase ceramic material, with the chemical formula: (Ti 0.45 Nb 0.45 Zr 0.1 )2AlC.

[0031] A method for preparing Ti-Nb-Zr multi-principal-component MAX phase ceramic materials includes the following steps: Commercially available Ti₂AlC powder, Nb₂AlC powder, Zr powder, Al powder, and C powder are used as raw materials, and the raw materials are prepared according to a stoichiometric molar ratio of Ti, Nb, Zr, Al, and C of 0.9:0.9:0.2:1.1:1. Because Al volatilizes at high temperatures and reacts with graphite molds, it is generally necessary to supplement with some Al powder to avoid Al deficiency.

[0032] Place the prepared raw material powder in a ball mill jar and ball mill twice, each time for 30 minutes, with a 30-minute interval. After ball milling, a mixed powder is obtained.

[0033] The ball-milled and uniformly mixed powder was placed in a glove box under an argon atmosphere and then loaded into a graphite mold. The mold was then placed in a high-temperature tube furnace for discharge plasma sintering. The temperature was increased to 1500℃ at a rate of 100℃ / min and held for 10 min, while maintaining a pressure of 50 MPa. After the holding period, the temperature was decreased to room temperature at a rate of 100℃ / min to obtain: (Ti 0.45 Nb 0.45 Zr 0.1 )2AlC.

[0034] Example 2 A Ti-Nb-Zr multi-principal-component MAX phase ceramic material, with the chemical formula: (Ti 0.4 Nb 0.4 Zr 0.2 )2AlC.

[0035] A method for preparing Ti-Nb-Zr multi-principal-component MAX phase ceramic materials includes the following steps: Commercially available Ti₂AlC powder, Nb₂AlC powder, Zr powder, Al powder, and C powder are used as raw materials, and the raw materials are prepared according to a stoichiometric molar ratio of Ti, Nb, Zr, Al, and C of 0.8:0.8:0.4:1.1:1. Because Al volatilizes at high temperatures and reacts with graphite molds, it is generally necessary to supplement with some Al powder to avoid Al deficiency.

[0036] Place the prepared raw material powder in a ball mill jar and ball mill twice, each time for 30 minutes, with a 30-minute interval. After ball milling, a mixed powder is obtained.

[0037] The ball-milled and uniformly mixed powder was placed in a glove box under an argon atmosphere and then loaded into a graphite mold. The mold was then placed in a high-temperature tube furnace for discharge plasma sintering. The temperature was increased to 1500℃ at a rate of 100℃ / min and held for 10 min, while maintaining a pressure of 50 MPa. After the holding period, the temperature was decreased to room temperature at a rate of 100℃ / min to obtain: (Ti 0.45 Nb 0.45 Zr 0.1 )2AlC.

[0038] Example 3 A Ti-Nb-Zr multi-principal-component MAX phase ceramic material, with the chemical formula: (Ti 0.35 Nb 0.35 Zr 0.3 )2AlC.

[0039] A method for preparing Ti-Nb-Zr multi-principal-component MAX phase ceramic materials includes the following steps: Commercially available Ti₂AlC powder, Nb₂AlC powder, Zr powder, Al powder, and C powder are used as raw materials, and the raw materials are prepared according to a stoichiometric molar ratio of Ti, Nb, Zr, Al, and C of 0.7:0.7:0.6:1.1:1. Because Al volatilizes at high temperatures and reacts with graphite molds, it is generally necessary to supplement with some Al powder to avoid Al deficiency.

[0040] Place the prepared raw material powder in a ball mill jar and ball mill twice, each time for 30 minutes, with a 30-minute interval. After ball milling, a mixed powder is obtained.

[0041] The ball-milled and uniformly mixed powder was placed in a glove box under an argon atmosphere and then loaded into a graphite mold. The mold was then placed in a high-temperature tube furnace for discharge plasma sintering. The temperature was increased to 1500℃ at a rate of 100℃ / min and held for 10 min, while maintaining a pressure of 50 MPa. After the holding period, the temperature was decreased to room temperature at a rate of 100℃ / min to obtain: (Ti 0.45 Nb 0.45 Zr 0.1 )2AlC.

[0042] Comparative Example To illustrate the effects of the present invention, a comparative example is provided, and the structure of the MAX phase ceramic material provided in this comparative example is as follows: (Ti 0.5 Nb 0.5 )2AlC.

[0043] The preparation method is exactly the same as the other steps in Example 1, except that Zr powder is not included, and the ingredients are prepared according to the stoichiometric molar ratio of Ti, Nb, Al and C of 1:1:1.1:1.

[0044] Figure 1 The figures show the X-ray diffraction patterns of the ceramic materials obtained in Examples 1-3 and the comparative example of this invention. As can be seen from the figures, the ceramic materials obtained in Examples 1-3 and the comparative example (Ti) show significant differences in X-ray diffraction patterns. 0.5 Nb 0.5 The diffraction peaks of the 2AlC standard cards were consistent and showed no obvious impurity peaks. It can be seen that the materials obtained in Examples 1-3 have better crystallinity and phase purity than the materials obtained in the comparative examples. The preparation method of this invention has not changed (Ti 0.5 Nb 0.5 The crystal structure of AlC material shows that Zr atoms partially replace Ti and Nb atoms through solid solution.

[0045] Figure 2 The crystal axis parameters of the ceramic materials obtained in Examples 1-3 and the materials obtained in the comparative examples of this invention are shown below. a shaft and c The curves showing the change in crystal axis parameters with Zr content. As can be seen from the figure, the crystal axis parameters of the ceramic materials obtained in Examples 1-3, through Zr solid solution treatment, change... a shaft and c The axes gradually increase with increasing Zr content, indicating that Zr was successfully introduced into the lattice and formed a solid solution phase structure.

[0046] Figure 3 The images show the scanning electron microscope backscattered electron (SEM) images and EDS elemental distribution maps of the ceramic materials obtained in Examples 1-3 of this invention. The ceramic materials obtained in Examples 1-3 were sanded from 80 grit to approximately 3000 grit using sandpaper, and their surfaces were polished successively with 1.5 μm and 1 μm diamond polishing paste. The different phases contained in the materials were observed using a high-vacuum backscattered electron (CBS) probe of a scanning electron microscope (SEM), and the elemental distribution of the samples was analyzed using a matching energy dispersive spectroscopy (EDS) instrument. The elemental proportions of the EDS analysis are shown in Table 1. It can be seen that the elemental proportions of Ti, Nb, Zr, Al, and C in the obtained ceramic materials are consistent with their stoichiometric ratios in their chemical formulas. The figures also show that the obtained MAX phase ceramic material samples have a uniform composition.

[0047] Table 1. Statistical results of atomic percentage of ceramic materials obtained in Examples 1-3

[0048] The ceramic materials obtained in Examples 1-3 and the materials obtained in the comparative examples were successively sanded to 3000 grit with sandpaper, polished with 1.5 micrometer and 1 micrometer silicon carbide polishing paste respectively, and then mechanical tests were conducted.

[0049] Mechanical tests were conducted on a Hysitron TI980 nanoindenter with a test load of 5 mN, a holding time of 5 s, and a loading and unloading rate of 1 mN / s. Each experimental data point was repeated at least 10 times, and the average value was calculated as the nanohardness and reduced modulus.

[0050] Figure 4 The figures show the average reduced modulus and nanoscale hardness of the ceramic materials obtained in Examples 1-3 and the comparative examples of this invention. As can be seen from the figures, with the increase of Zr content, the reduced modulus of the examples remained essentially unchanged or slightly increased compared to the comparative examples, while the nanoscale hardness remained essentially unchanged. Therefore, the introduction of Zr did not significantly affect the mechanical properties of the multi-principal-element (MAX) phase ceramic materials.

[0051] The lubrication performance of the ceramic materials obtained in Examples 1-3 and the materials obtained in the comparative examples was tested, and the results are as follows: Figure 5 As shown, the steps are as follows: The material samples were machined into elongated specimens measuring 25×5×2 mm using wire cutting, and then successively polished with sandpaper to a grit of 2000. Friction tests were conducted on an MS-M9000 friction tester, using 10 mm diameter ZrO2 microspheres as the friction pair. All tests were performed at room temperature and in air at 600 °C for 30 minutes, with a load of 5 N, a stroke of 1.5 mm, and a frequency of 5 Hz. The coefficient of friction was automatically recorded by a computer program. Each test data point was repeated at least three times, and the average value was calculated as the final coefficient of friction.

[0052] from Figure 5 As can be seen, under conditions of 25 and 200 °C, the lubrication performance is greatly improved with the increase of Zr content. The Ti-Nb-Zr based multi-principal MAX phase ceramic material prepared in Example 3 has average friction coefficients of 0.45, 0.32 and 0.49 at 25 °C, 200 °C and 400 °C, respectively, and exhibits good self-lubricating properties in the medium temperature range.

[0053] Scanning electron microscope (SEM) images and EDS elemental distribution maps of the ceramic material sample from Example 3 after the friction test were obtained, as shown below. Figure 6 As shown in the figure, after friction experiments, the Ti-Nb-Zr-based multi-principal MAX phase ceramic material exhibits obvious carbon accumulation regions on its surface. The improved lubrication performance of the Ti-Nb-Zr-based multi-principal MAX phase ceramic material in the medium temperature range can be attributed to the generation of amorphous carbon phases during friction.

[0054] This invention uses discharge plasma sintering to dissolve Zr in MAX phase ceramics and replace Ti and Nb elements in equal proportions. The resulting ceramic material has excellent self-lubricating properties without affecting its original mechanical properties.

Claims

1. A MAX phase ceramic material based on Ti-Nb-Zr multi-principal elements, characterized in that, The MAX phase ceramic material is: (Ti 0.5 x Nb 0.5 x Zr 2x )2AlC2, wherein x is 0.05 to 0.

15.

2. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material as described in claim 1, characterized in that, Includes the following steps: The desired MAX phase ceramic material can be obtained by mixing powders of Ti2AlC, Nb2AlC, Zr, Al and C, ball milling, and then performing discharge plasma sintering under a protective atmosphere. Al was added in excess.

3. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 2, characterized in that, Both Ti2AlC and Nb2AlC have a 211 phase MAX structure.

4. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 2, characterized in that, The Al powder was added in excess at a chemical dosage ratio of 1.

1.

5. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 2, characterized in that, The ball milling is an intermittent ball milling, and the number of ball milling cycles is N, where N≥2.

6. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 5, characterized in that, During the ball milling process, each milling session lasts for 30 minutes, followed by a 30-minute interval before the next milling session begins.

7. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 2, characterized in that, The discharge plasma sintering temperature is 1500 ℃, and the sintering time is 15 min.

8. The method for preparing a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 2, characterized in that, During the discharge plasma sintering process, a pressure of 50 MPa is applied, and the heating and cooling rates are both 100 ℃ / min.

9. The application of the Ti-Nb-Zr multi-principal-element MAX phase ceramic material as described in claim 1, characterized in that, The MAX phase ceramic material is used as a lubricant.

10. The application of a Ti-Nb-Zr multi-principal-element MAX phase ceramic material according to claim 9, characterized in that, The lubricating material is used under conditions of room temperature to 400°C.

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