A lubricated wear-resistant nickel-based composite material, a preparation method and application thereof

Abstract

This invention belongs to the technical field of lubricating and wear-resistant materials, specifically relating to a lubricating and wear-resistant nickel-based composite material, its preparation method, and its application. The preparation method of the lubricating and wear-resistant nickel-based composite material provided by this invention includes the following steps: mixing nickel powder, cobalt powder, and strontium sulfate powder; pressing the resulting mixture in a mold to obtain a molded material; and subjecting the molded material to vacuum hot pressing sintering to obtain the lubricating and wear-resistant nickel-based composite material. The lubricating and wear-resistant nickel-based composite material prepared by this invention contains SrCoO. 2.29 NiCo2S4 and Co9S8, under the action of frictional stress, form a friction surface composed of SrCoO 2.29 The synergistic lubrication film composed of NiCo2S4 and Co9S8 gives the composite material an excellent room temperature friction coefficient and low wear rate. It can be used to solve the lubrication and wear resistance problems of room temperature moving parts. The preparation method is simple, the raw materials are widely available, and the cost is low.

Description

Technical Field

[0001] This invention belongs to the field of lubricating and wear-resistant materials technology, specifically relating to a lubricating and wear-resistant nickel-based composite material, its preparation method, and its application. Background Technology

[0002] High-performance lubricating composite materials are key materials for achieving high precision and stable and reliable operation of transmission components in power transmission systems in fields such as aerospace, energy and chemical industry, marine engineering equipment, land transportation, and machinery manufacturing, under harsh conditions such as high temperature, high speed, and heavy load.

[0003] Currently, both metals and ceramics can be used as matrix materials for lubricating composites, but the inherent brittleness of ceramics is a fatal weakness. As matrix materials for high-temperature lubricating composites, high-temperature alloys (Ni-based, Co-based, and Fe-based) possess high strength, good fatigue performance, and fracture toughness, attracting widespread attention from materials scientists. Ag and silver molybdate (AgMo) x O y Adding solid lubricants to a metal matrix can significantly improve the high-temperature tribological properties of high-temperature alloy matrix composites. However, at room temperature, the frictional heat generated by high-speed operation causes oxidation of micro-protrusions on the wear surface, leading to the formation of metal oxides in the high-temperature alloy matrix. This results in a friction layer composed of the aforementioned metal oxides and solid lubricant on the wear surface. However, frictional stress can cause defects in the friction layer (cracks, spalling, etc.), exacerbating oxygen diffusion on the wear surface. New oxides then reform on the wear surface, and this repeated oxide formation-spalling cycle ultimately leads to poor lubrication and wear resistance in the composite material. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a lubricating and wear-resistant nickel-based composite material, its preparation method and application. The lubricating and wear-resistant nickel-based composite material provided by the present invention has an excellent room temperature friction coefficient and a low wear rate, and can be used to solve the lubrication and wear resistance problems of room temperature moving parts.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing a lubricating and wear-resistant nickel-based composite material, comprising the following steps:

[0007] Nickel powder, cobalt powder and strontium sulfate powder are mixed, and the resulting mixture is placed in a mold and pressed to form a molded material.

[0008] The molding material is subjected to vacuum hot pressing sintering to obtain a lubricating and wear-resistant nickel-based composite material.

[0009] Preferably, the mass ratio of nickel powder to cobalt powder is (79.2-85.5):(8.8-9.5).

[0010] Preferably, the mass ratio of nickel powder to strontium sulfate powder is (79.2-85.5):(5-12).

[0011] Preferably, the pressing pressure is 5-15 MPa and the holding time is 20-40 s.

[0012] Preferably, the vacuum hot pressing sintering temperature is 1050–1150°C, the pressure is 20–30 MPa, and the heat and pressure holding time is 30–90 min.

[0013] Preferably, the mixing of nickel powder, cobalt powder and strontium sulfate powder is performed by: first mixing nickel powder and cobalt powder and then ball milling them, followed by adding strontium sulfate powder and ball milling them a second time.

[0014] Preferably, the rotational speed of the first ball mill and the second ball mill are independently 200-450 rpm, and the time is independently 10-40 h.

[0015] Preferably, the first ball mill and the second ball mill are independently wet ball mills; the solid-liquid ratio in the wet ball mill is (25-100) g:(75-300) mL.

[0016] This invention also provides a lubricating and wear-resistant nickel-based composite material prepared by the preparation method described above, the composition of which includes: SrCoO 2.29 and Ni(Co) solid solution, or SrCoO 2.29 NiCo2S4, Co9S8, SrCO3 and Ni(Co) solid solutions.

[0017] The present invention also provides the application of the lubricating and wear-resistant nickel-based composite material described above in power transmission components.

[0018] This invention provides a method for preparing a lubricating and wear-resistant nickel-based composite material, comprising the following steps: mixing nickel powder, cobalt powder, and strontium sulfate powder; pressing the resulting mixture in a mold to obtain a molded material; and subjecting the molded material to vacuum hot pressing sintering to obtain the lubricating and wear-resistant nickel-based composite material. During the sintering process, strontium sulfate decomposes to form a weak oxygen environment (O2 / SO2), subsequently causing Co and Ni to oxidize, forming CoO and NiO, respectively. In this weak oxygen environment, CoO reacts with SrO, a decomposition product of strontium sulfate, to generate SrCoO. 2.29 Sulfur in the environment diffuses into the CoO / Co and NiO / Ni interfaces within the oxide film, causing a decrease in oxygen partial pressure and an increase in sulfur partial pressure within the oxide film, resulting in the appearance of NiCo2S4 and Co9S8 phases in the sintered composite material. The lubricating and wear-resistant nickel-based composite material prepared in this invention contains SrCoO2.29 NiCo2S4 and Co9S8, under the action of frictional stress, form a friction surface composed of SrCoO 2.29 The synergistic lubricating film composed of NiCo2S4 and Co9S8 gives nickel-based composite materials excellent room temperature friction coefficient and low wear rate. It can be used to solve the lubrication and wear resistance problems of moving parts at room temperature. The preparation method is simple, the raw materials are widely available, and the cost is low. Attached Figure Description

[0019] Figure 1 The X-ray diffraction patterns are of the mixed raw material powders in Examples 1-3 and Comparative Examples 1-2.

[0020] Figure 2 The images show X-ray diffraction patterns of the lubricating and wear-resistant nickel-based composite materials obtained by sintering in Examples 1-3 and Comparative Examples 1-2. Detailed Implementation

[0021] This invention provides a method for preparing a lubricating and wear-resistant nickel-based composite material, comprising the following steps:

[0022] Nickel powder, cobalt powder and strontium sulfate powder are mixed, and the resulting mixture is placed in a mold and pressed to form a molded material.

[0023] The molding material is subjected to vacuum hot pressing sintering to obtain a lubricating and wear-resistant nickel-based composite material.

[0024] Unless otherwise specified, the present invention does not have special requirements on the source of the raw materials used in the preparation, and commercially available products well known to those skilled in the art can be used.

[0025] This invention involves mixing nickel powder, cobalt powder, and strontium sulfate powder, and then pressing the resulting mixture into a mold to obtain a molded material.

[0026] In this invention, the particle size of the nickel powder is preferably 15-75 μm, more preferably 30-50 μm; the particle size of the cobalt powder is preferably 15-75 μm, more preferably 30-50 μm; the mass ratio of the nickel powder to the cobalt powder is preferably (79.2-85.5):(8.8-9.5), more preferably (80.1-82.8):(8.9-9.2); the mass ratio of the nickel powder to the strontium sulfate powder is preferably (79.2-85.5):(5-12), more preferably (80.1-82.8):(8-11).

[0027] In this invention, the mixing of nickel powder, cobalt powder and strontium sulfate powder is preferably carried out by first mixing nickel powder and cobalt powder and then ball milling them, followed by adding strontium sulfate powder and ball milling them a second time.

[0028] In this invention, the rotational speed of the first and second ball mills is preferably 200–450 rpm, more preferably 250–400 rpm, and the time is preferably 10–40 h, more preferably 20–30 h; the grinding balls used in the first and second ball mills are preferably stainless steel balls; the diameter of the stainless steel balls is preferably 3–20 mm, more preferably 5–15 mm; the ball-to-material ratio in the first and second ball mills is preferably (5–15):1, more preferably 10:1; the equipment used in the first and second ball mills is preferably a planetary high-energy ball mill.

[0029] In this invention, the first ball mill and the second ball mill are preferably wet ball mills; the liquid used in the wet ball mill is preferably ethanol; the solid-liquid ratio in the wet ball mill is preferably (25-100)g:(75-300)mL, more preferably (50-100)g:(100-300)mL.

[0030] This invention utilizes ball milling to thoroughly mix and refine the raw materials, enabling a solid-state reaction to occur between the nickel-based composite material components during sintering to form SrCoO. 2.29 Phases: NiCo2S4 and Co9S8.

[0031] After the second ball milling is completed, the present invention preferably dries the mixture after the second ball milling; the drying temperature is preferably 70-80°C, more preferably 75°C; the drying time is preferably 6-8 hours, more preferably 6.5-7 hours.

[0032] In this invention, the pressing pressure is preferably 5-15 MPa, more preferably 5-10 MPa, and the holding time is preferably 20-40 s, more preferably 30 s; the pressing is preferably carried out at room temperature; and the mold is preferably a graphite mold.

[0033] After obtaining the molding material, the present invention performs vacuum hot pressing sintering on the molding material to obtain a lubricating and wear-resistant nickel-based composite material.

[0034] In this invention, the equipment used for vacuum hot pressing sintering is preferably a vacuum hot pressing sintering furnace; the temperature of the vacuum hot pressing sintering is preferably 1050–1150°C, more preferably 1100°C; the pressure is preferably 20–30 MPa, more preferably 25 MPa; the holding time is preferably 30–90 min, more preferably 50–90 min; the heating rate to the vacuum hot pressing sintering temperature is preferably 5–15°C / min, more preferably 8–12°C / min; and the vacuum degree of the vacuum hot pressing sintering is preferably 1.0–5 × 10⁻⁶. -2 Pa, more preferably 1.0 × 10 Pa -2 Pa.

[0035] After the vacuum hot pressing sintering is completed, the present invention preferably cools the product obtained by the vacuum hot pressing sintering to room temperature; the cooling is preferably natural cooling in the furnace.

[0036] During sintering, strontium sulfate decomposes to form a weak oxygen environment (O2 / SO2), subsequently oxidizing Co and Ni to form CoO and NiO, respectively. In this weak oxygen environment, CoO reacts with SrO, a decomposition product of strontium sulfate, in a solid-state reaction to form SrCoO. 2.29 Sulfur in the environment diffuses into the CoO / Co and NiO / Ni interfaces within the oxide film, causing a decrease in oxygen partial pressure and an increase in sulfur partial pressure within the oxide film, resulting in the appearance of NiCo2S4 and Co9S8 phases in the sintered composite material. The lubricating and wear-resistant nickel-based composite material prepared in this invention contains SrCoO 2.29 NiCo2S4 and Co9S8, under the action of frictional stress, form a friction surface composed of SrCoO 2.29 The synergistic lubricating film composed of NiCo2S4 and Co9S8 gives nickel-based composite materials excellent room temperature friction coefficient and low wear rate. It can be used to solve the lubrication and wear resistance problems of room temperature moving parts. The preparation method is simple, the raw materials are widely available, and the cost is low.

[0037] This invention also provides a lubricating and wear-resistant nickel-based composite material prepared by the preparation method described above, the composition of which includes: SrCoO 2.29 and Ni(Co) solid solution, or SrCoO 2.29 NiCo2S4, Co9S8, SrCO3 and Ni(Co) solid solutions.

[0038] In this invention, the room temperature friction coefficient of the lubricating wear-resistant nickel-based composite material is preferably 0.37–0.39, more preferably 0.37–0.38; the wear rate of the lubricating wear-resistant nickel-based composite material is preferably 0.184–0.316 × 10⁻⁶. -14 m 3 ·N -1 ·m -1 More preferably, it is 0.184~0.253×10 -14 m 3 ·N -1 ·m -1 .

[0039] The lubricating and wear-resistant nickel-based composite material provided by this invention also has an excellent coefficient of friction at high temperatures (800°C).

[0040] The present invention also provides the application of the lubricating and wear-resistant nickel-based composite material described above in power transmission components.

[0041] The present invention does not impose any special limitations on the application of the lubricating and wear-resistant nickel-based composite material in power transmission components; any application method known in the art can be used.

[0042] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] A type containing SrCoO 2.29 The lubricating and wear-resistant nickel-based composite material is prepared from raw materials including: Ni 85.5 wt.%, Co 9.5 wt.%, and SrSO4 5 wt.%.

[0045] The preparation method includes the following steps:

[0046] Nickel powder (45 μm particle size) and cobalt powder (60 μm particle size) were mixed and wet-milled in a planetary high-energy ball mill with anhydrous ethanol for 20 hours at 300 rpm. The ratio of nickel powder / cobalt powder to anhydrous ethanol was 25 g:75 mL. The grinding balls were 10 mm diameter stainless steel balls with a ball-to-powder ratio of 5:1. The resulting premixed powder was then mixed with strontium sulfate powder and wet-milled for 20 hours at 300 rpm. The mixture was then dried at 75°C for 6 hours. The resulting powder mixture was then pressed into shape in a graphite mold at a pressure of 5 MPa for 30 seconds to obtain the molded material. The molded material was then placed in a vacuum hot-pressing sintering furnace at a pressure of 1.0 × 10⁻⁶ m² / h. -2 The temperature was increased to 1050℃ at a heating rate of 15℃ / min, and a pressure of 25MPa was applied. After holding the temperature and pressure for 90min, the temperature was lowered and the sample was taken out after cooling to room temperature in the furnace. The resulting lubricating and wear-resistant nickel-based composite material was denoted as Ni-Co-5SrSO4.

[0047] XRD analysis revealed that the phase composition of the sintered lubricating and wear-resistant nickel-based composite material was SrCoO. 2.29 and Ni(Co) solid solution.

[0048] Example 2

[0049] A type containing SrCoO 2.29 A lubricating and wear-resistant nickel-based composite material of NiCo2S4, Co9S8, and SrCO3, the raw materials for which are prepared include: Ni 81wt.%, Co 9wt.%, and SrSO4 10wt.%.

[0050] The preparation method includes the following steps:

[0051] Nickel powder (55 μm particle size) and cobalt powder (35 μm particle size) were mixed and wet-milled in a planetary high-energy ball mill with anhydrous ethanol for 30 h at 300 rpm. The ratio of nickel powder / cobalt powder to anhydrous ethanol was 50 g:100 mL. The grinding balls were 10 mm diameter stainless steel balls with a ball-to-powder ratio of 10:1. The resulting premixed powder was then mixed with strontium sulfate powder and wet-milled for 20 h at 400 rpm. The mixture was then dried at 75 °C for 7 h. The resulting mixed powder was placed in a graphite mold and pressed into shape at a pressure of 5 MPa for 30 s to obtain the molded material. The molded material was then placed in a vacuum hot-pressing sintering furnace at a pressure of 1.0 × 10⁻⁶ m² / h. -2 The temperature was increased to 1100℃ at a heating rate of 10℃ / min, and a pressure of 25MPa was applied. After holding the temperature and pressure for 60min, the temperature was lowered and the sample was taken out after cooling to room temperature in the furnace. The resulting lubricating and wear-resistant nickel-based composite material was denoted as Ni-Co-10SrSO4.

[0052] XRD analysis revealed that the phase composition of the sintered lubricating and wear-resistant nickel-based composite material was SrCoO. 2.29 Co9S8, SrCO3, NiCo2S4 and Ni(Co) solid solutions.

[0053] Example 3

[0054] A type containing SrCoO 2.29 Nickel-based lubricating and wear-resistant composite materials of NiCo2S4, Co9S8, and SrCO3 are prepared from raw materials including: Ni 79.2 wt.%, Co 8.8 wt.%, and SrSO4 12 wt.%.

[0055] The preparation method includes the following steps:

[0056] Nickel powder (25 μm particle size) and cobalt powder (45 μm particle size) were mixed and wet-milled in a planetary high-energy ball mill with anhydrous ethanol for 30 hours at 300 rpm. The ratio of nickel powder / cobalt powder to anhydrous ethanol was 100 g: 300 mL. The grinding balls were 10 mm diameter stainless steel balls with a ball-to-powder ratio of 10:1. The resulting premixed powder was then mixed with strontium sulfate powder and wet-milled for 30 hours at 300 rpm. The mixture was then dried at 75°C for 8 hours. The resulting powder mixture was then pressed into shape in a graphite mold at a pressure of 5 MPa for 30 seconds to obtain the molded material. The molded material was then placed in a vacuum hot-pressing sintering furnace at a pressure of 1.0 × 10⁻⁶ m² / h. -2The temperature was increased to 1150℃ at a heating rate of 5℃ / min, and a pressure of 25MPa was applied. After holding the temperature and pressure for 50min, the temperature was lowered and the sample was taken out after cooling to room temperature in the furnace. The resulting lubricating and wear-resistant nickel-based composite material was denoted as Ni-Co-12SrSO4.

[0057] XRD analysis revealed that the phase composition of the sintered lubricating and wear-resistant nickel-based composite material was SrCoO. 2.29 NiCo2S4, Co9S8, SrCO3 and Ni(Co) solid solutions.

[0058] Comparative Example 1

[0059] The difference from Example 1 is that the raw materials used in the preparation include 90 wt.% Ni and 10 wt.% Co, but do not include SrSO4. The rest of the contents are the same as in Example 1.

[0060] XRD analysis revealed that the phase composition of the sintered nickel-based alloy was a Ni(Co) solid solution.

[0061] Comparative Example 2

[0062] The difference from Example 1 is that the raw materials used in the preparation include 76.5 wt.% Ni, 8.5 wt.% Co, and 15 wt.% SrSO4, while the rest are the same as in Example 1.

[0063] XRD analysis revealed that the phase composition of the sintered lubricating and wear-resistant nickel-based composite material was SrCoO. 2.29 NiCo2S4, Co9S8, SrCO3 and Ni(Co) solid solutions.

[0064] Performance testing

[0065] (1) X-ray diffraction analysis was performed on the mixed raw material powders of Examples 1-3 and Comparative Examples 1-2 and the sintered lubricating and wear-resistant nickel-based composite materials. The X-ray diffraction patterns of the mixed raw material powders are shown below. Figure 1 As shown, the X-ray diffraction pattern of the obtained lubricating and wear-resistant nickel-based composite material is as follows. Figure 2 As shown.

[0066] Depend on Figure 1 and Figure 2 It can be seen that when the strontium sulfate content is 5 wt%, SrCoO appears in the lubricating and wear-resistant nickel-based composite material. 2.29 When the strontium sulfate content is in the range of 10-15 wt%, new phases Co9S8, NiCo2S4, and SrCO3 appear in the sintered lubricating composite material. At this time, the phase composition of the sintered lubricating and wear-resistant composite material changes from SrCoO 2.29 It consists of phases, NiCo2S4 phase, Co9S8 phase, SrCO3 phase and Ni(Co) solid solution phase.

[0067] (2) The present invention uses a ball-block contact friction testing machine to test the friction coefficient and wear rate of the wear-resistant composite materials obtained in Examples 1-3 and Comparative Examples 1-2. The results are shown in Tables 1 and 2. The test conditions are as follows: load 15N, frequency 300r / min, sliding time 30min, test temperature room temperature or 800℃, test time 30min, and the paired ball is an alumina ball with a diameter of 10mm. Table 1: Room temperature friction coefficient and wear rate of the lubricated wear-resistant composite materials obtained in Examples 1-3 and Comparative Examples 1-2.

[0068] Example 1 room temperature 0.37 0.316 Example 2 room temperature 0.37 0.184 Example 3 room temperature 0.39 0.253 Comparative Example 1 room temperature 0.40 0.394 Comparative Example 2 room temperature 0.51 0.685

[0069] As shown in Table 1, compared with the nickel-based alloy prepared in Comparative Example 1 and the lubricating and wear-resistant nickel-based composite material prepared in Comparative Example 2, the lubricating and wear-resistant nickel-based composite material prepared in this invention has a lower coefficient of friction and wear rate at room temperature.

[0070] Table 2. High-temperature friction coefficients of the lubricated wear-resistant composite materials obtained in Examples 1-3 and Comparative Examples 1-2.

[0071] Example 1 800℃ 0.32 Example 2 800℃ 0.27 Example 3 800℃ 0.26 Comparative Example 1 800℃ 0.42

[0072] Based on the room temperature tribological properties of the lubricating and wear-resistant nickel-based composite material (Table 1), Table 2 shows that the lubricating and wear-resistant nickel-based composite material prepared in this invention has a low coefficient of friction at 800℃.

[0073] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a lubricating and wear-resistant nickel-based composite material, characterized in that, Includes the following steps: Nickel powder, cobalt powder, and strontium sulfate powder are mixed, and the resulting mixture is placed in a mold and pressed to obtain a molded material; the mass ratio of nickel powder to cobalt powder is (79.2~85.5):(8.8~9.5); the mass ratio of nickel powder to strontium sulfate powder is (79.2~85.5):(5~12); the pressing pressure is 5~15MPa, and the holding time is 20~40s; The molding material is subjected to vacuum hot pressing sintering to obtain a lubricated and wear-resistant nickel-based composite material; the vacuum hot pressing sintering temperature is 1050~1150℃, the pressure is 20~30MPa, and the holding time is 30~90min.

2. The preparation method according to claim 1, characterized in that, The process of mixing nickel powder, cobalt powder, and strontium sulfate powder results in: Nickel powder and cobalt powder are first mixed and then ball-milled, followed by the addition of strontium sulfate powder for a second ball milling.

3. The preparation method according to claim 2, characterized in that, The rotational speed of the first ball mill and the second ball mill are independently 200~450 rpm, and the time is independently 10~40 h.

4. The preparation method according to claim 2, characterized in that, The first ball mill and the second ball mill are independently wet ball mills; the solid-liquid ratio in the wet ball mill is (25~100)g:(75~300)mL.

5. The lubricating and wear-resistant nickel-based composite material prepared by the preparation method according to any one of claims 1 to 4, characterized in that, Its components include: SrCoO 2.29 and Ni(Co) solid solution, or SrCoO 2.29 NiCo2S4, Co9S8, SrCO3 and Ni(Co) solid solutions.

6. The application of the lubricating and wear-resistant nickel-based composite material of claim 5 in power transmission components.

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