A micro-inclined hole structure TC16 base self-lubricating material with SnBiAg and Al2O3 as composite lubricants and a preparation method thereof

Abstract

The application relates to a micro-inclined hole structure TC16 base self-lubricating material with SnBiAg and Al2O3 as a composite lubricant, which takes TC16 spherical powder as raw material, adopts a selected area laser melting technology to prepare a base material with a surface micro-inclined hole structure, and then fills the composite lubricant SnBiAg and Al2O3 nano particles into the surface micro-inclined holes of the base material by using a vacuum pressure infiltration process, so as to realize a self-lubricating function. The self-lubricating material has a low friction coefficient and wear rate, compared with a self-lubricating material prepared by in-situ compounding a solid lubricant in a metal base, more lubricants can participate in lubrication, the mechanical performance of the base material is less affected, the friction reducing wear resistance and adhesion resistance of the TC16 titanium alloy used for aerospace fasteners are further improved, the process parameters are controllable in the preparation process, the formed piece is uniform in structure, high in density, good in mechanical performance, and has important engineering value and practical significance for improving the engineering application of the solid self-lubricating material and the tribology design of equipment.

Description

Technical Field

[0001] This invention relates to a micro-oblique-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants and its preparation method, belonging to the field of solid self-lubricating composite materials. Background Technology

[0002] With the increasing sophistication of my country's aerospace equipment, titanium alloy fasteners, possessing excellent properties such as light weight, high strength, corrosion resistance, non-magnetic properties, and good compatibility with composite materials, have enormous application prospects. As is well known, fasteners, as components that require repeated use, are prone to surface wear and even failure during disassembly and assembly, resulting not only in significant material waste but also potentially leading to serious accidents. The low surface hardness and poor wear resistance of titanium alloys significantly limit their application as fastener materials. Therefore, developing titanium alloy composite materials with excellent tribological properties to reduce frictional damage during the disassembly and assembly of titanium alloy fasteners is of great significance for improving their reliability and service life.

[0003] In recent years, solid self-lubricating technology has been widely used in the rotating and sliding parts of key mechanical components in aerospace, aviation, vehicles, and ships, becoming one of the most effective means to reduce friction and wear in friction pairs and reduce component wear failure. Currently, the main titanium alloy materials used for fasteners at home and abroad are TC4 titanium alloy and TC16 titanium alloy. Yang et al. compared and analyzed the tribological properties of TC4 titanium alloy and TC4-MOS2-TiC composite self-lubricating material under different loads. The results showed that MOS2 and TiC can play a good synergistic role on the friction surface. The lubricating film rich in MOS2 can reduce adhesive wear and surface roughness, while TiC effectively improves the hardness and wear resistance of the self-lubricating material and plays a supporting role in the lubricating film. Xue et al. prepared TC16-based self-lubricating material containing 1.5 wt.% multilayer graphene (MLG) and conducted dry sliding friction experiments. The results showed that under low-speed conditions, severe adhesive wear occurred on the friction surface, which was not conducive to the formation of the lubricating film. Under high-speed conditions, MLG gradually accumulated on the friction surface under the driving action of frictional heat-stress, thus forming a continuous lubricating film, which greatly reduced the friction coefficient and wear rate of the self-lubricating material.

[0004] The aforementioned titanium alloy-based solid self-lubricating materials were all prepared via in-situ synthesis. During high-temperature sintering, the lubricant partially lost its lubricating properties and, to some extent, disrupted the continuity of the matrix material, thus reducing the strength, toughness, and wear resistance of the self-lubricating materials. Ultimately, this resulted in complex and diverse frictional lubrication behaviors. Furthermore, the preparation process of the self-lubricating materials in the above studies primarily relied on powder metallurgy technology. The large heat gradient distribution during preparation affected the uniformity of the material's microstructure. Moreover, the preparation required specialized molds, keeping the material forming process limited to a simple block model, hindering the application of metal-based solid self-lubricating materials in complex industrial components. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a micro-oblique-pore structured TC16-based self-lubricating material and its preparation method, which uses SnBiAg and Al2O3 as composite lubricants, to address the shortcomings of the prior art. The composite lubricants SnBiAg and Al2O3 are filled into the micro-oblique pores on the surface of the TC16 matrix. The resulting friction interface layer allows more solid lubricant to participate in lubrication, realizing controllable adjustment of friction and lubrication behavior. Compared with the traditional in-situ synthesis method, it has less impact on the mechanical properties of the matrix material.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problems is as follows:

[0007] A micro-oblique-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants is disclosed. The material uses TC16 titanium alloy as the matrix material, and the matrix surface has a micro-oblique-pore structure. SnBiAg and Al2O3 are used as composite lubricants to fill the micro-oblique-pores on the surface, thereby exerting a synergistic lubrication effect.

[0008] According to the above scheme, the substrate surface has several micro-oblique holes arranged in a ring, with each micro-oblique hole having an angle of 40-50° with the radial direction. The structural parameters of the micro-oblique holes are as follows: the diameter of each micro-oblique hole is 400-600 μm, the hole depth is 2-3 mm, and the hole spacing is 3-4 mm. The spacing between two adjacent rings of micro-oblique holes is equal and is within the range of 3-4 mm.

[0009] According to the above scheme, the matrix material TC16 titanium alloy mainly includes elements such as Ti, Al, Mo, V, Fe, Si, Zr, and C. Preferably, the matrix material TC16 titanium alloy of the present invention contains the following elements by mass percentage: Al 2.2-3.8%, Mo 4.5-5.5%, V 4.0-5.0%, Fe ≤0.25%, Si ≤0.15%, Zr ≤0.30%, C ≤0.10%, and the balance Ti.

[0010] According to the above scheme, the mass percentage of each element in the SnBiAg alloy is Sn 40-50 wt.%, Ag 30-40 wt.%, and Bi 20 wt.%. Within the specified ratio range of each element in the spherical SnBiAg alloy powder of the present invention, its excellent tribological properties, wettability, and high-temperature thermal properties can be maintained, thus determining the optimal ratio range.

[0011] According to the above scheme, the amount of Al2O3 used is 5 to 7 wt.% of SnBiAg alloy. This is mainly because the influence of Al2O3 nanoparticles on the lubricating film bearing characteristics of soft metal SnBiAg alloy is taken into consideration. The combination ratio of the two can play an excellent synergistic lubrication role on the friction surface.

[0012] The preparation method of the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants mainly includes the following steps:

[0013] 1) Based on the constituent elements and their contents of TC16 titanium alloy, weigh the elemental powders of its constituent elements as matrix raw material powders; mix the matrix raw material powders to obtain the matrix composition.

[0014] 2) The matrix ingredients obtained in step 1) are melted under the protection of an inert gas to obtain a molten alloy liquid;

[0015] 3) The molten alloy liquid obtained in step 2) is atomized by vacuum. After the molten droplets are cooled and solidified, they form spherical metal powder, which is TC16 spherical powder.

[0016] 4) Selective laser melting technology is used to spread an appropriate amount of TC16 spherical powder on the substrate. The laser beam selects a specific area for powder melting according to the three-dimensional contour data (i.e. the set micro-oblique hole structural parameters) to process the contour of the current layer. Then, the powder is spread and processed again, and so on, layer by layer, to obtain a TC16 substrate with a surface micro-oblique hole structure.

[0017] 5) A certain proportion of Al2O3 nanoparticles are added to spherical SnBiAg alloy powder, and then the two are mixed evenly to obtain a composite lubricant; wherein, the composition of the spherical SnBiAg alloy powder is Sn 40-50 wt.%, Ag 30-40 wt.%, Bi 20 wt.%, and the particle size is 20-50 μm; the amount of Al2O3 nanoparticles added is 5.0-7.0 wt.% of the mass of the spherical SnBiAg alloy powder, and the particle size is 150-250 nm;

[0018] 6) Place the TC16 matrix from step 4) and the composite lubricant from step 5) into a vacuum pressure melting furnace. After heating and holding at that temperature for a period of time, raise the crucible containing the molten filler until the TC16 matrix is ​​completely submerged. Simultaneously, argon gas is introduced. Under the pressure inside the furnace, the molten filler gradually penetrates into the micro-pores on the surface of the TC16 matrix. After melting is complete, polish the sample to expose the micro-pore structure on the surface. The micro-pores are filled with the composite lubricant, resulting in a TC16-based self-lubricating material with a micro-pore structure using SnBiAg and Al2O3 as composite lubricants.

[0019] In the above scheme, the powder mixing in step 1) is carried out by vibration mixing, wherein the vibration frequency is 60-70Hz, the vibration force is 10000-11000N, and the oscillation time is 40-50min.

[0020] In the above scheme, nitrogen is preferred as the inert gas in step 2). Before filling with the inert gas, the vacuum is evacuated to a degree of <0.06 Pa; after filling with the inert gas, the oxygen content is <100 ppm; the melting temperature is 1050-1250℃.

[0021] In the above scheme, the protective gas used in step 3) is nitrogen; the inlet pressure of nitrogen in the atomizing device is 4.8 to 5.6 MPa, and the flow rate of the molten alloy liquid is 1.8 to 2.6 kg / min; the obtained TC16 spherical powder is screened, and the particle size is preferably controlled within the range of 20 to 40 μm.

[0022] In the above scheme, the selective laser melting technology parameters in step 4) are: laser power 150-170W, scanning rate 1000-1200m / s, scanning interval 50-70μm, single layer thickness 20-40μm, and protective gas is argon.

[0023] In the above scheme, the lubricant mixing in step 5) is carried out by vibration mixing, wherein the vibration frequency is 60-70Hz, the vibration force is 10000-11000N, and the oscillation time is 40-50min.

[0024] In the above scheme, before the melting and infiltration in step 6), the vacuum is evacuated to 20 Pa; during the melting and infiltration process, the furnace temperature is 220-250℃, the holding time is 20-30 min, the argon gas pressure is 0.4-0.6 MPa, and the melting and infiltration time is 50-60 min; after the melting and infiltration is completed, the temperature is lowered to 120-130℃, the temperature is held for 25-30 min, the power is turned off, and the furnace is cooled to room temperature.

[0025] The TC16-based self-lubricating material with a micro-oblique porous structure and SnBiAg and Al2O3 as composite lubricants, obtained in this invention, exhibits excellent tribological properties during friction and wear processes. It has a low coefficient of friction, averaging approximately 0.18–0.30 with minimal fluctuation, and a low wear rate, averaging approximately 4.4–5.6 × 10⁻⁶. -5 mm 3 / (Nm).

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] 1. The micro-oblique-pore structure TC16-based self-lubricating material of the present invention fills the micro-oblique pores on the surface of the TC16 matrix with composite lubricants SnBiAg and Al2O3. The resulting friction interface layer allows more solid lubricants to participate in lubrication, realizing controllable adjustment of friction lubrication behavior. Compared with the traditional in-situ synthesis method, it has less impact on the mechanical properties of the matrix material.

[0028] 2. This invention uses SnBiAg and Al2O3 as composite lubricants. The two can exert excellent synergistic lubrication on the friction surface. SnBiAg, with its excellent plasticity and low shear strength, can exert a significant friction-reducing and anti-adhesion effect. Some Al2O3 nanoparticles coated with SnBiAg can enhance the load-bearing capacity of the lubricating film to a certain extent. In addition, some Al2O3 nanoparticles exposed on the friction surface not only effectively reduce the adhesion and transfer between friction pairs, but also act as "micro-bearings", thereby further improving the self-lubricating friction-reducing and wear-resistant performance.

[0029] 3. This invention uses TC16 spherical powder as raw material and selective laser melting technology to prepare a matrix material with a surface micro-pore structure. Then, a vacuum pressure melting process is used to fill the surface micro-pores with composite lubricant SnBiAg and Al2O3 nanoparticles, realizing the controllable preparation of the friction interface layer. The preparation method is simple and easy to operate, and the process parameters are easy to control, making it suitable for large-scale mass production. Attached Figure Description

[0030] Figure 1 This is a flowchart of the preparation process of the self-lubricating material of the present invention.

[0031] Figure 2 This is an electron probe image of the TC16 spherical powder prepared in Example 1 of this invention.

[0032] Figure 3 This is an electron probe microanalysis image of spherical SnBiAg alloy powder.

[0033] Figure 4 This is a field emission scanning electron microscope image of Al2O3 nanoparticles.

[0034] Figure 5 This is an electron probe image of a single micro-oblique hole on the surface of the TC16 substrate prepared in Example 2 of the present invention.

[0035] Figure 6 This is an electron probe micrograph of the wear marks of the self-lubricating material in Embodiment 3 of the present invention after a sliding friction experiment.

[0036] Figure 7 This is a field emission scanning electron microscope image of the self-lubricating material of Example 3 of the present invention, showing the synergistic lubrication effect of SnBiAg and Al2O3 nanoparticles on the wear marks after a sliding friction experiment.

[0037] Figure 8 The average friction coefficient of the micro-oblique-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants prepared in Examples 1, 2 and 3 of this invention is given by the following test conditions: temperature 25-28℃, load 20N, sliding speed 0.2m / s, time 60min, and friction radius 6mm.

[0038] Figure 9 The average wear rate of the micro-oblique hole structure TC16-based self-lubricating materials with SnBiAg and Al2O3 as composite lubricants prepared in Examples 1, 2 and 3 of this invention is given by the following test conditions: temperature 25-28℃, load 20N, sliding speed 0.2m / s, time 60min, and friction radius 6mm. Detailed Implementation

[0039] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the present invention is not limited to the following embodiments.

[0040] In the following embodiments, the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants is prepared by selective laser melting and vacuum pressure infiltration using TC16 spherical powder, SnBiAg alloy powder as composite lubricant, and Al2O3 nanoparticles. This invention provides a specific preparation method, but does not limit the method. Micro-porous TC16-based self-lubricating materials with SnBiAg and Al2O3 as composite lubricants prepared by other methods that meet the requirements of this invention are also within the scope of protection of this invention.

[0041] Example 1

[0042] A micro-oblique-pore structure TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants is disclosed. The material primarily uses TC16 spherical powder as the matrix material, with a micro-oblique-pore structure on the matrix surface. SnBiAg alloy and Al2O3 are used as composite lubricants filling these micro-oblique pores. Specifically, the mass ratio of Al, Mo, V, Fe, Si, Zr, C, and Ti in the TC16 titanium alloy is 3.0:5.0:4.5:0.2:0.1:0.2:0.05:86.95; the mass ratio of Sn, Bi, and Ag in the SnBiAg alloy is 40:20:40; the Al2O3 content is 5 wt.% of the SnBiAg alloy mass; the micro-oblique-pore structure consists of multiple pores arranged in a ring, with a pore diameter of 400 μm, a pore depth of 2 mm, a pore spacing of 3 mm within the same ring, a pore spacing of 3 mm between adjacent rings, and an angle of 40° between each micro-oblique pore and the radial direction.

[0043] like Figure 1 As shown, the preparation method of the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants specifically includes the following steps:

[0044] 1) Based on the mass ratio of each element in TC16 titanium alloy, weigh the elemental powder of each element, mix them and place them in a vibrating mixer. The vibration frequency is 60Hz, the vibration force is 10000N, and the vibration time is 40 minutes to obtain the matrix material.

[0045] 2) Evacuate the melting chamber to a vacuum degree <0.06Pa, and fill it with inert nitrogen gas to make the oxygen content <100ppm; add the matrix material obtained in step 1) into the melting furnace, and melt the added matrix material into molten alloy liquid when the temperature rises to 1050℃;

[0046] 3) Evacuate the atomization chamber to a vacuum degree <0.06Pa, open the drain valve, and let the molten alloy liquid obtained in step 2) flow into the atomization chamber through the nozzle at a flow rate of 1.8kg / min; then connect the high-pressure nitrogen gas source with an inlet pressure of 4.8MPa. The introduced nitrogen gas atomizes the molten alloy liquid. After the resulting droplets are cooled and solidified, they are dried and sieved to obtain TC16 spherical powder with a particle size of 20-40μm.

[0047] Depend on Figure 2 It can be seen that the TC16 spherical powder prepared by vacuum atomization is a single spherical particle with a particle size of 20-40 μm and high sphericity, which meets the powder particle size requirements for selective laser melting.

[0048] 4) Set the parameters for selective laser melting technology: laser power 150W, scanning rate 1000m / s, scanning interval 50μm, single layer thickness 20μm, and protective gas argon. Spread an appropriate amount of TC16 spherical powder on the substrate. The laser beam selects a specific area for powder melting according to the three-dimensional contour data (multiple micro-oblique hole structures arranged in a ring, hole diameter 400μm, hole depth 2mm, hole spacing in the same ring 3mm, hole spacing between adjacent rings 3mm, and the angle between each micro-oblique hole and the radial direction 40°) to process the contour of the current layer. Then, the thickness of one layer is lowered by the lifting platform, and the roller spreads powder on the processed previous layer. The control program loads the data of the next layer for processing. This process is repeated layer by layer to obtain a TC16 substrate with a surface micro-oblique hole structure.

[0049] 5) Add 5 wt.% Al2O3 nanoparticles to spherical SnBiAg alloy powder, and then place the two in a vibratory mixer with a vibration frequency of 60 Hz, a vibration force of 10000 N, and an oscillation time of 40 minutes to obtain a composite lubricant.

[0050] Depend on Figure 3 , Figure 4 It can be seen that the particle size of the spherical SnBiAg alloy powder used in the composite lubricant is 20-50 μm, and the particle size of the Al2O3 nanoparticles is 150-250 nm.

[0051] 6) Place the TC16 matrix from step 4) and the composite lubricant from step 5) into a vacuum pressure melting furnace, and evacuate to 20 Pa. Then, heat the furnace to 220°C and hold for 20 minutes. Rotate the pressure handle to raise the crucible containing the molten filler until the TC16 matrix is ​​completely submerged. Simultaneously, introduce argon gas to raise the furnace pressure to 0.4 MPa, and continue melting for 50 minutes. Under the pressure of the furnace, the molten filler gradually penetrates into the micro-pores on the surface of the TC16 matrix, forming a micro-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants. After melting, cool to 120–130°C, hold for 25–30 minutes, then turn off the power and allow the furnace to cool to room temperature.

[0052] According to the HVS-1000 microhardness tester, the hardness of the TC16-based self-lubricating material with a micro-oblique pore structure prepared in Example 1, which uses SnBiAg and Al2O3 as composite lubricants, is about 3.98 GPa. Figure 8 (a) and Figure 9 (a) indicates that the self-lubricating material prepared in this embodiment has a low coefficient of friction, with an average value of approximately 0.30, and an average wear rate of approximately 5.6 × 10⁻⁶. -5 mm 3 / (Nm), exhibiting excellent tribological properties.

[0053] In addition, the equivalent stress of TC16 surfaces with non-porous, straight-hole, and micro-oblique-hole structures was compared and analyzed by finite element simulation. The results show that the stress structure of the micro-oblique-hole structure is closer to that of the non-porous structure and has less impact on the bearing strength of the friction interface.

[0054] Example 2

[0055] A micro-oblique-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants is mainly based on TC16 spherical powder as the matrix material. The matrix surface has a micro-oblique-pore structure, and SnBiAg alloy and Al2O3 are used as composite lubricants to fill the micro-oblique-pores on the surface. The TC16 titanium alloy has a mass ratio of Al, Mo, V, Fe, Si, Zr, C, and Ti of 3.0:5.0:4.5:0.2:0.1:0.2:0.05:86.95; the SnBiAg alloy has a mass ratio of Sn, Bi, and Ag of 45:20:35; the Al2O3 content is 6 wt.% of the SnBiAg alloy mass; the micro-oblique hole structure consists of multiple holes arranged in a ring, with a hole diameter of 500 μm, a hole depth of 2.5 mm, a hole spacing of 3.5 mm within the same ring, a hole spacing of 3.5 mm between adjacent rings, and an angle of 45° between each micro-oblique hole and the radial direction.

[0056] The preparation method of the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants specifically includes the following steps:

[0057] 1) Based on the mass ratio of each element in TC16 titanium alloy, weigh the elemental powders of each element, mix them, and place them in a vibrating mixer. The vibration frequency is 65Hz, the vibration force is 10500N, and the vibration time is 45 minutes to obtain the batching.

[0058] 2) Evacuate the melting chamber to a vacuum degree <0.06Pa, and fill it with inert nitrogen gas to make the oxygen content <100ppm; add the ingredients obtained in step 1) into the melting furnace, and melt the added ingredients into molten alloy liquid when the temperature rises to 1150℃;

[0059] 3) Evacuate the atomization chamber to a vacuum degree <0.06Pa, open the drain valve, and let the molten alloy liquid obtained in step 2) flow into the atomization chamber through the nozzle at a flow rate of 2.2kg / min; then connect the high-pressure nitrogen gas source with an inlet pressure of 5.2MPa. The introduced nitrogen gas atomizes the molten alloy liquid. After the resulting droplets are cooled and solidified, they are dried and sieved to obtain TC16 spherical powder with a particle size of 20-40μm.

[0060] 4) Set the parameters for selective laser melting technology: laser power 160W, scanning rate 1100m / s, scanning interval 60μm, single layer thickness 30μm, and protective gas argon. A suitable amount of TC16 spherical powder is spread evenly on the substrate. The laser beam selects a specific area for powder melting according to the three-dimensional contour data (multiple micro-oblique hole structures arranged in a ring, each micro-oblique hole having an angle of 45° with the radial direction, a hole diameter of 500μm, a hole depth of 2.5mm, a hole spacing of 3.5mm between the same ring, and a hole spacing of 3.5mm between adjacent rings) to process the contour of the current layer. Then, the thickness of one layer is lowered by a lifting platform, and the roller spreads powder evenly on the processed previous layer. The control program loads the data for the next layer for processing. This process is repeated layer by layer to obtain a TC16 substrate with a surface micro-oblique hole structure.

[0061] Depend on Figure 5 It can be seen that the TC16 substrate with surface micro-oblique hole structure prepared by selective laser melting technology has micro-oblique holes that meet the design requirements and have regular shapes.

[0062] 5) Add 6 wt.% Al2O3 nanoparticles to spherical SnBiAg alloy powder, and then place the two in a vibratory mixer with a vibration frequency of 65 Hz, a vibration force of 10500 N, and an oscillation time of 45 minutes to obtain a composite lubricant.

[0063] 6) Place the TC16 matrix from step 4) and the composite lubricant from step 5) into a vacuum pressure melting furnace, and evacuate to 20 Pa. Then, heat the furnace to 235°C and hold for 25 minutes. Rotate the pressure handle to raise the crucible containing the molten filler until the TC16 matrix is ​​completely submerged. Simultaneously, introduce argon gas to raise the furnace pressure to 0.5 MPa, and continue melting for 55 minutes. Under the pressure of the furnace, the molten filler gradually penetrates into the micro-pores on the surface of the TC16 matrix, forming a micro-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants. After melting, cool to 120–130°C, hold for 25–30 minutes, then turn off the power and allow the furnace to cool to room temperature.

[0064] The hardness of the TC16-based self-lubricating material with a micro-oblique pore structure and SnBiAg and Al2O3 as composite lubricants prepared in Example 2, as tested by an HVS-1000 microhardness tester, was 3.86 GPa. Figure 8 (b) and Figure 9 (b) This indicates that the self-lubricating material prepared in this embodiment has a low coefficient of friction, with an average value of approximately 0.18, and an average wear rate of approximately 4.4 × 10⁻⁶. -5 mm 3 / (Nm), exhibiting excellent tribological properties.

[0065] Example 3

[0066] A micro-oblique-pore structure TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants is disclosed. The material primarily uses TC16 spherical powder as the matrix material, with a micro-oblique-pore structure on the matrix surface. SnBiAg alloy and Al2O3 are used as composite lubricants filling these micro-oblique pores. Specifically, the mass ratio of Al, Mo, V, Fe, Si, Zr, C, and Ti in the TC16 titanium alloy is 3.0:5.0:4.5:0.2:0.1:0.2:0.05:86.95; the mass ratio of Sn, Bi, and Ag in the SnBiAg alloy is 50:20:30; the Al2O3 content is 7 wt.% of the SnBiAg alloy mass; the micro-oblique-pore structure consists of multiple pores arranged in a ring, with a pore diameter of 600 μm, a pore depth of 3 mm, a pore spacing of 4 mm within the same ring, a pore spacing of 4 mm between adjacent rings, and an angle of 50° between each micro-oblique pore and the radial direction.

[0067] The preparation method of the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants specifically includes the following steps:

[0068] 1) Based on the mass ratio of each element in TC16 titanium alloy, weigh the elemental powder of each element, mix them and place them in a vibrating mixer. The vibration frequency is 70Hz, the vibration force is 11000N, and the vibration time is 50 minutes to obtain the batch.

[0069] 2) Evacuate the melting chamber to a vacuum degree <0.06Pa, and fill it with inert nitrogen gas to make the oxygen content <100ppm; add the ingredients obtained in step 1) into the melting furnace, and melt the added ingredients into molten alloy liquid when the temperature rises to 1250℃;

[0070] 3) Evacuate the atomization chamber to a vacuum degree <0.06Pa, open the drain valve, and let the molten alloy liquid obtained in step 2) flow into the atomization chamber through the nozzle at a flow rate of 2.6kg / min; then connect the high-pressure nitrogen gas source with an inlet pressure of 5.6MPa. The introduced nitrogen gas atomizes the molten alloy liquid. After the resulting droplets cool and solidify, they are dried and sieved to obtain TC16 spherical powder with a particle size of 20-40μm.

[0071] 4) Set the parameters for selective laser melting technology: laser power 170W, scanning rate 1200m / s, scanning interval 70μm, single layer thickness 40μm, and protective gas argon. A suitable amount of TC16 spherical powder is spread evenly on the substrate. The laser beam selects a specific area for powder melting according to the three-dimensional contour data (multiple micro-oblique hole structures arranged in a ring, each micro-oblique hole having an angle of 50° with the radial direction, a hole diameter of 600μm, a hole depth of 3mm, a hole spacing of 4mm, and a spacing of 4mm between adjacent ring holes) to process the contour of the current layer. Then, the thickness of one layer is lowered by a lifting platform, and the roller spreads powder evenly on the processed previous layer. The control program loads the data for the next layer for processing. This process is repeated layer by layer to obtain a TC16 substrate with a surface micro-oblique hole structure.

[0072] 5) Add 7 wt.% Al2O3 nanoparticles to spherical SnBiAg alloy powder, and then place the two in a vibratory mixer with a vibration frequency of 70 Hz, a vibration force of 11000 N, and an oscillation time of 50 minutes to obtain a composite lubricant.

[0073] 6) Place the TC16 matrix from step 4) and the composite lubricant from step 5) into a vacuum pressure melting furnace, and evacuate to 20 Pa. Then, heat the furnace to 250°C and hold for 30 minutes. Rotate the pressure handle to raise the crucible containing the molten filler until the TC16 matrix is ​​completely submerged. Simultaneously, introduce argon gas to raise the furnace pressure to 0.6 MPa, and continue melting for 60 minutes. Under the pressure of the furnace, the molten filler gradually penetrates into the micro-pores on the surface of the TC16 matrix, forming a micro-pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants. After melting, cool to 120–130°C, hold for 25–30 minutes, then turn off the power and allow the furnace to cool to room temperature.

[0074] The hardness of the TC16-based self-lubricating material with a microporous structure and SnBiAg and Al2O3 composite lubricants prepared in Example 3, tested with an HVS-1000 microhardness tester, was 3.72 GPa. Figure 6 , Figure 7 The wear track pattern obtained after the friction and wear test of the micro-oblique pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants shows that the lubricant can be smoothly precipitated from the micro-oblique pores and then gradually spread along the sliding direction to form a dense lubricating film on the friction surface. At the same time, SnBiAg and Al2O3 nanoparticles can play a good synergistic lubrication role during the friction process.

[0075] Figure 8 (c) and Figure 9(c) This indicates that the self-lubricating material prepared in this embodiment has a low coefficient of friction, with an average value of approximately 0.25, and an average wear rate of approximately 4.9 × 10⁻⁶. -5 mm 3 / (Nm), exhibiting excellent tribological properties.

[0076] Based on the experimental results of the three embodiments described above, it is shown that the micro-porous TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants obtained in this invention exhibits excellent tribological properties during friction and wear processes. It has a low coefficient of friction, with an average value of approximately 0.18-0.30 and minimal fluctuation, and a low wear rate, with an average value of approximately 4.4-5.6 × 10⁻⁶. -5 mm 3 / (Nm).

[0077] In summary, this invention first uses a vacuum atomization process to prepare TC16 spherical powder; then, selective laser melting technology is used to obtain a TC16 matrix with a surface micro-oblique pore structure; finally, a vacuum pressure melting process is used to fill the surface micro-oblique pores with composite lubricant SnBiAg and Al2O3 nanoparticles to prepare a TC16-based self-lubricating material. The matrix exhibits uniform structure, high density, and good mechanical properties; the surface micro-oblique pores meet design requirements, are uniform in size, and have regular shapes; the lubricant and matrix have good bonding performance; and it possesses excellent tribological properties. Furthermore, the steps and methods involved in the preparation process are simple and feasible, laying a solid foundation for the engineering application of TC16-based self-lubricating materials.

[0078] All the raw materials listed in this invention can achieve this invention, as can the upper and lower limits and ranges of each raw material. The upper and lower limits and ranges of the process parameters of this invention (such as melting temperature, laser power, scanning speed, melting and infiltration time, etc.) can also achieve this invention. Examples are not listed one by one here.

[0079] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the inventive concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A micro-inclined hole structure TC16 base self-lubricating material with SnBiAg and Al203 as composite lubricant, characterized in that, It uses TC16 titanium alloy as the matrix material, and the matrix surface has a micro-oblique hole structure. SnBiAg alloy and Al2O3 nanoparticles are used as composite lubricants to fill the micro-oblique holes on the surface. The mass percentage of each element in the SnBiAg alloy is Sn 40~50wt.%, Ag 30~40wt.%, with the balance being Bi; the amount of Al2O3 nanoparticles is 5~7wt.% of the SnBiAg alloy; the mass percentage of each element in the TC16 titanium alloy is: Al 2.2~3.8 wt.%, Mo 4.5~5.5 wt.%, V 4.0~5.0wt.%, Fe≤0.25 wt.%, Si≤0.15 wt.%, Zr≤0.30 wt.%, C≤0.10 wt.%, with the balance being Ti. The micro-oblique hole structure consists of multiple micro-oblique holes arranged in a ring. The angle between each micro-oblique hole and the radial direction is 40-50°. The structural parameters of the micro-oblique holes are as follows: the diameter of each micro-oblique hole is 400-600 μm, the hole depth is 2-3 mm, and the hole spacing between adjacent micro-oblique holes in the same ring is 3-4 mm.

2. The method for preparing a micro-oblique-pore structured TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants according to claim 1, characterized in that, It uses TC16 spherical powder as raw material, spherical SnBiAg alloy powder and Al2O3 nanoparticles as composite lubricant, and prepares TC16-based self-lubricating material with surface micro-oblique pores filled with composite lubricant by selective laser melting technology and vacuum pressure melting process based on the structure of micro-oblique pores.

3. The method for preparing a micro-oblique-pore structured TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants according to claim 2, characterized in that, Includes the following steps: 1) Based on the constituent elements and their contents of TC16 titanium alloy, weigh the elemental powders of its constituent elements as matrix raw material powders; mix the matrix raw material powders to obtain the matrix composition. 2) The matrix ingredients obtained in step 1) are melted under the protection of an inert gas to obtain a molten alloy liquid; 3) The molten alloy liquid obtained in step 2) is atomized by vacuum. After the molten droplets are cooled and solidified, they form spherical metal powder, which is TC16 spherical powder. 4) Selective laser melting technology is used to spread an appropriate amount of TC16 spherical powder on the substrate. The laser beam selects a specific area according to the three-dimensional contour data to melt the powder and process the contour of the current layer. Then, the powder is spread and processed again. This process is carried out layer by layer to obtain a TC16 substrate with a surface micro-oblique hole structure. 5) Add a certain proportion of Al2O3 nanoparticles to spherical SnBiAg alloy powder, and then mix the two evenly to obtain a composite lubricant; 6) Place the TC16 matrix from step 4) and the composite lubricant from step 5) into a vacuum pressure melting furnace. After heating and holding at that temperature for a period of time, raise the crucible containing the molten composite lubricant until the TC16 matrix is ​​completely submerged. Simultaneously, argon gas is introduced. Under the action of the gas pressure inside the furnace, the molten composite lubricant gradually penetrates into the micro-slanted pores on the surface of the TC16 matrix, thus obtaining a micro-slanted pore structure TC16-based self-lubricating material with SnBiAg and Al2O3 as composite lubricants.

4. The method for preparing a micro-oblique-pore structured TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants according to claim 3, characterized in that, Step 2) The melting temperature is 1050~1250℃; Step 3) The particle size of the TC16 spherical powder is 20~40μm; In Step 4), the selective laser melting technology parameters are: laser power 150~170W, scanning rate 1000~1200m / s, scanning interval 50~70μm, single layer thickness 20~40μm, and the protective gas is argon.

5. A method for preparing a micro-oblique-pore structured TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants, as described in claim 2 or 3, characterized in that, The spherical SnBiAg alloy powder contains Sn 40-50 wt.%, Ag 30-40 wt.%, with the balance being Bi; the particle size of the spherical SnBiAg alloy powder is 20-50 μm; the amount of Al2O3 nanoparticles added is 5.0-7.0 wt.% of the mass of the spherical SnBiAg alloy powder, with a particle size of 150-250 nm.

6. A method for preparing a micro-oblique-pore structured TC16-based self-lubricating material using SnBiAg and Al2O3 as composite lubricants, as described in claim 2 or 3, characterized in that... Before melting and infiltration, the furnace is evacuated to 20 Pa. During melting and infiltration, the furnace temperature is 220~250℃, the holding time is 20~30 min, the argon pressure is 0.4~0.6 MPa, and the melting and infiltration time is 50~60 min. After melting and infiltration, the temperature is lowered to 120~130℃, held for 25~30 min, and then the power is turned off. The furnace is then cooled to room temperature.

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