Composite babbitt wire, its preparation method and application

Abstract

The present application relates to the alloy technical field, specifically, a kind of composite babbitt alloy wire and its preparation method and application.The composite babbitt alloy wire is made of the following components by mass percentage: chopped carbon fiber 1%~3%, Ni fiber 0.4%~1.6%, and the balance babbitt alloy powder.The present application can significantly improve the strength and hardness of the composite babbitt alloy wire, reduce the friction coefficient and wear rate of the composite babbitt alloy wire by adding chopped carbon fiber and Ni fiber simultaneously, so that it is not easy to deform and wear when bearing high load, and in addition, the high-temperature stability of the composite babbitt alloy wire can be improved, and the comprehensive performance is good.

Description

Technical Field

[0001] This invention relates to the field of alloy technology, and more specifically, to a composite Babbitt wire, its preparation method, and its application. Background Technology

[0002] Sliding bearing liners are typically made of Babbitt metal, copper alloys, and aluminum alloys. Among these, Babbitt metal is widely used as a liner material for sliding bearings due to its excellent mechanical properties. Babbitt metal is a low-melting-point alloy with tin, antimony, and copper as its main components. Its soft structure exhibits good tribological compatibility, conformability, and embeddability, while its hard particles possess a certain load-bearing capacity, forming a friction structure of soft matrix and hard bumps.

[0003] Existing Babbitt alloy materials have poor strength and hardness, or high friction coefficient and wear rate, or poor high temperature stability, which limits their application under high load and high speed conditions.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The primary objective of this invention is to provide a composite Babbitt wire. By simultaneously adding chopped carbon fibers and Ni fibers, the synergistic effect of both achieves a reinforcement effect greater than the sum of its parts (1+1>2), significantly improving the strength and hardness of the composite Babbitt wire, reducing its coefficient of friction and wear rate, making it less prone to deformation and wear under high loads. Furthermore, it also improves the high-temperature stability of the composite Babbitt wire, resulting in superior overall performance. This solves the problem of poor overall performance in existing Babbitt materials.

[0006] The second objective of this invention is to provide a method for preparing composite Babbitt wire.

[0007] A third objective of this invention is to provide applications of composite Babbitt wire in deep-sea, nuclear power, and ocean-going fields.

[0008] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0009] A composite Babbitt wire is made of the following components by mass percentage: 1% to 3% chopped carbon fibers, 0.4% to 1.6% Ni fibers, and the balance Babbitt powder.

[0010] In one embodiment, the average length of the chopped carbon fiber is 5-7 mm and the diameter is 4-6 μm.

[0011] In one embodiment, the density of the chopped carbon fibers is 1.70~1.82 g / cm³. 3 .

[0012] In one embodiment, the average diameter of the Ni fiber is 4~7 μm.

[0013] In one embodiment, the chemical composition of the Babbitt alloy powder, by mass percentage, includes: Sb 10%~12%, Cu 5.5%~6.5%, with the balance being Sn.

[0014] In one embodiment, the microhardness of the composite Babbitt wire is ≥38HV; the heat resistance of the composite Babbitt wire is ≥108℃.

[0015] A method for preparing the composite Babbitt wire includes the following steps:

[0016] Short-cut carbon fibers, Ni fibers, and Babbitt alloy powder are mixed and then cold isostatically pressed to obtain a billet.

[0017] After sintering, the blank is obtained as a sintered body;

[0018] The sintered body is extruded and drawn to obtain the composite Babbitt wire.

[0019] In one embodiment, the cold isostatic pressing method includes: first holding the pressure at 80~100MPa for 3~5 minutes, then holding the pressure at 200~230MPa for 3~5 minutes, and then holding the pressure at 275~300MPa for 3~8 minutes.

[0020] In one embodiment, the sintering temperature is 190~230℃, and the holding time is 1.5~3h.

[0021] In one embodiment, the sintering is vacuum sintering, wherein the vacuum degree of the vacuum sintering is >10. -3 Pa.

[0022] In one embodiment, the extrusion method includes warm extrusion, wherein the temperature of the warm extrusion is 120~170°C.

[0023] Applications of the composite Babbitt wire in deep-sea, nuclear power, and ocean-going fields.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) By adding short-cut carbon fiber and Ni fiber at the same time, the two work together to achieve a reinforcement effect of 1+1>2, which can significantly improve the strength and hardness of composite Babbitt wire, reduce the friction coefficient and wear rate of composite Babbitt wire, so that it is not easy to deform and wear when subjected to high load. In addition, it can also improve the high temperature stability of composite Babbitt wire, and has good comprehensive performance.

[0026] (2) The short-cut carbon fiber and Ni fiber in this invention have a synergistic effect, which is mainly reflected in the following three aspects: First, the balance between high strength and high toughness: The core shortness of Babbitt alloy is "low strength and insufficient toughness". It is difficult to achieve both by a single short-cut carbon fiber. The dual-fiber reinforcement of short-cut carbon fiber + Ni fiber can give full play to the rigid support of short-cut carbon fiber and also reflect the toughness compensation of Ni fiber. Compared with Babbitt alloy reinforced by a single short-cut carbon fiber, the impact strength of composite dual-fiber reinforced Babbitt alloy is increased by 15%~30%; the elastic modulus is increased by 10%~25%, achieving a mechanical balance of "strong but not brittle, tough but not soft". II. Dual Protection of High Temperature Resistance and Thermal Conductivity: The high-temperature softening resistance of chopped carbon fibers maintains high modulus at high temperatures, inhibiting high-temperature creep and softening of Babbitt alloy. The high thermal conductivity of Ni fibers can quickly conduct the heat generated during the operation of the composite Babbitt alloy, avoiding local overheating that leads to softening and wear. The synergistic reinforcement of chopped carbon fibers and Ni fibers can not only increase the heat distortion temperature of Babbitt alloy from about 150℃ to about 240℃, but also reduce the high-temperature wear rate of Babbitt alloy to about 1 / 4. III. Improved Compatibility and Enhanced Stress Transfer: Due to the poor wettability of chopped carbon fibers and Babbitt alloy, the interfacial bonding between chopped carbon fibers and Babbitt alloy is relatively weak, which is the core bottleneck restricting the reinforcement of single chopped carbon fibers. However, Ni fibers and Babbitt alloy are metallurgically bonded, and Ni fibers can also be physically entangled and adsorbed on the surface of chopped carbon fibers, improving the wettability between chopped carbon fibers and the Babbitt alloy matrix, reducing interfacial voids, and improving bonding strength. Compared to single chopped carbon fiber reinforcement, the addition of Ni fiber increases the bonding strength between the chopped carbon fiber and the Babbitt matrix by 20% to 35%. Stress can be efficiently transferred to the carbon fiber through the Ni fiber, avoiding carbon fiber debonding caused by stress concentration, and further enhancing the stability of the mechanical and frictional properties of the double-fiber reinforced Babbitt alloy. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 The SEM detection images of Experiment Example 2 at 200x magnification are provided, in which... Figure 1 (a) Figure 1 (b) Figure 1 (c) Figure 1 (d) Figure 1(e) Cold isostatically pressed microstructures corresponding to short-cut carbon fiber contents of 0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, and 4 wt.%, respectively;

[0029] Figure 2 The SEM detection images of Experiment Example 2 at 100x magnification are provided, in which... Figure 2 (a) Figure 2 (b) Figure 2 (c) Figure 2 (d) Figure 2 (e) Cold isostatic microstructures corresponding to short carbon fiber contents of 0 wt.%, 1 wt.%, 2 wt.%, 3 wt.%, and 4 wt.%, respectively. Detailed Implementation

[0030] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0031] Unless otherwise specified, in this invention, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0032] Unless otherwise specified, the terms "comprising" and "including" as used in this invention can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0033] Unless otherwise specified, in this invention, "one or more" or "at least one" refers to any one, any two, or any two or more of the listed items. "Several" refers to any two or more.

[0034] In a first aspect, the present invention provides a composite Babbitt wire, which is made of the following components by mass percentage: 1% to 3% chopped carbon fibers (e.g., 1%, 1.3%, 1.5%, 1.8%, 2%, 2.2%, 2.5%, 2.7% or 3%), 0.4% to 1.6% Ni fibers (e.g., 0.4%, 0.5%, 0.6%, 0.8%, 1.0%, 1.2%, 1.4% or 1.6%), and the balance Babbitt powder.

[0035] Short-cut carbon fibers have advantages such as high specific strength, wear resistance, corrosion resistance, high temperature resistance and strong fatigue resistance. Ni fibers have advantages such as good compatibility with Babbitt alloy and high temperature resistance. When the two are added to Babbitt alloy, they can work together to achieve a reinforcement effect of 1+1>2, significantly improving the strength and hardness of Babbitt alloy, making it less prone to deformation and wear when subjected to high loads, and also improving the high temperature stability of Babbitt alloy.

[0036] The composite Babbitt wire provided by this invention has high tensile and compressive strength. The mechanism is mainly due to the fact that the axial elastic modulus of the short-cut carbon fiber is much higher than that of Babbitt alloy. During tension and compression, it can suppress the plastic deformation of the matrix and improve the tensile and compressive strength of the composite Babbitt wire.

[0037] Composite Babbitt wire exhibits a low coefficient of friction and a low wear rate, primarily due to the formation of a transfer film on the graphite layer of the chopped carbon fiber surface during friction, which reduces frictional resistance. Simultaneously, the tin and antimony elements in the Babbitt alloy react with the chopped carbon fiber interface to generate a low-shear-strength Sn-C solid solution, inhibiting adhesive wear.

[0038] Furthermore, carbon fiber significantly improves the high-temperature stability of Babbitt alloy, increasing its heat resistance temperature from 80-100℃ to 130-150℃. This is mainly due to the thermal expansion coefficient of short-cut carbon fiber (0.2-0.3×10⁻⁶). -6 The temperature (°C) is much lower than that of Babbitt alloy (23~28×10). -6 / ℃), reducing thermal deformation through interfacial stress relaxation.

[0039] Furthermore, Ni fiber reinforced Babbitt alloys mainly enhance the mechanical properties of Babbitt alloys through the synergistic effect between high-hardness and brittle Ni fibers and soft Babbitt alloy matrix, and through load transfer, microstructure regulation, and the interface between carbon fibers, Ni fibers and Babbitt alloys. They also suppress the creep behavior of the Babbitt alloy matrix at high temperatures and improve its high-temperature stability.

[0040] Specifically, the synergistic effect of chopped carbon fiber and Ni fiber is mainly reflected in the following three aspects: (1) Balance between high strength and high toughness: The core weakness of Babbitt alloy is "low strength and insufficient toughness". It is difficult to achieve both with a single chopped carbon fiber. The dual fiber reinforcement of chopped carbon fiber + Ni fiber can give full play to the rigid support of chopped carbon fiber and also reflect the toughness compensation of Ni fiber. Compared with Babbitt alloy reinforced with a single chopped carbon fiber, the impact strength of composite dual fiber reinforced Babbitt alloy is increased by 15%~30%; the elastic modulus is increased by 10%~25%, achieving a mechanical balance of "strong but not brittle, tough but not soft". (2) Dual protection of high temperature resistance and thermal conductivity: The high temperature anti-softening properties of chopped carbon fibers can maintain high modulus at high temperature, inhibiting the high temperature creep and softening of Babbitt alloy. The high thermal conductivity of Ni fiber can quickly conduct the heat generated during the working process of composite Babbitt alloy, avoiding local overheating, which leads to softening and wear of Babbitt alloy. The synergistic reinforcement of chopped carbon fiber and Ni fiber can not only increase the heat deformation temperature of Babbitt alloy from about 150℃ to about 240℃, but also reduce the high temperature wear rate of Babbitt alloy to about 1 / 4. (3) Improve compatibility and strengthen stress transmission: Due to the poor wettability of chopped carbon fiber and Babbitt alloy, the interfacial bonding between chopped carbon fiber and Babbitt alloy is relatively weak, which is the core bottleneck restricting the reinforcement of single chopped carbon fiber. Ni fiber and Babbitt alloy are metal-alloy metallurgical bonded. At the same time, Ni fiber can also be physically wrapped and adsorbed on the surface of chopped carbon fiber, improving the wettability between chopped carbon fiber and Babbitt alloy matrix, reducing interfacial voids, and improving bonding strength. Compared to single chopped carbon fiber reinforcement, the addition of Ni fiber increases the bonding strength between the chopped carbon fiber and the Babbitt matrix by 20% to 35%. Stress can be efficiently transferred to the carbon fiber through the Ni fiber, avoiding carbon fiber debonding caused by stress concentration, and further enhancing the stability of the mechanical and frictional properties of the double-fiber reinforced Babbitt alloy.

[0041] Studies have found that when the content of chopped carbon fibers is too high, the composite Babbitt alloy wire becomes brittle and prone to breakage, making it difficult to form under cold isostatic pressing, increasing processing difficulty, and reducing the bonding force between the chopped carbon fibers and the Babbitt alloy matrix. This is mainly because chopped carbon fibers themselves have a certain degree of brittleness. When the content in Babbitt alloy is too high, it will reduce the overall toughness of the alloy and make it more brittle. At the same time, excessive chopped carbon fibers will significantly increase the hardness and strength of the alloy, increasing processing difficulty and processing costs. Furthermore, when the content of chopped carbon fibers exceeds a certain limit, the interface can no longer effectively transfer the load to the carbon fibers, resulting in a decrease in the bonding force between the chopped carbon fibers and the Babbitt alloy matrix, which can easily lead to problems such as interface debonding.

[0042] When the content of chopped carbon fibers is too low, the reinforcing effect is not obvious, the improvement in high-temperature resistance is insufficient, and the improvement in wear resistance is not significant. This is mainly because the primary function of chopped carbon fibers is to improve the strength, hardness, and wear resistance of Babbitt alloys. When the content is too low, the improvement in the mechanical properties, friction-reducing properties, and wear resistance of Babbitt alloys is limited, which cannot meet the requirements of some applications with high alloy performance requirements, such as high-speed and heavy-duty bearings. At the same time, too low a content of chopped carbon fibers cannot effectively improve the high-temperature resistance of Babbitt alloys, limiting its application range in high-temperature environments. For example, in some mechanical equipment that generates high heat, it may malfunction due to insufficient heat resistance.

[0043] When the Ni fiber content is too high, the toughness and impact resistance of the Babbitt alloy + chopped carbon fiber + Ni fiber composite decrease. This is mainly because Ni fiber itself is too hard and brittle compared to chopped carbon fiber and Babbitt alloy. When its content is too high, it will significantly deteriorate the toughness of the composite Babbitt alloy wire. When the Ni fiber content is too low, the fewer Ni fibers are insufficient to form a continuous "support skeleton," and the effect on improving the mechanical properties of the composite Babbitt alloy is not obvious.

[0044] In some specific implementations, the mass ratio of chopped carbon fibers to Ni fibers is 1.2 to 1.8:1, for example, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, or 1.8:1. Studies have found that when the Ni fiber content is excessive, its hard and brittle properties can damage the bonding surface between the chopped carbon fibers and the Babbitt alloy, affecting the internal bonding strength of the composite Babbitt alloy. Furthermore, when the chopped carbon fiber content is excessive, the chopped carbon fibers themselves may agglomerate, weakening their synergistic effect with Ni fibers and thus diminishing the mechanical properties of the composite Babbitt alloy.

[0045] In some specific embodiments, the average length of the chopped carbon fibers is 5-7 mm, for example, 5, 5.2, 5.5, 5.8, 6, 6.2, 6.5, 6.8, or 7 mm; the average diameter of the chopped carbon fibers is 4-6 μm, for example, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 5.8, or 6 μm. Studies have found that suitable chopped carbon fiber dimensions allow for uniform dispersion of the chopped carbon fibers within the Babbitt alloy matrix, forming an effective "skeletal support" and significantly improving the hardness and wear resistance of the Babbitt alloy and carbon fiber composite materials.

[0046] In some specific embodiments, the density of the chopped carbon fibers is 1.70~1.82 g / cm³. 3 .

[0047] In some specific embodiments, the carbon content in the chopped carbon fiber is >98.5 wt.%, and the impurity element content (including N, H, O) in the chopped carbon fiber is <1 wt.%.

[0048] In some specific embodiments, the average diameter of the Ni fibers is 4~7 μm, for example 4, 4.5, 5, 5.5, 6, 6.5 or 7. Studies have found that Ni fibers of suitable size are less prone to entanglement and clumping, can be fully mixed with Babbitt alloy, ensure the uniformity of the preform composition, and avoid subsequent forming defects.

[0049] In some specific embodiments, the nickel content in the Ni fiber is >99.9 wt.%, and the Si content, Fe content, and C content in the Ni fiber are <0.01 wt.%, <0.02 wt.%, and <0.03 wt.%, respectively.

[0050] In some specific embodiments, the Babbitt alloy powder includes 11-6 Babbitt alloy powder; compared with other grades of Babbitt alloy, this composition has higher hardness and load-bearing capacity, and better high-temperature stability. The chemical composition of the 11-6 Babbitt alloy powder, by mass percentage, includes: Sb 10%~12% (e.g., 10%, 10.5%, 11%, 11.5% or 12%), Cu 5.5%~6.5% (e.g., 5.5%, 5.6%, 5.8%, 6.0%, 6.2%, 6.3% or 6.5%), with the balance being Sn.

[0051] In some specific embodiments, the microhardness of the composite Babbitt wire is ≥38HV.

[0052] In some specific embodiments, the composite Babbitt wire has a heat resistance stability ≥108℃.

[0053] Secondly, the present invention provides a method for preparing the above-mentioned composite Babbitt wire, comprising the following steps:

[0054] Short-cut carbon fibers, Ni fibers, and Babbitt alloy powder are mixed evenly and then subjected to cold isostatic pressing to obtain a green body. By applying isotropic pressure evenly, the Babbitt alloy powder + short-cut carbon fibers + Ni fibers can be pressed into a uniform green body with high dimensional accuracy, laying the foundation for subsequent sintering processes.

[0055] The blank is sintered and cooled to obtain a sintered body. The purpose of sintering is to transform the mechanically bonded short-cut carbon fiber and Ni fiber reinforced Babbitt alloy after cold isostatic pressing into a metallurgical bond, thereby improving the bonding strength between the Babbitt alloy and the short-cut carbon fiber and Ni fiber structures, and improving the strength, wear resistance, and service stability of the short-cut carbon fiber and Ni fiber composite Babbitt alloy.

[0056] The sintered body is extruded and drawn to obtain the composite Babbitt wire. The purpose of extrusion is twofold: firstly, to achieve near-net-shape, continuous forming and dimensional control of the composite Babbitt wire; and secondly, to further reduce the porosity and increase the density of the Babbitt alloy + chopped carbon fiber + Ni fiber preform compared to cold isostatic pressing and sintering. The purpose of drawing is primarily to achieve precise forming of the composite Babbitt wire and improve surface smoothness.

[0057] This invention introduces short-cut carbon fibers and Ni fibers into Babbitt alloy powder, and prepares a composite Babbitt alloy wire with high comprehensive performance through processes such as powder mixing, cold isostatic pressing, sintering, extrusion, and drawing. This composite Babbitt alloy wire not only possesses high tensile and compressive strength, low coefficient of friction and low wear rate, but also exhibits excellent high-temperature stability.

[0058] In some specific implementations, a planetary ball mill is used for mixing. To ensure the consistency of alloy properties, the preferred milling speed is 150-250 r / min, with 5-10 min of forward rotation + 1-3 min of pause + 5-10 min of reverse rotation, for a total mixing time of 160-230 min, including 150-200 min of cumulative rotation and 10-30 min of cumulative pause. Studies have found that when the speed is too low, problems such as stratification, uneven mixing, and insufficient refinement of chopped carbon fibers occur after mixing; when the speed is too high, phenomena such as grinding balls "adhering to the wall" failure, overheating and oxidation of the alloy powder, and increased powder agglomeration occur. By controlling the parameters of forward and reverse rotation, the mixing and dispersion effects can be improved. The purpose of setting the pause is to avoid overheating and oxidation of the Babbitt alloy and chopped carbon fiber powders.

[0059] In some specific embodiments, the cold isostatic pressing is divided into three stages of pressurization and holding, specifically including: the first stage: holding pressure at 80~100MPa (e.g., 80MPa, 85MPa, 90MPa, 95MPa or 100MPa) for 3~5 minutes (e.g., 3 minutes, 4 minutes or 5 minutes); the second stage: holding pressure at 200~230MPa (e.g., 200MPa, 210MPa, 220MPa or 230MPa) for 3~5 minutes (e.g., 3 minutes, 4 minutes or 5 minutes); the third stage: holding pressure at 275~300MPa (e.g., 275MPa, 280MPa, 285MPa, 290MPa, 295MPa or 300MPa) for 3~8 minutes (e.g., 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes or 8 minutes).

[0060] The purpose of the first stage of pressurization is mainly to expel pore gas and initially compact the particles. Studies have found that when the pressure in the first stage is too high, the gas cannot be fully expelled, and internal stress is generated inside the billet, making it prone to cracking during subsequent processing and manufacturing. When the pressure in the first stage is too low, the density and strength of the billet are low, and internal pores, defects, powder shedding, and breakage will occur.

[0061] The purpose of the second stage of pressurization is to allow the Babbitt alloy powder, chopped carbon fibers, and Ni fibers to form a preliminary bond through mechanical interlocking and interatomic forces. Studies have found that when the pressure in the second stage is too low, the billet will exhibit insufficient density, low bonding strength, and uneven performance. When the pressure in the second stage is too high, the applied pressure will generate excessive internal stress within the billet, leading to cracking during subsequent processing.

[0062] The purpose of the third-stage pressurization is to close the residual pores through high pressure, achieving a density close to the theoretical density of the Babbitt alloy + chopped carbon fiber preform. Research has found that when the holding pressure in the third stage is too low, the density of the cold isostatically pressed preform is insufficient, and the residual pores cannot be fully closed. These pores act as stress concentration sources, causing cracks and fractures in the preform during subsequent extrusion, drawing, and other plastic processing. Conversely, when the pressure in the third stage is too high, the high pressure leads to excessive plastic deformation of the preform, intensifying the cold welding between the Babbitt alloy, chopped carbon fiber, and Ni fiber, and even causing an "extrusion effect," resulting in microcracks on the outer surface of the preform, especially at the edges.

[0063] Furthermore, research has found that when the holding time is too low, the gas inside the billet does not escape completely, leaving residual pores. The rearrangement of Babbitt alloy, chopped carbon fiber, and Ni fiber particles is insufficient, resulting in inadequate densification and poor density uniformity of the billet, exhibiting a density gradient of "dense on the outside and loose in the center." When the holding time is too high, prolonged holding time leads to excessive plastic deformation of the Babbitt alloy particles, exacerbating dislocation accumulation and causing work hardening, which is detrimental to subsequent plastic processing such as extrusion and drawing.

[0064] In some specific embodiments, the sintering is vacuum sintering, preferably at a vacuum degree > 10. -3 The process is carried out under vacuum conditions of Pa, which can prevent the low-melting-point Babbitt alloy components and easily oxidized short-cut carbon fiber components from oxidizing during the heating and holding process.

[0065] In some specific embodiments, the sintering temperature is 190~230℃, for example 190℃, 200℃, 210℃, 220℃ or 230℃.

[0066] Studies have shown that when the sintering temperature is too low, the softening effect of the Babbitt alloy matrix is ​​not obvious, and the flow and diffusion effects are relatively poor, making it difficult to form a sufficient bond with the surface of chopped carbon fibers and Ni fibers. Furthermore, microscopic observation of the sintered Babbitt alloy + chopped carbon fiber + Ni fiber surface reveals high porosity and poor density. When the sintering temperature is too high, approaching or exceeding the melting point of Babbitt alloy, the Babbitt matrix will exhibit a localized melting state, causing matrix deformation. Moreover, if the temperature exceeds 300℃, the overheated chopped carbon fiber component will undergo metallurgical bonding with the liquid Babbitt alloy, producing brittle tin-carbon compounds, which is detrimental to the subsequent processing of Babbitt alloy composites.

[0067] In some specific embodiments, the sintering holding time is 1.5 to 3 hours, for example, 1.5 hours, 2 hours, 2.5 hours or 3 hours.

[0068] Research has shown that when the holding time during sintering is too short, atomic diffusion between the Babbitt alloy components and the short-cut carbon fiber and Ni fiber components is insufficient, resulting in poor overall consistency and a tendency to break during compression and shear tests. Conversely, when the holding time during sintering is too long, excessive grain growth in the Babbitt alloy matrix and the burning off of low-melting-point Sn elements can occur, leading to a significant decrease in the hardness of the Babbitt alloy composite material (a decrease of >30%).

[0069] In some specific embodiments, the extrusion method includes warm extrusion, wherein the temperature of the warm extrusion is 120~170°C, for example 120°C, 130°C, 140°C, 150°C, 160°C or 170°C.

[0070] Studies have found that when the extrusion temperature is too low, the Babbitt alloy matrix has high hardness and greater resistance to deformation during extrusion, making the surface of the formed filament prone to cracks and wrinkles. Furthermore, the lower extrusion temperature also results in poor matrix fluidity. Microscopic observation reveals disordered and anisotropic orientation of the chopped carbon fibers and Ni fibers within the formed filament, failing to fully utilize their reinforcing properties. When the extrusion temperature is too high, exceeding the softening temperature of the Babbitt alloy, the matrix loses its structural support capacity and will leak out through the die gaps when subjected to high extrusion pressure.

[0071] In some specific embodiments, the diameter of the extruded material is 1.5~2mm.

[0072] In some specific implementations, the single-pass diameter reduction during drawing is no more than 1 wire (1 wire = 0.01 mm). Studies have found that when the single-pass diameter reduction is greater than 1 wire, microcracks and peeling will continuously appear on the surface of the composite Babbitt wire, affecting the finished quality of the wire.

[0073] Thirdly, the present invention provides applications of the above-mentioned composite Babbitt wire in the fields of deep sea, nuclear power and ocean.

[0074] Among them, composite Babbitt alloy wire can be used as a raw material for preparing sliding bearing liners. The composite Babbitt alloy wire has excellent comprehensive performance, which is beneficial to improving the performance of sliding bearings and expanding their applications.

[0075] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0076] Example 1

[0077] The composite Babbitt wire provided in this embodiment is made from the following components by mass percentage: 1.5% chopped carbon fiber, 0.9% Ni fiber, and the balance Babbitt powder. The chopped carbon fiber is selected from Jiangsu Zengtuo Composite Materials Technology Co., Ltd. - T01A, with an average length and average diameter of 5 mm and 6 μm, respectively, and a density of 1.78 g / cm³. 3 The Ni fiber is selected from Shaanxi Jiuwei Juxin Environmental Protection Technology Co., Ltd. - NA003, with an average diameter of 5μm. The Babbitt alloy powder is 11-6 Babbitt alloy powder, and its chemical composition by mass percentage is: Sb 10.8%, Cu 5.8%, and the balance Sn.

[0078] The method for preparing the composite Babbitt wire provided in this embodiment includes the following steps:

[0079] (1) Short-cut carbon fibers, Ni fibers and Babbitt alloy powder were mixed using a planetary ball mill at a speed of 170 r / min, with a mixing process of 5 min forward rotation + 1 min pause + 5 min reverse rotation to obtain a mixed powder. The mixed powder was then subjected to cold isostatic pressing as follows: the first stage was pressurized to 85 MPa and held for 3 min, the second stage was pressurized to 210 MPa and held for 3 min, and the third stage was pressurized to 280 MPa and held for 5 min to obtain a green body.

[0080] (2) The above-mentioned green body was vacuum sintered in a vacuum sintering furnace according to a sintering process of 210℃×2h to obtain a sintered body. The vacuum degree of the vacuum sintering was 10... -4 Pa.

[0081] (3) After preheating the above sintered body to 140°C, it is warm extruded into 1.72mm wire using a horizontal extruder. Then, it is processed into the final product specification using a wire drawing machine according to the diameter reduction process of 1.72mm-1.71mm-1.70mm (i.e., the 1.72mm wire is reduced by 1 wire in a single pass to 1.71mm, and then reduced by 1 wire in a single pass to the final product diameter of 1.70mm), thus obtaining composite Babbitt alloy wire.

[0082] Example 2

[0083] The composite Babbitt wire provided in this embodiment is made from the following components by mass percentage: 1% chopped carbon fiber, 0.9% Ni fiber, and the balance Babbitt alloy powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt alloy powder are the same as in Example 1. Based on this ratio, the composite Babbitt wire is prepared according to the preparation method and parameters of Example 1.

[0084] Example 3

[0085] The composite Babbitt wire provided in this embodiment is made from the following components by mass percentage: 3% chopped carbon fiber, 0.9% Ni fiber, and the balance Babbitt alloy powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt alloy powder are the same as in Example 1. Based on this ratio, the composite Babbitt wire is prepared according to the preparation method and parameters of Example 1.

[0086] Example 4

[0087] The composite Babbitt wire provided in this embodiment is made from the following components by mass percentage: 1.5% chopped carbon fiber, 0.4% Ni fiber, and the balance Babbitt alloy powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt alloy powder are the same as in Example 1. Based on this ratio, the composite Babbitt wire is prepared according to the preparation method and parameters of Example 1.

[0088] Example 5

[0089] The composite Babbitt wire provided in this embodiment is made from the following components by mass percentage: 1.5% chopped carbon fiber, 1.6% Ni fiber, and the balance Babbitt alloy powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt alloy powder are the same as in Example 1. Based on this ratio, the composite Babbitt wire is prepared according to the preparation method and parameters of Example 1.

[0090] Example 6

[0091] The composite Babbitt wire and its preparation method provided in this embodiment are basically the same as those in Example 1, except that: the chopped carbon fiber is selected from Jiangsu Zengtuo Composite Materials Technology Co., Ltd.-T01A, the average length of the chopped carbon fiber is 6mm, the average diameter is 5μm, and the density of the chopped carbon fiber is 1.76g / cm³.3 .

[0092] Example 7

[0093] The composite Babbitt wire and its preparation method provided in this embodiment are basically the same as those in Example 1, except that the Ni fiber is selected from Shaanxi Jiuwei Juxin Environmental Protection Technology Co., Ltd.-NA003, and the average diameter of the Ni fiber is 6μm.

[0094] Example 8

[0095] The composite Babbitt alloy wire and its preparation method provided in this embodiment are basically the same as those in Example 1. The difference is that in step (1), the mixed powder is subjected to cold isostatic pressing in the following manner: the first stage is pressurized to 95MPa and held for 3min, the second stage is pressurized to 230MPa and held for 3min, and the third stage is pressurized to 300MPa and held for 3min to obtain a blank.

[0096] Example 9

[0097] The composite Babbitt alloy wire and its preparation method provided in this embodiment are basically the same as those in Example 1, except that in step (2), vacuum sintering is carried out according to the sintering process of 230℃×2.5h.

[0098] Example 10

[0099] The composite Babbitt wire and its preparation method provided in this embodiment are basically the same as those in Example 1, except that in step (3), the temperature of warm extrusion is replaced with 170°C.

[0100] Comparative Example 1

[0101] 11-6 Babbitt alloy wire with a diameter of 1.70 mm was used, and its chemical composition was the same as that of 11-6 Babbitt alloy powder in Example 1.

[0102] Comparative Example 2

[0103] The composite Babbitt wire provided in this comparative example is made from the following components by mass percentage: 2.4% chopped carbon fibers and the balance Babbitt alloy powder. The parameters of the chopped carbon fibers and Babbitt alloy powder are the same as in Example 1. Based on this proportion, the composite Babbitt wire was prepared according to the preparation method and parameters of Example 1.

[0104] Comparative Example 3

[0105] The composite Babbitt wire provided in this comparative example is made from the following components by mass percentage: 1.6% Ni fiber and the balance Babbitt alloy powder. The parameters of both the Ni fiber and the Babbitt alloy powder are the same as in Example 1. Based on this proportion, the composite Babbitt wire was prepared according to the preparation method and parameters of Example 1.

[0106] Comparative Example 4

[0107] The composite Babbitt wire provided in this comparative example is made from the following components by mass percentage: 5% chopped carbon fiber, 0.9% Ni fiber, and the balance Babbitt alloy powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt alloy powder are the same as in Example 1. Based on this formulation, the composite Babbitt wire was prepared according to the preparation method and parameters of Example 1.

[0108] Comparative Example 5

[0109] The composite Babbitt wire provided in this comparative example is made from the following components by mass percentage: 1.5% chopped carbon fiber, 3% Ni fiber, and the balance Babbitt powder. The parameters of the chopped carbon fiber, Ni fiber, and Babbitt powder are the same as in Example 1. Based on this formulation, the composite Babbitt wire was prepared according to the preparation method and parameters of Example 1.

[0110] Experimental Example 1

[0111] The performance of the composite Babbitt wires prepared in each embodiment and each comparative example was tested, and the test results are shown in Table 1.

[0112] The microhardness testing method includes the following steps:

[0113] (1) Sample preparation: The composite Babbitt wire samples prepared in each example and each comparative example are polished to a mirror surface (roughness Ra≤0.02μm) to ensure that the indentation is clear and measurable.

[0114] (2) Instrument calibration: Use a standard hardness block (HV100) to calibrate the indenter and load accuracy.

[0115] (3) Loading indentation: Fix the sample on the stage of the microhardness tester, align it with the test area, select an appropriate load (50gf is a suitable load according to the hardness of the sample), and hold the load for a specified time after applying it.

[0116] (4) Result characterization: Record the microhardness values ​​automatically calculated by the microhardness tester based on the indentation. Take the microhardness values ​​of 15 different areas of the same sample and calculate the average value to avoid random errors.

[0117] Furthermore, the test method for heat resistance stability includes the following steps:

[0118] (1) Setting a temperature gradient: Based on the liquidus temperature of 11-6 Babbitt alloy, a temperature gradient of 110~180℃ was set, and a temperature value of 5℃ was taken to conduct a heat resistance stability test on the composite Babbitt alloy wire samples prepared in each embodiment and each comparative example.

[0119] (2) Heat treatment: Place each sample in a box annealing furnace and keep it at the temperature gradient of step (1) for 2 hours.

[0120] (3) Microhardness test: Microhardness test is performed on each sample according to the microhardness test method described above.

[0121] (4) Softening resistance temperature confirmation (industrial standard for softening resistance temperature confirmation): The microhardness of the untreated Babbitt alloy + carbon fiber composite sample is used as the benchmark. When the microhardness of the sample after annealing is ≤ 80% of the microhardness before annealing, the annealing temperature is taken as the softening resistance temperature of the sample.

[0122] Table 1 Performance test results of various composite Babbitt wires

[0123]

[0124] As can be seen from Table 1, compared with the comparative examples, the composite Babbitt wires prepared in each embodiment have high strength and high hardness, low coefficient of friction and low wear rate, good high temperature stability, and excellent comprehensive performance.

[0125] In Comparative Example 1, the microhardness and heat resistance of the composite Babbitt alloy were sharply reduced compared to Example 1 due to the absence of chopped carbon fibers and Ni fibers, with decreases of 48% and 26%, respectively. This was mainly due to the lack of composite reinforcement effect of chopped carbon fibers and Ni fibers on the Babbitt alloy matrix.

[0126] In Comparative Example 2, the absence of Ni fibers resulted in a significant decrease in the microhardness and thermal stability of the composite Babbitt alloy compared to Example 1, with reductions of 33% and 19%, respectively. This is primarily due to the high strength of Ni fibers, which, when added in appropriate amounts, can be uniformly dispersed within the Babbitt alloy matrix, forming a synergistic support structure with the carbon fibers. Under stress, the Babbitt alloy matrix can efficiently transfer external loads to the Ni and carbon fibers, with both sharing the load and reducing local deformation of the matrix, thereby improving the overall hardness of the composite Babbitt alloy. Furthermore, Ni fibers possess excellent high-temperature resistance, maintaining structural stability under high-temperature conditions. Their uniform dispersion within the Babbitt alloy matrix forms a "high-temperature resistant skeleton," inhibiting creep and grain growth in the Babbitt alloy matrix at high temperatures, delaying the softening process of the matrix, and thus improving the overall thermal stability of the composite Babbitt alloy.

[0127] Comparative Example 3, lacking the addition of chopped carbon fibers, resulted in a significant decrease in the microhardness and thermal stability of the composite Babbitt alloy compared to Example 1, with reductions of 44% and 24%, respectively. This is primarily due to the high strength and high modulus of the chopped carbon fibers themselves, which, when uniformly dispersed within the Babbitt alloy matrix, become crucial load-bearing units. When the composite Babbitt alloy is subjected to external loads, the Babbitt alloy matrix can efficiently transfer stress to the chopped carbon fibers, allowing the carbon fibers and matrix to collaboratively bear the load, preventing stress concentration solely on the relatively weak matrix and thus improving the microhardness of the composite Babbitt alloy. Furthermore, the uniform dispersion of chopped carbon fibers within the Babbitt alloy forms a high-temperature resistant "support skeleton." Under high-temperature conditions, this skeleton can inhibit grain growth in the Babbitt alloy matrix, delaying creep and softening processes. In addition, the thermal expansion coefficient of carbon fibers is much lower than that of Babbitt alloy; their addition reduces the overall thermal expansion coefficient of the composite material, decreasing internal stress caused by thermal expansion and contraction at high temperatures, preventing deformation and cracking in the composite Babbitt alloy, thereby improving its high-temperature stability.

[0128] In Comparative Example 4, the excessive addition of chopped carbon fibers led to a sharp decrease in the microhardness and thermal stability of the resulting composite Babbitt alloy, with reductions of 63% and 48%, respectively. This was primarily due to the tendency of excess carbon fibers to entangle and agglomerate. During the composite Babbitt alloy preparation process, such as sintering, these agglomerated carbon fibers hindered the tight bonding of the matrix metal powder and made it difficult to expel adsorbed gases and volatiles generated during molding, resulting in a large number of pores within the composite Babbitt alloy. These pores became stress concentration points under stress, and under external pressure, local deformation or even collapse easily occurred around the pores, significantly reducing the composite Babbitt alloy's resistance to indentation deformation and ultimately leading to a decrease in microhardness. Furthermore, when excessive chopped carbon fibers were added, some fibers may have developed initial micro-defects due to entanglement and compression during the preparation process. Under high-temperature conditions, these micro-defects would continue to expand, and the C-C bonds in the carbon fiber molecular chains might break, leading to a decrease in the strength of the carbon fibers themselves. When a large number of damaged carbon fibers could no longer bear the support at high temperatures, they could not suppress the high-temperature softening and structural deterioration of the Babbitt alloy matrix. In addition, excessive carbon fiber may affect the overall thermal conductivity of the composite Babbitt alloy, causing heat to be unable to spread evenly. Local overheating will accelerate the performance degradation of the matrix and carbon fiber, thereby reducing the heat resistance stability of the composite Babbitt alloy.

[0129] In Comparative Example 5, the excessive addition of Ni fibers resulted in a significant decrease in the microhardness and thermal stability of the composite Babbitt alloy compared to Example 1, with reductions of 42% and 22%, respectively. This is mainly because the excessive addition of Ni fibers causes Ni fiber agglomerates to act as internal impurities, disrupting the continuity of the Babbitt alloy matrix and hindering the uniform dispersion of chopped carbon fibers within the matrix, thus damaging the collaborative load-bearing system between the Babbitt alloy matrix and carbon fibers. During hardness testing, deformation easily occurs in the indentation area at the gap between the agglomerates and the matrix, and the agglomerated Ni fibers cannot evenly distribute the load, concentrating the load in the weak areas of the matrix. This leads to a decrease in the overall resistance of the Babbitt alloy to indentation deformation and a reduction in microhardness. Furthermore, the coefficient of thermal expansion of Ni fibers is approximately 13.2 × 10⁻⁶. -6 The temperature of Ni fiber is much higher than that of carbon fiber, and its thermal expansion characteristics differ from those of Babbitt alloy. With an appropriate amount of Ni fiber, this difference can be mitigated through interfacial coordination, but excessive Ni fiber will drastically amplify the contradiction of thermal expansion differences within the Babbitt alloy. Under high-temperature conditions, the expansion of Ni fiber is much greater than that of carbon fiber and the Babbitt alloy matrix, generating enormous thermal stress among the three. This stress accumulates continuously at the interfaces between Ni fiber and the matrix, and between Ni fiber and carbon fiber, causing existing microcracks to continue to expand and inducing new cracks. These cracks compromise the structural integrity of the material. When the temperature changes repeatedly or the material is exposed to high temperatures for extended periods, the cracks further propagate, ultimately leading to deformation or even fracture of the composite Babbitt alloy, resulting in a significant decrease in its thermal stability.

[0130] In summary, the chopped carbon fibers and Ni fibers in the composite Babbitt wire have a synergistic effect, resulting in a reinforcement effect greater than the sum of its parts (1+1>2). This significantly improves the strength and hardness of the composite Babbitt wire, reduces its coefficient of friction and wear rate, making it less prone to deformation and wear under high loads. In addition, it also improves the high-temperature stability of the composite Babbitt wire, resulting in good overall performance.

[0131] Experimental Example 2

[0132] In Sampling Example 2, based on the cold isostatic pressing process of the billet in step (1), the microstructure of the cold isostatic pressing state was observed by scanning electron microscopy at 200x and 100x magnification, respectively, and the corresponding results were obtained. Figure 1 (b) Figure 2 (b) SEM image.

[0133] Furthermore, based on Example 2, the mass percentage of chopped carbon fibers in the composite Babbitt wire was modified to 0%, 2%, 3%, and 4%, respectively, and scanning electron microscopy (SEM) analysis was performed as described above (when the chopped carbon fiber content is 3 wt.%, it can be considered as the blank after cold isostatic pressing in Example 3), thus obtaining the following results. Figure 1 , Figure 2SEM images of the region. Among them, Figure 1 (a) Figure 2 (a) SEM images at 200x and 100x magnification, respectively, when the content of short-cut carbon fibers is 0 wt.%. Figure 1 (c) Figure 2 (c) SEM images at 200x and 100x magnification, respectively, for a short-cut carbon fiber content of 2 wt.%. Figure 1 (d) Figure 2 (d) SEM images at 200x and 100x magnification, respectively, for a short-cut carbon fiber content of 3 wt.%. Figure 1 (e) Figure 2 (e) SEM images at 200x and 100x magnification, respectively, when the content of short-cut carbon fiber is 4 wt.%.

[0134] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A method for preparing composite Babbitt wire, characterized in that, The composite Babbitt wire is made from the following components by mass percentage: 1%~3% chopped carbon fiber, 0.4%~1.6% Ni fiber, and the balance Babbitt powder; The average length of the chopped carbon fibers is 5.2~7 mm, and the diameter is 4~6 μm; The chemical composition of the Babbitt alloy powder, by mass percentage, includes: Sb 10%~12%, Cu 5.5%~6.5%, with the balance being Sn; The preparation method includes the following steps: mixing short-cut carbon fibers, Ni fibers and Babbitt alloy powder and then performing cold isostatic pressing to obtain a blank; sintering the blank to obtain a sintered body; and extruding and drawing the sintered body to obtain the composite Babbitt alloy wire. The cold isostatic pressing method includes: first holding the pressure at 80~100MPa for 3~5min, then holding the pressure at 200~230MPa for 3~5min, and then holding the pressure at 275~300MPa for 3~8min; The sintering temperature is 190~230℃, and the holding time is 1.5~3h; The sintering is vacuum sintering, and the vacuum degree of the vacuum sintering is >10. -3 Pa.

2. The method for preparing the composite Babbitt wire according to claim 1, characterized in that, The density of the chopped carbon fibers is 1.70~1.82 g / cm³. 3 .

3. The method for preparing the composite Babbitt wire according to claim 1, characterized in that, The average diameter of the Ni fiber is 4~7μm.

4. The method for preparing the composite Babbitt wire according to claim 1, characterized in that, The microhardness of the composite Babbitt wire is ≥38HV; And / or, the heat resistance of the composite Babbitt wire is ≥108℃.

5. The method for preparing the composite Babbitt wire according to claim 1, characterized in that, The extrusion method includes warm extrusion, wherein the temperature of the warm extrusion is 120~170℃.

6. The application of the composite Babbitt wire prepared by the preparation method according to any one of claims 1 to 5 in the fields of deep sea, nuclear power and ocean.

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