High thermal conductivity bearing bush and method of manufacturing the same

Abstract

The application provides a high-thermal-conductivity bushing and a preparation method thereof. The preparation method comprises the following steps: pretreating raw materials to prepare a preformed block alloy slurry; mixing the preformed block alloy slurry with high-thermal-conductivity fibers to obtain a preformed alloy block; performing surface treatment on a steel base body; welding the steel base body subjected to the surface treatment and the preformed alloy block to obtain a crude high-thermal-conductivity bushing; and performing heat treatment on the crude high-thermal-conductivity bushing to obtain the high-thermal-conductivity bushing. The preformed block alloy slurry comprises at least one of Sb, Cu, Ni, Ag, Co, Yb and Sn. The application solves the problem that, in the prior art, the wettability of the reinforcing body is poor, the density of the reinforcing body and the base body are not matched, and segregation is prone to occur, which results in the difficulty in preparing the babbitt layer on the surface of the bushing and thus affects the processing efficiency of the babbitt layer on the surface of the bushing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing bush processing, in particular to a high-thermal-conductivity bearing bush and a preparation method thereof. BACKGROUND

[0002] The Babbitt alloy, also known as white alloy, has hard phase particles distributed in a soft phase matrix, and the soft phase matrix has good potentiality, compliance and anti-seizure performance. During service, the soft phase is concave, the hard phase is convex, a small gap is generated between the two, which becomes a lubricating oil channel, which is beneficial to reducing wear, and the convex hard particles play a supporting role. The Babbitt alloy is widely used in key components of large motors, water turbines, compressors, gearboxes and other mechanical equipment in high-speed, heavy-load, high-power and high-precision mechanical equipment.

[0003] However, during service, the service environment of the tin-based bearing bush deteriorates continuously, and the service life and performance stability of the bearing bush are severely tested. Under high-speed and heavy-load working conditions, the performance of the Babbitt alloy decreases sharply with the increase of temperature, and then severe adhesive wear occurs, resulting in bearing bush burning accidents. Adding carbon fibers and glass fibers to the Babbitt alloy can improve the thermal conductivity of the alloy layer and thus improve the high-temperature strength during service, and can also significantly improve the load-carrying capacity and wear resistance of the Babbitt alloy.

[0004] The existing problems in the prior art are that: at present, part of the Babbitt alloy layer on the surface of the bearing bush is prepared by gravity casting or centrifugal casting process, but this method has a large difference between the density of the reinforcing body and the matrix Babbitt alloy, and the reinforcing body will float up, causing serious segregation problem; another part is to weld alloy wires on the surface of the workpiece by additive manufacturing process, but this super-fine diameter alloy wire is difficult to prepare, and in the additive process, the reinforcing body has poor wettability in the matrix Babbitt alloy, and will shrink and aggregate, which is difficult to flow and spread.

[0005] In summary, the existing technical problems in the prior art are that: in the process of preparing the Babbitt alloy layer on the surface of the bearing bush, the reinforcing body has poor wettability, and the density of the reinforcing body and the matrix do not match, which is easy to cause segregation, resulting in difficulty in preparing the Babbitt alloy layer on the surface of the bearing bush, thereby affecting the processing efficiency of the Babbitt alloy layer on the surface of the bearing bush. SUMMARY

[0006] The problem solved by the present application is that in the process of preparing the Babbitt alloy layer on the surface of the bearing bush, the reinforcing body has poor wettability, and the density of the reinforcing body and the matrix do not match, which is easy to cause segregation, resulting in difficulty in preparing the Babbitt alloy layer on the surface of the bearing bush, thereby affecting the processing efficiency of the Babbitt alloy layer on the surface of the bearing bush.

[0007] To solve the above problems, the application realizes the preparation of a high-thermal-conductivity Babbitt layer on the surface of a bearing bush by integrally welding a steel matrix and a high-thermal-conductivity precast alloy block in a furnace, and improves the processing efficiency of the preparation of the Babbitt layer on the surface of the bearing bush. The application provides a preparation method of a high-thermal-conductivity bearing bush, which comprises the following steps: pretreating raw materials to prepare a precast block alloy slurry; mixing the precast block alloy slurry with high-thermal-conductivity fibers to obtain a precast alloy block; performing surface treatment on a steel matrix; welding the steel matrix after the surface treatment and the precast alloy block to obtain a rough high-thermal-conductivity bearing bush; and performing heat treatment on the rough high-thermal-conductivity bearing bush to obtain a high-thermal-conductivity bearing bush; wherein the precast block alloy slurry comprises at least one of Sb, Cu, Ni, Ag, Co, Yb and Sn.

[0008] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the application precasts a high-thermal-conductivity precast alloy block on the surface of a workpiece matrix by integrally welding a steel matrix and a precast alloy block in a furnace, overcomes the problem that it is difficult to prepare a composite Babbitt alloy layer containing a reinforcing body with poor wettability and a reinforcing body with a density that is not matched with the matrix and is prone to segregation, successfully prepares a Babbitt alloy layer on the surface of a steel matrix, and solves the problem that it is difficult to prepare a Babbitt alloy layer containing high-thermal-conductivity carbon fibers or glass fibers on the surface of a bearing bush. The above preparation method can be operated in large quantities and continuously, and batches of materials can be put into the furnace at the same time, so the processing efficiency is high, the equipment investment is small, and the production cost can be significantly reduced.

[0009] In an example of the application, the pretreatment of the raw materials to prepare the precast block alloy slurry comprises the following steps: melting and treating the raw materials and a refining agent under a protective gas, stirring once, and heat treating the raw materials and the refining agent to obtain a first melt; and performing a first cooling treatment on the first melt to obtain the precast block alloy slurry; wherein the raw materials comprise: 3-13 parts by mass of Sb, 3-10 parts by mass of Cu, 0-0.5 parts by mass of Ni, 0-0.2 parts by mass of Ag, 0-1.6 parts by mass of Co, 0-0.1 parts by mass of Yb, and the balance of Sn.

[0010] Compared with the prior art, the technical effects achieved by the technical scheme are as follows: the addition of the refining agent during melting can remove impurities, so that the first melt is purer. The preparation steps of the precast block alloy slurry are simple and convenient, and the Babbitt alloy layer obtained from the precast block alloy slurry prepared from the above raw materials has high thermal conductivity.

[0011] In an example of the present application, the temperature of the smelting process is 500-800 DEG C; and / or the speed of the first stirring is 1000-1500 r / min; and / or the time of the first stirring is 15-45 min; and / or the time of the holding process is 10-30 min; and / or the target temperature of the first cooling process is 200-550 DEG C; and / or the refining agent is one or more of zinc chloride, ammonium chloride and sodium chloride.

[0012] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: the smelting temperature and the holding temperature can be any temperature within the temperature range of 500-800 DEG C, the smelting time and the holding time can be any time within the time range of 10-30 min, the stirring speed can be any speed within the speed range of 1000-1500 r / min, the stirring time can be any time within the time range of 15-45 min, and the target temperature of the cooling process can be any temperature within the temperature range of 200-550 DEG C. By adjusting the smelting temperature, the holding time, the stirring speed and the stirring time, the first melt is more fully melted. By adding any of the above refining agents, the first melt is more pure.

[0013] In an example of the present application, the mixing of the preformed block alloy slurry with the high-thermal-conductivity fiber to obtain the preformed alloy block comprises:

[0014] The high-thermal-conductivity fiber is added to the preformed block alloy slurry and subjected to secondary stirring to obtain a second melt; the second melt is subjected to secondary cooling process, and the second melt after the secondary cooling process is processed to obtain the preformed alloy block.

[0015] Or

[0016] One end of the high-thermal-conductivity fiber is fixed to the inner bottom of the casting mold, and the preformed block alloy slurry is cast into the casting mold; the casting mold with the high-thermal-conductivity fiber and the preformed block alloy slurry placed therein is placed on the placement platform of the ultrasonic vibration device to perform ultrasonic treatment on the mixture composed of the high-thermal-conductivity fiber and the preformed block alloy slurry in the casting mold to obtain a third melt; the third melt is subjected to three times of cooling process, and the third melt after the three times of cooling process is processed to obtain the preformed alloy block.

[0017] The high-thermal-conductivity fiber is 0-5 parts by mass of glass fiber and / or 0-5 parts by mass of carbon fiber.

[0018] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: by adding the high-thermal-conductivity fiber, not only the thermal conductivity of the preformed alloy block is improved, but also the mechanical properties of the preformed alloy block are improved, so that the preformed alloy block has good tensile and impact resistance.

[0019] Specifically, through secondary stirring and secondary cooling treatment, the high thermal conductivity fiber can be better combined with the alloy slurry, thereby improving the mechanical properties of the prefabricated alloy block, so that the prefabricated alloy block has good tensile and impact resistance.

[0020] Specifically, the prefabricated alloy slurry is cast into a casting mold with high thermal conductivity fibers. Under the action of ultrasonic waves, the fibers with relatively low density rapidly float up and stretch straight, while promoting the floating of bubbles in the alloy slurry and refining the grains to obtain a non-dendritic structure, accelerating the homogenization of the composition and temperature of the molten metal melt. The prefabricated alloy block obtained by the above method is a high thermal conductivity Babbitt alloy layer. The high thermal conductivity fibers in the casting mold are beneficial to improving the mechanical properties and thermal conductivity of the alloy layer. The high thermal conductivity fibers can be glass fibers or carbon fibers. Further, under the action of ultrasonic waves, the glass fibers and / or carbon fibers in the casting mold rapidly float up and stretch straight, while promoting the floating of bubbles in the alloy slurry and refining the grains to obtain a non-dendritic structure. The addition of carbon fibers and / or glass fibers is beneficial to improving the mechanical properties and thermal conductivity of the Babbitt alloy layer.

[0021] In one example of the present application, the secondary stirring time is 15-45 min; and / or the secondary stirring speed is 1000-1500 r / min; and / or the ultrasonic treatment power is 2.5-3.5 kW, the frequency is 15-21 kHz, the vibration time is 2-5 min, and the heating temperature is 450-550℃.

[0022] In one example of the present application, the surface treatment of the steel substrate includes: removing the oxides and oil stains on the surface of the steel substrate; drying the steel substrate; modifying the dried steel substrate; and removing the impurities on the surface of the steel substrate after cooling the modified steel substrate to room temperature.

[0023] Compared with the prior art, the technical effects achieved by using this technical solution are: in order to avoid affecting the adhesion of the coating during the modification process, it is necessary to first remove the oxides and oil stains on the surface of the steel substrate. After modification, in order to avoid affecting the adhesion of the steel substrate and the prefabricated alloy block, it is necessary to remove the impurities on the surface of the steel substrate.

[0024] In one example of the present application, the modification treatment of the steel substrate after drying treatment comprises: immersing the steel substrate after drying treatment into a container containing a tin plating solution for immersion plating treatment; wherein the temperature of the immersion plating treatment is 200-250°C, the time of the immersion plating treatment is 30-60 minutes, and the tin plating solution comprises the following components by mass fraction: Ag: 0.01-5 mass fraction, Cu: 0.1-2 mass fraction, Ni: 0.05-0.5 mass fraction, La: 0.01-0.1 mass fraction, Yb: 0.01-0.06 mass fraction, P: 0.01-0.05 mass fraction, and the balance is Sn.

[0025] Compared with the prior art, the technical effects achieved by the technical scheme are: since the surface of the steel substrate has been cleaned of peroxides and oil stains, a uniform tin plating diffusion layer can be formed on the surface of the steel substrate after it is immersed in the tin plating solution, and the adhesion is good. The temperature of the immersion plating can be 200°C, 210°C, 220°C, 230°C, 240°C, or 250°C, and the time of the immersion plating can be 30 minutes, 40 minutes, 50 minutes, or 60 minutes. By adjusting the immersion plating time and temperature, the tin plating diffusion layer on the surface of the steel substrate can be diffusion strengthened, and through the modification treatment, the adhesion of the prefabricated alloy block to the workpiece substrate during subsequent welding can be increased, so that the two are tightly combined together.

[0026] Further, after the steel substrate is immersed in the tin plating solution, a tin plating diffusion layer is formed on the surface thereof, so as to form a metallurgical bond with the babbitt alloy layer. The tin plating solution process is easy to control, can replace tin plating on the surface of the steel, and the thickness range of the plating layer obtained by using the tin plating solution is wide, which is suitable for industrial production.

[0027] In one example of the present application, the welding of the steel substrate after surface treatment and the prefabricated alloy block to obtain a crude high-thermal-conductivity bearing is specifically: respectively brushing solder paste around the steel substrate and the prefabricated alloy block after completing the surface treatment; placing the prefabricated alloy block coated with solder paste above the steel substrate coated with solder paste to obtain a composite prefabricated body; heating and heat-insulating the composite prefabricated body to obtain a crude high-thermal-conductivity bearing; wherein the thickness of the solder paste is 0.1-0.5 mm, the heating temperature is 180-230°C, and the heat-insulating time is 10-50 minutes.

[0028] Compared with the prior art, the technical effects achieved by the technical scheme are: through the chemical method for welding, the solder paste brushed during heating and heat-insulating is melted and flows to fill the gap between the prefabricated alloy block and the steel substrate.

[0029] In an example of the present application, the rough high-thermal-conductivity bearing bush is heat treated to obtain the high-thermal-conductivity bearing bush, comprising: adjusting the temperature of the heat treatment to 50-90 DEG C and keeping the temperature for 1-6 hours.

[0030] Compared with the prior art, the technical effects achieved by the technical scheme are: the internal stress between the workpiece base body and the babbitt alloy layer can be eliminated through the above heat treatment.

[0031] On the other hand, the present application also provides a high-thermal-conductivity bearing bush prepared by the preparation method in any of the above technical schemes.

[0032] Compared with the prior art, the technical effects achieved by the technical scheme are: since the high-thermal-conductivity bearing bush in the present technical scheme is prepared by the preparation method in any of the above technical schemes, the high-thermal-conductivity bearing bush in the present technical scheme has the beneficial effects in any of the above technical schemes, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0033] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which:

[0034] Figure 1 The electron microscope of the high-thermal-conductivity bearing bush provided for the embodiment of the present application Figure 1 .

[0035] Figure 2 The electron microscope of the high-thermal-conductivity bearing bush provided for the embodiment of the present application Figure 2 . DETAILED DESCRIPTION

[0036] In order to make the above object, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application are described in detail below.

[0037] The present application provides a preparation method of a high-thermal-conductivity bearing bush, the preparation method comprising the following steps: pretreating raw materials to prepare a precast block alloy slurry; mixing the precast block alloy slurry with high-thermal-conductivity fibers to obtain a precast alloy block; performing surface treatment on a steel base body; welding the steel base body after the surface treatment and the precast alloy block to obtain a rough high-thermal-conductivity bearing bush; and heat treating the rough high-thermal-conductivity bearing bush to obtain the high-thermal-conductivity bearing bush; wherein the precast block alloy slurry comprises at least one of Sb, Cu, Ni, Ag, Co, Yb and Sn.

[0038] Further, the processing of the raw material to prepare the preformed block alloy slurry comprises the following steps: subjecting the raw material and the refining agent to a melting treatment under a protective gas and a first stirring, and subjecting the raw material and the refining agent to a holding treatment to obtain a first melt; subjecting the first melt to a first cooling treatment to obtain the preformed block alloy slurry; wherein the raw material comprises: Sb: 3-13 parts by mass, Cu: 3-10 parts by mass, Ni: 0-0.5 parts by mass, Ag: 0-0.2 parts by mass, Co: 0-1.6 parts by mass, Yb: 0-0.1 parts by mass, and the balance being Sn.

[0039] Specifically, the melting treatment can be induction melting or resistance melting.

[0040] Specifically, the protective gas is nitrogen or argon.

[0041] Further, the temperature of the melting treatment is 500-800°C; and / or the speed of the first stirring is 1000-1500 r / min; and / or the time of the first stirring is 15-45 min; and / or the time of the holding treatment is 10-30 min; and / or the target temperature of the first cooling treatment is 200-550°C; and / or the refining agent is one or more of zinc chloride, ammonium chloride, and sodium chloride.

[0042] Further, the mixing of the preformed block alloy slurry with the high-thermal-conductivity fiber to obtain the preformed alloy block comprises:

[0043] adding the high-thermal-conductivity fiber to the preformed block alloy slurry and performing a second stirring to obtain a second melt; subjecting the second melt to a second cooling treatment, and processing the second melt after the second cooling treatment to obtain the preformed alloy block.

[0044] or

[0045] fixing one end of the high-thermal-conductivity fiber to the inner bottom of a casting mold, and pouring the preformed block alloy slurry into the casting mold; placing the casting mold with the high-thermal-conductivity fiber and the preformed block alloy slurry on a placement platform of an ultrasonic vibration device to perform ultrasonic treatment on the mixture composed of the high-thermal-conductivity fiber and the preformed block alloy slurry in the casting mold to obtain a third melt; subjecting the third melt to a third cooling treatment, and processing the third melt after the third cooling treatment to obtain the preformed alloy block.

[0046] wherein the high-thermal-conductivity fiber is 0-5 parts by mass of glass fiber and / or 0-5 parts by mass of carbon fiber.

[0047] Further, the second stirring time is 15-45 min; and / or the second stirring speed is 1000-1500 r / min; and / or the ultrasonic treatment power is 2.5-3.5 Kw, the frequency is 15-21 kHz, the vibration time is 2-5 min, and the heating temperature is 450-550℃.

[0048] Further, the surface treatment of the steel substrate includes: removing the oxides and oil stains on the surface of the steel substrate; drying the steel substrate; modifying the dried steel substrate; and removing the impurities on the surface of the steel substrate after the modified steel substrate is cooled to room temperature.

[0049] Preferably, the cooling is air cooling.

[0050] Further, the modification of the dried steel substrate includes: immersing the dried steel substrate in a container containing a tin plating solution for immersion plating treatment; wherein the immersion plating treatment temperature is 200-250℃, the immersion plating treatment time is 30-60 min, and the tin plating solution comprises the following components by mass fraction: Ag: 0.01-5 mass fraction, Cu: 0.1-2 mass fraction, Ni: 0.05-0.5 mass fraction, La: 0.01-0.1 mass fraction, Yb: 0.01-0.06 mass fraction, P: 0.01-0.05 mass fraction, and the balance is Sn.

[0051] Further, after the steel substrate is immersed in the tin plating solution, a tin plating diffusion layer is formed on the surface of the steel substrate to form a metallurgical bond with the babbitt alloy layer. The tin plating solution process is easy to control, can replace tin plating on the surface of the steel, and the thickness range of the plating layer obtained by using the tin plating solution is wide, which is suitable for industrial production.

[0052] Further, the welding of the steel substrate after surface treatment and the preformed alloy block to obtain a crude high-thermal-conductivity bearing includes: brushing solder paste around the steel substrate and the preformed alloy block after surface treatment respectively; placing the preformed alloy block coated with solder paste on top of the steel substrate coated with solder paste to obtain a composite preform; heating and holding the composite preform to obtain a crude high-thermal-conductivity bearing; wherein the thickness of the solder paste is 0.1-0.5 mm, the heating temperature is 180-230℃, and the holding time is 10-50 min.

[0053] Further, the heat treatment of the crude high-thermal-conductivity bearing to obtain a high-thermal-conductivity bearing includes: adjusting the heat treatment temperature to 50-90℃ and holding for 1-6 h.

[0054] Further, the surface roughness of the welding layer of the final high-thermal-conductivity bearing bush and the size of the high-thermal-conductivity alloy layer can be inconsistent with the target size, and thus the high-thermal-conductivity bearing bush can be machined to tightly fit the subsequent rotating shaft.

[0055] The present application overcomes the problem of difficulty in preparing a composite babbitt alloy layer with poor wettability of the reinforcing body, easy segregation of the reinforcing body density and the base body, and the like, by pre-preparing a high-thermal-conductivity pre-prepared alloy block on the surface of a workpiece base body in a way of integral furnace welding of the steel base body and the pre-prepared alloy block, successfully preparing a babbitt alloy layer on the surface of the workpiece, the babbitt alloy layer being uniform in structure and forming a metallurgical bond with the workpiece base body, and solving the problem of difficulty in preparing a high-thermal-conductivity carbon fiber composite babbitt alloy and a glass fiber babbitt alloy layer on the surface of the bearing bush. The above preparation method can be operated in large quantities in a continuous manner, and the workpieces are simultaneously put into the furnace, so that the processing efficiency is high, the equipment investment is small, and the production cost can be significantly reduced.

[0056] The present application also provides a high-thermal-conductivity bearing bush prepared by the preparation method of any one of the above technical solutions.

[0057] Embodiment One:

[0058] The present embodiment provides a high-thermal-conductivity babbitt alloy layer, which comprises the following components in mass parts: Sn: 81 mass parts, Sb: 11 mass parts, Cu: 6 mass parts, and carbon fiber: 2 mass parts.

[0059] Further, the present embodiment also provides a preparation method of a high-thermal-conductivity bearing bush, which comprises the following steps:

[0060] I. Preparation of a pre-prepared alloy block

[0061] 1) Preparation of a pre-prepared alloy block slurry: obtain raw materials, and the specific components of the raw materials are as follows: Sn: 81 mass parts, Sb: 11 mass parts, Cu: 6 mass parts, and carbon fiber: 2 mass parts; place the raw materials except the carbon fiber and zinc chloride in a crucible, melt them under nitrogen by using an induction melting process, the melting temperature is 700 DEG C, stirring is performed during the melting process, the stirring speed is 1500 revolutions per minute, stirring is performed for 30 minutes, and the first melt is obtained after the melting process; the first melt is cooled to 500 DEG C after the melting process is completed, and the first melt is subjected to a first cooling treatment to obtain a pre-prepared alloy block slurry, and waiting for casting.

[0062] 2) One end of the high-thermal-conductivity carbon fiber is fixed to the inner bottom of the casting mold, the carbon fiber is 2 mass parts, the carbon fiber is uniformly distributed on the bottom of the entire casting mold, and the length of the carbon fiber is 1.2 times the length of the casting mold.

[0063] 3) Casting the preform alloy slurry into the casting mold preformed with high thermal conductivity fibers, wherein the casting mold is placed on a platform applying ultrasonic vibration, the power of the ultrasonic vibration device is set to 3Kw, the frequency is 20kHz, the vibration time is 5min, the platform has a heating and insulation function, and the heating temperature is 500℃.

[0064] 4) Rapidly cooling the melt in the casting mold by water cooling, and solidifying the slurry to obtain a solid composite.

[0065] 5) Machining the solid composite to obtain a preform alloy block of a desired size.

[0066] II. Surface treatment of the steel substrate

[0067] 1) Sandblasting the surface of the steel substrate to remove oxides on the surface of the steel substrate, then wiping the surface of the steel substrate with a degreasing agent to remove surface oil, then wiping with alcohol, and drying for use;

[0068] 2) Immersing the dried steel substrate into a metal tank containing a tin plating solution to modify the steel substrate, wherein the tin plating solution comprises the following components by mass fraction: Ag: 5 mass fraction, Cu: 2 mass fraction, Ni: 0.5 mass fraction, La: 0.1 mass fraction, Yb: 0.06 mass fraction, P: 0.05 mass fraction, and the balance being Sn; the temperature of the immersion plating is 250℃, and the time of the immersion plating is 60min;

[0069] 3) After the immersion plating is completed, the steel substrate is taken out of the metal tank, air-cooled to room temperature, and then the surface scale and other impurities are removed by a sandblasting machine, then placed in an ultrasonic cleaning machine containing alcohol for 5min, taken out after cleaning, and dried for use.

[0070] III. Preparation of a crude high thermal conductivity bearing

[0071] 1) Brushing a layer of 0.3mm of solder paste (Sn-0.7Cu, Sn-Ag-Cu) on the surface of the steel substrate after surface treatment and around the preform alloy block;

[0072] 2) Placing the preform alloy block coated with solder paste above the steel substrate coated with solder paste to obtain a composite preform;

[0073] 3) Placing the composite preform into a vacuum air drying oven, heating at a temperature of 230℃ for 50min to realize welding of the preform alloy block and the steel substrate, and obtaining a crude high thermal conductivity bearing.

[0074] IV. Heat treatment

[0075] After the welding is completed, the temperature of the heated vacuum air drying oven is adjusted to 90℃, and the holding time is 6h, and then the oven is cooled to room temperature, and the high thermal conductivity bearing bush is obtained.

[0076] Referring to Figure 1 , Figure 1 The electron microscope of the high thermal conductivity bearing bush prepared in this embodiment Figure 1 (200x), Figure 2 The electron microscope of the high thermal conductivity bearing bush prepared in this embodiment Figure 2 (500x), it can be seen that the babbitt layer has uniform structure.

[0077] Comparative Example 1: SnSb11Cu6

[0078] This comparative example provides a babbitt layer, which comprises the following components by mass fraction: Sn: 83 mass fraction, Sb: 11 mass fraction, Cu: 6 mass fraction.

[0079] This comparative example also provides a method for preparing a bearing bush, comprising the following steps:

[0080] I. Preparation of a pre-alloy block

[0081] 1) Preparation of a pre-alloy block slurry: raw materials are obtained, and the specific components of the raw materials are as follows: Sn: 83 mass fraction, Sb: 11 mass fraction, Cu: 6 mass fraction; the raw materials and zinc chloride are placed in a crucible, and an induction melting process is used to melt them under nitrogen, with a melting temperature of 700℃, stirring at a speed of 1500 revolutions / min during the melting process, stirring for 30min, and holding for 20min to obtain a first melt; after the melting is completed, the first melt is cooled to 500℃, and the first melt is subjected to a first cooling treatment to obtain a pre-alloy block slurry, which is ready for casting.

[0082] 2) The pre-alloy block slurry is cast into a casting mold, wherein the casting mold is placed on a platform with ultrasonic vibration, and the power of the ultrasonic vibration device is set to 3Kw, the frequency is 20kHz, and the vibration time is 5min, and the platform has a heating and holding function, and the heating temperature is 500℃.

[0083] 4) The melt in the casting mold is rapidly cooled by water cooling, and the solidified slurry is obtained as a solid composite.

[0084] 5) The solid composite is machined to the desired size to obtain a pre-alloy block.

[0085] II. Surface treatment of the steel base

[0086] 1) Steel substrate surface sand blasting to remove the steel substrate surface of the oxide, then using the oil removal detergent wipe the steel substrate surface to remove surface oil, then wipe alcohol, dry after use;

[0087] 2) The dry steel substrate is immersed in a metal tank containing a tin plating solution, wherein the tin plating solution comprises the following components by mass fraction: Ag: 5 mass fraction, Cu: 2 mass fraction, Ni: 0.5 mass fraction, La: 0.1 mass fraction, Yb: 0.06 mass fraction, P: 0.05 mass fraction, and the balance is Sn; the temperature of immersion plating is 250℃, and the time of immersion plating is 60min;

[0088] 3) After the end of immersion plating, the steel substrate is taken out of the metal tank, and the surface scale and other impurities are removed by using a sand blasting machine after air cooling to room temperature, then it is placed in an ultrasonic cleaner containing alcohol for ultrasonic cleaning for 5min, taken out after cleaning, and dried for use.

[0089] Three, preparation of a rough bearing

[0090] 1) A layer of 0.3mm of solder paste (Sn-0.7Cu, Sn-Ag-Cu) is brushed on the surface of the steel substrate and around the preformed alloy block, respectively;

[0091] 2) The preformed alloy block coated with solder paste is placed above the steel substrate coated with solder paste to obtain a composite preform;

[0092] 3) The composite preform is placed in a vacuum air drying oven, the heating temperature is 230℃, and the holding time is 50min, realizing the welding of the preformed alloy block and the steel substrate, and obtaining a rough bearing.

[0093] Four, heat treatment

[0094] After welding, the heating temperature of the vacuum air drying oven is adjusted to 90℃, and the holding time is 6h, then the furnace is cooled to room temperature, and the product bearing is obtained.

[0095] Example two:

[0096] The present embodiment provides a high-thermal-conductivity Babbitt alloy layer, which comprises the following components by mass fraction: Sn: 86 mass fraction, Sb: 8 mass fraction, Cu: 4 mass fraction, and carbon fiber: 2 mass fraction.

[0097] The present embodiment also provides a high-thermal-conductivity bearing, and the preparation method is described in Example 1, which is not repeated here, and the difference lies in that the mass fraction of the raw materials of the high-thermal-conductivity Babbitt alloy layer is different from that of Example 1. The present embodiment provides a high-thermal-conductivity Babbitt alloy layer, which comprises the following components by mass fraction: Sn: 86 mass fraction, Sb: 8 mass fraction, Cu: 4 mass fraction, and carbon fiber: 2 mass fraction.

[0098] Comparative Example 2: SnSb8Cu4

[0099] This comparative example provides a Babbitt alloy layer comprising the following components by mass: Sn: 88 parts by mass, Sb: 8 parts by mass, Cu: 4 parts by mass.

[0100] This comparative example also provides a method for preparing a bearing bush, the preparation method of which is the same as that in Comparative Example 1. The difference is that the mass ratio of the raw materials for the Babbitt alloy layer is different from that in Comparative Example 1. The Babbitt alloy layer provided in this comparative example includes the following components by mass: Sn: 88 parts by mass, Sb: 8 parts by mass, Cu: 4 parts by mass.

[0101] Furthermore, the performance of the Babbitt alloy layers obtained in Example 1, Comparative Example 1, Example 2, and Comparative Example 2 was tested respectively, and the test results are shown in Table 1.

[0102] Table 1. Friction coefficients of Babbitt alloys in the examples and comparative examples.

[0103]

[0104] As shown in Table 1, the Babbitt alloy layer provided in Example 1 has the lowest coefficient of friction. Therefore, it experiences less wear and has a longer service life under the same conditions.

[0105] Example 3:

[0106] This embodiment provides a high thermal conductivity Babbitt alloy layer, which includes the following components by mass: Sn: 80 parts by mass, Sb: 11 parts by mass, Cu: 6 parts by mass, and carbon fiber: 3 parts by mass.

[0107] This embodiment also provides a method for preparing a high thermal conductivity bearing. The steps of the preparation method are the same as those in Embodiment 1, and will not be repeated here. The only difference is the amount of carbon fiber used in the mold pre-fabricated with high thermal conductivity fibers.

[0108] Example 4:

[0109] This embodiment provides a high thermal conductivity Babbitt alloy layer, which includes the following components by mass: Sn: 79 parts by mass, Sb: 11 parts by mass, Cu: 6 parts by mass, and carbon fiber: 4 parts by mass.

[0110] This embodiment also provides a method for preparing a high thermal conductivity bearing. The steps of the preparation method are the same as those in Embodiment 1, and will not be repeated here. The only difference is the amount of carbon fiber used in the mold pre-fabricated with high thermal conductivity fibers.

[0111] The performance of the Babbitt alloy layers obtained in Comparative Example 1, Example 1, Example 3, and Example 4 was tested, and the test results are shown in Table 2.

[0112] Table 2 Performance test parameters of the babbitt alloys of the examples and the comparative examples

[0113]

[0114] According to Table 2, adding the carbon fibers is beneficial to improving the mechanical properties and the heat conduction properties of the alloy layer, and the babbitt alloy layer provided in Example Four has the highest tensile strength and the largest heat conduction coefficient at 150 DEG C, and has the best performance.

[0115] It can be clearly known that the bush prepared by using the high-heat-conductivity babbitt alloy layer provided in the examples of the present application also has high heat conductivity. The present application successfully prepares the babbitt alloy layer on the surface of the workpiece, and the babbitt alloy layer has uniform structure and forms metallurgical bonding with the workpiece substrate, thereby solving the problem of difficult preparation of the babbitt alloy layer containing the high-heat-conductivity carbon fiber composite on the surface of the bush.

[0116] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, and therefore the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A method for preparing a high thermal conductivity bearing, characterized in that, The preparation method includes the following steps: The raw materials are pretreated to prepare preformed alloy slurry; The preformed alloy slurry is mixed with high thermal conductivity fibers to obtain a preformed alloy block; Surface treatment of the steel substrate; The steel substrate and the precast alloy block, after the surface treatment, are integrally welded in a furnace to obtain a rough high thermal conductivity bearing. The crude high thermal conductivity bearing is heat-treated to obtain the high thermal conductivity bearing. The raw materials include: Sb: 3 to 13 parts by mass, Cu: 3 to 10 parts by mass, Ni: 0 to 0.5 parts by mass, Ag: 0 to 0.2 parts by mass, Co: 0 to 1.6 parts by mass, Yb: 0 to 0.1 parts by mass, and the balance being Sn; The high thermal conductivity fiber is 5 parts by weight of glass fiber and / or 2 to 5 parts by weight of carbon fiber; Adjust the temperature of the heat treatment to 50℃-90℃ and hold it at that temperature for 1h-6h.

2. The preparation method according to claim 1, characterized in that, The process of processing the raw materials to prepare the preformed alloy slurry includes the following steps: The raw materials and refining agent are smelted and stirred once under a protective gas, and then kept at a constant temperature to obtain a first melt. The first melt is subjected to a cooling treatment to obtain the preformed block alloy slurry.

3. The preparation method according to claim 2, characterized in that, The melting process is carried out at a temperature of 500℃ to 800℃; and / or The stirring speed is 1000 r / min to 1500 r / min; and / or The stirring time for each stirring session is 15 min to 45 min; and / or The heat preservation treatment time is 10 min to 30 min; and / or The target temperature for the first cooling process is 200℃~550℃; and / or The refining agent is one or more of zinc chloride, ammonium chloride, and sodium chloride.

4. The preparation method according to claim 2, characterized in that, The step of mixing the preformed alloy slurry with high thermal conductivity fibers to obtain the preformed alloy block includes: The high thermal conductivity fiber is added to the preformed block alloy slurry and stirred twice to obtain a second melt. The second melt is subjected to a secondary cooling treatment, and the second melt after the secondary cooling treatment is processed to obtain the precast alloy block; or One end of the high thermal conductivity fiber is fixed to the inner bottom of the casting mold, and the preformed block alloy slurry is poured into the casting mold. The casting mold containing the high thermal conductivity fiber and the preformed alloy slurry is placed on the placement platform of the ultrasonic vibration device to ultrasonically treat the mixture of the high thermal conductivity fiber and the preformed alloy slurry in the casting mold to obtain a third melt. The third melt is subjected to three cooling treatments, and the third melt after the three cooling treatments is processed to obtain the precast alloy block.

5. The preparation method according to claim 4, characterized in that, The secondary stirring time is 15 min to 45 min; and / or The secondary stirring speed is 1000 r / min to 1500 r / min; and / or The ultrasonic treatment has a power of 2.5 kW to 3.5 kW, a frequency of 15 kHz to 21 kHz, a vibration time of 2 min to 5 min, and a heating temperature of 450 ℃ to 550 ℃.

6. The preparation method according to claim 1, characterized in that, The surface treatment of the steel substrate includes: Remove oxides and oil stains from the surface of the steel substrate; The steel substrate is dried. The dried steel substrate is then subjected to a modification treatment. After the modified steel substrate is cooled to room temperature, impurities on the surface of the steel substrate are removed.

7. The preparation method according to claim 6, characterized in that, The modification treatment of the dried steel substrate includes: The dried steel substrate is immersed in a container containing a tin plating solution for immersion plating. The immersion plating process is carried out at a temperature of 200℃ to 250℃ for 30 to 60 minutes. The tin plating solution comprises the following components by mass: Ag: 0.01 to 5 parts by mass, Cu: 0.1 to 2 parts by mass, Ni: 0.05 to 0.5 parts by mass, La: 0.01 to 0.1 parts by mass, Yb: 0.01 to 0.06 parts by mass, P: 0.01 to 0.05 parts by mass, with the balance being Sn.

8. The preparation method according to claim 1, characterized in that, The step of welding the surface-treated steel substrate and the prefabricated alloy block to obtain a rough, high thermal conductivity bearing specifically includes: Solder paste is applied around the steel substrate and the precast alloy block after the surface treatment is completed. A precast alloy block coated with solder paste is placed on top of a steel substrate coated with solder paste to obtain a composite precast body; The composite preform is heated and kept at a constant temperature to obtain the coarsely prepared high thermal conductivity bearing. The solder paste has a thickness of 0.1mm-0.5mm, the heating temperature is 180℃-230℃, and the holding time is 10min-50min.

9. A high thermal conductivity bearing, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 8.

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