Preparation method of tin-based babbitt alloy bushing and tin-based babbitt alloy bushing

Abstract

The invention relates to the technical field of thrust bearings, in particular to a preparation method of a tin-based babbitt metal bushing and the tin-based babbitt metal bushing. The preparation method of the tin-based babbitt metal bushing comprises the following steps that a transition layer containing tin is arranged on the surface of a thrust pad, plate-strip-shaped tin-based babbitt metal is arranged on the transition layer, pressure and ultrasonic waves are applied to the surface of the plate-strip-shaped tin-based babbitt metal, and welding is completed through ultrasonic pressure welding. According to the method, the tin-containing transition layer is arranged on the surface of the thrust pad, the thrust pad bushing is rapidly prepared through ultrasonic pressure welding, and element diffusion and hydrogen element escape among the bushing, the transition layer and the steel backing and atomic lattice distortion and electron movement between the babbitt metal bushing and the transition layer are promoted through the coupling effect of extrusion force and high-frequency vibration; the plate-strip-shaped tin-based babbitt metal is welded to the surface of the thrust pad to form the bushing, the prepared babbitt metal bushing coating is uniform and compact, the preparation technology is greatly simplified, and environment friendliness is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of thrust bearings, and in particular to a preparation method of a tin-based babbitt alloy shaft liner and a tin-based babbitt alloy shaft liner. Background Art

[0002] The thrust bearing of steam turbine, water turbine and generator is an important part of its work. Its main function is to bear the axial thrust of the rotor and prevent the rotor from shaking along the axial direction. Therefore, the thrust bushing needs to have good wear resistance, strength, hardness and corrosion resistance.

[0003] Babbitt alloy is often used as the lining material for thrust bearing bushings. The microstructure of Babbitt alloy is mainly composed of α phase, β phase and η phase. Among them, α phase plays a role in reducing friction and embedding, while β phase and η phase improve strength, hardness and corrosion resistance. At present, conventional lining preparation methods include casting, surfacing, laser cladding, tinning + cold spraying, friction welding, resistance brazing and explosion welding, but there are certain limitations. It is very important to develop a more efficient and stable lining preparation method.

[0004] The Chinese patent with the announcement number CN 110227809 B combines the babbitt alloy with the steel back metallurgical process through the centrifugal casting process, but the casting method has a bad working environment and is prone to defects such as pores, shrinkage, and oxidation inclusions. The Chinese patent with the announcement number CN110004324 B uses the arc deposition method to build up the babbitt alloy on the steel back surface, but the build-up welding method is prone to produce a large amount of smoke and welding spatter, the working environment is not friendly, and the welding efficiency is low. The Chinese patent with the announcement number CN 114875402 B uses the laser cladding method to melt the babbitt alloy wire on the surface of the substrate to achieve additive manufacturing of babbitt alloy. However, this method has high equipment cost, complex technology and operation, low processing efficiency, and is difficult to achieve batch processing. The Chinese patent with the announcement number CN 111687506 B realizes the welding of the bearing or bearing assembly with the babbitt alloy block by resistance brazing. However, the temperature control of resistance brazing is difficult, and it is impossible to accurately control the heating temperature to ensure that the brazing material can melt, while avoiding overheating, melting or performance degradation of the base material due to excessive temperature. The Chinese patent with announcement number CN 117564432 B provides a method and device for explosive forming of babbitt alloy and steel back, which realizes the forming of babbitt alloy and steel back by igniting the detonator to detonate the explosive. However, the explosive welding method has a dangerous working environment, causes pollution to the environment, and the welding quality is unstable, and it is impossible to achieve mass processing. The Chinese patent with announcement number CN 111560578 B sprays the mixed alloy powder onto the surface of the steel back by cold spraying, but this method is costly and has low processing efficiency, and is not suitable for mass production.

[0005] Therefore, it is of great significance to provide a method for preparing a babbitt alloy shaft liner with a uniform and dense shaft liner coating, simple process, mass production and environmental friendliness.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The first purpose of the present invention is to provide a method for preparing a tin-based babbitt alloy bushing, which adopts a prefabrication molding and solid phase connection method to quickly prepare a thrust bearing bushing through a transition layer, a prefabricated bushing and ultrasonic pressure welding. The prepared babbitt alloy bushing coating is uniform and dense, which greatly simplifies the preparation process and is environmentally friendly.

[0008] The second object of the present invention is to provide a tin-based babbitt alloy shaft liner, which is prepared by the preparation method of the tin-based babbitt alloy shaft liner as described above.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] A method for preparing a tin-based babbitt alloy shaft liner comprises the following steps:

[0011] A tin-containing transition layer is arranged on the surface of the thrust pad, a plate-shaped tin-based babbitt alloy is placed on the transition layer, pressure and ultrasonic waves are applied to the surface of the plate-shaped tin-based babbitt alloy, and welding is completed by ultrasonic pressure welding.

[0012] Preferably, the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy during the ultrasonic pressure welding process is 10-100 MPa, and the welding time of the ultrasonic pressure welding is 10-30 s.

[0013] Preferably, the ultrasonic pressure welding adopts a segmented pressure welding method. In the first stage of welding, the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy is 10-25MPa, and the welding time is 5-15s; in the second stage of welding, the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy is 30-100MPa, and the welding time is 5-15s.

[0014] Preferably, the ultrasonic frequency of the ultrasonic pressure welding is 20-40kHz, and the output power is 5000-8000W.

[0015] Preferably, the flatness of the surface to be welded of the transition layer is 0.01-0.05 mm, and the surface roughness Ra is 0.16-10 μm;

[0016] And / or, the planarity and surface roughness of two surfaces of the plate-shaped tin-based babbitt alloy and the transition layer that are close to each other are the same.

[0017] Preferably, the step of providing the transition layer on the surface of the thrust pad comprises: cleaning the surface of the thrust pad, melting a tin-containing metal raw material to obtain a melt, and plating the melt onto the surface of the thrust pad to form the transition layer.

[0018] Preferably, the surface of the thrust pad is cleaned by spraying alcohol and / or acid onto the surface of the thrust pad.

[0019] Preferably, the melting temperature of the tin-containing metal raw material is 300-380°C.

[0020] Preferably, the transition layer is a tin-based babbitt alloy transition layer.

[0021] Preferably, the thickness of the transition layer is 0.1-0.3 mm.

[0022] A tin-based babbitt alloy shaft liner is prepared by using the preparation method of the tin-based babbitt alloy shaft liner described in any one of the aforementioned embodiments.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention prepares a tin-based babbitt alloy shaft lining by the method of "prefabrication forming and solid phase connection". A tin-containing transition layer is plated on the surface of the thrust pad to achieve metallurgical bonding of heterogeneous materials between the transition layer and the steel back, and then a welding strip with the same size as the thrust pad is obtained by prefabrication forming. Finally, ultrasonic pressure welding is used to achieve homogeneous material connection between the transition layer and the babbitt alloy shaft lining; the coupling effect of the extrusion force and high-frequency vibration promotes the diffusion of elements and the escape of hydrogen elements between the shaft lining, the transition layer and the steel back, and promotes the solid solution of Sn in Fe in the transition layer and the formation of intermetallic compounds; the effect of the coupling field promotes the atomic lattice distortion and electron movement between the tin-based babbitt alloy shaft lining and the tin-containing transition layer, and promotes the formation of metal bonds. The babbitt alloy shaft lining prepared by the method of the present invention has a uniform and dense coating, greatly simplifies the preparation process, can realize mass production of thrust pad shaft linings, and the production process is environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of an ultrasonic pressure welding process provided by an embodiment of the present invention;

[0027] Figure 2The scanning electron microscope analysis diagrams of the bonding interfaces in Examples 1, 7 and 8 of the present invention, wherein (a) is Example 1, (b) is Example 7, and (c) is Example 8;

[0028] Figure 3 The microstructure diagrams of the prefabricated strip-shaped tin-based babbitt alloy in Example 1 of the present invention before and after ultrasonic pressure welding, wherein (a) is the microstructure diagram before ultrasonic pressure welding, and (b) is the microstructure diagram after ultrasonic pressure welding;

[0029] Figure 4 PT detection defect diagrams before and after ultrasonic pressure welding of the prefabricated strip-shaped tin-based babbitt alloy in Example 1 of the present invention, wherein (a) is the PT detection defect diagram before ultrasonic pressure welding, and (b) is the PT detection defect diagram after ultrasonic pressure welding. DETAILED DESCRIPTION

[0030] The technical scheme of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments, but it will be understood by those skilled in the art that the following described embodiments are part of embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0031] A first aspect of the present invention provides a method for preparing a tin-based babbitt alloy shaft liner, comprising the following steps:

[0032] A tin-containing transition layer is set on the surface of the thrust washer, and a plate-shaped tin-based babbitt alloy is placed on the transition layer. The plate-shaped tin-based babbitt alloy has the same size as the surface of the thrust washer. Pressure and ultrasonic waves are applied to the surface of the plate-shaped tin-based babbitt alloy, and welding is completed by ultrasonic pressure welding.

[0033] The present invention prepares a tin-based babbitt alloy bushing by the method of "prefabrication and solid phase connection", realizes metallurgical bonding between the thrust bearing and the steel back heterogeneous material by plating a tin-containing transition layer on the surface of the thrust bearing, obtains a welding strip with the same size as the thrust bearing by prefabrication, and finally realizes the connection between the tin-containing transition layer and the tin-based babbitt alloy bushing by ultrasonic pressure welding. The coupling effect of extrusion force and high-frequency vibration is utilized to promote the diffusion of elements between the bushing, transition layer and steel back, the escape of hydrogen elements, the solid solution of Sn in Fe in the transition layer, and the formation of intermetallic Fe-Sn compounds; the effect of the coupling field promotes the atomic lattice distortion and electron movement between the tin-based babbitt alloy bushing and the tin-containing transition layer, and promotes the formation of metal bonds. The method of the present invention can quickly prepare thrust bearing bushings, and the prepared thrust bearing bushing coating is uniform and dense, which greatly simplifies the preparation process and is environmentally friendly.

[0034] Ultrasonic pressure welding process Figure 1 As shown, the ultrasonic transducer is connected to the ultrasonic radiation rod pressure head, and the high-frequency electrical energy is converted into high-frequency mechanical oscillation through the piezoelectric effect or magnetostrictive effect; the ultrasonic radiation rod is also connected to the high-pressure oil cylinder, which is responsible for transmitting the extrusion force; the ultrasonic radiation rod pressure head can completely cover the plate-shaped tin-based babbitt alloy. During the welding process, when the babbitt alloy shaft liner is subjected to strong extrusion force, the babbitt alloy shaft liner and the transition layer are deformed, and the deformation energy causes the oxide film on the surface of the babbitt alloy shaft liner and the transition layer to rupture, exposing the pure metal substance, and at the same time, the hydrogen element escapes. As the extrusion force increases, the pure metal undergoes plastic deformation and the crystal structure changes. At this time, the free electrons in the atoms move freely in the metal lattice, forming a strong interaction with the positive ions to form a metal bond, thereby achieving connection. During the extrusion process, the ultrasonic system is turned on, and the high-frequency vibration energy of the ultrasonic wave is efficiently transmitted to the interface between the babbitt alloy liner and the transition layer, and the interface between the transition layer and the thrust bearing matrix, promoting the diffusion of elements between the transition layer and the thrust bearing matrix, which is beneficial to promoting the solid solubility of Sn in Fe and the formation of intermetallic compounds, and increasing the bonding strength between heterogeneous materials; promoting the atomic lattice distortion and electron movement between the babbitt alloy liner and the transition layer, promoting the formation of metal bonds, and thus improving the bonding strength.

[0035] At present, there is no report on the preparation of babbitt alloy shaft lining by ultrasonic pressure welding. The reason is that when ultrasonic pressure welding is used, since the carbon steel matrix, shaft lining and coating contain hydrogen atoms, which exist in dissolved state, interstitial atomic state or chemical state, it has a negative impact on the mechanical properties of the metal, causes microscopic defects or stress concentration inside the metal, increases the brittleness of the metal, and is difficult to achieve solid-phase connection of babbitt alloy. The present invention reasonably controls the pressure, ultrasonic parameters, flatness and surface roughness of the welding surface during the welding process, and uses ultrasonic pressure welding to achieve solid-phase connection of tin-based babbitt alloy strips with coatings and thrust bearing substrates, and has few welding defects and high bonding strength.

[0036] In some specific embodiments of the present invention, the pressure applied to a unit area of ​​a plate-shaped tin-based babbitt alloy during ultrasonic pressure welding is 10-100 MPa, for example, it can be any point value among 10 MPa, 15 MPa, 20 MPa, 25 MPa, 30 MPa, 40 MPa, 50 MPa, 60 MPa, 70 MPa, 80 MPa, 90 MPa, 100 MPa, or a range value consisting of any two point values, and the welding time of ultrasonic pressure welding is 10-30 s, for example, it can be any point value among 10 s, 15 s, 20 s, 25 s, 30 s, or a range value consisting of any two point values.

[0037] In some preferred embodiments of the present invention, ultrasonic pressure welding adopts a segmented pressure welding method. The pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy in the first stage of welding is 10-25MPa, for example, it can be any point value among 10MPa, 15MPa, 20MPa, and 25MPa, or a range value composed of any two point values, and the welding time is 5-15s, for example, it can be any point value among 5s, 8s, 10s, 12s, and 15s, or a range value composed of any two point values; the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy in the second stage of welding is 30-100MPa, for example, it can be any point value among 30MPa, 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, and 100MP, or a range value composed of any two point values, and the welding time is 5-15s, for example, it can be any point value among 5s, 8s, 10s, 12s, and 15s, or a range value composed of any two point values.

[0038] The present invention adopts a segmented cold pressing composite ultrasonic technology. The first stage of welding is a pre-pressing process, which causes the babbitt alloy plate and the transition layer to deform. The deformation can promote the rupture of the oxide film on the surface of the babbitt alloy plate and the transition layer, exposing pure metal substances. At the same time, it promotes the diffusion of hydrogen atoms in each metal to the interface; the second stage of welding increases the pressure, causing the pure metal to undergo plastic deformation and change the lattice structure. At this time, the free electrons in the atoms move freely in the metal lattice, forming a strong interaction with the positive ions to form a metal bond, thereby achieving connection; the first stage and the second stage are both accompanied by ultrasonic vibration. The high-frequency vibration energy of the ultrasonic wave promotes the migration of electrons between the babbitt alloy plate and the transition layer, the diffusion of elements between the transition layer and the thrust bearing matrix interface, and the diffusion and migration of hydrogen atoms in the metal. The combined effect of segmented cold pressing and ultrasonic vibration promotes tissue refinement, hard phase crushing, hydrogen atom precipitation, electron migration in the lattice and the formation of metal bond compounds, thereby improving the shaft liner bonding strength.

[0039] In some specific embodiments of the present invention, the ultrasonic frequency of ultrasonic pressure welding is 20-40kHz, for example, it can be any point value among 20kHz, 25kHz, 30kHz, 35kHz, and 40kHz, or a range value consisting of any two point values; the ultrasonic output power is 5000-8000W, for example, it can be any point value among 5000W, 5500W, 6000W, 6500W, 7000W, 7500W, and 8000W, or a range value consisting of any two point values.

[0040] In some specific embodiments of the present invention, the step of mechanically processing the surface to be welded of the transition layer is also included so that its flatness and surface roughness meet the requirements.

[0041] In some specific embodiments of the present invention, the flatness of the transition layer surface to be welded is 0.01-0.05 mm, for example, it can be any point value among 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, or a range value consisting of any two point values; the surface roughness Ra is 0.16-10 μm, for example, it can be any point value among 0.16 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, or a range value consisting of any two point values.

[0042] And / or, the flatness and surface roughness of two surfaces of the plate-strip tin-based babbitt alloy and the transition layer that are close to each other are the same.

[0043] If the surface roughness of the welding surface is too high, the effective contact area between the interfaces will be reduced, and the free movement of free electrons in atoms in the metal lattice will be reduced, which will cause the bonding strength to decrease; if the roughness is too low, the adhesion / friction between the interfaces will be reduced, and slip will occur during the cold pressing process, which is not conducive to the migration of free electrons in the metal lattice, and the bonding strength will decrease; reasonable control of the surface roughness of the welding surface will help improve the welding strength. Making the flatness and surface roughness of the two surfaces close to each other in the strip-shaped tin-based babbitt alloy and the transition layer the same can increase the effective contact area and further improve the bonding strength.

[0044] In some specific embodiments of the present invention, the step of providing a transition layer on the thrust pad surface includes: cleaning the thrust pad surface, melting the tin-containing metal raw material to obtain a melt, and plating the melt onto the thrust pad surface to form a transition layer.

[0045] In some specific embodiments of the present invention, the surface of the thrust pad is cleaned by spraying alcohol and / or acid on the surface of the thrust pad to remove oil stains and oxides on the surface of the thrust pad substrate.

[0046] In some specific embodiments of the present invention, the melting temperature of the tin-containing metal raw material is 300-380°C, for example, it can be any point value among 300°C, 310°C, 320°C, 330°C, 340°C, 350°C, 360°C, 370°C, 380°C, or a range value consisting of any two point values.

[0047] In some specific embodiments of the present invention, the transition layer is a tin-based babbitt alloy transition layer, and the composition of the tin-based babbitt alloy transition layer and the plate-shaped tin-based babbitt alloy may be the same or different.

[0048] In some specific embodiments of the present invention, the tin-based babbitt alloy transition layer and the plate-shaped tin-based babbitt alloy shaft lining material can be independently selected from any one of SnSb4Cu4, SnSb8Cu4, SnSb8Cu8, SnSb9Cu7, SnSb11Cu6, SnSb12Cu6, SnSb12Cu6Cd1, and SnSb12Pb10Cu4.

[0049] In some specific embodiments of the present invention, the thickness of the transition layer is 0.1-0.3 mm, for example, it can be any value among 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, or a range consisting of any two values.

[0050] A second aspect of the present invention provides a tin-based babbitt alloy shaft liner, which is prepared by the preparation method of the tin-based babbitt alloy shaft liner described in any one of the aforementioned embodiments.

[0051] The following is a detailed description of some embodiments of the present invention in conjunction with specific examples. The raw materials used in the examples can be purchased from the market unless otherwise specified.

[0052] Example 1

[0053] S1. Spray alcohol and acid on the surface of the thrust bearing to remove the oil and oxide on the surface of the thrust bearing;

[0054] S2. The ingot of Babbitt alloy SnSb11Cu6 is heated to 300°C, melted to obtain a melt, and a small amount of the melt is plated on the surface of the thrust pad to form a transition layer, the thickness of the transition layer is 0.1 mm, and the surface to be welded of the transition layer is machined. After machining, the flatness of the surface to be welded of the transition layer is 0.01 mm, and the surface roughness Ra is 0.5 μm;

[0055] S3. Cut the plate-shaped tin-based babbitt alloy SnSb11Cu6 into a size consistent with the surface size of the thrust washer, keep the flatness and surface roughness of the welding surface consistent with the transition layer, and place it above the transition layer, apply pressure and ultrasonic waves to the surface of the plate-shaped tin-based babbitt alloy, perform ultrasonic pressure welding, and obtain a tin-based babbitt alloy shaft lining; adopt a two-stage pressure application method for welding, wherein the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy in the first stage of welding is 20MPa, and the action time is 10s; the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy in the second stage of welding is 40MPa, and the action time is 10s; ultrasonic waves are turned on in both the first and second stage welding, the ultrasonic frequency is 25kHz, and the ultrasonic output power is 8000W.

[0056] Example 2

[0057] Example 2 is similar to Example 1, except that the babbitt alloy transition layer and the babbitt alloy shaft liner are made of SnSb12Cu6, the transition layer thickness is 0.3mm, the flatness is 0.03mm, the surface roughness Ra is 3μm, the first stage pressure is 15MPa, the second stage pressure is 50MPa, the ultrasonic frequency is 35kHz, and the ultrasonic output power is 5000W.

[0058] Example 3

[0059] Example 3 is similar to Example 1, except that the babbitt alloy transition layer and the babbitt alloy shaft liner are made of SnSb12Cu6Cd1, the transition layer thickness is 0.2mm, the flatness is 0.05mm, the surface roughness Ra is 8μm, the first stage pressure is 10MPa, the second stage pressure is 60MPa, the ultrasonic frequency is 40kHz, and the ultrasonic output power is 8000W.

[0060] Example 4

[0061] Example 4 is similar to Example 1, with the only difference being that the pressure of the entire ultrasonic pressure welding process is 20 MPa, the welding time is 20 s, and the other conditions are the same as those of Example 1.

[0062] Example 5

[0063] Example 5 is similar to Example 1, with the only difference being that the pressure of the entire ultrasonic pressure welding process is 40 MPa, the welding time is 20 s, and the other conditions are the same as those of Example 1.

[0064] Example 6

[0065] Example 6 is similar to Example 1, with the only difference being that the surface roughness Ra of the transition layer surface to be welded is 0.5 μm, the surface roughness Ra of the plate-shaped tin-based babbitt alloy surface to be welded is 10 μm, and the other conditions are the same as those of Example 1.

[0066] Example 7

[0067] Example 7 is similar to Example 1, with the only difference being that the surface roughness Ra of the transition layer surface to be welded and the surface of the plate-shaped tin-based babbitt alloy to be welded are both 0.05 μm, and the other conditions are the same as those of Example 1.

[0068] Example 8

[0069] Example 8 is similar to Example 1, with the only difference being that the surface roughness Ra of the transition layer surface to be welded and the surface of the plate-shaped tin-based babbitt alloy to be welded are both 20 μm, and the other conditions are the same as those of Example 1.

[0070] Test example

[0071] The bushings obtained in Examples 1 to 8 were tested for bonding strength using the method specified in GB / T 12948-1991 “Destructive test method for bonding strength of bimetallic sliding bearings”. The test results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] It can be seen from the data in Table 1 that segmented pressure is helpful to improve the bonding strength between the liner and the substrate. Too much or too little surface roughness of the transition layer and the plate-shaped tin-based babbitt alloy will lead to a decrease in bonding strength.

[0076] Scanning electron microscope analysis was performed on Example 1, Example 7 and Example 8, and the results were as follows: Figure 2 As shown in the figure, when the surface roughness is 0.5μm, the effective contact area between the transition layer and the substrate is large, which promotes the diffusion of elements between the transition layer and the thrust bearing substrate, and is beneficial to promoting the solid solubility of Sn in Fe and the formation of intermetallic compounds. The intermetallic compound transition zone is 6-8μm, which increases the bonding strength between heterogeneous materials. When the surface roughness is 0.05μm, the adhesion / friction between the interfaces is reduced, and slip occurs during the cold pressing process, which is not conducive to the migration of free electrons in the metal lattice. The intermetallic compound transition zone is only 1-2μm, resulting in a decrease in bonding strength; when the surface roughness is 20μm, the surface roughness of the welding surface is too high, the effective contact area between the interfaces is reduced, the free movement of free electrons in atoms in the metal lattice is reduced, and the intermetallic compound transition zone is only 1-2μm, which causes a decrease in bonding strength.

[0077] like Figure 3As shown, (a) is the microstructure diagram of the prefabricated plate-shaped tin-based babbitt alloy before welding in Example 1, and (b) is the microstructure diagram of the prefabricated plate-shaped tin-based babbitt alloy in Example 1 after the segmented cold pressing composite ultrasonic technology. It can be seen from the figure that after the segmented cold pressing composite ultrasonic technology, the microstructure is refined and the second phase microstructure is broken.

[0078] like Figure 4 As shown, (a) is the PT detection defect diagram of the prefabricated plate-strip tin-based babbitt alloy before welding in Example 1, and (b) is the PT detection defect diagram of the prefabricated plate-strip tin-based babbitt alloy in Example 1 after the segmented cold pressing composite ultrasonic technology. It can be seen from the figure that after the segmented cold pressing composite ultrasonic technology, the hydrogen atoms existing in the dissolved state, interstitial atoms or compounded state are discharged.

[0079] Although the present invention has been illustrated and described with specific embodiments, it should be appreciated that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Those skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some or all of the technical features thereof may be replaced by equivalents without departing from the spirit and scope of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. Therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A method for preparing a tin-based babbitt alloy bushing, characterized in that: The following steps are involved: A tin-containing transition layer is arranged on the surface of the thrust pad, a plate-shaped tin-based babbitt alloy is placed on the transition layer, pressure and ultrasonic waves are applied to the surface of the plate-shaped tin-based babbitt alloy, and welding is completed by ultrasonic pressure welding.

2. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy during the ultrasonic pressure welding process is 10-100 MPa, and the welding time of the ultrasonic pressure welding is 10-30 s.

3. The method for preparing a tin-based babbitt alloy bushing according to claim 2, characterized in that: The ultrasonic pressure welding adopts a segmented pressure welding method. In the first stage of welding, the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy is 10-25MPa, and the welding time is 5-15s. In the second stage of welding, the pressure applied to the unit area of ​​the plate-shaped tin-based babbitt alloy is 30-100 MPa, and the welding time is 5-15 seconds.

4. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The ultrasonic frequency of the ultrasonic pressure welding is 20-40kHz, and the output power is 5000-8000W.

5. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The flatness of the transition layer to be welded is 0.01-0.05 mm, and the surface roughness Ra is 0.16-10 μm; And / or, the planarity and surface roughness of two surfaces of the plate-shaped tin-based babbitt alloy and the transition layer that are close to each other are the same.

6. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The step of arranging the transition layer on the surface of the thrust pad includes: cleaning the surface of the thrust pad, melting the tin-containing metal raw material to obtain a melt, and plating the melt onto the surface of the thrust pad to form the transition layer.

7. The method for preparing a tin-based babbitt alloy bushing according to claim 6, characterized in that: Cleaning the surface of the thrust washer by spraying alcohol and / or acid on the surface of the thrust washer; And / or, the melting temperature of the tin-containing metal raw material is 300-380°C.

8. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The transition layer is a tin-based babbitt alloy transition layer.

9. The method for preparing a tin-based babbitt alloy bushing according to claim 1, characterized in that: The thickness of the transition layer is 0.1-0.3 mm.

10. A tin-based babbitt alloy bushing, characterized in that: The tin-based babbitt alloy shaft liner is prepared by the preparation method of any one of claims 1 to 9.

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