A bialuminum composite material and a preparation method and application thereof

Abstract

The present application relates to a kind of double aluminium composite material and its preparation method and application.Double aluminium composite material, including the pure aluminium layer, aluminium tin alloy layer and aluminium zinc copper magnesium alloy layer arranged in sequence.The present application also provides a kind of preparation method of double aluminium composite material as described in the present application, comprising the following steps: pure aluminium, aluminium tin alloy and aluminium zinc copper magnesium alloy group blank, then pass through one pass cold rolling and multiple pass warm rolling, first annealing treatment, obtain the three-layer plate of pure aluminium layer / aluminium tin alloy layer / aluminium zinc copper magnesium alloy layer;Steel plate is heated and treated, then three-layer plate is stacked on steel plate, pass through one pass rolling composite, second annealing treatment, obtain double aluminium composite material.The present application also provides a kind of application of double aluminium composite material as described in the present application, and the double aluminium composite material is used as the preparation material of the bearing bush of low-speed machine.The present application solves the problem of insufficient bearing capacity of existing bearing bush material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing shell materials, in particular to a double-aluminum composite material and a preparation method and application thereof. BACKGROUND

[0002] Due to excellent corrosion resistance, good embedding resistance and occlusion resistance of aluminum-tin alloy, the aluminum-tin alloy / pure aluminum / steel multilayer material can be matched with a soft shaft without surface plating of a soft alloy, so that the aluminum-tin alloy / pure aluminum / steel multilayer material has been widely applied to engine bearing shells of automobiles, internal combustion locomotives and ships at home and abroad. So far, its production output has been the first among various bearing shell materials.

[0003] However, the bearing shell material has general load bearing capacity and only has moderate load bearing capacity. This is mainly related to the pure aluminum layer between the aluminum-tin alloy and the steel back. Tin is prone to reacting with iron to form a hard and brittle tin-iron phase, which affects the bonding strength of the aluminum-tin alloy and the steel back. In order to prevent direct contact between the aluminum-tin alloy and the steel back, a layer of pure aluminum is added in the middle. However, as the load bearing capacity of the bearing shell increases, the pure aluminum layer will yield and reach its load limit, causing the bearing shell to fail.

[0004] With the development of engines towards high speed and high load, the aluminum-tin alloy / pure aluminum / steel multilayer material cannot meet the development needs of modern industry for bearing shells. Therefore, it is necessary to develop a double-aluminum composite material for bearing shells to solve the problem of insufficient load bearing capacity of the above-mentioned bearing shell materials. SUMMARY

[0005] The present application aims to provide a double-aluminum composite material and a preparation method and application thereof to solve the problem of insufficient load bearing capacity of existing bearing shell materials.

[0006] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0007] A double-aluminum composite material, comprising a pure aluminum layer, an aluminum-tin alloy layer and an aluminum-zinc-copper-magnesium alloy layer arranged in sequence.

[0008] Preferably, the composition of the aluminum-tin alloy layer comprises, by mass percentage: 22-27% of tin (Sn), 0.7-1.2% of manganese (Mn), 0.8-1.3% of copper (Cu), less than or equal to 0.2% of titanium (Ti), less than or equal to 0.1% of silicon (Si), less than or equal to 0.1% of iron (Fe), and the balance of aluminum (Al).

[0009] Preferably, the aluminum-zinc-copper-magnesium alloy layer comprises, by mass percentage, 3.5-4.3% zinc (Zn), 0.7-1.1% copper (Cu), 0.8-1.3% magnesium (Mg), less than or equal to 0.16% titanium (Ti), less than or equal to 0.1% iron (Fe), and the balance aluminum (Al).

[0010] Preferably, the aluminum-zinc-copper-magnesium alloy layer comprises, by mass percentage, 3.5-4.3% zinc (Zn), 0.7-1.1% copper (Cu), 0.8-1.3% magnesium (Mg), less than or equal to 0.16% titanium (Ti), less than or equal to 0.1% iron (Fe), and the balance aluminum (Al).

[0011] Preferably, the steel layer is a high-quality low-carbon steel available on the market, such as 08 steel, 08Al steel, No. 10 steel, and SPHC steel.

[0012] The application also provides a preparation method of the double-aluminum composite material as described above, comprising the following steps:

[0013] S1, the pure aluminum, aluminum-tin alloy and aluminum-zinc-copper-magnesium alloy are grouped, and then a one-pass cold rolling and multiple-pass warm rolling are performed, and a first annealing treatment is performed to obtain a three-layer plate of the pure aluminum layer / aluminum-tin alloy layer / aluminum-zinc-copper-magnesium alloy layer;

[0014] S2, the steel plate is heated, the three-layer plate is then stacked on the steel plate, a one-pass rolling is performed to composite, and a second annealing treatment is performed to obtain the double-aluminum composite material.

[0015] Preferably, the preparation method of the double-aluminum composite material comprises the following steps:

[0016] S1, the aluminum-zinc-copper-magnesium alloy, aluminum-tin alloy and pure aluminum are surface mechanically treated, the pure aluminum, aluminum-tin alloy and aluminum-zinc-copper-magnesium alloy are grouped, and then a one-pass room-temperature cold rolling and multiple-pass warm rolling are performed, the pure aluminum and aluminum-zinc-copper-magnesium alloy are coated on the surface of the aluminum-tin alloy with a high tin content to form a three-layer plate of the pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy with a thickness of 2 mm, the three-layer plate is subjected to a first annealing treatment to be softened, and the three-layer plate of the pure aluminum layer / aluminum-tin alloy layer / aluminum-zinc-copper-magnesium alloy layer is obtained.

[0017] S2, the three-layer plate obtained in S1 and the surface of the steel plate are mechanically polished, the steel plate is heated, the three-layer plate is then stacked on the steel plate, a one-pass cold rolling is performed to composite, the three-layer plate is formed into a four-layer composite plate of the pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel back, a second annealing softening treatment is performed, and the double-aluminum composite material with uniform and dispersed tin phases of the aluminum-tin alloy and good interface bonding quality is obtained.

[0018] The annealing heat treatment softening process can promote the recovery and recrystallization of the aluminum-tin alloy layer, the aluminum-zinc-copper-magnesium layer and the aluminum alloy, and improve the interface bonding quality of the aluminum-tin alloy, the aluminum-zinc-copper-magnesium and the steel back. On the other hand, the tin strips extended due to rolling deformation in the aluminum-tin alloy layer are melted and diffused to be disconnected, and are uniformly distributed on the grain boundaries of the aluminum, which is beneficial to the prepared double-aluminum composite material to exhibit better friction-reducing and wear-resistant effects.

[0019] Preferably, the rolling reduction of the one-pass cold rolling is between 50% and 60%.

[0020] Preferably, the temperature of the multi-pass warm rolling is between 150℃ and 200℃, the holding time between adjacent passes is 10-15min, and the rolling reduction of each pass is less than or equal to 20%.

[0021] Preferably, the number of the multi-pass warm rolling is between 6 and 10.

[0022] Preferably, the rolling reduction of the one-pass cold rolling is between 45% and 60%.

[0023] Preferably, the temperature of the first annealing treatment is between 280℃ and 360℃, and the time is between 1 and 4h.

[0024] Preferably, the steel plate is heated to a temperature between 200℃ and 250℃.

[0025] Preferably, the temperature of the second annealing treatment is between 280℃ and 360℃, and the time is between 4 and 10h.

[0026] Preferably, the thickness of the pure aluminum plate is between 0.8 and 1.2mm, and it should be subjected to recrystallization softening at 350-400℃ for 4-10h.

[0027] Preferably, the preparation method of the aluminum-tin alloy comprises: heating a pure aluminum ingot to 740-760℃, adding aluminum-manganese alloy and tin blocks in batches, then using hexachloroethane refining, cooling to 715-730℃, and water-cooled copper mold casting to obtain aluminum-tin alloy cast blanks.

[0028] Preferably, the preparation method of the aluminum-tin alloy comprises: heating a pure aluminum ingot to 740-760℃, adding aluminum-manganese alloy and tin blocks in batches after the pure aluminum ingot is completely melted, and using electromagnetic technology to fully stir the molten liquid; then using hexachloroethane refining, cooling to 715-730℃, and water-cooled copper mold casting to obtain aluminum-tin alloy cast blanks with a thickness of 25mm, and milling the upper and lower surfaces to a thickness of 20mm using a milling machine to obtain aluminum-tin alloy cast blanks.

[0029] Preferably, the preparation method of the aluminum-zinc-copper-magnesium alloy comprises: heating pure aluminum ingot to 750-780 DEG C, adding aluminum-silicon intermediate alloy and zinc block in batches, then refining with hexachloroethane, cooling to 730-750 DEG C, water-cooling copper mold casting, and obtaining aluminum-zinc-copper-magnesium alloy cast blank.

[0030] Preferably, the preparation method of the aluminum-zinc-copper-magnesium alloy comprises: heating pure aluminum ingot to 750-780 DEG C, adding aluminum-silicon intermediate alloy and zinc block in batches, then refining with hexachloroethane, cooling to 730-750 DEG C, water-cooling copper mold casting, and obtaining aluminum-zinc-copper-magnesium alloy cast blank.

[0031] Preferably, the preparation method of the aluminum-zinc-copper-magnesium alloy further comprises: heating the aluminum-zinc-copper-magnesium alloy cast blank at 480-500 DEG C for 8-12 h, multi-pass hot rolling at 360-420 DEG C, with 5-10 min of holding between adjacent passes, and rolling reduction of less than or equal to 30% per pass, and rolling thickness of 0.5-0.8 mm; softening treatment at 380-400 DEG C for 4-6 h, and obtaining aluminum-zinc-copper-magnesium alloy strip.

[0032] The application further provides a use of the double-aluminum composite material as claimed in the application as a preparation material of a bearing bush of a low-speed machine.

[0033] Preferably, the double-aluminum composite material is used as a preparation material of a bearing bush in a high-power marine low-speed machine.

[0034] The application has the following beneficial effects:

[0035] The present invention relates to a double-aluminum composite material for bearing bushes and its preparation method. Through room temperature cold rolling and multi-pass warm rolling, pure aluminum and an aluminum-zinc-copper-magnesium alloy are coated onto the surface of an aluminum-tin alloy to form a three-layer plate of pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy. Then, the three-layer plate is softened and annealed before being rolled together with a heated steel plate in a single rolling process to form a four-layer composite plate of pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel backing. This is followed by annealing and softening treatment to obtain a double-aluminum composite material with uniform and dispersed tin phase and good interfacial bonding. The load-bearing capacity of the double-aluminum composite plate of the present invention is increased to 50 MPa, which is about 25% higher than that of existing bearing bush materials (where the pure aluminum layer is between the aluminum-tin alloy and the steel backing, with a load-bearing capacity of around 40 MPa). Therefore, using the double-aluminum composite material of the present invention as a material for bearing bushes in high-power marine low-speed engines can greatly improve the load-bearing capacity of the bearing bushes. Furthermore, the preparation method of the present invention has the advantages of simple operation, low cost, and ease of implementation, and has significant application value in the field of bearing bush material technology. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of the preparation method of the double aluminum composite material of the present invention;

[0037] Figure 2 The image shows the metallographic structure of the double aluminum composite material prepared in Example 1.

[0038] Figure 3 The image shows the metallographic structure of the double aluminum composite material prepared in Example 3. Detailed Implementation

[0039] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0040] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0041] Example 1

[0042] like Figure 1 As shown, the preparation method of the double aluminum composite material includes the following steps:

[0043] S1, heat the pure aluminum ingot to 760℃, after completely melting, add aluminum-manganese alloy and tin block in batches, use electromagnetic technology to fully stir the molten liquid; then use hexachloroethane refining, when the molten liquid cools to 721℃, water-cooled copper mold casting is carried out, and then the surface is planed and milled to obtain aluminum-tin alloy cast blank, wherein the aluminum-tin alloy cast blank comprises, by mass percentage: 22.5% of tin (Sn), 0.8% of manganese (Mn), 1.28% of copper (Cu), 0.19% of titanium (Ti), 0.09% of silicon (Si), 0.08% of iron (Fe), and the rest is aluminum (Al), and the thickness of the aluminum-tin alloy cast blank is 20mm;

[0044] S2, heat the pure aluminum ingot to 750℃, after completely melting, add aluminum-silicon intermediate alloy and zinc block in batches, use electromagnetic technology to fully stir the molten liquid; then use hexachloroethane refining, when the molten liquid cools to 730℃, water-cooled copper mold casting is carried out, and then the surface is planed and milled to obtain aluminum-zinc-copper-magnesium alloy cast blank, wherein the aluminum-zinc-copper-magnesium alloy cast blank comprises, by mass percentage: 3.5% of zinc (Zn), 1.1% of copper (Cu), 1.06% of magnesium (Mg), 0.16% of titanium (Ti), 0.09% of iron (Fe), and the rest is aluminum (Al), and the thickness of the aluminum-zinc-copper-magnesium alloy cast blank is 20mm;

[0045] S3, heat the aluminum-zinc-copper-magnesium alloy cast blank at a temperature of 480℃ for 12h; then carry out multi-pass hot rolling at a temperature of 360℃, and the holding time between adjacent passes is 10min, and the rolling reduction of each pass is 20%, so that the thickness of the aluminum-zinc-copper-magnesium alloy cast blank is 0.8mm; then carry out softening treatment at a temperature of 400℃ for 4h to obtain aluminum-zinc-copper-magnesium alloy strip;

[0046] S4, heat the pure aluminum plate with a thickness of 1.2mm at a temperature of 400℃ for 4h for recrystallization softening; the contact surfaces of the pure aluminum, the aluminum-tin alloy and the aluminum-zinc-copper-magnesium alloy need to be mechanically polished, which is generally performed by using a steel wire brush roller to roughen the surface;

[0047] S5, first, cold roll the pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy stack in one pass with a large reduction, and the rolling reduction is controlled at 50%; then, carry out multi-pass warm rolling, and the warm rolling temperature is controlled at 150℃, the holding time between adjacent passes is 10min, and the rolling reduction of each pass is 20%, so that the thickness of the pure aluminum layer / aluminum-tin alloy layer / aluminum-zinc-copper-magnesium alloy layer three-layer plate is 2mm; then, carry out softening treatment of the three-layer plate at a temperature of 280℃ for 4h;

[0048] S6. The aluminum-zinc-copper-magnesium alloy layer of the three-layer sheet is mechanically treated with a wire brush roller, and the surface of the steel plate is mechanically roughened with a sanding belt. The steel plate is heated to 200℃, and then the three-layer sheet is stacked on the steel plate for one-pass rolling composite. The rolling reduction is 45%, in which the aluminum-zinc-copper-magnesium alloy layer of the three-layer sheet is in direct contact with the steel plate. Then, the rolled pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel multilayer sheet is softened by holding it at a temperature of 360℃ for 4 hours to obtain a double aluminum composite material.

[0049] According to the test results, the aluminum-tin alloy of the double aluminum composite material prepared in this embodiment has a uniform distribution of tin phase, good bonding between the interfaces of each layer, and does not crack when bent at 180°. After the plate is processed into a tile, its load-bearing capacity is measured to be 51.2 MPa by a sapphire fatigue testing machine.

[0050] The metallographic structure of the double aluminum composite material prepared in this embodiment is shown in the figure below. Figure 2 As shown, from Figure 2 Analysis shows that the tin phase in the aluminum-tin alloy layer is evenly distributed, and the pure aluminum layer / aluminum-tin alloy layer, aluminum-tin alloy layer / aluminum-zinc-copper-magnesium layer, and aluminum-tin-copper-magnesium layer / steel have good bonding.

[0051] Example 2

[0052] like Figure 1 As shown, the preparation method of the double aluminum composite material includes the following steps:

[0053] S1. Heat pure aluminum ingots to 740℃. After they are completely melted, add aluminum-manganese alloy and tin ingots in batches. Use electromagnetic technology to stir the melt thoroughly. Then refine with hexachloroethane. When the melt is cooled to 716℃, cast it in a water-cooled copper mold. Then mill the surface to obtain an aluminum-tin alloy billet. The aluminum-tin alloy billet contains, by mass percentage: 24.9% tin (Sn), 1.2% manganese (Mn), 0.85% copper (Cu), 0.1% titanium (Ti), 0.06% silicon (Si), 0.06% iron (Fe), and the remainder is aluminum (Al). The thickness of the aluminum-tin alloy billet is 20mm.

[0054] S2. Heat pure aluminum ingots to 780℃. After they are completely melted, add aluminum-silicon master alloy and zinc blocks in batches. Use electromagnetic technology to thoroughly stir the melt. Then refine with hexachloroethane. When the melt is cooled to 750℃, cast it in a water-cooled copper mold. Then mill the surface to obtain an aluminum-zinc-copper-magnesium alloy billet. The aluminum-zinc-copper-magnesium alloy billet, by mass percentage, includes: 3.86% zinc (Zn), 0.92% copper (Cu), 1.29% magnesium (Mg), 0.10% titanium (Ti), 0.06% iron (Fe), and the remainder is aluminum (Al). The thickness of the aluminum-zinc-copper-magnesium alloy billet is 20mm.

[0055] S3, the aluminum-zinc-copper-magnesium alloy cast blank is heated at a temperature of 500 DEG C for 8 h, then is subjected to multi-pass hot rolling at a temperature of 390 DEG C, the holding time between adjacent passes is 8 min, the rolling reduction of each pass is 26%, and the thickness of the aluminum-zinc-copper-magnesium alloy after rolling is 0.6 mm; then the aluminum-zinc-copper-magnesium alloy is subjected to softening treatment at a temperature of 390 DEG C for 5 h, and an aluminum-zinc-copper-magnesium alloy strip is obtained;

[0056] S4, a pure aluminum plate with a thickness of 1.0 mm is subjected to recrystallization softening at a temperature of 380 DEG C for 8 h; the contact surfaces of the pure aluminum, the aluminum-tin alloy and the aluminum-zinc-copper-magnesium alloy need to be subjected to mechanical polishing treatment, which is generally performed by using a steel wire brush roller to roughen the surface;

[0057] S5, the pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy assembly is first subjected to one-pass cold rolling with a large reduction, and the rolling reduction is controlled at 60%; then the assembly is subjected to multi-pass warm rolling, the warm rolling temperature is controlled at 200 DEG C, the holding time between adjacent passes is 15 min, and the rolling reduction of each pass is 10%, so as to obtain a three-layer plate of a pure aluminum layer / aluminum-tin alloy layer / aluminum-zinc-copper-magnesium alloy layer with a thickness of 2 mm; and then the three-layer plate is subjected to softening treatment at a temperature of 360 DEG C for 1 h;

[0058] S6, the aluminum-zinc-copper-magnesium alloy layer of the three-layer plate is subjected to mechanical treatment by using a steel wire brush roller, the surface of the steel plate is mechanically roughened by using a sand belt, the steel plate is heated to 230 DEG C, and then the three-layer plate is stacked on the steel plate and subjected to one-pass rolling to be combined, and the rolling reduction is 55%, wherein the aluminum-zinc-copper-magnesium alloy layer of the three-layer plate directly contacts the steel plate; and then the multi-layer plate of the pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel after rolling is subjected to softening treatment at a temperature of 320 DEG C for 6 h, and a double-aluminum composite material is obtained.

[0059] It is determined that the tin phase in the aluminum-tin alloy of the double-aluminum composite material prepared in the embodiment is uniformly distributed, the interfaces of the layers are well combined, and the double-aluminum composite material does not crack after 180 DEG C bending; after the plate is processed into a tile, the bearing capacity of the tile is measured by a sapphire fatigue testing machine, and the bearing capacity is 49.3 MPa.

[0060] Example 3

[0061] As shown in Figure 1 the preparation method of the double-aluminum composite material comprises the following steps:

[0062] S1, heat the pure aluminum ingot to 749 DEG C, after all melt, batch adding aluminum manganese alloy and tin block, using electromagnetic technology to melt liquid is fully stirred, then using hexachloroethane refining, when the melt is cooled to 716 DEG C, water-cooled copper mold casting, then on its surface is planed and milled, obtain aluminum tin alloy cast blank, wherein, aluminum tin alloy cast blank includes: 26.72% tin (Sn), 1.05% manganese (Mn), 1.10% copper (Cu), 0.15% titanium (Ti), 0.04% silicon (Si), 0.03% iron (Fe), the rest is aluminum (Al), the thickness of aluminum tin alloy cast blank is 20mm;

[0063] S2, heat the pure aluminum ingot to 765 DEG C, after all melt, batch adding aluminum silicon intermediate alloy and zinc block, using electromagnetic technology to melt liquid is fully stirred, then using hexachloroethane refining, when the melt is cooled to 740 DEG C, water-cooled copper mold casting, then on its surface is planed and milled, obtain aluminum zinc copper magnesium alloy cast blank, wherein, aluminum zinc copper magnesium alloy cast blank, includes: 4.30% zinc (Zn), 0.71% copper (Cu), 0.85% magnesium (Mg), 0.08% titanium (Ti), 0.07% iron (Fe), the rest is aluminum (Al), the thickness of aluminum zinc copper magnesium alloy cast blank is 20mm;

[0064] S3, aluminum zinc copper magnesium alloy cast blank, heated at a temperature of 490 DEG C and kept for 10h, then multi-pass hot rolling is carried out at a temperature of 420 DEG C, and the temperature is kept for 5min between adjacent passes, and the rolling reduction is 30% for each pass, and the thickness is 0.5mm, and then softening treatment is carried out at a temperature of 380 DEG C and kept for 6h, to obtain aluminum zinc copper magnesium alloy strip;

[0065] S4, the pure aluminum plate with a thickness of 0.8mm is kept at a temperature of 350 DEG C for 10h for recrystallization softening, and the contact surfaces of pure aluminum, aluminum tin alloy and aluminum zinc copper magnesium alloy need to be mechanically polished, which is generally roughened by using a steel wire brush roller;

[0066] S5, pure aluminum / aluminum tin alloy / aluminum zinc copper magnesium alloy assembly is first cold rolled at room temperature with a large reduction, and the rolling reduction is controlled to be 55%, then warm rolling is carried out with a temperature controlled to be 180 DEG C, and the temperature is kept for 13min between adjacent passes, and the rolling reduction is 15% for each pass, to obtain a three-layer plate of pure aluminum layer / aluminum tin alloy layer / aluminum zinc copper magnesium alloy layer with a thickness of 2mm, and then the three-layer plate is kept at a temperature of 320 DEG C for 2.5h for softening treatment;

[0067] S6. The aluminum-zinc-copper-magnesium alloy layer of the three-layer sheet is mechanically treated with a wire brush roller, and the surface of the steel plate is mechanically roughened with a sanding belt. The steel plate is heated to 250°C, and then the three-layer sheet is stacked on the steel plate for one-pass rolling composite. The rolling reduction is 60%, in which the aluminum-zinc-copper-magnesium alloy layer of the three-layer sheet is in direct contact with the steel plate. Then, the rolled pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel multilayer sheet is softened by holding it at a temperature of 280°C for 10 hours to obtain a double aluminum composite material.

[0068] According to the test results, the aluminum-tin alloy of the double aluminum composite material prepared in this embodiment has a uniform distribution of tin phase, good bonding between the interfaces of each layer, and does not crack when bent at 180°. After the plate is processed into a tile, its load-bearing capacity is measured to be 50.6 MPa by a sapphire fatigue testing machine.

[0069] The metallographic structure of the double aluminum composite material prepared in this embodiment is shown in the figure below. Figure 3 As shown, from Figure 3 Analysis shows that the tin phase in the aluminum-tin alloy layer is evenly distributed, and the pure aluminum layer / aluminum-tin alloy layer, aluminum-tin alloy layer / aluminum-zinc-copper-magnesium layer, and aluminum-tin-copper-magnesium layer / steel have good bonding.

[0070] In summary, the bearing bush double aluminum composite material and its preparation method of the present invention involve coating pure aluminum and aluminum-zinc-copper-magnesium alloy onto the surface of an aluminum-tin alloy through room temperature cold rolling and multi-pass warm rolling to form a three-layer plate of pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy; then, after softening and annealing the three-layer plate of pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy, it is rolled together with a heated steel plate in one rolling process to form a four-layer composite plate of pure aluminum / aluminum-tin alloy / aluminum-zinc-copper-magnesium alloy / steel back; finally, it undergoes annealing and softening treatment to obtain a uniform and dispersed tin phase with good interfacial bonding. The high-quality double-aluminum composite material of this invention increases the load-bearing capacity to 50 MPa, which is about 25% higher than that of existing bearing materials (a pure aluminum layer between the aluminum-tin alloy and the steel backing, with a load-bearing capacity of about 40 MPa). Therefore, using the double-aluminum composite material of this invention as the bearing material in high-power marine low-speed engines can greatly improve the load-bearing capacity of the bearings. Moreover, the preparation method of this invention has the advantages of simple operation, low cost and easy implementation, and has promotion and application value in the field of bearing plate technology.

[0071] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A method for preparing a double aluminum composite material, characterized in that, Includes the following steps: S1. For pure aluminum, aluminum-tin alloy, and aluminum-zinc-copper-magnesium alloy billets, a three-layer plate is obtained by cold rolling in one pass and warm rolling in multiple passes, followed by a first annealing treatment. The plate has a pure aluminum layer, an aluminum-tin alloy layer, and an aluminum-zinc-copper-magnesium alloy layer. The rolling reduction in the cold rolling pass is between 50% and 60%. The temperature of the warm rolling in multiple passes is between 150°C and 200°C, with a holding time of 10 to 15 minutes between adjacent passes. The rolling reduction in each pass is less than or equal to 20%, and the number of warm rolling passes is between 6 and 10. S2. Heat the steel plate, then stack the three-layer plate on the steel plate, and after one rolling composite process and a second annealing process, obtain the double aluminum composite material. The rolling reduction of the one rolling composite process is between 45% and 60%.

2. The method for preparing the double aluminum composite material according to claim 1, characterized in that, The composition of the aluminum-tin alloy, by mass percentage, includes: 22-27% tin, 0.7-1.2% manganese, 0.8-1.3% copper, less than or equal to 0.2% titanium, less than or equal to 0.1% silicon, less than or equal to 0.1% iron, with the balance being aluminum.

3. The method for preparing the double aluminum composite material according to claim 1, characterized in that, The composition of the aluminum-zinc-copper-magnesium alloy, by mass percentage, includes: 3.5-4.3% zinc, 0.7-1.1% copper, 0.8-1.3% magnesium, less than or equal to 0.16% titanium, less than or equal to 0.1% iron, and the balance being aluminum.

4. The method for preparing the double aluminum composite material according to claim 1, characterized in that, The temperature of the first annealing treatment is between 280℃ and 360℃, and the time is between 1 and 4 hours. And / or heat the steel plate to a temperature between 200°C and 250°C; And / or the temperature of the second annealing treatment is between 280℃ and 360℃, and the time is between 4 and 10 hours.

5. The method for preparing the double aluminum composite material according to claim 1, characterized in that, The method for preparing the aluminum-tin alloy includes: heating pure aluminum ingots to 740°C~760°C, adding aluminum-manganese alloy and tin blocks in batches, refining with hexachloroethane, cooling to 715°C~730°C, and casting in a water-cooled copper mold to obtain an aluminum-tin alloy billet.

6. The application of a double aluminum composite material prepared by the method according to any one of claims 1 to 5, characterized in that, The double aluminum composite material is used as the material for the bearing bush of the low-speed machine.

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