Aluminum-tin alloy-steel clad plate and rolling method thereof
By using differential temperature rolling and aluminum foil covering the steel surface, the problems of low interfacial bonding strength and high equipment requirements in the rolling process of aluminum-tin alloy/steel composite plates were solved, enabling continuous production of high-quality aluminum-tin alloy-steel composite plates.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING UNIV
- Filing Date
- 2024-04-25
- Publication Date
- 2026-05-15
AI Technical Summary
Existing aluminum-tin alloy/steel composite plates suffer from problems such as low interfacial bonding strength, easy cracking, high equipment requirements, and high energy consumption during the rolling process. In particular, the reaction between tin and iron to form hard and brittle tin-iron compounds reduces the bonding strength, and aluminum-tin alloys have low strength and poor plasticity.
The process employs a differential temperature rolling method, involving multiple passes of room temperature rolling and heat treatment, combined with aluminum foil covering the steel surface to first form an aluminum/steel composite plate. This is then differentially rolled with an aluminum-tin alloy-clad aluminum plate to form a tight bonding interface, preventing the formation of tin-iron compounds.
It improved the interfacial shear strength by 15%, reduced equipment requirements, extended the service life of the rolling mill, and enabled the continuous production of high-quality aluminum-tin alloy-steel composite plates.
Smart Images
Figure CN118357272B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of composite sheet technology, specifically relating to an aluminum-tin alloy-steel composite sheet and its rolling method. Background Technology
[0002] Compared to other bearing materials such as copper-lead alloys and cast iron, aluminum-tin alloys have been widely used in modern internal combustion engine bearings due to their excellent friction-reducing and wear-resistant properties, corrosion resistance, anti-galling, and embedding properties. However, because aluminum-tin alloys have relatively low strength and soft texture, they need to be combined with low-carbon steel to further improve the fatigue strength and load-bearing capacity of the material.
[0003] Currently, the most common and efficient bonding method for aluminum alloys and steel is the rolling composite method. However, in the rolling process of aluminum-tin alloys and steel, the tin in the alloy readily reacts with iron to form hard and brittle tin-iron compounds, reducing the bonding strength of the composite plate. Furthermore, aluminum-tin alloys have low casting strength and poor billet plasticity, making them prone to cracking when directly rolled with steel plates. Therefore, in industry, it is generally common practice to first coat an aluminum-tin alloy billet with a pure aluminum plate (which has better plasticity) to produce an aluminum / aluminum-tin alloy / aluminum composite plate (clad aluminum plate), and then roll the clad aluminum plate and steel plate together.
[0004] Because tin has a low melting point, high rolling temperatures can cause tin in aluminum-tin alloys to seep out from the surface, reducing the alloy's performance.
[0005] The traditional solution to this problem is to use room temperature rolling to prepare aluminum-tin alloy / steel composite plates. However, this process requires a large reduction (generally more than 50%) to achieve a good interfacial bond due to the low rolling temperature, which places high demands on the rolling mill and affects its service life. Moreover, due to the significant differences in properties between aluminum and steel, the uncoordinated plastic deformation during rolling severely affects the quality of the interfacial bond. Furthermore, the plate undergoes severe work hardening after cold rolling, often requiring prolonged low-temperature annealing, resulting in high processing costs and energy consumption. Summary of the Invention
[0006] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the main objective of this invention is to provide an aluminum-tin alloy-steel composite sheet and a method for rolling the same.
[0007] The objective of this invention is achieved through the following technical solution:
[0008] A rolling method for aluminum-tin alloy-steel composite sheet includes the following steps:
[0009] 1) Pure aluminum, aluminum-tin alloy and pure aluminum are riveted into a billet, which is then rolled at room temperature in multiple passes and subjected to a first heat treatment, and then cooled to room temperature to obtain a pure aluminum / aluminum-tin alloy / pure aluminum composite plate.
[0010] 2) Cover the steel plate with aluminum foil and rivet it in place. After one pass of room temperature rolling, an aluminum / steel composite plate is obtained.
[0011] 3) Rivet the pure aluminum / aluminum-tin alloy / pure aluminum composite plate and the heat-treated aluminum / steel composite plate into a billet, then perform heterogeneous rolling on the billet and a second heat treatment to obtain the aluminum-tin alloy-steel composite plate.
[0012] In some specific implementations, the process parameters for multi-pass room temperature rolling in step 1) are: the first pass reduction is 50%, and the subsequent reduction for each pass is 5-10%.
[0013] In some specific implementations, the process parameters for the first heat treatment in step 1) are: heat treatment temperature of 280℃~325℃, heat treatment time of 1h, followed by annealing.
[0014] In some specific implementations, the reduction amount of the room temperature rolling in step 2) is 10%.
[0015] In some specific embodiments, the process parameters for the heat treatment in step 3) are: the heat treatment temperature is 500°C and the heating time is 0.5h.
[0016] In some specific embodiments, the process parameters for the differential temperature rolling in step 3) are as follows: the temperature of the pure aluminum / aluminum-tin alloy / pure aluminum composite plate is room temperature, the temperature of the aluminum / steel composite plate is 500°C, and the rolling reduction is 30-40%.
[0017] In some specific embodiments, the process parameters for the second heat treatment in step 3) are: heat treatment temperature of 325°C, heat treatment time of 3-4 hours, followed by annealing.
[0018] An aluminum-tin alloy-steel composite plate prepared by the aforementioned rolling method.
[0019] Compared with the prior art, the present invention has at least the following advantages:
[0020] 1) The differential temperature rolling method adopted in this invention changes the predicament of traditional processes that force large reduction cold rolling composite of aluminum-tin alloy / steel. By heating and softening the steel layer, the uneven deformation phenomenon during the rolling process of the composite plate is reduced, thereby promoting the coordinated deformation of the composite plate during the rolling process. Under the same reduction rate, the interfacial shear strength is increased by 15% compared with traditional cold rolling.
[0021] 2) The rolling method of the aluminum-tin alloy-steel of the present invention firstly involves room temperature rolling of the aluminum / steel composite plate with low pressure, reducing the requirements for rolling equipment; it also avoids the oxidation of the aluminum layer and steel plate during the preparation of the aluminum / steel composite plate, as well as the problem of deformation incoordination between the aluminum foil and steel plate with large thickness differences, thereby improving the interfacial strength between the aluminum / steel composite plates and providing a basis for forming a strong bonding interface with the aluminum-tin alloy-clad aluminum plate during subsequent temperature rolling; secondly, aluminum foil is used to cover the steel surface, which is easy to bond with harder steel due to its good ductility; thirdly, covering the steel surface with aluminum foil can effectively solve the problem of easy oxide film formation during steel plate heating; finally, the aluminum layer in the aluminum / steel composite plate is tightly bonded to the pure aluminum layer in the aluminum-tin alloy-clad aluminum plate, avoiding the formation of intermetallic compounds, thereby ensuring the interfacial bonding strength between the tin-aluminum alloy / steel composite plates and greatly improving the bonding quality of the tin-aluminum alloy / steel composite plates.
[0022] 3) The aluminum-tin alloy-steel rolling method provided by this invention has simple equipment and is easy to modify. It can effectively reduce the initial reduction rate of the rolling composite, thereby reducing the burden on the rolling mill and increasing the service life of the rolling mill; it can realize continuous and large-scale production. Attached Figure Description
[0023] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below.
[0024] Figure 1 This is a schematic diagram of the preparation process of the novel aluminum-tin alloy / steel composite material of the present invention;
[0025] Figure 2 The image shows the interface morphology of the aluminum-tin alloy / steel composite plate prepared in the embodiment.
[0026] Figure 3 The side shear fracture morphology of the composite steel plate obtained by the differential temperature rolling process and cold rolling process of the present invention is shown.
[0027] Figure 4 This invention compares the interfacial shear strength of composite plates with the same reduction amount produced by the differential temperature rolling process and the cold rolling process of the present invention.
[0028] Figure 5 These are comparison diagrams showing the state of aluminum foil-coated steel plates and uncoated steel plates before and after reheating in Embodiment 2 and Comparative Example 1 of the present invention. Detailed Implementation
[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are merely descriptive and not limiting, and should not be construed as limiting the scope of protection of the present invention.
[0030] When a quantity, concentration, or other value or parameter is described as a range, preferred range, or preferred upper and lower limits, it should be understood that it is equivalent to specifically disclosing any range by combining any pair of upper or preferred values with any lower or preferred values, regardless of whether the range is specifically disclosed. Unless otherwise stated, the numerical range values listed herein include the endpoints of the range and all integers and fractions within that range.
[0031] Unless otherwise stated, all percentages, parts, ratios, etc. in this document are by weight.
[0032] The materials, methods, and embodiments described herein are exemplary and should not be construed as limiting unless otherwise stated.
[0033] Example 1
[0034] The rolling method for aluminum-tin alloy-steel composite plates provided by this invention includes the following steps:
[0035] 1) A 1mm thick AA1060 pure aluminum plate and a 10mm thick aluminum-tin alloy (AlSn) 40 The surface of the Cu alloy billet was polished with a wire brush, and then aluminum rivets were used to press AA1060 / AlSn. 40 Cu / AA1060 are sequentially stacked and riveted into a group of blanks;
[0036] 2) The billet obtained in step 1) is subjected to room temperature rolling with a first pass reduction of 50% and subsequent passes reduction of 5% until AA1060 / AlSn is achieved. 40 The thickness of the Cu / AA1060 composite plate is 1.5mm. The rolled aluminum-clad plate is then annealed at 280℃ for 2 hours to soften it. Finally, it is cooled to room temperature to obtain the aluminum-clad plate.
[0037] 3) Polish the 5mm thick 10# high-quality low carbon steel plate with a flap wheel, clean the surface of the 0.4mm thick AA1060 aluminum foil with alcohol, then cover the polished surface of the steel plate with aluminum foil and rivet it into a blank with aluminum rivets. Roll the blank obtained in step 3) at room temperature with a reduction of 10% to obtain an aluminum / steel composite plate.
[0038] 4) Use aluminum rivets to rivet the aluminum-clad plate (at room temperature) from step 2) to the aluminum / steel composite plate from step 3) after heating to 500°C. Then, quickly feed it into the rolls and roll it at a 30% reduction for 0.5 hours. Then, anneal it at 325°C for 4 hours to obtain the aluminum-tin alloy-steel composite plate.
[0039] Example 2
[0040] The rolling method for aluminum-tin alloy-steel composite plates provided by this invention includes the following steps:
[0041] 1) A 1mm thick AA1060 pure aluminum plate and a 10mm thick aluminum-tin alloy (AlSn) 40 The surface of the Cu alloy billet was polished with a wire brush, and then aluminum rivets were used to press AA1060 / AlSn. 40 Cu / AA1060 are sequentially stacked and riveted into a group of blanks;
[0042] 2) The billet obtained in step 1) is subjected to room temperature rolling with a first pass reduction of 50% and subsequent passes reduction of 8% until AA1060 / AlSn is achieved. 40 The thickness of the Cu / AA1060 composite plate is 1.5mm. The rolled aluminum-clad plate is then annealed at 325℃ for 1 hour to soften it. Finally, it is cooled to room temperature to obtain the aluminum-clad plate.
[0043] 3) Polish the 5mm thick 10# high-quality low carbon steel plate with a flap wheel, clean the surface of the 0.4mm thick AA1060 aluminum foil with alcohol, then cover the polished surface of the steel plate with aluminum foil and rivet it into a blank with aluminum rivets. Roll the blank obtained in step 3) at room temperature with a reduction of 10% to obtain an aluminum / steel composite plate.
[0044] 4) Use aluminum rivets to rivet the aluminum-clad plate (at room temperature) prepared in step 2) to the aluminum / steel composite plate in step 3) which is heated to 500°C in step 3). Then, quickly feed it into the rolls and roll it at a 40% reduction for 0.5 hours. Then, anneal it at 325°C for 4 hours to obtain the aluminum-tin alloy-steel composite plate.
[0045] Example 3
[0046] The rolling method for aluminum-tin alloy-steel composite plates provided by this invention includes the following steps:
[0047] 1) A 1mm thick AA1060 pure aluminum plate and a 10mm thick aluminum-tin alloy (AlSn) 40 The surface of the Cu alloy billet was polished with a wire brush, and then aluminum rivets were used to press AA1060 / AlSn. 40 Cu / AA1060 sequentially stacked and riveted into a group of blanks;
[0048] 2) The billet obtained in step 1) is subjected to room temperature rolling with a first pass reduction of 50% and subsequent passes reduction of 10% until AA1060 / AlSn is achieved. 40The thickness of the Cu / AA1060 composite plate (aluminum clad plate) is 1.5mm. The rolled aluminum clad plate is then annealed at 300℃ for 1.5h to soften it. Finally, it is cooled to room temperature to obtain the aluminum clad plate.
[0049] 3) Polish the 5mm thick 10# high-quality low carbon steel plate with a flap wheel, clean the surface of the 0.4mm thick AA1060 aluminum foil with alcohol, then cover the polished surface of the steel plate with aluminum foil and rivet it into a blank with aluminum rivets. Roll the blank obtained in step 3) at room temperature with a reduction of 10% to obtain an aluminum / steel composite plate.
[0050] 4) Use aluminum rivets to rivet the aluminum-clad plate (room temperature) from step 2) to the aluminum / steel composite plate (500°C) from step 3) after heat treatment to 500°C. Then, quickly feed it into the rolls and roll it at a 35% reduction for 0.5 hours. Then, anneal it at 325°C for 3.5 hours to obtain the aluminum-tin alloy-steel composite plate.
[0051] Comparative Example 1
[0052] The rolling method of the aluminum-tin alloy-steel composite plate provided in this comparative example is basically the same as that in Example 2, except that the low carbon steel plate in step 3) is not covered with aluminum foil. Specifically, the 5mm thick 10# high-quality low carbon steel plate is subjected to flap wheel grinding treatment.
[0053] Comparative Example 2
[0054] The aluminum-tin alloy-steel composite sheet provided in this comparative example is prepared using a conventional room temperature rolling process with the same reduction, specifically including the following steps:
[0055] 1) A 1mm thick AA1060 pure aluminum plate and a 10mm thick aluminum-tin alloy (AlSn) 40 The surface of the Cu alloy casting billet is polished with a wire brush, and then aluminum rivets are used to stack and rivet the billets in the order of pure aluminum plate / aluminum-tin alloy / pure aluminum plate to form a group of billets.
[0056] 2) The billet obtained in step 1) is subjected to room temperature rolling with a first pass reduction of 50% and subsequent passes reduction of 8% until AA1060 / AlSn is achieved. 40 The thickness of the Cu / AA1060 composite plate (aluminum clad plate) is 1.5mm. The rolled aluminum clad plate is then annealed at 280℃ for 2 hours to soften it. Finally, it is cooled to room temperature to obtain the heat-treated aluminum clad plate.
[0057] 3) Polish the 5mm thick 10# high-quality low-carbon steel plate with a flap wheel.
[0058] 4) The aluminum-clad plate and the steel plate are riveted together with aluminum rivets, and then quickly fed into the rolls for room temperature rolling with a reduction of 40%. The rolled plate is then annealed at 325°C for 6 hours to obtain room temperature rolled aluminum-tin alloy-steel composite plate.
[0059] Comparative Example 3
[0060] The aluminum-tin alloy-steel composite plate provided in this comparative example is basically the same as that in Example 2, except that in step 3), the aluminum / steel composite plate is prepared by heterothermal rolling. Specifically, a 5mm thick 10# high-quality low-carbon steel plate is polished with a flap wheel, and the surface of a 0.4mm thick AA1060 aluminum foil is cleaned with alcohol. Then, the aluminum foil and steel plate (room temperature) heated to 400℃ are riveted together, and then quickly fed into the rolls for heterothermal rolling with a 10% reduction to obtain the aluminum / steel composite plate.
[0061] This application uses Example 2 as an example to conduct performance tests on the aluminum-tin alloy-steel composite plates prepared in Example 2, Comparative Example 1, and Comparative Example 2; specifically:
[0062] 1) Morphological testing
[0063] 11) Interface appearance test
[0064] The interface morphology of the aluminum-tin alloy-steel composite plate prepared in Example 2 is shown in the figure below. Figure 2 As shown, from Figure 2 Analysis shows that the composite material consists of 1-steel plate, 2-AA1060 aluminum layer (bonding layer), and 3-AlSn. 40 The Cu aluminum-tin alloy layer and the AA1060 pure aluminum layer (not shown in the figure) show that the metal interfaces of each layer are well bonded without obvious defects such as pores. The tin phase in the aluminum-tin alloy layer is evenly distributed in the aluminum matrix in a network pattern.
[0065] 12) Fracture morphology test
[0066] Microscopic morphology images were taken of the side shear fracture surfaces of the composite plates in Example 2 and Comparative Example 2. The results are as follows: Figure 3 As shown (where Figure 3 (a) is the fracture surface of heterothermal rolling. Figure 3(b) shows the fracture surface after room temperature rolling. Figure c shows the energy dispersive spectroscopy (EDS) spectrum of phase A, Figure d shows the EDS spectrum of phase B, and Figure f shows the EDS spectrum of phase C. The figures show that in the conventional room temperature rolling process (Comparative Example 2), the steel matrix is partially exposed at the fracture surface, indicating that the bonding strength between steel and aluminum in some areas is weaker than that of the aluminum-tin alloy layer, resulting in some areas of weak bonding. In contrast, the steel side fracture surface of the heterothermal rolling process (Example 2) does not expose the steel matrix, indicating that the aluminum / steel interface bonding strength is higher than that of the aluminum-tin alloy layer under this process, and the interface bonding is strong.
[0067] 13) Appearance
[0068] In Example 2 and Comparative Example 1, the actual state of the aluminum foil-coated steel sheet and the uncoated steel sheet obtained in step 4 were observed with the naked eye, and the results are as follows: Figure 4 As shown, where Figure 4 (a) is a diagram showing the state before heating. Figure 4 (b) is a diagram of the state after heating; it can be seen from the diagram that the surface of the uncoated aluminum foil steel plate turns black after heating. This is because a layer of iron oxide film is formed on the surface of the uncoated aluminum foil steel plate during heating, which affects the bonding strength.
[0069] 2) Tensile shear strength test:
[0070] The composite plates from Example 2 and Comparative Example 2 were subjected to tensile shear tests, and the results are as follows: Figure 5 As shown in the figure, compared to traditional room temperature rolling, the rolling method of this invention can improve the interfacial bonding strength by 15% under the same reduction rate.
[0071] 3) Interface bonding strength
[0072] Comparing Example 2 and Comparative Example 3, this application prepares aluminum-tin alloy / steel composite plates by isothermal rolling of aluminum / steel composite plates and then isothermal rolling with cladding plates. First, it was found that during the isothermal rolling process of aluminum / steel composite plates, a dense Al2O3 oxide film forms on the surface of the aluminum foil during heating, which hinders the metallurgical bonding between the aluminum foil and the steel plate. On the one hand, this reduces the bonding strength, and on the other hand, areas with loose bonding are prone to oxidation during subsequent heating of the steel plate, further reducing the bonding strength. As shown in Example 2 and Comparative Example 3, when aluminum / steel composite plates are prepared by isothermal rolling and then isothermal rolling with cladding plates to prepare aluminum-tin alloy / steel composite plates, discontinuous layers are easily formed between the aluminum / steel composite plates and the cladding plates, thereby reducing the interfacial bonding force between the aluminum / steel composite plates and the cladding plates. This leads to poor interfacial bonding strength between the aluminum-tin alloy / steel composite plates, and may even prevent bonding between the layers of the aluminum-tin / steel composite plates.
[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A rolling method for aluminum-tin alloy-steel composite plates, characterized in that, Includes the following steps: 1) Pure aluminum, aluminum-tin alloy and pure aluminum are riveted into a billet, which is then rolled at room temperature in multiple passes and subjected to a first heat treatment. After cooling to room temperature, a pure aluminum / aluminum-tin alloy / pure aluminum composite plate is obtained. 2) Cover the steel plate with aluminum foil and fix it with rivets. After one room temperature rolling process, an aluminum / steel composite plate is obtained. 3) Rivet the pure aluminum / aluminum-tin alloy / pure aluminum composite plate and the heat-treated aluminum / steel composite plate into a billet, then perform heterothermal rolling on the billet and a second heat treatment to obtain the aluminum-tin alloy-steel composite plate. In step 2), the reduction of the room temperature rolling in one pass is 10%. The process parameters for the first heat treatment in step 1) are: heat treatment temperature of 280℃~325℃, heat treatment time of 1h, followed by annealing. The process parameters for the heterothermal rolling in step 3) are: the temperature of the pure aluminum / aluminum-tin alloy / pure aluminum composite plate is room temperature, the temperature of the aluminum / steel composite plate is 500℃, and the rolling reduction is 30-40%. The process parameters for the second heat treatment in step 3) are: heat treatment temperature of 325℃, heat treatment time of 3-4h, followed by annealing.
2. The rolling method for aluminum-tin alloy-steel composite plates according to claim 1, characterized in that, The process parameters for multi-pass room temperature rolling in step 1) are: the first pass reduction is 50%, and the subsequent passes each have a reduction of 5-10%.
3. The rolling method for aluminum-tin alloy-steel composite plates according to claim 2, characterized in that, The process parameters for the heat treatment in step 3) are: heating temperature of 500℃ and heating time of 0.5h.
4. An aluminum-tin alloy-steel composite plate prepared by the rolling method according to any one of claims 1-3.