A method for preparing flat titanium / aluminum composite plate based on wave-flat rolling

Abstract

The present application belongs to the technical field of titanium / aluminum composite plate, and discloses a method for preparing flat titanium / aluminum composite plate through asynchronous rolling based on wave-flat rolling, which comprises the following steps: firstly, cleaning, polishing and secondary cleaning of titanium and aluminum plate materials; heating treatment after laminating and assembling; feeding the heated titanium / aluminum composite plate blank into a wave-flat rolling machine for differential asynchronous rolling; feeding into a double flat roller rolling machine for two-pass rolling and post-rolling heat treatment after re-furnace heat preservation. The asynchronous wave-flat rolling of the present application enlarges the compression strain and shear strain generated at the interface, amplifies the effect of metal extrusion deformation at the bonding interface, is beneficial to the outflow and penetration of fresh metal of titanium and aluminum at the bonding interface, promotes the rupture of the hardening layer and oxidation layer of the surface to be combined during the metal rolling process, and is beneficial to the improvement of the metal bonding strength; the metal flow direction is inconsistent in the rolling deformation zone during the two-pass rolling process, which is beneficial to further enhancing the bonding strength of the titanium / aluminum composite plate.

Description

Technical Field

[0001] This invention relates to the field of titanium / aluminum composite plate technology, and more particularly to a method for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling. Background Technology

[0002] With the rapid development of my country's modern industry, single metal sheets can no longer meet the comprehensive performance requirements of various applications, making the research of composite materials crucial. Metal composite plates can combine the advantages of individual components while mitigating the shortcomings of single materials, significantly improving the overall properties of the material. Metal composite materials generally refer to novel materials that achieve a good bond between two or more significantly different metal materials through special preparation methods, thus serving as a high-quality new material with high strength, high corrosion resistance, high wear resistance, and controllable cost.

[0003] Titanium / aluminum composite panels possess superior properties such as lightweight, high temperature resistance, good thermal conductivity, high wear and corrosion resistance, and high strength, making them one of the most popular metal composite materials today. Titanium ranks tenth in abundance in the Earth's crust, with low density and a high melting point. Therefore, titanium and titanium alloys exhibit excellent performance as structural materials, such as being lightweight, high-strength, wear-resistant, and corrosion-resistant. However, it remains a rare and expensive metal, hindering large-scale applications. Aluminum alloys also possess advantages such as lightweight, good electrical conductivity, and corrosion resistance, and are inexpensive. Therefore, the emergence of titanium / aluminum composite panels combines the excellent properties of both, showing broad application prospects and significant development potential in aerospace, aviation, petroleum, chemical, and automotive engineering fields.

[0004] Existing mainstream methods for preparing titanium / aluminum composite plates include rolling bonding and explosive bonding. Explosive bonding suffers from severe surface quality issues, poor bonding stability, and serious environmental problems. Traditional hot rolling processes easily generate brittle interfacial compounds, resulting in significant problems with plate shape and surface quality, leading to warping and edge cracking in titanium / aluminum composite plates. Recent advancements in corrugated-flat rolling for producing titanium / aluminum composite plates have lower rolling temperatures and significantly increased bonding area, but warping and other shape quality issues still exist. Therefore, this paper proposes a differential corrugated-flat rolling process to amplify the shearing effect of the corrugated rolls, improve plate shape quality, and further enhance the bonding strength of the composite plate, thereby successfully preparing titanium / aluminum composite plates with excellent shape and high bonding strength. Summary of the Invention

[0005] The present invention aims to provide a method for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling, so as to solve the technical problems of warping and low bonding strength of titanium / aluminum composite plates in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling includes the following steps:

[0008] S1. Billet Preparation: Prepare titanium and aluminum plates. Clean the surfaces of the titanium and aluminum plates separately with alcohol. Then, use a wire brush to polish the surfaces of the titanium and aluminum plates to be joined. Place the polished titanium and aluminum plates in an ultrasonic cleaner to remove impurities and oxide scale from the surfaces to be joined. Then, stack the surfaces of the titanium and aluminum plates to be joined together and use fine aluminum wire to roll and bind them at the rolling biting end to obtain a titanium / aluminum composite billet.

[0009] S2. Heating in the heating furnace: Preheat the heating furnace. When the preset temperature is reached, place the assembled titanium / aluminum composite slab from step S1 into the heating furnace for heating treatment.

[0010] S3, Wave-flat differential speed rolling: The titanium / aluminum composite plate billet heated in step S2 is fed into the wave-flat rolling mill for one differential speed rolling. The reduction amount is set according to the shape of the corrugated rolls so that the reduction amount can ensure that the corrugations can fully penetrate to the bonding interface.

[0011] S4. Second pass heat preservation: The titanium / aluminum composite plate rolled in one pass of the wave-flat mill in step S3 is put back into the heating furnace for a short heat preservation.

[0012] S5. Second pass double-roll rolling: The titanium / aluminum composite plate that has been heat-preserved again in step S4 is fed into a double-roll mill for second pass rolling, and the reduction is made to ensure that the corrugations are completely flattened.

[0013] S6. Post-rolling treatment: The titanium / aluminum composite plate prepared in step S5 is subjected to post-rolling heat treatment to prepare a titanium / aluminum composite plate with high bonding strength.

[0014] Furthermore, in step S1, the titanium plate is industrial pure titanium or titanium alloy plate, including any one of TA1, TA2, TA3, TA4, TC4 or Ti60, with a thickness of 0.5mm-3mm, and the aluminum plate is aluminum alloy plate with a thickness of 2-10mm. The thickness ratio of the titanium plate to the aluminum plate is 1:8-1:12.

[0015] Furthermore, in step S2, the preset temperature is 250℃-450℃, and the heating time is 20min-40min.

[0016] Furthermore, in step S3, the corrugated roll in the corrugated-flat rolling mill acts directly on the upper surface of the titanium plate as the upper corrugated roll, while the aluminum plate is in direct contact with the lower flat roll, and the asynchronous speed ratio between the upper corrugated roll and the lower flat roll is greater than 1.

[0017] Furthermore, in step S3, the working speed of the lower flat roller is 1.3 rad·s. -1 -1.75 rad·s -1 .

[0018] Furthermore, in step S3, the working speed ratio between the upper corrugated roller and the lower flat roller is an asynchronous speed ratio greater than 1 and less than or equal to 1.3.

[0019] Furthermore, in step S3, both the upper corrugated roller and the lower flat roller have a diameter of 150mm and a reduction amount of 30%-45%.

[0020] Furthermore, in step S6, the heat treatment temperature is 400℃-500℃, and the treatment time is 30min-120min.

[0021] In summary, the present invention has the following beneficial effects:

[0022] 1. The overall strain uniformity of asynchronous wave-flat rolling increases. While titanium generates a larger compressive strain, the average compressive strain of aluminum decreases. At the same time, the compressive strain at the interface also increases. The shear strain on the titanium side and at the interface increases significantly, while the shear strain on the lower surface of aluminum decreases. This increases the strain of titanium while reducing the strain of aluminum, thereby promoting the deformation coordination of titanium and aluminum during the rolling process of composite plates. By increasing the compressive and shear strains at the interface, the effect of metal extrusion deformation at the interface is amplified, which is conducive to the outflow and penetration bonding of fresh metal at the interface between titanium and aluminum.

[0023] 2. Asynchronous wave-flat rolling increases the difference in shear stress between the upper and lower surfaces of the metal, as well as the difference in relative flow velocity between the upper and lower metal surfaces. This significantly enhances the rolling action and the shearing effect of the rolls on the composite plate. Simultaneously, the number of metal stress states exhibiting strong shear at the bonding interface increases significantly, further promoting the rupture of the hardened and oxide layers on the surfaces to be bonded during rolling, which is beneficial for improving the bonding strength. Furthermore, due to the increased relative flow and strong shearing effect within the rolling zone, the degree of metal grain fragmentation and refinement increases, thereby promoting the deformation coordination of titanium and aluminum during the rolling process.

[0024] 3. During the two-pass rolling process, the originally corrugated composite plate is gradually flattened. Because titanium has greater deformation resistance than aluminum, the raised peaks of the first-pass composite plate are fully recessed into the aluminum due to sufficient reduction. Therefore, the compressive strain generated by the original peaks is the greatest. Since the extension in the RD direction is the largest during rolling, this process further increases the bonding area between the titanium and aluminum metals. After the second pass, the shear strain at the bonding interface is greater than that generated in the first pass. During the second pass rolling process, due to the special characteristics of the corrugated plate, the metal flow direction is inconsistent within the rolling deformation zone, and the corrugated plate experiences strong shear force, which further enhances the bonding strength of the titanium / aluminum composite plate. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the process for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling according to the present invention.

[0026] Figure 2 The titanium / aluminum composite plate specimen after one synchronous rolling in Comparative Example 1;

[0027] Figure 3 The titanium / aluminum composite plate specimen after one asynchronous rolling process in Example 1;

[0028] Figure 4 The following are the plate shape conditions of titanium / aluminum composite plates produced by asynchronous rolling in one pass in Example 1, Comparative Example 1, and Comparative Example 2: a) Equivalent strain under different differential speed ratios, b) Statistics on the warpage of the composite plates produced by rolling experiments under different differential speed ratios.

[0029] Figure 5 The image shows the compressive strain distribution cloud map of the titanium / aluminum composite plate rolled in one pass in Example 1 and Comparative Example 1.

[0030] Figure 6 The shear strain distribution cloud map is shown for the titanium / aluminum composite plate rolled in one pass in Example 1 and Comparative Example 1. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments:

[0032] Example 1

[0033] Industrial pure titanium TA1 (180mm×60mm×1mm) was selected as the cladding material, and aluminum alloy 6061 (180mm×60mm×8mm) was selected as the base material for the assembly. The surfaces of the titanium and aluminum slabs were cleaned with alcohol, and then the interface to be laminated was ground along the rolling direction using a 0.15mm diameter T-shaped steel wire brush. After grinding, the composite plate was cleaned with an ultrasonic cleaner to ensure that the surfaces to be bonded were free of impurities and oxide scale. The titanium and aluminum slabs were then stacked face-to-face, and the bite-in ends of the slabs were bound together using fine aluminum wire. The furnace was preheated, and after reaching the preset temperature of 300℃, the assembled composite slabs were placed in the furnace for a 30-minute heating treatment. The heated titanium / aluminum composite slab is fed into a corrugated roll mill for a single differential speed rolling pass. The titanium plate is positioned above, contacting the upper corrugated roll, while the aluminum plate is positioned below, directly contacting the lower flat roll. The rolling temperature is 300℃, and the reduction is 35%. The initial slab dimensions are 180mm × 60mm × 9mm. Both the upper corrugated roll and the lower flat roll have a diameter of 150mm. The roll speeds are selected as follows: upper corrugated roll 143mm / s, lower flat roll 125mm / s, i.e., the asynchronous speed ratio between the upper corrugated roll and the lower flat roll is 1.15. After rolling, the titanium / aluminum composite slab is briefly placed back into the heating furnace for heat treatment. After this second heat treatment, the titanium / aluminum composite slab is fed into a double flat roll mill for a second rolling pass, with the reduction ensuring complete smoothing of the corrugations. The prepared titanium / aluminum composite slab undergoes post-rolling heat treatment at 450℃ for 120 minutes.

[0034] In this embodiment, the peel strength of the titanium / aluminum composite plate is 34 N / mm, the peel strength after heat treatment is 50 N / mm, and the tensile shear strength is 100 MPa.

[0035] Comparative Example 1

[0036] Industrial pure titanium TA1 (180mm×60mm×1mm) was selected as the cladding material, and aluminum alloy 6061 (180mm×60mm×8mm) was selected as the base material for the assembly. The surfaces of the titanium and aluminum slabs were cleaned with alcohol, and then the interface to be laminated was ground along the rolling direction using a 0.15mm diameter T-shaped steel wire brush. After grinding, the composite plate was cleaned with an ultrasonic cleaner to ensure that the surfaces to be bonded were free of impurities and oxide scale. The titanium and aluminum slabs were then stacked face-to-face, and the bite-in ends of the slabs were bound together using fine aluminum wire. The furnace was preheated, and after reaching the preset temperature of 300℃, the assembled composite slabs were placed in the furnace for a 30-minute heating treatment. The heated titanium / aluminum composite plate slab is fed into a corrugated roll mill for a single rolling pass. Aluminum is positioned above, contacting the upper corrugated roll, and below, directly contacting the lower flat roll. The rolling temperature is 300℃, and the reduction is 35%. The initial slab dimensions are 180mm × 60mm × 9mm. Both the upper corrugated roll and the lower flat roll have a diameter of 150mm. The roll speeds are set at 125mm / s for both the upper and lower corrugated rolls (a synchronous speed ratio of 1). After rolling, the composite plate is briefly reheated in a furnace. Following this second heat treatment, the composite plate is fed into a double flat roll mill for a second rolling pass, with the reduction ensuring complete smoothing of the corrugations. The prepared titanium / aluminum composite plate undergoes post-rolling heat treatment at 450℃ for 120 minutes.

[0037] In this comparative example, the peel strength of the titanium / aluminum composite plate is 25 N / mm, the peel strength after heat treatment is 35 N / mm, and the tensile shear strength is 80 MPa.

[0038] Comparative Example 2

[0039] Industrial pure titanium TA1 (180mm×60mm×1mm) was selected as the cladding material, and aluminum alloy 6061 (180mm×60mm×8mm) was selected as the base material for the assembly. The surfaces of the titanium and aluminum slabs were cleaned with alcohol, and then the interface to be laminated was ground along the rolling direction using a 0.15mm diameter T-shaped steel wire brush. After grinding, the composite plate was cleaned with an ultrasonic cleaner to ensure that the surfaces to be bonded were free of impurities and oxide scale. The titanium and aluminum slabs were then stacked face-to-face, and the bite-in ends of the slabs were bound together using fine aluminum wire. The furnace was preheated, and after reaching the preset temperature of 300℃, the assembled composite slabs were placed in the furnace for a 30-minute heating treatment. The heated titanium / aluminum composite plate slab is fed into a corrugated roll mill for a single rolling pass. Aluminum is positioned above, contacting the upper corrugated roll, and below, directly contacting the lower flat roll. The rolling temperature is 300℃, and the reduction is 35%. The initial slab dimensions are 180mm × 60mm × 9mm. Both the upper corrugated roll and the lower flat roll have a diameter of 150mm. The roll speeds are selected as follows: upper corrugated roll 112.5mm / s, lower flat roll 125mm / s (synchronous speed ratio 0.9). After rolling, the composite plate is briefly reheated in a furnace. Following this second heat treatment, the composite plate is fed into a double flat roll mill for a second rolling pass, with the reduction ensuring complete smoothing of the corrugations. The prepared titanium / aluminum composite plate undergoes post-rolling heat treatment at 450℃ for 120 minutes.

[0040] The difference between Example 1 and Comparative Example 1 is that in one rolling pass, the upper corrugated roll and the lower flat roll roll are rolled at different differential speed ratios. That is, Example 1 is asynchronous differential corrugated-flat rolling, while Comparative Example 1 is synchronous differential corrugated-flat rolling. Figure 5 As shown, the compressive strain generated in the upper and lower parts of the composite plate obtained by asynchronous wave-flat rolling is significantly different, while the compressive strain generated in the composite plate obtained by synchronous wave-flat rolling is more uniform. This suggests that the upper part of the asynchronous wave-flat rolling composite plate generates a larger compressive strain than the lower part, thus positively promoting plate shape coordination. Since the titanium is completely rolled and embedded in the aluminum, the compressive strain generated in the aluminum at the joint is greater than that in the titanium. Similarly, the compressive strain generated at the joint interface by asynchronous wave-flat rolling is greater than that generated by synchronous wave-flat rolling, thus having a positive effect on the bonding strength of the composite plate. Figure 6 As shown, the corrugated rolls caused greater shear deformation to the upper titanium metal and the area near the interface than to the lower metal. However, the asynchronous wave-flat rolling process had a greater and more uniform positive shear strain than the synchronous wave-flat rolling process. This indicates that the asynchronous wave-flat rolling process caused greater shear deformation to the composite plate. This behavior greatly promoted the elongation of the titanium metal and the cracking at the junction with the aluminum, thus increasing the bonding strength between the two metals.

[0041] The above description is merely an embodiment of the present invention, and common knowledge such as specific technical solutions or characteristics in the solution is not described in detail here. It should be noted that those skilled in the art can make several modifications and improvements without departing from the technical solution of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling, characterized in that, Includes the following steps: S1. Billet preparation: Prepare titanium plates and aluminum plates. Clean the surfaces of the titanium plates and aluminum plates separately with alcohol. Then, use a wire brush to polish the surfaces of the titanium plates and aluminum plates to be joined. Place the polished titanium plates and aluminum plates in an ultrasonic cleaner to remove impurities and oxide scale from the surfaces to be joined. Then, stack the surfaces of the titanium plates and aluminum plates to be joined together and use fine aluminum wire to roll and bind them at the rolling bite end to obtain a titanium / aluminum composite billet. S2. Heating in the heating furnace: Preheat the heating furnace. When the preset temperature is reached, place the assembled titanium / aluminum composite slab from step S1 into the heating furnace for heating treatment. S3, Wave-flat differential speed rolling: The titanium / aluminum composite plate billet heated in step S2 is fed into the wave-flat rolling mill for one differential speed rolling. The reduction amount is set according to the shape of the corrugated rolls so that the reduction amount can ensure that the corrugations can fully penetrate to the bonding interface. The corrugated roller acts directly on the upper surface of the titanium plate as the upper corrugated roller, while the aluminum plate is in direct contact with the lower flat roller. The working speed ratio of the upper corrugated roller to the lower flat roller is an asynchronous speed ratio greater than 1 and less than or equal to 1.

3. S4. Second pass heat preservation: The titanium / aluminum composite plate rolled in one pass of the wave-flat mill in step S3 is put back into the heating furnace for a short heat preservation. S5. Second pass double-roll rolling: The titanium / aluminum composite plate that has been heat-preserved again in step S4 is fed into a double-roll mill for second pass rolling, and the reduction is made to ensure that the corrugations are completely flattened. S6. Post-rolling treatment: The titanium / aluminum composite plate prepared in step S5 is subjected to post-rolling heat treatment to prepare a titanium / aluminum composite plate with high bonding strength.

2. The method for preparing flat titanium / aluminum composite plates based on asynchronous rolling using wave-flat rolling according to claim 1, characterized in that, In step S1, the titanium plate is industrial pure titanium or titanium alloy plate, including any one of TA1, TA2, TA3, TA4, TC4 or Ti60, with a thickness of 0.5 mm-3 mm; the aluminum plate is aluminum alloy plate with a thickness of 2-10 mm, and the thickness ratio of the titanium plate to the aluminum plate is 1:8-1:

12.

3. The method for preparing flat titanium / aluminum composite plates based on asynchronous rolling using wave-flat rolling according to claim 1, characterized in that, In step S2, the preset temperature is 250℃-450℃, and the heating time is 20 min-40 min.

4. The method for preparing flat titanium / aluminum composite plates based on asynchronous rolling using wave-flat rolling according to claim 1, characterized in that, In step S3, the working speed of the lower flat roller is 1.3 rad·s. -1 -1.75 rad·s -1 .

5. A method for preparing flat titanium / aluminum composite plates by asynchronous rolling based on wave-flat rolling according to claim 1 or 4, characterized in that, In step S3, the diameter of both the upper corrugated roller and the lower flat roller is 150 mm, and the reduction is 30%-45%.

6. The method for preparing flat titanium / aluminum composite plates based on asynchronous rolling using wave-flat rolling according to claim 1, characterized in that, In step S6, the heat treatment temperature is 400℃-500℃, and the treatment time is 30 min-120 min.

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