A composite sheet strip and a method of manufacturing the same

Abstract

The present application relates to a kind of composite sheet and its preparation method, belong to metal composite sheet technical field.The preparation method of the present application includes the following steps: taking two single corrugated surface metal plate strip, the corrugated surface of one or two single corrugated surface metal plate strip is coated with graphene to form graphene coating layer and make the surface of graphene coating layer retain the waveform of corrugated surface, then two single corrugated surface metal plate strip is stacked and is formed into a billet, then flat roll is used to roll, namely obtained;The corrugation of the surface of two single corrugated surface metal plate strip is matched, the corrugated surface of two single corrugated surface metal plate strip is opposite when stacking and two single corrugated surface metal plate strip is engaged each other.The preparation method of the present application can form structure with uniform contact interface and good mechanical engagement at bonding interface, improve interface bonding degree, can inhibit metal composite plate warping along the rolling direction, improve plate shape quality, and also can improve the strength, plasticity and conductivity of composite sheet.

Description

Technical Field

[0001] This invention relates to a composite plate and strip and its preparation method, belonging to the technical field of metal composite plate and strip. Background Technology

[0002] Metal composite sheet and strip refers to a sheet or strip with one metal layer on top of another. Through a certain process, the layers of metal sheet and strip are combined in a metallurgical or mechanical way. This allows the advantages of each component material to be brought into play, resulting in excellent comprehensive performance. It can meet the performance requirements that a single metal cannot meet, and at the same time, it can save precious metals to a certain extent. It is widely used in aerospace, rail transportation and other fields.

[0003] Metal composite plates and strips can be prepared by methods such as melting and casting composite, explosive composite, welding composite, and rolling composite. Among them, rolling composite has the advantages of high efficiency and easy process control, making it one of the main processes for preparing multilayer metal composite plates. However, the interfacial bonding performance of metal composite plates and strips prepared by rolling composite is relatively poor compared with other methods, specifically manifested in low bonding strength, easy warping, and low yield, which restricts the application of this method in preparing metal composite plates and strips. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing composite strips, which improves the bonding strength and yield of composite strips, and the prepared composite strips are less prone to warping.

[0005] The present invention also provides a composite plate and strip prepared by the above-mentioned method.

[0006] To achieve the above objectives, the technical solution adopted in the preparation method of the composite plate and strip of the present invention is as follows:

[0007] A method for preparing a composite sheet and strip includes the following steps: taking two single-corrugated metal sheet and strip, coating one or two of the single-corrugated metal sheet and strip with graphene to form a graphene coating layer, and keeping the corrugated waveform on the surface of the graphene coating layer; then stacking the two single-corrugated metal sheet and strip to form a blank, and then rolling it with flat rolls to obtain the composite sheet and strip; the corrugations on the surfaces of the two single-corrugated metal sheet and strip are matched, and when stacked, the corrugated surfaces of the two single-corrugated metal sheet and strip are opposite to each other and the two single-corrugated metal sheet and strip are interlocked.

[0008] The method for preparing the composite sheet / strip of this invention involves stacking two single-corrugated metal sheet / strips with matching corrugations before rolling. The two corrugated metal sheet / strips interlock, forming a structure with uniform contact and good mechanical interlocking at the interface. This improves the interfacial bonding while suppressing warping of the metal composite sheet along the rolling direction, improving sheet shape quality. Furthermore, the corrugated surface has a larger area than the planar surface, increasing the amount of graphene coating. Graphene, as a two-dimensional material, has a strength and elastic modulus of 125 GPa and 1100 GPa, respectively, and an electrical conductivity of up to 10⁻⁶. 6 Graphene's two-dimensional planar structure gives it a larger specific surface area, allowing for more contact with the composite matrix and making it a better reinforcing material. Furthermore, graphene exhibits good plasticity and toughness due to in-plane slip dislocation movement under external pressure. Combining graphene with metal sheets and strips produces a synergistic effect, thereby improving the strength, plasticity, and conductivity of the composite sheets and strips, resulting in multilayer composite sheets and strips with excellent overall performance.

[0009] Furthermore, the two single-corrugated metal strips are independently selected from strip A or strip B; strip A is obtained by single-pass corrugated roll rolling of metal strip; strip B includes two or more metal layers, and any two adjacent metal layers are compounded by single-pass corrugated roll rolling. Before compounding, the surfaces of the two metal layers to be compounded are corrugated surfaces that can mesh with each other during rolling, and graphene is coated on the surface of at least one metal layer to be compounded to form a graphene layer, and the graphene coating layer retains the corrugated waveform. The corrugated roll rolling is performed using two rolls. One of the two rolls used in the corrugated roll rolling is a corrugated roll, and the other roll is a flat roll. For example, both single-corrugated metal strips are strip B, and one strip B has two metal layers, while the other strip B has four metal layers.

[0010] Further, the strip material B is prepared by a method including the following steps: the metal strip material is rolled by a single pass of corrugated rolls to obtain the strip material to be composited; two strip materials to be composited are taken, and graphene is coated on one or two corrugated surfaces of the strip materials to be composited to form a graphene coating layer, and the surface of the graphene coating layer retains the corrugated waveform; then the two strip materials to be composited are stacked to form a blank, and then rolled by a single pass of corrugated rolls to obtain the composite material; the corrugations on the surfaces of the two strip materials to be composited are matched, and when stacked, the corrugated surfaces of the two strip materials to be composited face each other and the two strip materials to be composited mesh with each other.

[0011] Furthermore, during the preparation of strip A and strip B, a uniformly distributed graphene coating layer is applied to the corrugated surface. If the graphene coating layer is too thin, it is difficult to prepare and the increase in the mechanical properties of the strip is not significant; conversely, if the graphene coating layer is too thick, it is detrimental to the bonding between the strips and can easily lead to a deterioration in mechanical properties. Further, the thickness of the graphene coating layer is 0.1–2 μm, for example, 0.16 μm. Further, the graphene coating layer is formed using an ultrasonic spraying method. The coating solution used in ultrasonic spraying is a dispersion of few-layer graphene, with a graphene mass fraction of 0.5%. The coating solution is formed by dispersing few-layer graphene in a mixed solvent of N-methylpyrrolidone and isopropanol.

[0012] Furthermore, the amplitude of the corrugations formed on the strip by the corrugated rolls during corrugated roll rolling is 0.4–0.6 mm, for example, 0.5 mm. That is to say, the amplitude of the corrugations formed on the strip by the corrugated rolls during the corrugated roll rolling process of strip A and strip B is 0.4–0.6 mm.

[0013] Furthermore, the corrugated rolls used in corrugated roll rolling form triangular, sinusoidal, or trapezoidal corrugations on the strip.

[0014] Furthermore, the corrugated rolls used in corrugated roll rolling form triangular corrugations on the strip. On the cross-section of the strip perpendicular to the direction of the corrugation crest, the angle between the two interior angles of the triangle formed by connecting the highest point of the crest with the lowest point of the adjacent trough is 30°–60°, more preferably 45°–60°. Controlling the angle within 30°–60° increases the interfacial contact area, which is beneficial for interlayer meshing and also improves the problem of strip warping. An angle that is too large or too small will affect the contact area and interlayer meshing, thus affecting strip warping. When the included angle is within the range of 30°–60°, the strip shape is basically straight.

[0015] Furthermore, during corrugated roll rolling, the direction of the crest extension on the corrugated surface formed on the strip by the corrugated roll is perpendicular to the direction of movement of the strip during the rolling process.

[0016] During flat rolling, the warpage of the composite plate increases with increasing reduction rate. Preferably, the reduction rate for flat rolling is in the range of 10% to 30%, for example, 20%. During corrugated roll rolling, the warpage of the composite plate decreases with increasing reduction rate. Preferably, the reduction rate for corrugated roll rolling is in the range of 40% to 60%, for example, 50%.

[0017] The technical solution adopted in the composite plate and strip of the present invention is as follows:

[0018] A composite sheet / strip prepared by the above-described method.

[0019] The composite strip of the present invention is prepared by the above-described method and has excellent comprehensive mechanical properties and good plate quality. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the upper and lower rolls of the rolling mill used in steps 1) and 4) of Example 1.

[0021] Figure 2 This is a schematic diagram of the copper composite strip obtained in step 2) of Example 1;

[0022] Figure 3 This is a schematic diagram of the composite plate blank obtained in step 3) of Example 1;

[0023] Figure 4 This is a schematic diagram of the single-corrugated composite metal sheet / strip obtained in step 4) of Example 1;

[0024] Figure 5 This is a schematic diagram of the upper and lower rolls of the rolling mill used in step 5) of Example 1;

[0025] Among them, 1-corrugated roller, 2-flat roller, 3-graphene coating layer, 4-single corrugated surface metal sheet / strip to be composited, and 5-corrugated surface. Detailed Implementation

[0026] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0027] The graphene coating solutions used in Examples 1-5 were prepared using a method comprising the following steps:

[0028] Graphene was dispersed in a mixed solution of N-methylpyrrolidone (NMP) and isopropanol (volume ratio 5:1) to form a 2 mg / mL solution. After ultrasonic dispersion for 12 h, the solution was centrifuged at 3000 r / min for 5 min to remove precipitated agglomerated graphene particles. The supernatant was then centrifuged at 8000 r / min for 10 min to separate the supernatant (enriched with few-layer graphene). The collected few-layer graphene suspension was dried in a vacuum drying oven at 70 °C for 12 h to obtain few-layer graphene. Then, a mixed solvent of NMP and ethylene glycol (EG) (volume ratio 2:1) was added to a beaker, followed by the dried few-layer graphene. The mixture was stirred at high speed for 0.5 h and ultrasonically dispersed for 5 h to prepare a 0.5% (w / w) graphene dispersion, which is the graphene coating solution. The prepared graphene coating solution was bottled for later use.

[0029] To test whether few-layer graphene would undergo stratification or agglomeration in different ratios of dispersion solvents, graphene was dispersed in a mixed solution of NMP and EG with volume ratios of NMP to EG of 1:0, 2:1, 1:2, and 0:1. After standing for one week in different mixed solutions, the graphene exhibited good dispersibility and no agglomeration, stratification, or sedimentation occurred.

[0030] Example 1

[0031] The method for preparing the composite strip in this embodiment includes the following steps:

[0032] 1) Select a 3mm thick T2 industrial pure copper plate and feed it into a rolling mill for single-pass rolling, controlling the reduction rate at 50%, to obtain a single-corrugated surface metal strip to be composite; the rolling rolls used during rolling are as follows: Figure 1 As shown, the upper roller is a corrugated roller 1 and the lower roller is a flat roller 2. The corrugated roller 1 forms a triangular wave on the copper plate with an amplitude of 0.5 mm. In the cross section of the single-corrugated surface of the metal strip to be composited, perpendicular to the direction of the wave crest extension on the corrugated surface, the angles of the two interior angles with the wave crest as the vertex are both 45° in the triangle formed by connecting the high point of the wave crest and the low point of the adjacent wave crest. During the rolling process, the direction of the wave crest extension on the corrugated surface formed by the corrugated roller 1 on the strip is perpendicular to the direction of the strip movement.

[0033] 2) Then, using non-woven fabric soaked in acetone, water, and ethanol respectively, wipe the corrugated surface of the rolled single-corrugated metal strip to be composited, removing surface stains. After drying, use ultrasonic spraying to coat the corrugated surface with graphene coating liquid (0.1 mL of graphene coating liquid per square centimeter of T2 industrial pure copper plate surface). Then dry at 70℃ for 6 hours to form a uniformly distributed graphene coating layer with a thickness of 1.6 μm on the corrugated surface, obtaining the copper composite strip. The obtained copper composite strip is shown below. Figure 2 As shown, it includes a single-corrugated surface metal strip to be composited 4 and a graphene coating layer 3 coated on the corrugated surface of the single-corrugated surface metal strip to be composited 4.

[0034] 3) Select one pre-prepared copper composite strip as the substrate, and select another pre-prepared copper composite strip as the cladding, such as... Figure 3 As shown, the composite plate and the substrate are stacked together, with the graphene coating layer of the composite plate facing the graphene coating layer of the substrate. After stacking, the composite plate and the substrate interlock, and then are pressed together and the four corners are fixed together (to ensure that the substrate and the composite plate will not be misaligned or deviated when subjected to non-uniform tangential force during the rolling process), thus obtaining a composite plate blank with graphene as the bonding area.

[0035] 4) The obtained composite plate slab is fed into a rolling mill for rolling, with the reduction rate controlled at 50%, to obtain a single-corrugated composite metal sheet / strip; the rolling rolls used during rolling are as follows: Figure 1 As shown, the upper roller is a corrugated roller 1, and the lower roller is a flat roller 2. The corrugations formed by the corrugated roller 1 on the composite plate blank are triangular waves with an amplitude of 0.5 mm. The resulting single-corrugated composite metal strip is made with the two interior angles of the triangle formed by connecting the peak of the wave with the two adjacent troughs on the cross-section of the corrugated surface perpendicular to the direction of the wave peak extension. The angles of the two interior angles with the trough as the vertex are both 45°. During the rolling process, the direction of the wave peak extension on the corrugated surface formed by the corrugated roller 1 on the composite plate blank is perpendicular to the direction of movement of the composite plate blank.

[0036] The single-corrugated composite metal sheet and strip obtained after rolling, such as Figure 4 The upper surface shown is corrugated, the lower surface is flat, and the middle layer bonding surface is graphene.

[0037] 5) The corrugated surfaces of the two well-bonded single-corrugated composite metal strips are ultrasonically coated with graphene using the same method as in step 2). After the graphene coating, a uniformly distributed graphene coating layer with a thickness of 1.6 μm is formed on the corrugated surfaces of the two single-corrugated composite metal strips. One of them is used as the substrate, and the other as the cladding. The substrate and the cladding are then stacked, with the graphene coating layer of the cladding facing the graphene coating layer of the substrate. After stacking, the cladding and the substrate interlock, are then pressed together, and the four corners are fixed together to form a composite slab. This slab is then fed into a rolling mill using flat rolls (two flat rolls such as...). Figure 5 (As shown) Rolling is performed with a reduction rate of 20% to obtain a copper composite strip with a smooth surface and graphene as the three-layer bonding surface.

[0038] Example 2

[0039] The method for preparing composite sheet and strip in this embodiment differs from the method for preparing composite sheet and strip in Embodiment 1 only in that: during rolling in steps 1) and 4) of this embodiment, the corrugated rollers used ensure that the angle between the extension direction of the crest of the corrugations on the surface of the single-corrugated composite metal sheet and strip after rolling and the angle between the extension direction of the crest of the corrugations on the surface of the single-corrugated composite metal sheet and strip and the direction of movement of the sheet and strip during rolling is 60°.

[0040] Example 3

[0041] The method for preparing the composite strip in this embodiment differs from that in Example 1 only in that: in step 3) of this embodiment, the single-corrugated metal strip to be composited obtained in step 1) is used as the substrate (the corrugated surface is not coated with graphene). The content not mentioned is entirely the same as in Example 1. The composite strip prepared in this embodiment consists of three bonding layers: a single-layer graphene, a double-layer graphene, and a single-layer graphene composite plate.

[0042] Example 4

[0043] The method for preparing the composite strip in this embodiment differs from that in Example 1 only in that: in step 5) of this embodiment, the single corrugated composite metal strip obtained in step 4) is used as the substrate (the corrugated surface is not coated with graphene). The contents not mentioned are completely the same as in Example 1.

[0044] Example 5

[0045] The method for preparing composite strip in this embodiment differs from that in Example 1 only in that: in this embodiment, the composite slab before flat rolling in step 5) of Example 1 is fed into the rolling mill for rolling according to step 4) of Example 1 to obtain composite strip I. Then, composite strip I replaces a single corrugated composite metal strip in step 5) of Example 1, and finally a copper composite strip with a flat surface and five layers of graphene bonding is obtained.

[0046] Example 6

[0047] The method for preparing composite strip in this embodiment differs from the method for preparing composite strip in Example 1 only in that the corrugated roller used in steps 1) and 4) of this embodiment forms trapezoidal corrugations on the strip during rolling.

[0048] Example 7

[0049] The method for preparing composite strip in this embodiment differs from the method for preparing composite strip in Example 1 only in that: during rolling in steps 1) and 4) of this embodiment, the reduction rate is controlled at 40%; during rolling in step 5), the reduction rate is controlled at 30%.

[0050] Example 8

[0051] The method for preparing composite strip in this embodiment differs from the method for preparing composite strip in Example 1 only in that: during rolling in steps 1) and 4) of this embodiment, the surface corrugations of the corrugated roller 1 are triangular waves with an amplitude of 0.4 mm.

[0052] Example 9

[0053] The composite strip material of this embodiment is prepared by the method described in Embodiments 1, 2, 3, 4, 5, 6, 7, or 8 above, and will not be repeated here.

[0054] Comparative Example

[0055] The preparation method of the composite plate and strip in this comparative example includes the following steps:

[0056] A 3mm thick T2 industrial pure copper plate is selected and fed into a rolling mill for single-pass rolling. The reduction rate is controlled at 20% to obtain a flat-rolled composite strip. The rolling rolls used during the rolling process are as follows: Figure 5 As shown.

[0057] Experimental Example

[0058] The electrical conductivity, tensile strength, elongation, and bond strength of the composite strips prepared in Examples 1-8 and the comparative examples, as well as the T2 industrial pure copper plate used in Example 1, were tested respectively. The test samples were cut into small blocks, and the conductivity was tested using a Sigma2008B1 digital conductivity meter. Each sample was tested five times, and the average value was taken. Tensile specimens were prepared according to the national standard GB / T 228.1-2010, and room temperature tensile and peel tests were performed using a universal tensile testing machine. This universal tensile testing machine, model INSTRON-5969, is a double-column testing machine with a maximum test force of 50kN and an effective tensile space of 126mm-1756mm. It can display the test force and displacement in real time and can perform static tensile, compression, and peel tests. To avoid errors, three specimens were tested in each group to calculate the average value. The test results are shown in Table 1.

[0059] Table 1. Performance test results of Examples 1-8, Comparative Examples, and T2 industrial pure copper plate.

[0060]

[0061]

[0062] As shown in Table 1, the performance of the composite strips prepared in Examples 1 to 8 is significantly improved compared to the T2 industrial pure copper plate and the comparative flat-rolled composite plate. For example, the conductivity of the composite strip prepared in Example 1 increased by 10% compared to the T2 industrial pure copper plate, the tensile strength increased by 40%, the elongation increased by 8%, the bonding strength increased by 167% compared to the comparative flat-rolled composite plate, and the warpage was much lower than that of the comparative flat-rolled composite plate, resulting in a significant improvement in overall performance.

Claims

1. A method for preparing a composite plate or strip, characterized in that: Includes the following steps: Two single-corrugated metal strips are taken, and graphene is coated on one or both of the corrugated surfaces to form a graphene coating layer, while retaining the corrugated waveform on the surface of the graphene coating layer. Then, the two single-corrugated metal strips are stacked to form a blank, and then rolled using flat rolls to obtain the desired product. The corrugations on the surfaces of the two single-corrugated metal strips are matched, and when stacked, the corrugated surfaces of the two single-corrugated metal strips face each other and mesh with each other. The two single-corrugated metal strips are obtained by single-pass corrugated roll rolling. The corrugated rolls used during corrugated roll rolling form triangular waves on the strips.

2. The method for preparing the composite plate and strip according to claim 1, characterized in that: The two single-corrugated metal strips are independently selected from strip A or strip B; The strip material A is obtained by single-pass corrugated roll rolling of metal strip material; The strip material B includes two or more metal layers. Any two adjacent metal layers are rolled together by a single pass of corrugated rolls. Before rolling, the surfaces of the two metal layers to be rolled together are corrugated surfaces that can mesh with each other during rolling. Graphene is coated on the surface of at least one metal layer to be rolled together to form a graphene layer and the graphene coating layer retains the waveform of the corrugated surface. The corrugated roll rolling process uses two rolls, one of which is a corrugated roll and the other is a flat roll.

3. The method for preparing the composite plate and strip according to claim 2, characterized in that: The strip material B is prepared by a method including the following steps: the metal strip material is rolled by a single pass of corrugated rolls to obtain the strip material to be composited; two strip materials to be composited are taken, and graphene is coated on one or two corrugated surfaces of the strip materials to form a graphene coating layer, and the surface of the graphene coating layer retains the corrugated waveform; then the two strip materials to be composited are stacked to form a blank, and then rolled by a single pass of corrugated rolls to obtain the composite material; the corrugations on the surfaces of the two strip materials to be composited are matched, and when stacked, the corrugated surfaces of the two strip materials to be composited face each other and the two strip materials to be composited mesh with each other.

4. The method for preparing the composite plate / strip according to claim 1, 2, or 3, characterized in that: The thickness of the graphene coating is 0.1–2 μm.

5. The method for preparing the composite plate / strip according to claim 2 or 3, characterized in that: The amplitude of the corrugations formed on the strip by the corrugated rolls during corrugated roll rolling is 0.4 to 0.6 mm.

6. The method for preparing the composite plate / strip according to claim 2 or 3, characterized in that: The corrugated rolls used in corrugated roll rolling form triangular waves on the strip. On the cross section of the strip perpendicular to the direction of the wave crest extension on the corrugated surface, the angle between the two interior angles with the trough as the vertex is 30° to 60° in the triangle formed by connecting the highest point of the wave crest with the two adjacent lowest points of the wave trough.

7. The method for preparing the composite plate and strip according to claim 6, characterized in that: The direction of the crest extension on the corrugated surface formed by the corrugated rollers on the strip during corrugated tube rolling is perpendicular to the direction of movement of the strip during the rolling process.

8. The method for preparing the composite plate / strip according to claim 2 or 3, characterized in that: When using flat rolls for rolling, the reduction rate is 10% to 30%, while when using corrugated rolls, the reduction rate is 40% to 60%.

9. A composite sheet or strip prepared by the method for preparing composite sheet or strip as described in any one of claims 1-8.

Images