A nickel-aluminum composite strip and its production process

Abstract

The invention discloses a nickel-aluminum composite strip and a production process thereof. The nickel-aluminum composite strip is made of a sandwich structure consisting of an aluminum strip, a nickel-aluminum mixed powder and a nickel strip through multiple rolling processes, and the nickel strip is provided with a sink for cold isostatic pressing of the nickel-aluminum mixed powder. The nickel strip, the nickel-aluminum mixed powder and the aluminum strip are combined by adopting the sandwich structure, and the nickel-aluminum mixed powder is used as an intermediate combining part, thereby significantly enhancing the interface bonding strength between the nickel strip and the aluminum strip, and solving the problem of low bonding strength between the nickel strip and the aluminum strip.

Description

Technical Field

[0001] The invention relates to the technical field of metal material processing, and in particular to a nickel-aluminum composite strip and a production process thereof. Background Art

[0002] Nickel-aluminum composite tape is a strip material made of two metal materials, nickel and aluminum, through a specific process. It has excellent physical and chemical properties. It has high strength and can withstand large tensile and compressive forces. In high temperature and humid environments, nickel-aluminum composite tape exhibits good corrosion resistance and is not easy to rust or oxidize. Nickel-aluminum composite tape also has good wear resistance and can withstand high-speed friction and impact. Therefore, nickel-aluminum composite tape is often used to manufacture electronic components such as resistors, inductors, and capacitors. Its excellent conductivity and high temperature resistance make it an ideal choice.

[0003] At present, the preparation methods of nickel-aluminum composite strips mainly include hot rolling, cold rolling and explosive bonding. Among them, the hot rolling method is suitable for nickel-aluminum composite strips with a thickness greater than 1 mm, the cold rolling method is suitable for nickel-aluminum composite strips with a thickness less than 1 mm, and the explosive bonding method is suitable for nickel-aluminum composite strips with special requirements. However, the traditional cold rolling method and hot rolling method both have the problem of low bonding strength between aluminum strips and nickel strips to a certain extent, and the explosive bonding method has high technical requirements, is difficult to accurately control, and involves the use of explosives, which poses certain safety risks. Therefore, there is a need for a nickel-aluminum composite strip and a production process thereof that can effectively improve the interface bonding strength between nickel strips and aluminum strips. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a nickel-aluminum composite strip and a production process thereof.

[0005] The technical solution of the present invention is: a nickel-aluminum composite strip, which is made of a sandwich structure consisting of an aluminum strip, a nickel-aluminum mixed powder and a nickel strip through multiple rolling, and the nickel strip has a sink for cold isostatic pressing of the nickel-aluminum mixed powder.

[0006] Description: The sandwich structure consisting of aluminum strip, nickel-aluminum mixed powder and nickel strip is adopted. By using the nickel-aluminum mixed powder as the middle bonding part, the interface bonding strength between the nickel strip and the aluminum strip can be significantly enhanced, thereby effectively improving the problem of low bonding strength between the nickel strip and the aluminum strip.

[0007] Furthermore, the nickel-aluminum mixed powder is prepared by mixing nickel powder and aluminum powder in a mass ratio of 5 to 7:2, and the particle size of the nickel powder is 1 to 2 μm, and the particle size of the aluminum powder is 12 to 15 μm.

[0008] Note: By using the nickel-aluminum mixed powder with the above ratio, the density after cold isostatic pressing can be improved. At the same time, by mixing nickel powder with smaller particle size with aluminum powder, it can effectively play its bonding role at the same temperature in subsequent processing, thereby enhancing the interface bonding strength of nickel strip and aluminum strip, and improving the performance of nickel-aluminum composite strip.

[0009] Furthermore, the aluminum strip has a thickness of 10 mm to 20 mm and a width of 20 to 100 mm; the nickel strip has a thickness of 10 mm to 20 mm and a width of 20 to 100 mm.

[0010] Note: Due to the process requirements of the nickel-aluminum composite strip of the present invention, the thickness of the nickel strip should not be too thin or too narrow. Therefore, a nickel strip with a thickness of more than 10 mm and a width of more than 20 mm is preferably used as the nickel strip substrate of the present invention. The specifications and dimensions of the aluminum strip are not limited and can be selected according to the actual size of the nickel strip, as long as they are consistent with the specifications and dimensions of the nickel strip.

[0011] Furthermore, the width of the nickel strip is X1, the thickness is Y, the width of the sink is 3 / 5X1 to 4 / 5X1, and the depth is 1 / 2Y to 2 / 3Y.

[0012] Note: Since the sinking groove specifications are different under different nickel strip size specifications, by using the above formula to limit the sinking groove specifications, it is possible to provide a setting standard for the milling of the sinking groove under the nickel strip size specifications, thereby providing the nickel strip with a suitable sinking groove specification.

[0013] If the sinking tank size is too small, it will affect the nickel-aluminum mixed powder and the interface bonding strength of the nickel and aluminum strips after subsequent processing. If the sinking tank size is too large, it will affect the structural strength of the nickel strip, and then affect the performance of the nickel-aluminum composite strip. Therefore, by setting the appropriate sinking tank specification standards, the effects of the nickel-aluminum mixed powder and the process methods can be more effectively exerted, and the performance of the nickel-aluminum composite strip can be improved.

[0014] The present invention also provides a production process of a nickel-aluminum composite strip, comprising the following steps:

[0015] Step 1, soft annealing the nickel strip, and then milling a groove on the nickel strip to obtain a pretreated nickel strip, wherein the temperature of the soft annealing is 600-700° C., and the holding time of the soft annealing is 40-90 minutes;

[0016] Step 2, filling the nickel-aluminum mixed powder into the sink of the nickel strip and performing cold isostatic pressing to obtain a cold isostatically pressed nickel strip, wherein the cold isostatic pressing pressure is 150 to 300 MPa and the holding time is 7 to 12 minutes;

[0017] Step 3, in an inert atmosphere, heating the cold isostatically pressed nickel strip to 750-800° C. and keeping the temperature, then heating the aluminum strip to 450-550° C. and stacking and rolling the aluminum strip with the cold isostatically pressed nickel strip to obtain a rolled composite strip, wherein the deformation of the rolling composite is 5-15%;

[0018] Step 4, reheating the rolled composite strip to 450-550° C. and then rolling it multiple times, wherein the deformation of a single rolling is 5-10% and the total deformation is 25-35%;

[0019] Step 5: Diffusion annealing the rolled composite strip at 350-450° C. for 120-240 min to obtain a nickel-aluminum composite strip blank, and then process the nickel-aluminum composite strip blank into a nickel-aluminum composite strip of required size and specification.

[0020] Description: By using the above-mentioned production process of nickel-aluminum composite strip, the production and preparation of nickel-aluminum composite strip composed of aluminum strip, nickel-aluminum mixed powder and nickel strip can be effectively coordinated. Through multiple rolling processes, the force, temperature, speed and other factors in the rolling process can be more accurately controlled, thereby obtaining better quality products. At the same time, compared with single-pass rolling, the surface of the multi-pass rolled product is more uniform and smooth, and the internal structure is denser, thereby improving the overall quality of the product. In addition, the material thickness can be gradually reduced through multiple rolling processes. At the same time, the above-mentioned temperature control treatment can be used to effectively control the microstructure and performance of the material.

[0021] Furthermore, the sink of the nickel strip is etched so that the inner wall of the sink has grooves, and the grooves are in any one of a honeycomb shape and a grid shape, and the etching process is laser etching.

[0022] Description: Etching in the sink of the nickel strip can enhance the sandwich structure of the nickel-aluminum composite strip, thereby improving the interface bonding strength between the nickel strip and the aluminum strip and improving the performance of the nickel-aluminum composite strip.

[0023] Furthermore, the rolled composite strip is subjected to lateral extrusion treatment during the interval between adjacent single rolling operations, and the steps of the lateral extrusion treatment are as follows:

[0024] 1) Laterally extruding both sides of the rolled composite strip, the width of the rolled composite strip is X2, the lateral extrusion speed is (X2-2X2) / X1 mm / s, and the deformation is 3-10%;

[0025] 2) During the extrusion process, the temperature of the rolled composite strip is controlled. Before the lateral extrusion begins, the temperature of the rolled composite strip is controlled at 400-420°C. Then, as the lateral extrusion begins, the temperature of the rolled composite strip is increased at a rate of 10-20°C / s until the lateral extrusion is completed;

[0026] 3) The rolled composite strip is reheated to the single rolling temperature of the previous pass to carry out the next single rolling.

[0027] Description: By interspersing lateral extrusion treatment between single rolling passes of adjacent passes, the above-mentioned temperature control treatment can be combined to effectively control the microstructure and properties of the material, so that the grains undergo further plastic deformation, high-density deformation and dislocation are generated inside the grains, and the grain boundaries are continuously split due to the influence of stress, thereby reducing the grain size, increasing the grain boundaries, and improving the performance of the nickel-aluminum composite strip.

[0028] Furthermore, after the lateral extrusion is completed, the pressure is maintained for 3 to 5 minutes, and during the pressure maintenance period, the rolled composite strip is heated to the single rolling temperature of the previous pass.

[0029] Description: By carrying out a certain period of pressure holding treatment after the lateral extrusion is completed and coordinating the rewarming, on the one hand, the operating parameters are provided for the rewarming rate, and on the other hand, the treatment effect of the lateral extrusion can be improved, making the performance of the prepared nickel-aluminum composite strip more stable.

[0030] The beneficial effects of the present invention are:

[0031] (1) The nickel-aluminum composite strip of the present invention adopts a sandwich structure to combine nickel strip, nickel-aluminum mixed powder and aluminum strip, and uses the nickel-aluminum mixed powder as the intermediate bonding part, thereby significantly enhancing the interface bonding strength between the nickel strip and the aluminum strip, solving the problem of low bonding strength between the nickel strip and the aluminum strip.

[0032] (2) The production process of the nickel-aluminum composite strip of the present invention can effectively match the structure of the nickel-aluminum composite strip, and through multiple rolling processes, the force, temperature, speed, etc. during the rolling process can be more accurately controlled to effectively prepare a nickel-aluminum composite strip with high interface bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a rolled composite cross-sectional view of the nickel-aluminum composite strip of the present invention;

[0034] Among them, 1-aluminum strip, 2-nickel-aluminum mixed powder, 3-nickel strip. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with specific implementation methods to better reflect the advantages of the present invention.

[0036] Embodiment 1: A nickel-aluminum composite strip, such as Figure 1 As shown, the nickel-aluminum composite strip is made of a sandwich structure consisting of an aluminum strip 1, a nickel-aluminum mixed powder 2, and a nickel strip 3 through five rolling processes, and the nickel strip 3 has a sink for cold isostatic pressing of the nickel-aluminum mixed powder 2.

[0037] The aluminum strip 1 has a thickness of 14 mm and a width of 40 mm; the nickel strip 3 has a thickness of 16 mm and a width of 40 mm. In this embodiment, the lengths of the aluminum strip 1 and the nickel strip 3 are both 200 mm; the nickel-aluminum mixed powder 2 is made of nickel powder and aluminum powder in a mass ratio of 3:1, and the particle size of the nickel powder is 1-2 μm, and the particle size of the aluminum powder is 12-15 μm.

[0038] At the same time, the width of the nickel strip 3 is X1, and the thickness is Y. The width of the sink is 7 / 10X1, and the depth is 7 / 12Y. The calculation results are as follows: the width of the sink is 28 mm, and the depth is 9 mm.

[0039] Embodiment 2: This embodiment also provides a production process for the nickel-aluminum composite strip of Embodiment 1, comprising the following steps:

[0040] Step 1, soft annealing the nickel strip 3, then milling a sink groove on the nickel strip 3, and etching the sink groove of the nickel strip 3 so that the inner wall of the sink groove has a honeycomb groove with a depth and width of 1 mm, the etching treatment is laser etching, and the pretreated nickel strip is obtained, wherein the temperature of the soft annealing is 680° C., and the holding time of the soft annealing is 75 min;

[0041] Step 2, loading the nickel-aluminum mixed powder 2 into the sink of the nickel strip 3 and performing cold isostatic pressing to obtain a cold isostatically pressed nickel strip, wherein the cold isostatic pressing pressure is 240 MPa and the holding time is 10 min;

[0042] Step 3, in an inert atmosphere, heating the cold isostatically pressed nickel strip to 780° C. and keeping the temperature, then heating the aluminum strip 1 to 530° C. and stacking and rolling the aluminum strip with the cold isostatically pressed nickel strip to obtain a rolled composite strip, wherein the deformation of the rolled composite is 10%;

[0043] Step 4, reheating the rolled composite strip to 530° C. and rolling it four times, wherein the deformation of a single rolling is 8% and the total deformation is 32%;

[0044] Step 5: Diffusion annealing the rolled composite strip at 420° C. for 210 min to obtain a nickel-aluminum composite strip blank, and then process the nickel-aluminum composite strip blank into a nickel-aluminum composite strip of required size and specification.

[0045] It should be noted that when the nickel strip 3 is milled out of the sink groove, the nickel scraps produced by milling are collected and can be used as raw materials for the production of nickel powder. The production of nickel powder is not described here and can be prepared using existing production processes.

[0046] The nickel-aluminum composite strip of Example 1 was prepared by the method of Example 2, and then the prepared nickel-aluminum composite strip was tested for the nickel-aluminum strip interface bonding strength.

[0047] At the same time, a control is set up, specifically, the nickel strip 3 is subjected to softening annealing to obtain a pretreated nickel strip, wherein the softening annealing temperature is 680°C and the holding time of the softening annealing is 75 minutes; under an inert atmosphere, the aluminum strip 1 is heated to 530°C and rolled with the pretreated nickel strip to obtain a rolled composite strip, wherein the deformation amount of the rolling is 42%; the rolled composite strip is diffusion annealed at 420°C and kept warm for 210 minutes to obtain a nickel-aluminum composite strip blank, and then the nickel-aluminum composite strip blank is processed into a nickel-aluminum composite strip of required size specifications;

[0048] The nickel-aluminum strip interface bonding strength of the above two nickel-aluminum composite strips is now compared, and the results are shown in Table 1 below:

[0049] Table 1 Comparison of interface bonding strength between nickel and aluminum strips

[0050] Group Nickel-aluminum strip interface bonding strength / MPa Example 1 97.4 Comparison 43.7

[0051] It can be seen from the results in Table 1 above that the optimization of the nickel-aluminum composite strip and the optimization of the process method of the present invention can significantly improve the interface bonding strength of the nickel-aluminum strip. Compared with the traditional rolling process, the strength is increased by 53.7 MPa, thereby effectively improving the problem of low connection strength between the nickel strip 3 and the aluminum strip 1, and improving the performance of the nickel-aluminum composite strip.

[0052] Embodiment 3: This embodiment is different from Embodiment 1 in that the aluminum strip 1 has a thickness of 10 mm and a width of 20 mm; the nickel strip 3 has a thickness of 10 mm and a width of 20 mm.

[0053] Embodiment 4: This embodiment is different from Embodiment 1 in that the aluminum strip 1 has a thickness of 20 mm and a width of 100 mm; the nickel strip 3 has a thickness of 20 mm and a width of 100 mm.

[0054] Embodiment 5: This embodiment is different from Embodiment 1 in that the width of the sink is 3 / 5X1, and the depth is 1 / 2Y. After rounding, the width of the sink is 24 mm, and the depth is 8 mm.

[0055] Embodiment 6: This embodiment is different from Embodiment 1 in that the width of the sink is 4 / 5X1, and the depth is 2 / 3Y. After rounding, the width of the sink is 32 mm, and the depth is 11 mm.

[0056] Example 7: This example is different from Example 1 in that the nickel-aluminum mixed powder 2 is a mixture of nickel powder and aluminum powder in a mass ratio of 5:2.

[0057] Example 8: This example is different from Example 1 in that the nickel-aluminum mixed powder 2 is a mixture of nickel powder and aluminum powder in a mass ratio of 7:2.

[0058] In order to further verify the influence of various parameters of the nickel-aluminum composite strip on the performance of the nickel-aluminum composite strip, the nickel-aluminum composite strips of Examples 5-8 were prepared respectively by the method of Example 2, and then the prepared nickel-aluminum composite strips were tested for the nickel-aluminum strip interface bonding strength. The results are shown in Table 2 below:

[0059] Table 2 Comparison of interface bonding strength of nickel-aluminum strip

[0060] Group Nickel-aluminum strip interface bonding strength / MPa Example 5 91.5 Example 6 93.3 Example 7 95.8 Example 8 94.7

[0061] It can be seen from the results in Table 2 above that the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strip prepared using the nickel-aluminum composite strip and method of the present invention is significantly better than that of the control, but there are some performance differences in the nickel-aluminum composite strips prepared under the parameters of different nickel-aluminum composite strips. The following analysis is made based on the data comparison in Table 2 above:

[0062] 1) Influence of different sinking tank specifications on the performance of nickel-aluminum composite strip under the same nickel strip 3 size

[0063] By comparing Example 5 and Example 6 with Example 1, it can be seen that the use of different trough specifications has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 1, reducing or increasing the size specifications of the trough causes the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip to be reduced to a certain extent. Therefore, the nickel-aluminum composite strip prepared in Example 1 is relatively optimal.

[0064] 2) Effect of different nickel-aluminum mixed powders 2 on the properties of nickel-aluminum composite strips

[0065] By comparing Example 7 and Example 8 with Example 1, it can be seen that the nickel-aluminum mixed powder 2 obtained by mixing different nickel powders and aluminum powders has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 1, the ratio of nickel powder and aluminum powder in the aluminum-nickel mixed powder is changed, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is reduced to a certain extent. Therefore, the nickel-aluminum composite strip prepared in Example 1 is relatively optimal.

[0066] At the same time, in order to further explore the role of the sink and the nickel-aluminum mixed powder 2 in the nickel-aluminum composite strip, a control was set up, specifically, the nickel strip 3 was softened and annealed to obtain a pretreated nickel strip, wherein the softening annealing temperature was 680°C, and the holding time of the softening annealing was 75 minutes; under an inert atmosphere, the pretreated nickel strip was heated to 780°C and kept warm, and then the aluminum strip 1 was heated to 530°C and stacked with the pretreated nickel strip and rolled to obtain a rolled composite strip, wherein the deformation of the rolling composite was 10%; the rolled composite strip was warmed to 530°C and then rolled four times, wherein the deformation of a single rolling was 8% and the total deformation was 32%; the rolled composite strip was diffusion annealed at 420°C and kept warm for 210 minutes to obtain a nickel-aluminum composite strip blank, and then the nickel-aluminum composite strip blank was processed into a nickel-aluminum composite strip of the required size;

[0067] The nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strip prepared by the above control is tested, and the results are shown in Table 3 below:

[0068] Table 3 Comparison of interface bonding strength between nickel and aluminum strips

[0069] Group Nickel-aluminum strip interface bonding strength / MPa Comparison 69.2

[0070] It can be seen from the results in Table 3 above that the nickel-aluminum composite strip of the present invention can significantly improve the interface bonding strength of the nickel-aluminum strip. By opening a sink on the nickel strip 3 and using the nickel-aluminum mixed powder 2 for cold isostatic pressing, the prepared nickel-aluminum composite strip is under the same production process (it should be noted that because the structure of the nickel-aluminum composite strip of the present invention has process operations such as cold isostatic pressing, this step is unique to the production process of the present invention and the control does not have it), the nickel-aluminum composite strip's nickel-aluminum strip interface bonding strength is increased from 69.2MPa to 97.4MPa.

[0071] Example 9: This example is different from Example 2 in that the temperature of the softening annealing is 600° C. and the holding time of the softening annealing is 40 min.

[0072] Example 10: This example is different from Example 2 in that the temperature of the softening annealing is 700° C. and the holding time of the softening annealing is 90 min.

[0073] Example 11: This example is different from Example 2 in that the cold isostatic pressing pressure is 150 MPa and the holding time is 7 min.

[0074] Example 12: This example is different from Example 2 in that the cold isostatic pressing pressure is 300 MPa and the holding time is 12 min.

[0075] Example 13: This example is different from Example 2 in that, in step 3, under an inert atmosphere, the cold isostatically pressed nickel strip is heated to 750°C and kept warm, and then the aluminum strip 1 is heated to 450°C and stacked with the cold isostatically pressed nickel strip and rolled to obtain a rolled composite strip, wherein the deformation of the rolling composite is 5%.

[0076] Example 14: This example is different from Example 2 in that, in step 3, under an inert atmosphere, the cold isostatically pressed nickel strip is heated to 800°C and kept warm, and then the aluminum strip 1 is heated to 550°C and stacked with the cold isostatically pressed nickel strip and rolled to obtain a rolled composite strip, wherein the deformation of the rolled composite is 15%.

[0077] Example 15: This example differs from Example 2 in that, in step 4, the rolled composite strip is reheated to 530°C and then rolled five times, wherein the deformation of a single rolling is 5% and the total deformation is 25%.

[0078] Example 16: This example is different from Example 2 in that, in step 4, the rolled composite strip is reheated to 530°C and then rolled three times, wherein the deformation of a single rolling is 10% and the total deformation is 30%.

[0079] Example 17: This example differs from Example 2 in that the rolled composite strip is diffusion annealed at 350°C for 120 minutes.

[0080] Example 18: This example differs from Example 2 in that the rolled composite strip is diffusion annealed at 450° C. for 240 min.

[0081] In order to further verify the influence of various parameters in the production process of nickel-aluminum composite strip on the performance of nickel-aluminum composite strip, the production processes of the above-mentioned embodiments 9-18 are used to prepare the nickel-aluminum composite strip of embodiment 1 respectively, and then the prepared nickel-aluminum composite strip is tested for the interface bonding strength of the nickel-aluminum strip. The results are shown in Table 4 below:

[0082] Table 4 Comparison of interface bonding strength between nickel and aluminum strips

[0083] Group Nickel-aluminum strip interface bonding strength / MPa Example 9 94.6 Example 10 97.5 Embodiment 11 93.8 Example 12 97.7 Embodiment 13 96.9 Embodiment 14 97.4 Embodiment 15 97.1 Example 16 96.7 Embodiment 17 96.5 Embodiment 18 97.6

[0084] It can be seen from the results in Table 4 above that the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strips prepared by the production methods of different nickel-aluminum composite strips of the present invention is significantly better than that of the control, but there are some performance differences in the nickel-aluminum composite strips prepared under different process parameters for producing nickel-aluminum composite strips. The following analysis is made based on the data comparison in Table 4 above:

[0085] 1) Effect of different softening annealing parameters on the properties of nickel-aluminum composite strip

[0086] By comparing Example 9 and Example 10 with Example 2, it can be seen that the use of different softening annealing parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 2, the temperature and holding time parameters of the softening annealing are reduced, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is reduced to a certain extent. On the basis of Example 2, the temperature and holding time parameters of the softening annealing are increased, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is improved to a certain extent, but the improvement is not obvious. Therefore, from the perspectives of economy, production efficiency, etc., the nickel-aluminum composite strip prepared in Example 2 is relatively optimal.

[0087] 2) Effect of different cold isostatic pressing parameters on the properties of nickel-aluminum composite strip

[0088] By comparing Example 11 and Example 12 with Example 2, it can be seen that the use of different cold isostatic pressing parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 2, the pressure and holding time parameters of the cold isostatic pressing parameters are reduced, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is reduced to a certain extent. On the basis of Example 2, the pressure and holding time parameters of the cold isostatic pressing parameters are increased, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is improved to a certain extent, but the improvement is not obvious. Therefore, theoretically, the higher the cold isostatic pressing pressure, the denser the powder pressing will be. However, due to the limited conditions of the existing equipment and the lower and lower improvement amplitude, the cold isostatic pressing parameters can be selected as needed according to the actual production equipment.

[0089] 3) Effect of different rolling composite parameters on the properties of nickel-aluminum composite strip

[0090] By comparing Example 13 and Example 14 with Example 2, it can be seen that the use of different rolling composite parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 2, the various parameters of rolling composite are reduced, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is reduced to a certain extent. On the basis of Example 2, the various parameters of rolling composite are increased, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip does not change significantly, and the interface bonding strength value is the same as that of Example 2. Therefore, from the perspectives of economy, production efficiency, etc., the nickel-aluminum composite strip prepared in Example 2 is relatively optimal.

[0091] 4) Effect of different rolling parameters on the properties of nickel-aluminum composite strip

[0092] By comparing Example 15 and Example 16 with Example 2, it can be seen that the use of different multiple rolling parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 2, lowering or increasing the various parameters of multiple rolling causes the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip to be reduced to a certain extent. Therefore, the nickel-aluminum composite strip prepared in Example 2 is relatively optimal.

[0093] 5) Effect of different diffusion annealing parameters on the properties of nickel-aluminum composite strip

[0094] By comparing Example 17 and Example 18 with Example 2, it can be seen that the use of different diffusion annealing parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 2, the temperature and holding time parameters of the diffusion annealing are reduced, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is reduced to a certain extent. On the basis of Example 2, the temperature and holding time parameters of the diffusion annealing are increased, so that the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip is improved to a certain extent, but the improvement is not obvious. Therefore, from the perspectives of economy, production efficiency, etc., the nickel-aluminum composite strip prepared in Example 2 is relatively optimal.

[0095] Embodiment 19: This embodiment differs from Embodiment 2 in that a lateral extrusion process is performed on the rolled composite strip during the interval between adjacent single rolling processes, and the steps of the lateral extrusion process are as follows:

[0096] 1) Lateral extrusion is performed on both sides of the rolled composite strip, and the width of the rolled composite strip is X2. In this embodiment, X2 is 56 mm, the lateral extrusion speed is 1.5X2 / X1 mm / s, the deformation is 8%, and the lateral extrusion speed is calculated to be 2.1 mm / s;

[0097] 2) During the extrusion process, the temperature of the rolled composite strip is controlled. Before the lateral extrusion begins, the temperature of the rolled composite strip is controlled at 410°C. Then, as the lateral extrusion begins, the temperature of the rolled composite strip is increased at a rate of 15°C / s until the lateral extrusion is completed;

[0098] 3) The rolled composite strip is reheated to the single rolling temperature of the previous pass to carry out the next single rolling.

[0099] Example 20: This example differs from Example 19 in that the lateral extrusion speed is X2 / X1 mm / s, the deformation amount is 8%, and the calculated lateral extrusion speed is 1.4 mm / s.

[0100] Example 21: This example differs from Example 19 in that the lateral extrusion speed is 2X2 / X1mm / s, the deformation amount is 8%, and the calculated lateral extrusion speed is 2.8mm / s.

[0101] Example 22: This example differs from Example 19 in that the amount of deformation is 3%, and before the start of lateral extrusion, the temperature of the rolled composite strip is controlled at 400°C. Then, as the lateral extrusion starts, the temperature of the rolled composite strip is increased at a rate of 10°C / s until the lateral extrusion is completed.

[0102] Example 23: This example differs from Example 19 in that the deformation amount is 10%, and before the start of lateral extrusion, the temperature of the rolled composite strip is controlled at 420°C. Then, as the lateral extrusion starts, the temperature of the rolled composite strip is increased at a rate of 20°C / s until the lateral extrusion is completed.

[0103] In order to further verify the influence of different production processes of nickel-aluminum composite strips on the performance of nickel-aluminum composite strips, the production processes of the above-mentioned embodiments 19-23 are used to prepare the nickel-aluminum composite strips of embodiment 1 respectively, and then the prepared nickel-aluminum composite strips are tested for the nickel-aluminum strip interface bonding strength. The results are shown in Table 5 below:

[0104] Table 5 Comparison of interface bonding strength between nickel and aluminum strips

[0105] Group Nickel-aluminum strip interface bonding strength / MPa Embodiment 19 98.9 Embodiment 20 98.7 Embodiment 21 98.6 Embodiment 22 98.5 Embodiment 23 98.3

[0106] It can be seen from the results in Table 5 above that the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strips prepared by the production methods of different nickel-aluminum composite strips of the present invention is significantly better than that of the control, and after lateral extrusion treatment, the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strip of Example 1 is improved to a certain extent, from 97.4MPa to 98.9MPa, but there are some performance differences in the nickel-aluminum composite strips prepared by the production methods of different nickel-aluminum composite strips. The following analysis is made based on the data comparison in Table 5 above:

[0107] 1) Effect of different lateral extrusion speeds on the properties of nickel-aluminum composite strip

[0108] By comparing Example 20, Example 21 with Example 19, it can be seen that the use of different lateral extrusion speeds has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 19, lowering or increasing the lateral extrusion speed causes a certain degree of reduction in the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. Therefore, the nickel-aluminum composite strip prepared in Example 19 is relatively optimal.

[0109] 2) Effect of different lateral extrusion parameters on the properties of nickel-aluminum composite strip

[0110] By comparing Example 22, Example 23 with Example 19, it can be seen that the use of different lateral extrusion parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 19, lowering or increasing the relevant parameters of lateral extrusion will cause the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip to be reduced to a certain extent. Therefore, the nickel-aluminum composite strip prepared in Example 19 is relatively optimal.

[0111] Example 24: This example is different from Example 19 in that the pressure is maintained for 4 minutes after the lateral extrusion is completed, and the rolled composite strip is warmed to the single rolling temperature of the previous pass during the pressure maintenance period.

[0112] Example 25: This example is different from Example 24 in that the pressure is maintained for 3 minutes after the lateral extrusion is completed.

[0113] Example 26: This example is different from Example 24 in that the pressure is maintained for 5 minutes after the lateral extrusion is completed.

[0114] In order to further verify the influence of the production processes of different nickel-aluminum composite strips on the performance of the nickel-aluminum composite strips, the production processes of the above-mentioned embodiments 24-26 are used to prepare the nickel-aluminum composite strips of embodiment 1 respectively, and then the prepared nickel-aluminum composite strips are tested for the nickel-aluminum strip interface bonding strength. The results are shown in Table 6 below:

[0115] Table 6 Comparison of interface bonding strength between nickel and aluminum strips

[0116]

[0117]

[0118] It can be seen from the results in Table 6 above that the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strips prepared by the production methods of different nickel-aluminum composite strips of the present invention is significantly better than that of Example 19. By holding the pressure after lateral extrusion, the nickel-aluminum strip interface bonding strength of the nickel-aluminum composite strip of Example 19 is improved to a certain extent, from 98.9 MPa to 99.4 MPa, but there are some performance differences in the nickel-aluminum composite strips prepared using different holding pressure parameters. The following analysis is made based on the data comparison in Table 6 above:

[0119] By comparing Example 25, Example 26 with Example 24, it can be seen that the use of different holding pressure parameters has a certain influence on the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip. On the basis of Example 24, lowering or increasing the holding pressure parameters will cause the nickel-aluminum strip interface bonding strength of the prepared nickel-aluminum composite strip to decrease to a certain extent. Therefore, the nickel-aluminum composite strip prepared in Example 24 is relatively optimal.

Claims

1. A nickel-aluminum composite strip, characterized in that: The nickel-aluminum composite strip is made of a sandwich structure consisting of an aluminum strip, a nickel-aluminum mixed powder, and a nickel strip through multiple rolling processes, and the nickel strip is provided with a sink for cold isostatic pressing of the nickel-aluminum mixed powder.

2. A nickel-aluminum composite strip as claimed in claim 1, characterized in that: The nickel-aluminum mixed powder is prepared by mixing nickel powder and aluminum powder in a mass ratio of 5 to 7:2, and the particle size of the nickel powder is 1 to 2 μm, and the particle size of the aluminum powder is 12 to 15 μm.

3. A nickel-aluminum composite strip as claimed in claim 1, characterized in that: The thickness of the aluminum strip is 10 mm to 20 mm, and the width is 20 to 100 mm; the thickness of the nickel strip is 10 mm to 20 mm, and the width is 20 to 100 mm.

4. A nickel-aluminum composite strip as claimed in claim 1, characterized in that: The width of the nickel strip is X1, and the thickness is Y. The width of the sink is 3 / 5X1 to 4 / 5X1, and the depth is 1 / 2Y to 2 / 3Y.

5. The production process of a nickel-aluminum composite strip according to claim 1, characterized in that: The following steps are involved: Step 1, soft annealing the nickel strip, and then milling a groove on the nickel strip to obtain a pretreated nickel strip, wherein the temperature of the soft annealing is 600-700° C., and the holding time of the soft annealing is 40-90 minutes; Step 2, filling the nickel-aluminum mixed powder into the sink of the nickel strip and performing cold isostatic pressing to obtain a cold isostatically pressed nickel strip, wherein the cold isostatic pressing pressure is 150 to 300 MPa and the holding time is 7 to 12 minutes; Step 3, in an inert atmosphere, heating the cold isostatically pressed nickel strip to 750-800° C. and keeping the temperature, then heating the aluminum strip to 450-550° C. and stacking and rolling the aluminum strip with the cold isostatically pressed nickel strip to obtain a rolled composite strip, wherein the deformation of the rolling composite is 5-15%; Step 4, reheating the rolled composite strip to 450-550° C. and then rolling it multiple times, wherein the deformation of a single rolling is 5-10% and the total deformation is 25-35%; Step 5: Diffusion annealing the rolled composite strip at 350-450° C. for 120-240 min to obtain a nickel-aluminum composite strip blank, and then process the nickel-aluminum composite strip blank into a nickel-aluminum composite strip of required size and specification.

6. A process for producing a nickel-aluminum composite strip as claimed in claim 5, characterized in that: The sink of the nickel strip is etched so that the inner wall of the sink has grooves, and the grooves are in any one of a honeycomb shape and a grid shape, and the etching process is laser etching.

7. A process for producing a nickel-aluminum composite strip as claimed in claim 5, characterized in that: The rolled composite strip is subjected to lateral extrusion treatment during the interval between adjacent single rolling operations, wherein the steps of the lateral extrusion treatment are as follows: 1) Laterally extruding both sides of the rolled composite strip, the width of the rolled composite strip is X2, the lateral extrusion speed is (X2-2X2) / X1 mm / s, and the deformation is 3-10%; 2) During the extrusion process, the temperature of the rolled composite strip is controlled. Before the lateral extrusion begins, the temperature of the rolled composite strip is controlled at 400-420°C. Then, as the lateral extrusion begins, the temperature of the rolled composite strip is increased at a rate of 10-20°C / s until the lateral extrusion is completed; 3) The rolled composite strip is reheated to the single rolling temperature of the previous pass to carry out the next single rolling.

8. A process for producing a nickel-aluminum composite strip as claimed in claim 7, characterized in that: After the lateral extrusion is completed, the pressure is maintained for 3 to 5 minutes, and during the pressure maintenance period, the rolled composite strip is heated to the single rolling temperature of the previous pass.

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