High-strength metal composite strip and preparation method thereof

Abstract

The invention discloses a high-strength metal composite strip and a preparation method thereof.The high-strength metal composite strip is composed of a first outer-layer alloy, a middle-layer alloy and a second outer-layer alloy which are sequentially stacked, the first outer-layer alloy and the second outer-layer alloy are Ni-9wt.% W alloy, the middle-layer alloy is Ni-12wt.% W-3% Mo alloy, and the second outer-layer alloy is Ni-12wt.% W-3% Mo alloy. Wherein the content of the cubic texture of the composite strip is not lower than 90%, and the yield strength of the composite strip is not lower than 480 MPa. According to the composite strip, a strong cubic texture is formed on the surface layer, and the whole strip is high in strength and free of ferromagnetism.

Description

Technical Field

[0001] The present invention relates to the technical field of metal substrate preparation for second-generation high-temperature coated superconducting tapes, and in particular to a method for preparing a high-strength cubic textured metal tape. Background Art

[0002] Metal strips with a strong cubic texture are a common substrate material used in the fabrication of second-generation, high-temperature coated superconducting tapes. Industrially produced, high-performance superconducting tapes require substrates with a strong cubic texture, high yield strength, and no ferromagnetism. Ni-W alloys are a well-studied metal substrate. High-W content alloy strips offer high strength, but achieving a strong cubic texture is difficult. Currently, a strong cubic texture is readily achieved in high-distortion metal strips, but the strength is typically low, making it difficult to achieve high-temperature coated superconducting tape applications. Strengthening layered composite materials offers a promising approach to achieving both strong cubic texture and high-strength metal strips. This approach can achieve the balance of mechanical properties and cubic texture formation that is difficult to achieve in single-layer metal strips. However, current research on layered composite strips remains limited to the laboratory stage, hindering large-scale application. Therefore, developing methods for preparing high-performance layered composite strips suitable for cubic texture formation is of great industrial value for promoting the industrialization of second-generation, high-temperature coated superconducting tapes. Summary of the Invention

[0003] In view of the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a high-strength metal composite strip and a preparation method thereof, which has a strong cubic texture and high strength.

[0004] The present invention provides a high-strength metal composite strip, which is composed of three layers of alloys, namely a first outer layer alloy, an intermediate layer alloy and a second outer layer alloy, stacked in sequence. The first outer layer alloy and the second outer layer alloy are both Ni-9wt.%W alloys, and the intermediate layer alloy is a Ni-12wt.%W-3%Mo alloy. The content of cubic texture of the composite strip is not less than 90%, and the yield strength is not less than 480MPa.

[0005] As a preferred embodiment, the thickness of the composite strip is 80 μm.

[0006] In another aspect, the present application provides a method for preparing the high-strength metal composite strip as described above, which comprises the following steps: Step (1): preparing a blank before cold rolling, cold rolling a Ni-9wt.%W alloy to a thickness of 2.0 mm with a deformation of 90% to 95%, and then annealing at 600°C for 1 hour; recrystallizing a Ni-12wt.%W-3%Mo alloy with a thickness of 5.5 mm to form a recrystallized Ni-12wt.%W-3%Mo alloy; Step (2): taking the Ni-9wt.%W alloy as a first outer layer alloy and a second outer layer alloy, taking the Ni-12wt.%W-3%Mo alloy as an intermediate layer alloy, and cold rolling a three-layer alloy plate formed by sequentially stacking the first outer layer alloy, the intermediate layer alloy, and the second outer layer alloy into a layered composite material with a pass deformation of 60% to 70%; Step (3): annealing the composite strip obtained in Step (2) at 750°C to 800°C for 2 hours; Step (4): cold rolling the composite strip obtained in Step (3) to a thickness of 0.5 mm; Step (5): heat treating the cold-rolled strip obtained in Step (4) by annealing at 580°C to 600°C for 30 minutes; Step (6): cold rolling the strip obtained in Step (5) to a thickness of 80 μm; and Step (7): heat treating the strip obtained in Step (6) by annealing at 1230°C to 1250°C for 1 to 2 hours at a heating rate of 2°C / min to 5°C / min.

[0007] As a preferred mode, in the step (2), the pass deformation is 65%; in the step (3), the composite strip obtained in the step (2) is annealed at 800°C for 2 hours; in the step (5), the cold-rolled strip obtained in the step (4) is heat treated by annealing at 600°C for 30 minutes; and in the step (7), the strip obtained in the step (6) is heat treated by annealing at 1230°C for 2 hours at a heating rate of 3°C / min.

[0008] As a preferred mode, in the step (2), the pass deformation is 60%; in the step (3), the composite strip obtained in the step (2) is annealed at 750°C for 2 hours; in the step (5), the cold-rolled strip obtained in the step (4) is heat treated by annealing at 600°C for 30 minutes; and in the step (7), the strip obtained in the step (6) is heat treated by annealing at 1250°C for 2 hours at a heating rate of 2°C / min.

[0009] Compared with the prior art, the application realizes the growth of the deformed structure suitable for the cubic texture by the alloy component design of the inner and outer layers, the Ni-9W alloy as the outer layer material, the large deformation cold rolling and recovery annealing before the cold rolling compounding, the deformed structure suitable for the cubic texture growth obtained by combining the cold rolling compounding process, the high W and high Mo added in the intermediate layer, the overall strength of the composite strip increased, the strong cubic texture formed on the surface layer after the cold rolling, recovery and recrystallization annealing, the high strength and non-ferromagnetic of the overall strip, and the preparation of the high-performance superconducting strip.

[0010] The application has the beneficial technical effects that the industrial production can be realized by the cold rolling compounding, the Ni9W alloy which is not easy to obtain the cubic texture is subjected to the large deformation cold rolling and recrystallization annealing to obtain the initial cubic orientation "seed" with a certain content before the compounding, the low-temperature annealing is carried out after the compounding, the dislocation slip deformation mechanism is realized in the subsequent cold rolling process, the formation of the twin crystal is inhibited, more cubic orientation crystal nucleus is further obtained, and the strong cubic texture is obtained on the surface layer by the final recrystallization annealing. Since the core layer of the composite strip is the alloy with high W and high Mo content, it is difficult to obtain the strong cubic texture on the core layer, but the core layer can provide high strength due to the solid solution strengthening effect of W and Mo, and the strong cubic texture on the surface of the composite strip and the overall high strength can be finally obtained by combining the cubic texture formation idea of the surface layer Ni9W alloy. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 ODF diagram of the outer layer alloy in example 1 before compounding;

[0012] Figure 2 {001} pole figure of the composite strip in example 1 finally;

[0013] Figure 3 {001} pole figure of the composite strip in example 2 finally;

[0014] Figure 4 {001} pole figure of the composite strip in example 3 finally;

[0015] Figure 5 Table of mechanical properties and cubic texture content of the strip in examples 1-3. DETAILED DESCRIPTION

[0016] Hereinafter, an embodiment of a high-strength metal composite strip and a method for manufacturing the same according to the present application will be described with reference to the accompanying drawings.

[0017] The embodiments described herein are illustrative and are not intended to limit or restrict the scope of the application in any way. Such alterations and modifications to the embodiments described herein and such further applications of the principles of the application as described herein are contemplated as would normally occur to one of ordinary skill in the art to which the application pertains and the scope of the application should not be limited by the specific embodiments described in the examples, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

[0018] The drawings accompanying the specification are presented solely to aid in the understanding of the application and are not intended to limit or restrict the scope of the application in any way. The drawings are not necessarily drawn to scale.

[0019] A high-strength metal composite strip of the present application is composed of three layers of alloys, i.e., a first outer layer alloy, an intermediate layer alloy and a second outer layer alloy, the first outer layer alloy and the second outer layer alloy are both Ni-9wt.% W alloy, and the intermediate layer alloy is Ni-12wt.% W-3% Mo alloy, the content of cubic texture of the composite strip is not less than 90%, and the yield strength is not less than 480 MPa. The thickness of the composite strip is preferably 80 μm. The first outer layer alloy and the second outer layer alloy are collectively referred to as outer layer alloy.

[0020] The method for preparing the high-strength metal composite strip of the present application comprises the following steps:

[0021] Step (1): preparing the blank before cold rolling, cold rolling the Ni-9wt.% W alloy to 2.0 mm thick with a deformation of 90% to 95%, and then annealing at 600°C for 1 hour; recrystallizing the 5.5 mm thick Ni-12wt.% W-3% Mo alloy to form a recrystallized Ni-12wt.% W-3% Mo alloy;

[0022] Step (2): taking the Ni-9wt.% W alloy as the first outer layer alloy and the second outer layer alloy, and taking the Ni-12wt.% W-3% Mo alloy as the intermediate layer alloy, cold rolling the three-layer alloy plate formed by stacking the first outer layer alloy, the intermediate layer alloy and the second outer layer alloy in order into a layered composite material in one pass with a deformation of 60% to 70%;

[0023] Step (3): annealing the composite strip obtained in step (2) at 750 to 800°C for 2 hours;

[0024] Step (4): cold rolling the composite strip obtained in step (3) to 0.5 mm thick;

[0025] Step (5): heat treating the cold-rolled strip obtained in step (4) at a temperature of 580-600° C. for 30 minutes;

[0026] Step (6): cold rolling the strip obtained in step (5) to a thickness of 80 μm;

[0027] Step (7): heat-treating the strip obtained in step (6) at a temperature of 1230-1250° C. for 1-2 hours and a heating rate of 2-5° C. / min.

[0028] Three specific examples are given below with reference to the accompanying drawings.

[0029] Example 1

[0030] A Ni-9wt.%W alloy with a thickness of 2.0 mm and a cold rolling deformation of 90% was heated at 600℃ for 1 hour as the outer layer alloy. The ODF diagram of the outer layer alloy is shown in FIG. Figure 1 As shown, a mixed texture of cubic texture + rolling texture is formed, which provides cubic nuclei for the formation of cubic texture in the final strip. Using a Ni-12wt.%W-3%Mo alloy with a thickness of 5.5mm that has undergone recrystallization annealing as the intermediate layer alloy, the three-layer alloy sheet is cold-rolled into a layered composite material in one pass with a deformation of 60%. The cold-rolled composite strip is kept at 750°C for 2 hours and then cold-rolled to a thickness of 0.5mm. The cold-rolled strip is then heat-treated with the following process: keeping at 600°C for 30 minutes. The obtained strip is then cold-rolled to a thickness of 80μm and finally heat-treated with the following process: keeping at 1250°C for 2 hours and a heating rate of 2°C / min, forming a strong cubic texture, as shown Figure 2 shown.

[0031] The strength and cube texture content of the tape of Example 1 are as follows Figure 5 As shown in the table, through the solid solution strengthening of Mo and W, without sacrificing the cube texture content, the ultimate yield strength reaches 480 MPa and the cube texture content is 92%.

[0032] Example 2

[0033] A Ni-9wt.%W alloy with a thickness of 2.0 mm and a cold rolling reduction of 95% was used as the outer layer alloy, a Ni-12wt.%W-3%Mo alloy with a thickness of 5.5 mm and recrystallized annealed was used as the intermediate layer alloy, and the three-layered alloy sheet was cold rolled into a layered composite material with a thickness of 5.5 mm in one pass with a reduction of 70%. The cold-rolled composite material was annealed at 750 °C for 2 hours, and then cold-rolled to a thickness of 0.5 mm. The cold-rolled material was then heat treated at 580 °C for 30 min. The obtained material was cold-rolled to a thickness of 80 μιη, and finally heat treated at 1230 °C for 2 hours with a heating rate of 5 °C / min to form a strong cubic texture, as shown in FIG. 1. Figure 3

[0034] The strength and cubic texture content of the material of Example 1 are shown in the table of FIG. 2. The final yield strength reached 480 MPa, and the cubic texture content was 90% through solid solution strengthening of Mo and W without sacrificing the cubic texture content. Figure 5

[0035] Example 3

[0036] A Ni-9wt.%W alloy with a thickness of 2.0 mm and a cold rolling reduction of 90% was used as the outer layer alloy, a Ni-12wt.%W-3%Mo alloy with a thickness of 5.5 mm and recrystallized annealed was used as the intermediate layer alloy, and the three-layered alloy sheet was cold rolled into a layered composite material with a thickness of 5.5 mm in one pass with a reduction of 65%. The cold-rolled composite material was annealed at 800 °C for 2 hours, and then cold-rolled to a thickness of 0.5 mm. The cold-rolled material was then heat treated at 600 °C for 30 min. The obtained material was cold-rolled to a thickness of 80 μιη, and finally heat treated at 1230 °C for 1 hour with a heating rate of 3 °C / min to form a strong cubic texture, as shown in FIG. 3. Figure 4

[0037] The strength and cubic texture content of the material of Example 3 are shown in the table of FIG. 4. The final yield strength reached 495 MPa, and the cubic texture content was 90% through solid solution strengthening of Mo and W without sacrificing the cubic texture content. Figure 5

[0038] ​​​​The above describes the embodiments of the high-strength metal composite strip and the preparation method thereof, and the purpose is to explain the spirit of the present application. The specific features of the concept of the present application can be designed according to the functions of the above disclosed features, and these designs can be realized by those skilled in the art. Moreover, the above disclosed technical features are not limited to the disclosed combinations with other features, and those skilled in the art can also make other combinations between technical features according to the purpose of the present application, and the purpose of the present application is achieved.

Claims

1. A high-strength metal composite strip, wherein: The composite strip is composed of three layers of alloys, namely a first outer layer alloy, an intermediate layer alloy and a second outer layer alloy, stacked in sequence. The first outer layer alloy and the second outer layer alloy are both Ni-9wt.%W alloys, and the intermediate layer alloy is a Ni-12wt.%W-3%Mo alloy. The content of cubic texture of the composite strip is not less than 90%, and the yield strength is not less than 480MPa.

2. The high-strength metal composite strip according to claim 1, characterized in that: The thickness of the composite strip was 80 μm.

3. A method for preparing the high-strength metal composite strip according to claim 1, comprising the following steps: Step (1): preparing a blank before cold rolling and cladding, cold rolling a Ni-9wt.%W alloy to a thickness of 2.0 mm through a deformation of 90% to 95%, and then holding the alloy at 600°C for 1 hour; performing recrystallization annealing on a 5.5 mm thick Ni-12wt.%W-3%Mo alloy to form a recrystallized Ni-12wt.%W-3%Mo alloy; Step (2): using a Ni-9wt.% W alloy as a first outer layer alloy and a second outer layer alloy, and using a Ni-12wt.% W-3% Mo alloy as an intermediate layer alloy, and subjecting a three-layer alloy plate formed by sequentially stacking the first outer layer alloy, the intermediate layer alloy, and the second outer layer alloy to a single pass cold rolling to form a layered composite material, with a single pass deformation of 60-70%; Step (3): keeping the composite strip obtained in step (2) at 750-800° C. for 2 hours; Step (4): cold rolling the composite strip obtained in step (3) to a thickness of 0.5 mm; Step (5): heat treating the cold-rolled strip obtained in step (4) at a temperature of 580-600° C. for 30 minutes; Step (6): cold rolling the strip obtained in step (5) to a thickness of 80 μm; as well as Step (7): heat-treating the strip obtained in step (6) at a temperature of 1230-1250° C. for 1-2 hours and a heating rate of 2-5° C. / min.

4. The preparation method according to claim 3, wherein In the step (2), the deformation amount per pass is 65%; in the step (3), the composite strip obtained in the step (2) is kept at 800°C for 2 hours; in the step (5), the cold-rolled strip obtained in the step (4) is heat-treated, and the process is: keeping at 600°C for 30 minutes; and, in the step (7), the strip obtained in the step (6) is heat-treated, and the process is: keeping at 1230°C for 2 hours, and the heating rate is 3°C / min.

5. The preparation method according to claim 3, wherein In the step (2), the deformation amount per pass is 60%; in the step (3), the composite strip obtained in the step (2) is kept at 750°C for 2 hours; in the step (5), the cold-rolled strip obtained in the step (4) is heat-treated, and the process is: keeping at 600°C for 30 minutes; and, in the step (7), the strip obtained in the step (6) is heat-treated, and the process is: keeping at 1250°C for 2 hours, and the heating rate is 2°C / min.

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