High-strength cubic texture metal strip and preparation method thereof

Abstract

The invention discloses a high-strength cubic texture metal strip and a preparation method thereof.By means of alloy component and composition design, Ni-Cu-Cr-Al-N alloy is deposited on Ni-12W-Fe-Mo alloy through the laser additive manufacturing technology, an initial structure suitable for forming of a strong cubic texture is obtained by means of the thought of a multi-layer composite material, and the high-strength cubic texture metal strip is obtained. And the high-strength strong cube texture metal strip can be finally obtained by combining solid solution strengthening and precipitation strengthening modes. By adding a proper amount of Cr, Al and N into the Ni-Cu alloy, the strength of the alloy strip can be obviously improved, and meanwhile, ferromagnetism can be avoided. A columnar crystal initial structure of a cubic texture can be obtained on the surface layer through a laser deposition method, and the strong cubic texture can be finally formed on the surface of the strip through cold rolling and subsequent high-temperature heat treatment by means of the texture genetic effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of high-strength metal substrates for second-generation high-temperature coated superconducting tapes, and particularly relates to a high-strength cubic-textured metal strip and a preparation method thereof. Background Art

[0002] Second-generation coated superconducting materials represented by YBCO have wide application values in fields such as electric power and transportation. Due to the brittleness of YBCO itself, it is necessary to deposit a transition layer and a YBCO superconducting thin film on a high-strength and tough metal strip to obtain a multi-layer coated superconducting tape. High-performance coated superconducting tapes require the metal substrate to have high strength, no ferromagnetism under liquid nitrogen, and strong cubic texture. Ni-W alloys are metal substrate materials that have been studied more. Nickel-based alloys with a high W content have high strength and no ferromagnetism, and have great application prospects, but it is difficult to simultaneously achieve a strong cubic texture. Layered composite strips can simultaneously achieve strength, no ferromagnetism, and strong cubic texture, but the preparation process is complex, and it is difficult to mass-produce and apply. Designing new alloy compositions and new methods for synthesizing cubic texture is the key to realizing a metal strip with no ferromagnetism, high strength, and strong cubic texture. Summary of the Invention

[0003] Aiming at the deficiencies of the above-mentioned existing technologies, the present invention provides a high-strength cubic-textured metal strip and a preparation method thereof. By adding appropriate amounts of Cr, Al, and N to a Ni-Cu alloy, the strength of the alloy strip can be significantly improved, and at the same time, no ferromagnetism can be obtained.

[0004] The present invention is realized through the following technical solutions. A high-strength cubic-textured metal strip is characterized in that: the initial ingot for preparing the metal strip is composed of three layers of metals. The chemical compositions and mass percentages of the upper and lower layers are both 40% - 45% Cu, 1% - 1.8% Al, 2% - 3% Cr, 0.1% - 0.2% N, and the balance is Ni; the chemical composition and mass percentage of the central layer are: 12% W, 0.5 - 0.8% Fe, 2 - 2.8% Mo, and the balance is Ni.

[0005] The preparation method of the high-strength cubic-textured metal strip described in the present invention is characterized in that the specific steps are as follows: Step S1: Obtain an alloy ingot with the composition of the central layer of the above initial ingot through vacuum induction melting. The alloy ingot is a cuboid with dimensions of 500mm × 100mm × 20mm; Step S2: Obtain alloy powders with the compositions of the upper and lower layers of the above initial ingot through gas atomization; Step S1: Obtain the alloy ingot with the composition of the central layer of the initial ingot through vacuum induction melting. The alloy ingot is a cuboid with dimensions of 500mm × 100mm × 20mm; Step S2: Obtain alloy powders with the compositions of the upper and lower layers of the initial ingot by gas atomization method; Step S3: Deposit the alloy powders obtained in Step S2 onto the upper and lower surfaces of the alloy ingot obtained in Step S1 by laser directed deposition to obtain a laminated composite ingot, and the deposition thicknesses of the upper and lower surfaces are the same, both being 2 - 3 mm; Step S4: Cold roll the laminated composite ingot obtained in Step S3 to 0.07 - 0.08 mm, and then conduct high - temperature heat treatment. The specific process of the high - temperature heat treatment is: in a non - oxygen atmosphere, put it into the furnace when reaching the temperature, keep it at 880 - 950 °C for 3 - 7 min and then immediately cool it to room temperature, and then in a non - oxygen atmosphere, put it into the furnace when reaching the temperature, keep it at 1100 - 1120 °C for 8 - 12 min and then immediately cool it to room temperature; Step S5: Conduct low - temperature heat treatment on the strip obtained in Step S4 again. The specific process of the low - temperature heat treatment is: in an air atmosphere, heat it up with the furnace, keep it at 500 - 580 °C for 1 - 3 h and then cool it with the furnace to room temperature, and finally obtain a high - strength cube - textured metal strip.

[0006] Furthermore, the particle size of the alloy powders in Step S2 is 80 - 200 μm.

[0007] Furthermore, the process parameters of the laser directed deposition in Step S3 are that the laser power is 700 W, the scanning speed is 1800 mm / s, and the layer thickness is 280 - 380 μm.

[0008] Furthermore, the non - oxygen atmosphere in Step S4 is a mixed gas of nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 4:1.

[0009] Compared with the prior art, the present invention has the following advantages and beneficial effects: By adding appropriate amounts of Cr, Al, and N to the Ni - Cu alloy, the strength of the alloy strip can be significantly improved, and at the same time, non - ferromagnetic property can be obtained. Using the laser deposition method, a columnar crystal initial structure with cube texture can be obtained on the surface layer. Utilizing the texture inheritance effect, through cold rolling and subsequent high - temperature heat treatment, the formation of strong cube texture can be finally realized on the surface of the strip. In addition, by designing the recrystallization atmosphere, the reaction between N element and hydrogen can be inhibited, thereby reserving more dispersed and fine second phases for the subsequent low - temperature treatment. Finally, by using low - temperature heat treatment, without sacrificing the content of cube texture, a large number of precipitated phases can be obtained on the surface layer of the strip, further improving the strength of the alloy strip. Description of the Drawings

[0010] Figure 1 It is the EBSD map of the cross - section of the strip after final recrystallization annealing in Example 1.

[0011] Figure 2The pole figure of the {111} plane on the strip surface after the final recrystallization annealing in Example 1.

[0012] Figure 3 The pole figure of the {111} plane on the strip surface after the final recrystallization annealing in Example 2.

[0013] Figure 4 The pole figure of the {111} plane on the strip surface after the final recrystallization annealing in Example 3. Detailed implementation manners

[0014] The above content of the present invention will be further described in detail through the following examples. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples. Any technology implemented based on the above content of the present invention belongs to the scope of the present invention. Example 1

[0015] The intermediate layer alloy ingot was prepared by vacuum induction melting. Its chemical composition and mass percentage were: 12% W, 0.5% Fe, 2% Mo, and the balance was Ni. The alloy powder was obtained by gas atomization. The particle size of the alloy powder was 80 - 200 μm, and its chemical composition and mass percentage were: 40% Cu, 1% Al, 2% Cr, 0.1% N, and the balance was Ni. The obtained alloy powder was deposited on the upper and lower surfaces of the central layer alloy ingot by laser direct deposition. The deposition thickness of both the upper and lower surfaces was 2 mm, and a laminated composite ingot was obtained. The process parameters of laser direct deposition were: laser power was 700 W, scanning speed was 1800 mm / s, and layer thickness was 280 μm. Then the laminated composite ingot was cold rolled to 0.08 mm, and then high-temperature heat treatment was carried out. The specific process of high-temperature heat treatment was: in a non-oxidizing atmosphere, it was put into the furnace at the arrival temperature, held at 880 °C for 5 min and then immediately cooled to room temperature, and then in a non-oxidizing atmosphere, it was put into the furnace at the arrival temperature, held at 1100 °C for 10 min and then immediately cooled to room temperature. The non-oxidizing atmosphere was a mixed gas of nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen was 4:1. The EBSD map of the strip cross-section was as Figure 1 shown. The red grains were cubic orientation. It was obvious that most of the grains on the surface layer were cubic orientation, and the white part in the core was non-cubic orientation grains. Figure 2 The pole figure of the {111} plane on the strip surface was a strong cubic texture. Finally, the obtained strip was subjected to low-temperature heat treatment again. The specific process of low-temperature heat treatment was: in an air atmosphere, it was heated in the furnace with the furnace temperature rising, held at 500 °C for 2 h and then cooled to room temperature with the furnace. Without sacrificing the cubic texture, the strength of the alloy was further improved. The cubic texture content and tensile strength were shown in Table 1. Due to the generation of N-containing precipitation phases, the strength of the surface layer alloy was greatly improved, and the overall tensile strength of the final metal strip was close to 1000 MPa. Example 2

[0016] The intermediate layer alloy ingot is prepared by vacuum induction melting, and its chemical composition and mass percentage are as follows: 12% W, 0.8% Fe, 2.8% Mo, and the balance is Ni. The alloy powder is obtained by gas atomization. The particle size of the alloy powder is 80 - 200 μm, and its chemical composition and mass percentage are as follows: 45% Cu, 1.8% Al, 3% Cr, 0.2% N, and the balance is Ni. The obtained alloy powder is deposited on the upper and lower surfaces of the central layer alloy ingot by laser direct deposition. The deposition thickness of both the upper and lower surfaces is 3 mm, and a layered composite ingot is obtained. The process parameters of laser direct deposition are: laser power is 700 W, scanning speed is 1800 mm / s, and layer thickness is 380 μm. Then the layered composite ingot is cold-rolled to 0.07 mm, and then high-temperature heat treatment is carried out. The specific process of high-temperature heat treatment is: in a non-oxidizing atmosphere, it is put into the furnace at the arrival temperature, held at 950 °C for 5 min and then immediately cooled to room temperature, and then in a non-oxidizing atmosphere, it is put into the furnace at the arrival temperature, held at 1120 °C for 10 min and then immediately cooled to room temperature. The non-oxidizing atmosphere is a mixed gas of nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 4:1. The {111} pole figure on the surface of the strip is as Figure 3 shown, which is a strong cubic texture; finally, the obtained strip is subjected to low-temperature heat treatment again. The specific process of low-temperature heat treatment is: in an air atmosphere, it is heated in the furnace at a rate of furnace heating, held at 580 °C for 2 h and then cooled in the furnace to room temperature. Without sacrificing the cubic texture, the strength of the alloy is further improved. The cubic texture content and tensile strength are shown in Table 1. Due to the generation of N-containing precipitates, the strength of the surface layer alloy is greatly improved, and the overall tensile strength of the final metal strip is close to 1000 MPa. Example 3

[0017] The intermediate layer alloy ingot is prepared by vacuum induction melting. Its chemical composition and mass percentage are as follows: 12% W, 0.7% Fe, 2.5% Mo, and the balance is Ni. The alloy powder is obtained by gas atomization. The particle size of the alloy powder is 80 - 200 μm, and its chemical composition and mass percentage are as follows: 42% Cu, 1.5% Al, 2.5% Cr, 0.15% N, and the balance is Ni. The obtained alloy powder is deposited on the upper and lower surfaces of the central layer alloy ingot by laser direct deposition. The deposition thickness of both the upper and lower surfaces is 2.5 mm, and a layered composite ingot is obtained. The process parameters of laser direct deposition are: laser power is 700 W, scanning speed is 1800 mm / s, and layer thickness is 300 μm. Then the layered composite ingot is cold-rolled to 0.075 mm, and then high-temperature heat treatment is carried out. The specific process of high-temperature heat treatment is: in a non-oxidizing atmosphere, it is put into the furnace at the arrival temperature, held at 900 °C for 5 min and then immediately cooled to room temperature, and then in a non-oxidizing atmosphere, it is put into the furnace at the arrival temperature, held at 1100 °C for 10 min and then immediately cooled to room temperature. The non-oxidizing atmosphere is a mixed gas of nitrogen and hydrogen, and the volume ratio of nitrogen to hydrogen is 4:1. The {111} pole figure on the surface of the strip is as Figure 4 shown, which is a strong cubic texture; finally, the obtained strip is subjected to low-temperature heat treatment again. The specific process of low-temperature heat treatment is: in an air atmosphere, it is heated in the furnace at a rate of heating with the furnace, held at 550 °C for 2 h and then cooled to room temperature with the furnace. Without sacrificing the cubic texture, the strength of the alloy is further improved. The cubic texture content and tensile strength are shown in Table 1. Due to the generation of N-containing precipitation phases, the strength of the surface layer alloy is greatly improved, and the overall tensile strength of the final metal strip is close to 1000 MPa.

[0018] Table 1 Tensile strength and cubic texture content of the metal strips in Examples 1 - 3

[0019] The above examples describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above examples. What is described in the above examples and the specification only illustrates the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A high-strength cubic textured metal strip, characterized in that: The initial billet for preparing the metal strip is composed of three layers of metal, wherein the chemical composition and mass percentage of the upper and lower layers are 40%~45% Cu, 1%~1.8% Al, 2%~3% Cr, 0.1%~0.2% N, and the balance is Ni; the chemical composition and mass percentage of the center layer are 12% W, 0.5~0.8% Fe, 2~2.8% Mo, and the balance is Ni.

2. A method for preparing the high-strength cubic textured metal strip according to claim 1, characterized in that The specific steps are: Step S1: obtaining an alloy ingot having the composition of the central layer of the initial billet by vacuum induction melting, wherein the alloy ingot is a cuboid with a size of 500 mm×100 mm×20 mm; Step S2: obtaining alloy powders of upper and lower layer components of the initial ingot by a gas atomization method; Step S3: depositing the alloy powder obtained in step S2 onto the upper and lower surfaces of the alloy ingot obtained in step S1 by laser directional deposition to obtain a layered composite ingot, wherein the deposition thickness of the upper and lower surfaces is the same, both of which are 2-3 mm; Step S4: cold rolling the layered composite ingot obtained in step S3 to 0.07-0.08 mm, and then performing high-temperature heat treatment. The specific process of high-temperature heat treatment is: in a non-oxygen atmosphere, the ingot is heated to 880-950° C. for 3-7 minutes, and then immediately cooled to room temperature, and then in a non-oxygen atmosphere, the ingot is heated to 1100-1120° C. for 8-12 minutes, and then immediately cooled to room temperature; Step S5: The strip obtained in step S4 is subjected to low-temperature heat treatment again. The specific process of low-temperature heat treatment is: in an atmospheric atmosphere, the strip is heated at 500-580°C for 1-3 hours and then cooled to room temperature, thereby finally obtaining a high-strength cubic textured metal strip.

3. The method for preparing a high-strength cubic textured metal strip according to claim 2, characterized in that: The particle size of the alloy powder in step S2 is 80-200 μm.

4. The method for preparing a high-strength cubic textured metal strip according to claim 2, characterized in that: The process parameters of the laser directional deposition in step S3 are: laser power of 700 W, scanning speed of 1800 mm / s, and layer thickness of 280-380 μm.

5. The method for preparing a high-strength cubic textured metal strip according to claim 2, characterized in that: The non-oxygen atmosphere in step S4 is a mixed gas of nitrogen and hydrogen, wherein the volume ratio of nitrogen to hydrogen is 4:1.

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