Preparation method of FeCrCoW4.5 alloy foil

Abstract

The invention belongs to the technical field of alloy foil preparation, and particularly relates to a preparation method of a FeCrCoW4.5 alloy foil. Comprising the following steps that N passes of cold rolling are conducted on a FeCrCoW4.5 alloy blank, N is larger than or equal to 3, the deformation amount of each pass of cold rolling is 40-70%, annealing treatment is conducted at the temperature of 1000-1200 DEG C after the last pass, work hardening generated by cold rolling is eliminated, final cold rolling is conducted after annealing treatment till the thickness is 0.06 mm, and the alloy foil is obtained. Through multi-pass cold rolling and annealing combined machining, during cold rolling, a large number of dislocation and other defects can be generated in a material, so that the hardness of the material is increased, and the plasticity is reduced; and annealing is carried out after multi-pass cold rolling, atoms in the material can obtain certain energy, dislocation and other defects are rearranged and combined, and part of the defects are eliminated, so that the hardness of the material is reduced, certain plasticity is recovered, and the comprehensive mechanical property of the material is improved.

Description

Technical Field

[0001] This invention belongs to the field of alloy foil preparation technology, specifically relating to a FeCrCoW... 4.5 Preparation method of alloy foil. Background Technology

[0002] FeCrCoW 4.5 Metallic materials are the main materials used to manufacture the sensitive grids of resistance strain gauges. They are mainly composed of four elements: iron, chromium, cobalt, and tungsten, with tungsten accounting for 4.5% by mass. This alloy material possesses excellent mechanical and electrical properties and is widely used in structural components in aerospace, medical device manufacturing, and wearable devices.

[0003] Currently, regarding FeCrCoW 4.5 The current processing technology for metallic materials mainly relies on single-pass cold rolling combined with direct annealing or multiple-pass cold rolling. These approaches have significant shortcomings. Single-pass cold rolling combined with direct annealing easily leads to large thickness deviations, and annealing cannot fully eliminate the work hardening caused by cold rolling, resulting in high material hardness and limited plasticity recovery. Without further cold rolling after annealing to correct the thickness, the final product has large thickness accuracy deviations. While multi-pass cold rolling improves thickness accuracy to some extent, it allows internal defects such as dislocations to accumulate, increasing hardness, reducing plasticity, and even causing defects such as cracks, making it difficult to achieve high-precision control of material thickness and optimization of comprehensive mechanical properties.

[0004] Existing methods, such as single-pass cold rolling combined with direct annealing or multiple-pass cold rolling, are prone to thickness deviations and cannot fully eliminate work hardening. They may also lead to increased material hardness, reduced plasticity, or even cracks, making it difficult to achieve high-precision thickness control and optimization of comprehensive mechanical properties. Summary of the Invention

[0005] To address the above problems, this invention provides a FeCrCoW 4.5 The preparation method of alloy foil involves a combination of multi-pass cold rolling and annealing. Cold rolling effectively reduces the material thickness, while annealing plays a crucial role in the cold-rolled material. Annealing eliminates work hardening that occurs during cold rolling. During cold rolling, numerous dislocations and other defects are generated within the material, leading to increased hardness and decreased plasticity. Annealing allows the atoms within the material to gain energy, causing dislocations and other defects to rearrange and recombine, eliminating some defects. This results in a suitable reduction in hardness, restoration of plasticity, and improvement of the material's overall mechanical properties. Furthermore, a second cold rolling process after annealing further reduces the thickness. This processing method facilitates precise control of the final dimensions of the material, meeting the dimensional requirements for metal foil.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions.

[0007] The purpose of this invention is to provide a FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: The alloy billet is subjected to N cold rolling passes, where N≥3, and the deformation amount of each cold rolling pass is 40% to 70%, which refines the grains and causes dislocations. After the last pass, it is annealed at 1000℃ to 1200℃ to eliminate the work hardening caused by cold rolling. After annealing, it is finally cold rolled to a thickness of 0.06mm to obtain the alloy foil.

[0008] Furthermore, the annealing time is 15 min to 30 min.

[0009] Furthermore, the rolling speed for each pass is 3 m / s to 12 m / s, and the rolling force is 400 t to 1000 t.

[0010] Furthermore, N is 3, the rolling speed per pass is 5 m / s to 12 m / s, and the rolling force is 500 t to 800 t. Furthermore, the deformation amount of the first cold rolling pass is 45% to 55%, the deformation amount of the second cold rolling pass is 40% to 50%, and the deformation amount of the third cold rolling pass is 60% to 68%.

[0011] Furthermore, the deformation amount of the final cold rolling is 60% to 75%.

[0012] Furthermore, the final cold rolling speed is 0.5m / s to 1.5m / s, and the rolling force is 300 to 500t.

[0013] Furthermore, the thickness of the alloy billet is ≤5mm.

[0014] Compared with the prior art, the present invention has the following advantages: The preparation method provided by this invention, through a combination of multi-pass cold rolling and annealing, can transform FeCrCoW 4.5The material is precisely processed from its initial thickness to 0.06 mm. Cold rolling effectively reduces the material's thickness, and annealing (1000℃~1200℃) plays a crucial role in the cold-rolled material. Annealing eliminates work hardening that occurs during cold rolling. During cold rolling, numerous dislocations and other defects are generated within the material, leading to increased hardness and decreased plasticity. Annealing allows the atoms within the material to gain energy, causing dislocations and other defects to rearrange and recombine, eliminating some defects. This results in a suitable reduction in hardness, restoration of plasticity, and improvement of the material's overall mechanical properties. Furthermore, cold rolling is performed again after annealing to further reduce the thickness. This processing method facilitates precise control of the final dimensions of the material, meeting the dimensional requirements for metal foils. Attached Figure Description

[0015] Figure 1 The FeCrCoW prepared for this invention 4.5 Process flow diagram of alloy foil.

[0016] Figure 2 FeCrCoW was prepared for Example 1 of the present invention. 4.5 EBSD scan of alloy foil, Figure 2 In the text, 'a' represents the FeCrCoW layer 0.2 mm after the second pass. 4.5 Alloy, b is 0.06mm FeCrCoW 4.5 Alloy foil.

[0017] Figure 3 The FeCrCoW obtained in Comparative Examples 1 and 2 of this invention 4.5 Microstructure diagram of alloy foil. Figure 3 (a) is Comparative Example 2, and (b) is Comparative Example 1. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the technical terms used in this invention are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.

[0020] Currently, existing technologies are used to prepare FeCrCoW 4.5When producing foil, a single cold rolling followed by direct annealing can easily lead to thickness deviations and fail to adequately eliminate work hardening. Multi-pass cold rolling without proper annealing can increase material hardness, reduce plasticity, and even cause cracks, making it difficult to achieve high-precision thickness control and optimize overall mechanical properties. Therefore, to address these issues, this invention employs alternating cold rolling and annealing processes. First, cold rolling initially reduces the thickness; then, annealing eliminates processing stress; and finally, cold rolling refines the thickness and optimizes the microstructure. This addresses the shortcomings of existing technologies in terms of thickness control precision and material performance optimization. Specifically:

[0021] A FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: Provide a FeCrCoW with a thickness of ≤5mm 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet is subjected to N cold rolling passes, where N≥3, to refine the grains and induce dislocations. After the last pass, it is annealed at 1000℃~1200℃ for 15min~30min to eliminate the work hardening caused by cold rolling. After annealing, it is subjected to final cold rolling with a deformation of 60%~75% to make the alloy foil thickness 0.06mm, thus obtaining the alloy foil.

[0022] In some embodiments, the rolling speed per pass is 3 m / s to 12 m / s, and the rolling force is 400 t to 1000 t.

[0023] It should be noted that FeCrCoW 4.5 The initial thickness of the alloy billet shall not exceed 5 mm. The corresponding rolling passes shall be set according to the initial thickness. When the initial thickness is greater than 5 mm, a short-time high-temperature annealing treatment shall be performed before cold rolling. The annealing temperature shall be 1000℃~1200℃ and the time shall be 15min~30min.

[0024] This invention utilizes a combination of multi-pass cold rolling and annealing to precisely process FeCrCoW4.5 material from its initial thickness to 0.06 mm. The cold rolling process effectively reduces the material thickness, while annealing (1000℃~1200℃ / 15min~30min) plays a crucial role in the post-cold-rolled material. Annealing eliminates work hardening that occurs during cold rolling. During cold rolling, numerous dislocations and other defects are generated within the material, leading to increased hardness and decreased plasticity. Annealing allows the atoms within the material to gain energy, causing dislocations and other defects to rearrange and recombine, eliminating some defects and thus appropriately reducing the material's hardness, restoring some plasticity, and improving the material's overall mechanical properties. Furthermore, a second cold rolling process after annealing further reduces the thickness. This processing method facilitates precise control of the final material dimensions, meeting the dimensional requirements for metal foils.

[0025] In a preferred embodiment, N is 3, the rolling speed per pass is 5 m / s to 12 m / s, the rolling force is 500 t to 800 t, the cold rolling deformation in the first pass is 45% to 55%, the cold rolling deformation in the second pass is 40% to 50%, and the cold rolling deformation in the third pass is 60% to 68%. As a preferred embodiment of the present invention, FeCrCoW... 4.5 The initial thickness of the alloy billet is 2 mm. The deformation amount in the first cold rolling pass is 50%, the deformation amount in the second cold rolling pass is 40%, and the deformation amount in the third cold rolling pass is 66.6%. By deforming in three stages through cold rolling, a reasonable redistribution of stress and strain field is achieved, and an optimized balance is obtained between microstructure refinement, dimensional accuracy control, and equipment load balance.

[0026] In some embodiments, the final cold rolling speed is 0.2 m / s to 3 m / s, and the rolling force is 200 t to 600 t. As a preferred embodiment of the invention, the final cold rolling speed is 0.5 m / s to 1.5 m / s, and the rolling force is 300 t to 500 t. This invention, by precisely controlling parameters such as rolling force and rolling speed, and strictly controlling the temperature and time during the annealing process, can accurately process metal materials to 60 micrometers. This is highly advantageous in applications with extremely high requirements for metal material thickness, contributing to the miniaturization and thinning of electronic devices. Through the synergistic effect of "multi-pass cold rolling + annealing at 1000℃ to 1200℃ for 15 min to 30 min + single cold rolling," the mechanical properties of the material are optimized. Its yield strength reaches 1114.543 MPa, an increase of 97.66%, and the Vickers hardness increases by 11.14%, meeting various complex operating conditions.

[0027] The following specific examples will provide further explanation.

[0028] Example 1 A FeCrCoW 4.5 Methods for preparing alloy foil, such as Figure 1 As shown, it includes the following steps: Provide a 2mm thick FeCrCoW 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet undergoes three cold rolling passes: the first pass (2mm → 1mm, deformation 50%), rolling speed 10m / s, and rolling force 700t; the second pass (1mm → 0.6mm, deformation 40%), rolling speed 8m / s, and rolling force 750t; and the third pass (0.6mm → 0.2mm, deformation 66.6%), rolling speed 6m / s, and rolling force 750t.

[0029] After the third pass, annealing was performed at 1100℃ for 15 minutes, followed by final cold rolling: 0.2mm → 0.06mm, with a deformation of 70%, a rolling speed of 0.5m / s, and a rolling force of 500t, resulting in an alloy foil thickness of 0.06mm, yielding FeCrCoW. 4.5 Alloy foil.

[0030] In this embodiment, the yield strength was increased from 237 MPa to 615 MPa, an increase of 159%, and the tensile strength was increased from 687 MPa to 1200 MPa, an increase of 75%, through a multi-pass cold rolling process. However, the elongation decreased from 24.2% to 6.1%, and the grain size was significantly refined to conform to the Hall-Petch relationship. The total deformation was distributed across multiple passes through multi-pass cold rolling, resulting in lower stress in each pass and a more uniform stress distribution, which reduced crack formation. However, internal residual stress and work hardening were not released.

[0031] Figure 2 FeCrCoW was prepared for Example 1 of the present invention. 4.5 EBSD scan of alloy foil, Figure 2 In the text, 'a' represents the FeCrCoW layer 0.2 mm after the second pass. 4.5 Alloy, b is 0.06mm FeCrCoW 4.5 Alloy foil. For example... Figure 2 As shown, when the alloy thickness is 0.2 mm, the grain size shows a further reduction trend, and coarse grains almost disappear. The grains maintain their elongation characteristics along the rolling direction, forming a large number of rolling deformation zones in this direction, exhibiting a strip-like distribution. This phenomenon reveals that the alloy has excellent processing and deformation properties. When the alloy thickness is 0.06 mm, the coarse grains become fragmented and fine, and the grain size further decreases. Fine grains can be observed under a metallographic microscope, and the rolling deformation bands are obvious.

[0032] Example 2 A FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: Provide a 2mm thick FeCrCoW 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet undergoes three cold rolling passes: the first pass (2mm → 1.2mm, deformation 40%), rolling speed 8m / s, and rolling force 750t; the second pass (1.2mm → 0.6mm, deformation 50%), rolling speed 10m / s, and rolling force 700t; and the third pass (0.6mm → 0.22mm, deformation 63.3%), rolling speed 8m / s, and rolling force 680t.

[0033] After the third pass, annealing was performed at 1100℃ for 20 minutes, followed by final cold rolling: 0.2mm → 0.06mm, with a deformation of 70%, a rolling speed of 1m / s, and a rolling force of 400t, resulting in an alloy foil thickness of 0.06mm, yielding FeCrCoW. 4.5 Alloy foil.

[0034] In this embodiment, the yield strength was increased from 237 MPa to 573 MPa through a multi-pass cold rolling process, an increase of 141.2%; the tensile strength was increased from 687 MPa to 1114 MPa, an increase of 62%. However, the elongation decreased from 24.2% to 5.03%, and the grain size was significantly refined to conform to the Hall-Petch relationship. The total deformation was distributed across multiple passes through multi-pass cold rolling, resulting in lower stress in each pass and a more uniform stress distribution, which reduced crack formation. However, internal residual stress and work hardening were not released.

[0035] Example 3 A FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: Provide a 2mm thick FeCrCoW 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet undergoes three cold rolling passes: the first pass (2mm → 0.9mm, deformation 55%), rolling speed 10m / s, and rolling force 800t; the second pass (0.9mm → 0.5mm, deformation 44.4%), rolling speed 7m / s, and rolling force 700t; and the third pass (0.5mm → 0.2mm, deformation 60%), rolling speed 7m / s, and rolling force 700t.

[0036] After the third pass, annealing was performed at 1100℃ for 30 minutes, followed by final cold rolling: 0.2mm → 0.06mm, with a deformation of 70%, a rolling speed of 1m / s, and a rolling force of 400t, resulting in an alloy foil thickness of 0.06mm, yielding FeCrCoW. 4.5 Alloy foil.

[0037] In this embodiment, the yield strength was increased from 237 MPa to 510 MPa, an increase of 115%, and the tensile strength was increased from 687 MPa to 1183 MPa, an increase of 72%, through a multi-pass cold rolling process. However, the elongation decreased from 24.2% to 5.74%, and the grain size was significantly refined to conform to the Hall-Petch relationship. The total deformation was distributed across multiple passes through multi-pass cold rolling, resulting in lower stress in each pass and a more uniform stress distribution, which reduced crack formation. However, internal residual stress and work hardening were not released.

[0038] Comparative Example 1 A FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: Provide a 2mm thick FeCrCoW 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet undergoes three cold rolling passes: the first pass (2mm → 1mm, deformation 50%), rolling speed 10m / s, and rolling force 700t; the second pass (1mm → 0.6mm, deformation 40%), rolling speed 8m / s, and rolling force 750t; and the third pass (0.6mm → 0.4mm, deformation 33.3%), rolling speed 12m / s, and rolling force 550t.

[0039] After the third pass, annealing was performed at 1100℃ for 15 minutes, followed by final cold rolling: 0.4mm → 0.2mm, at a rolling speed of 5m / s and a rolling force of 800t, to achieve a alloy foil thickness of 0.2mm, yielding FeCrCoW. 4.5 Alloy foil.

[0040] Comparative Example 2 A FeCrCoW 4.5 The method for preparing alloy foil includes the following steps: Provide a 2mm thick FeCrCoW 4.5 Alloy billet, for FeCrCoW 4.5 The alloy billet underwent three cold rolling passes: Pass 1: 2mm → 1mm, deformation 50%, rolling speed 10m / s, rolling force 700t; Pass 2: 1mm → 0.6mm, deformation 40%, rolling speed 8m / s, rolling force 750t; Pass 3: 0.6mm → 0.4mm, deformation 33.3%, rolling speed 12m / s, rolling force 550t; Final cold rolling: 0.4mm → 0.2mm, rolling speed 5m / s, rolling force 800t, yielding FeCrCoW. 4.5 Alloy foil.

[0041] Figure 3 The FeCrCoW obtained in Comparative Examples 1 and 2 of this invention 4.5 Microstructure diagram of alloy foil. Figure 3 In the examples, (a) is Comparative Example 2, and (b) is Comparative Example 1. Figure 3 As shown, the deformation band of the rolled alloy after annealing is significantly reduced. After annealing at 1100℃ for 15 min, the alloy underwent recovery recrystallization, exhibiting a fully recrystallized structure. The partially recrystallized grains coarsened, forming coarse grains. The alloy rolled to 0.2 mm after annealing has a hardness of 475 Hv, which is 13.16% lower than that of the alloy rolled directly to 0.2 mm. In terms of electrical properties, this is because the alloy grains increase in size and the number of grain boundaries decreases after annealing, leading to a reduction in electron scattering caused by the grain boundaries.

[0042] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described here to avoid redundancy. Although preferred embodiments of the invention have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this invention.

[0043] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A FeCrCoW 4.5 A method for preparing alloy foil, characterized in that, Includes the following steps: FeCrCoW 4.5 The alloy billet is subjected to N cold rolling passes, where N≥3, and the deformation amount of each cold rolling pass is 40% to 70%, which refines the grains and causes dislocations. After the last pass, it is annealed at 1000℃ to 1200℃ to eliminate the work hardening caused by cold rolling. After annealing, it is finally cold rolled to a thickness of 0.06mm to obtain the alloy foil.

2. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, The annealing time is 15 min to 30 min.

3. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, The rolling speed for each pass is 3 m / s to 12 m / s, and the rolling force is 400 t to 1000 t.

4. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, N is 3, the rolling speed per pass is 5m / s to 12m / s, and the rolling force is 500t to 800t.

5. The FeCrCoW according to claim 4 4.5 A method for preparing alloy foil, characterized in that, The deformation amount in the first cold rolling pass is 45%–55%, the deformation amount in the second cold rolling pass is 40%–50%, and the deformation amount in the third cold rolling pass is 60%–68%.

6. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, The deformation amount of the final cold rolling is 60% to 75%.

7. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, The final cold rolling speed is 0.5m / s to 1.5m / s, and the rolling force is 300 to 500t.

8. The FeCrCoW according to claim 1 4.5 A method for preparing alloy foil, characterized in that, The thickness of the alloy billet is ≤5mm.

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