Low-cost high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire and preparation method thereof

Abstract

This invention discloses a low-cost, high-strength, and high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire and its preparation method, belonging to the field of metallic materials technology. The alloy composition is dominated by Ni, Fe, and Al, and does not contain expensive rare elements such as Co, significantly reducing raw material costs. The entire processing flow eliminates the need for hot working and frequent annealing, greatly reducing the thermal process in traditional wire drawing and exhibiting low carbon emissions. The preparation method includes: vacuum melting and casting the raw materials to obtain an ingot; wire-cutting the ingot into plates; cold-rolling and wire-cutting the cut plates into bars; subsequently performing multiple cold drawing passes to form the wire of the final size; and finally, recrystallizing and annealing the wire. This invention achieves an extremely high yield strength and good tensile plasticity match in the alloy wire. The method has a simple process flow, produces wires with uniform diameter and a continuous, defect-free surface, making it suitable for industrial mass production.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials technology, specifically relating to a low-cost, high-strength, high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire and its preparation method. Background Technology

[0002] There is a significant need for micron-sized high-strength structural wires in aerospace, biomedicine, mobile communications, automotive, and the fabrication of precision devices such as microelectronics and sensors, requiring higher surface quality and stronger mechanical properties. While traditional cold-drawn pearlitic steel wires can achieve yield strengths approaching 6 GPa at room temperature, their strength contribution is largely due to dislocation strengthening and grain boundary strengthening, making them prone to recovery and recrystallization during long-term service or at intermediate temperatures. Traditional nickel-based alloy wires typically sacrifice room-temperature strength for high-temperature stability, and also have low specific strength and high cost. Therefore, there is an urgent need to develop and fabricate novel micron-sized high-strength and high-toughness alloy wires with high surface quality to replace traditional alloys.

[0003] Since Professors Ye Junwei and Cantor introduced the concept of "high entropy" in 2004, multi-principal alloys have attracted considerable attention from international materials scientists due to their excellent strength and ductility. However, due to the extremely high solid solubility of early single-phase multi-principal alloys, macroscopic / microscopic segregation easily occurs during casting, leading to the formation of brittle second phases (such as σ phase) distributed macroscopically / microscopically. Secondly, multi-principal alloys typically exhibit significant work hardening rates, making it difficult to directly apply traditional alloy wire drawing methods to medium-entropy alloys. Wire breakage or surface defects are prone to occur during drawing, and multiple annealing and hot drawing processes significantly increase processing power consumption and costs. Finally, existing high-performance multi-principal alloys generally contain large amounts of expensive Co, resulting in high production costs and making them unsuitable as the first choice for downstream enterprises. These factors greatly hinder the industrial production of multi-principal alloys. Therefore, designing a eutectic alloy with good casting performance, machinability, low cost, and compliance with low-carbon emission requirements is an urgent problem to be solved in this field. Summary of the Invention

[0004] To address the aforementioned technical problems, or some of them, this invention proposes a low-cost nickel-iron-aluminum multi-principal-element eutectic alloy wire and its preparation method. After casting, a nickel-iron-aluminum eutectic alloy within a certain composition range can be transformed into a eutectic multi-principal-element alloy wire with excellent strength and plasticity through simple cold rolling / cold drawing deformation and rapid low-temperature annealing.

[0005] To achieve the above objectives, the present invention provides a low-cost, high-strength, high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire. The elemental composition range of the nickel-iron-aluminum eutectic multi-principal-element alloy wire, in atomic percentage, is Ni: 48-52 at%, Fe: 28-32 at %, Al: 18-22 at %; the nickel-iron-aluminum eutectic multi-principal-element alloy wire has a eutectic structure with face-centered cubic and body-centered cubic phases.

[0006] Furthermore, the nickel-iron-aluminum eutectic multi-principal alloy wire is allowed to contain trace amounts of Cr, V, Mo, W, Zr, B, C, La, Ce, etc. as modifiers, thereby forming a multi-principal eutectic alloy of nickel-iron-aluminum and trace elements.

[0007] Furthermore, the eutectic structure encompasses structures with components near the eutectic point, including but not limited to fully eutectic structures, and can also be hypoeutectic and hypereutectic structures, mainly determined by the Al element content.

[0008] A method for preparing a low-cost, high-strength, and high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire, specifically including the following steps: (1) Clean the metal raw materials according to the elements of the nickel-iron-aluminum multi-principal eutectic alloy, and then weigh the elements according to atomic percentage; (2) The metal raw materials are smelted in a non-consumable argon protective vacuum arc furnace. After the smelting is completed, the alloy is cast into a multi-principal alloy ingot using a non-consumable vacuum arc furnace. (3) Cut the core plate from the ingot and roll it at room temperature; (4) The rolled plate is machined into bars, and the bars are drawn in multiple passes at room temperature to form alloy wires of the target size; (5) The alloy wire is subjected to short-time annealing and then air-cooled to room temperature to obtain a multi-principal eutectic alloy wire.

[0009] Further, in step (1), the purity of the metal raw material is ≥99.9wt%, and the oxide scale is removed and the material is cleaned.

[0010] Furthermore, in step (2), the vacuum level inside the vacuum arc melting furnace needs to be controlled at 1×10 before melting. -4 The pressure is below Pa, and argon inert gas is introduced as a protective gas. During smelting, the titanium ingot must be smelted first to absorb the residual oxygen in the vacuum arc melting furnace, and then the raw material is smelted repeatedly at least 4 times. After smelting, the alloy is cast into a rectangular ingot with a final size of 80×15×15 mm.

[0011] Further, in step (3), the ingot is cut into plates using electrical discharge wire cutting. The plates need to be cut away from the ingot riser, the central loose area and the surface oxidation area. The rolling reduction is controlled at 60%-80% to finally obtain plates with a thickness of 1mm-2mm.

[0012] Further, in step (4), the obtained plate needs to be cut into rods using an electric discharge wire cutting device according to the plate thickness; the rods are drawn at room temperature, and lubricant is applied to the die during the drawing process. The drawing speed is 10 mm / s, and the cross-section reduction is 10-50% per pass until the wire is drawn to the target size.

[0013] Further, in step (5), wires of different diameters are annealed at a temperature of 400-750℃ for 1-30 minutes and then air-cooled to room temperature.

[0014] A low-cost, high-strength, and high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire is prepared according to the above-mentioned preparation method.

[0015] Compared with the prior art, the present invention exhibits the following advantages and technical effects: This invention relates to a low-cost, high-strength, and high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire. It has a simple composition and low density, resulting in lower cost compared to other multi-principal-element alloys. The preparation method of this low-carbon multi-principal-element eutectic alloy wire does not require high-temperature homogenization treatment after raw material melting, nor does it require heat treatment during processing, thus featuring a simple preparation process and low carbon footprint. Furthermore, the wire involved in this invention exhibits a uniform internal structure and a defect-free surface after cold drawing, requiring only a short-term low-temperature annealing treatment to achieve a high strength-to-ductility balance. Attached Figure Description

[0016] Figure 1 This is a SEM image of the φ80μm nickel-iron-aluminum multi-principal-element eutectic alloy wire provided by the present invention. Figure 2 These are room temperature tensile stress-strain diagrams of the φ80μm nickel-iron-aluminum multi-principal-element eutectic alloy wire provided by this invention under different annealing states. Figure 3 This is a room temperature tensile stress-strain diagram of nickel-iron-aluminum multi-principal eutectic alloy wires of different diameters provided by the present invention under annealing at 520℃. Detailed Implementation

[0017] The application and implementation of the present invention will be further illustrated below through specific embodiments: Example 1: This embodiment provides a method for preparing nickel-iron-aluminum multi-principal-element eutectic alloy wire, wherein the multi-principal-element alloy has the following atomic percentages: Ni: 50 at%, Fe: 30 at %, Al: 20 at %. The specific preparation process is as follows: Step (1): Wash the elemental raw materials with anhydrous ethanol for 30 minutes and then dry them. Then weigh the elements according to atomic percentage, with each button ingot weighing about 100g. Step (2): Multi-principal alloys are smelted using a non-consumable argon-protected vacuum arc furnace. Before smelting, the vacuum level inside the vacuum arc furnace must be controlled at 1×10⁻⁶. -4 The pressure is below Pa, and argon inert gas is introduced as a protective gas. During the smelting process, the titanium ingots are first smelted to absorb the residual oxygen in the vacuum arc smelting furnace. The smelting is repeated 4 times and electromagnetic stirring is used to ensure uniform composition. After the smelting is completed, two button ingots are melted into one and then cast into a multi-principal eutectic alloy ingot with an ingot size of 80×15×15 mm. Step (3): Cut the ingot into 5mm plates using electrical discharge wire cutting. The plates should be cut away from the ingot riser, the central loose area and the surface oxidation area. Then, roll the plates in multiple passes at room temperature with a reduction of about 80% to a thickness of 1mm. Step (4): The rolled sheet is wire-cut into bars with a cross section of about 1mm×1mm, and the obtained bars are drawn in multiple passes at room temperature. During the drawing process, lubricant is applied to the die. The cross section shrinkage rate is reduced by 20% in each pass. The cold drawing rate is 10mm / s to obtain a wire with a diameter of 80μm. Step (5): Perform short-time annealing on the cold-drawn wire at a temperature of 520℃ for 5 minutes, followed by air cooling.

[0018] In this embodiment, the eutectic high-entropy alloy wire has a uniform diameter, uniform internal structure, and no surface defects. Figure 1 As shown.

[0019] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) alloy wire at -520℃ / 5min was 2067.8±20.7 MPa, the ultimate tensile strength was 1641.7±16.4 MPa, and the elongation at break was 17.6±0.7% (e.g., ...). Figure 2 (As shown).

[0020] Example 2: The only difference between this embodiment and embodiment 1 is the annealing temperature in step (5), which is 510°C.

[0021] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) -510℃ / 5min alloy wire was 1922.4±19.2 MPa, the ultimate tensile strength was 2162.3±21.6 MPa, and the elongation at break was 12.5±0.4% (e.g., ...). Figure 2 (As shown).

[0022] Example 3: The only difference between this embodiment and embodiment 1 is the annealing temperature and annealing time in step (5). In this embodiment, the annealing temperature is 450°C and the annealing time is 30 min.

[0023] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) alloy wire at -450℃ / 30min was 1587.1±14.9 MPa, the ultimate tensile strength was 2926.6±29.3 MPa, and the elongation at break was 15.8±0.5% (e.g., ...). Figure 2 (As shown).

[0024] Example 4: The only difference between this embodiment and embodiment 1 is the annealing temperature in step (5), which is 650°C.

[0025] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) -650℃ / 5min alloy wire was 1205.2±12.0 MPa, the ultimate tensile strength was 1506.8±15 MPa, and the elongation at break was 20.6±0.9% (e.g., ...). Figure 2 (As shown).

[0026] Example 5: The only difference between this embodiment and embodiment 1 is the annealing temperature in step (5), which is 750°C.

[0027] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) -700℃ / 5min alloy wire was 908.2±9.1 MPa, the ultimate tensile strength was 1302.4±13.0 MPa, and the elongation at break was 24.6±1.2% (e.g., ...). Figure 2 (As shown).

[0028] Example 6: The only difference between this embodiment and embodiment 1 is step (4), in which the diameter of the filament is 100 μm.

[0029] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) alloy wire at -520℃ / 5min was 1872.3±18.7 MPa, the ultimate tensile strength was 2098.5±21.0 MPa, and the elongation at break was 12.0±0.5% (e.g., ...). Figure 3 (As shown).

[0030] Example 7: The only difference between this embodiment and embodiment 1 is step (4), in which the diameter of the filament is 150 μm.

[0031] Mechanical property testing: Approximately 10 cm sections were cut from the heat-treated alloy wire and subjected to room temperature tensile testing. The yield strength of the Ni50Fe30Al20 (at%) alloy wire at -520℃ / 5min was 1655.1±16.5 MPa, the ultimate tensile strength was 1860.5±18.2 MPa, and the elongation at break was 9.6±0.5% (e.g., ...). Figure 3 (As shown).

[0032] The results show that the nickel-iron-aluminum multi-principal-element eutectic alloy wire can achieve extremely high strength-ductility matching through a simple process. The process is characterized by low energy consumption, and the alloy composition is characterized by low cost, proving that the alloy has the potential for industrial production.

[0033] The low-cost, high-strength, and high-toughness multi-principal-element eutectic alloy wire of this invention can be used in the manufacture of wires for aerospace, mobile communications, automotive, and precision devices such as microelectronics / sensors.

[0034] The above embodiments are merely several specific implementations of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A low-cost, high-strength, high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire, characterized in that, The elemental composition range of the nickel-iron-aluminum multi-principal eutectic alloy wire, in atomic percentage, is Ni: 48-52 at%, Fe: 28-32 at %, Al: 18-22 at %; the nickel-iron-aluminum multi-principal eutectic alloy wire has a eutectic structure with face-centered cubic and body-centered cubic phases.

2. The low-cost, high-strength, high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire according to claim 1, characterized in that, It contains ≤5 at % of a regulator, wherein the regulator contains at least one of the elements Cr, V, Mo, W, Zr, B, C, La, and Ce.

3. A method for preparing a low-cost, high-strength, high-toughness nickel-iron-aluminum multi-principal-element eutectic alloy wire, characterized in that, Includes the following steps: The elements of the nickel-iron-aluminum multi-principal-element eutectic alloy according to claim 1 or 2 are cleaned, and then the elements are weighed according to atomic percentage. The metal raw materials are smelted using a non-consumable argon-protected vacuum arc furnace. After smelting, the alloy is cast into a multi-principal element alloy ingot using the non-consumable vacuum arc furnace. The core plate is cut from the ingot and rolled at room temperature; The rolled sheet is machined into bars, and the bars are drawn in multiple passes at room temperature to form alloy wires of the target size. The alloy wire was subjected to short-time annealing and then air-cooled to room temperature to obtain nickel-iron-aluminum multi-principal eutectic alloy wire.

4. The preparation method according to claim 3, characterized in that, The purity of the metal raw material is ≥99.9wt%, and the oxide scale is removed and the material is cleaned.

5. The preparation method according to claim 3, characterized in that, Before the melting process, the vacuum level inside the vacuum arc melting furnace is controlled at 1×10⁻⁶. -4 The pressure is below Pa, and argon inert gas is introduced as a protective gas. During smelting, the titanium ingot is first smelted to absorb the residual oxygen in the vacuum arc melting furnace, and then the raw material is smelted repeatedly at least 4 times. After smelting, the alloy is cast into a rectangular ingot with a final size of 80×15×15 mm.

6. The preparation method according to claim 3, characterized in that, The process of cutting the core plate from the ingot involves using electrical discharge wire cutting to cut the ingot into plates, avoiding the ingot riser, the central loose area, and the surface oxidation area during cutting, and controlling the rolling reduction at 60%-80% to finally obtain a 1mm-2mm thick plate.

7. The preparation method according to claim 3, characterized in that, The process of machining the rolled sheet into bars involves cutting the sheet into bars using an electrical discharge wire cutting device according to the sheet thickness; the drawing process is room temperature drawing at a speed of 10 mm / s, with a cross-sectional reduction of 10-50% per pass, until the wire is drawn to the target size.

8. The preparation method according to claim 3, characterized in that, The annealing temperature for the short-time annealing is 400-750℃, and the annealing time is 1-30min.

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