A method for rapid preparation of ultra-long platinum-nickel composite wires

Abstract

This invention relates to a method for rapidly preparing ultra-long platinum-nickel composite wires, comprising: 1) melting nickel in a medium-frequency melting furnace and casting it into ingots, then extruding and drawing the ingots into wires; 2) performing surface oxidation treatment on the nickel wires, followed by reduction annealing; 3) heating platinum in a medium-frequency melting furnace until it melts, then immersing one end of the nickel wire into the platinum liquid, keeping the nickel wire portion fully submerged while rapidly winding it up, thus depositing a platinum layer on the surface of the nickel wire; 4) repeating step 3) to deposit a platinum layer on the surface of the nickel wire until the platinum layer reaches the required thickness, after which conventional drawing processing is performed. The method of this invention allows control of the platinum layer thickness by adjusting the winding speed and number of immersions during platinum layer deposition. The resulting platinum-nickel composite wire has no cracks or platinum leaks on its surface, and the platinum layer is uniform in thickness and firmly bonded to the nickel layer without delamination. Compared with other methods, this method allows for the preparation of ultra-long platinum-nickel composite wires by joining multiple sections of nickel wire, resulting in a shorter process, higher efficiency, and lower cost.

Description

Technical Field

[0001] This invention belongs to the field of double-layer metal composite wire technology, and specifically relates to a method for rapidly preparing ultra-long platinum-nickel composite wires. Background Technology

[0002] Platinum possesses a high melting point (1772℃), a low coefficient of thermal expansion, good electrical conductivity, and excellent oxidation resistance, while nickel has a lower melting point (1455℃) but offers better electrothermal properties and processability. By combining platinum and nickel, their respective advantages can be leveraged, saving precious platinum and reducing costs while meeting performance requirements. Electrodes, heating elements, coils, and resistance wires made from platinum-nickel composite wires can be used in electronic components, detection elements, sensors, and other fields.

[0003] The preparation method reported in "Preparation of Platinum-Nickel 30 / 70 Composite Wire" (Yang Yingkui et al., Electrical Materials, 2006, Issue 01) is as follows: (1) Platinum melting - hot forging - rolling - platinum tube fabrication; (2) Nickel bar hot forging - precision machining - surface treatment; (3) Sheathing - welding - surface treatment; (4) Combining platinum tube and nickel bar - electron beam sealing - extrusion - annealing - cold drawing - pickling - cold drawing - annealing - inspection. This method has defects such as complex process and uneven platinum layer distribution.

[0004] CN114932209A discloses a process for preparing a platinum-nickel composite guide wire: platinum tube - static pressing of nickel powder to obtain a nickel column - applying pressure to press the nickel column into the platinum tube to obtain a platinum-nickel rod - high-temperature melting of the platinum-nickel rod. Its main drawbacks include complex processes and difficulty in controlling the nickel-platinum bonding interface.

[0005] CN113564531A discloses a process for preparing platinum-nickel composite wire: surface treatment, coating treatment, heat treatment, and drawing treatment. Its main drawbacks include complex processes, high costs, small platinum layer thickness, and short composite wire length. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of current preparation techniques by providing a method for rapidly preparing ultra-long platinum-nickel composite wires. This method boasts high production efficiency and low cost, enabling the preparation of ultra-long platinum-nickel composite wires with controllable platinum layer thickness.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for rapidly preparing ultra-long platinum-nickel composite wires, characterized in that the preparation method includes the following steps:

[0009] (1) Nickel is melted in a medium-frequency melting furnace and cast into ingots. The ingots are then machined, extruded and drawn into wires.

[0010] (2) The surface of the nickel wire is oxidized and then subjected to hydrogen reduction annealing.

[0011] (3) After heating the platinum in a medium-frequency melting furnace until it melts, immerse one end of the nickel wire into the platinum liquid, keep the nickel wire part submerged in the platinum liquid while quickly winding up the nickel wire so that the surface of the nickel wire is plated with a platinum layer.

[0012] (4) Repeat step (3) to immerse the nickel wire surface in platinum layer until the platinum layer on the nickel wire surface reaches the required thickness before performing conventional drawing process.

[0013] The nickel wire in step (1) is in a hardened state with a diameter of 1.5 to 3.0 mm. This allows for the connection of multiple nickel wire segments to form an ultra-long nickel wire, thereby improving production efficiency. At the same time, it can prevent the nickel wire from melting over a large area due to the high temperature of the platinum liquid during the hot-dip platinum plating process, which would result in uneven platinum layer or breakage of the nickel wire.

[0014] In step (2), the nickel wire is subjected to oxidation treatment at 500±15℃ for 10-20s in an atmospheric atmosphere. A thin nickel oxide layer is generated on the surface through the oxidation treatment. Then, it is subjected to reduction annealing treatment at 400-415℃ for 10-15min in a hydrogen atmosphere. A porous nickel layer is generated on the surface. The generation of porous nickel reduces the melting of the nickel wire surface during hot dipping and promotes the adhesion of platinum liquid to the nickel wire surface.

[0015] In step (3), the temperature of the platinum liquid is 1772-1800℃, the length of the nickel wire immersed in the platinum liquid is 120-180mm, and the winding speed of the nickel wire is 250-450mm / s. This reduces the melting of the nickel wire surface while ensuring that the platinum liquid adheres to the nickel wire surface as much as possible. The composite wire passes vertically through the center of a 12mm diameter annular argon nozzle in the winding direction. The gas pressure at the nozzle is 0.25-0.4MPa. The gas is concentrated and sprayed onto the composite wire at a distance of 5-10mm from the platinum liquid surface, forcing the platinum to adhere evenly to the nickel wire surface and accelerating the solidification of the platinum, resulting in a platinum-nickel composite wire with a smooth surface, concentric platinum-nickel layers, and a strong bond.

[0016] The platinum layer thickness determination in step (4) is achieved by measuring the diameter of the composite wire. When the platinum layer thickness meets the requirements, the diameter of the platinum-nickel composite wire (Φ) is... Pt / Ni )satisfy: (Nipper wire diameter: Φ) Ni Actual weight of nickel wire: W Ni Theoretical weight of platinum layer W Pt ).

[0017] The platinum-nickel composite wire of the present invention has a platinum layer to nickel layer weight ratio between 10:90 and 32:68, and the finished platinum-nickel composite wire has a diameter of 0.10 to 1.2 mm, thereby ensuring that the platinum and nickel do not separate during the drawing process after platinum plating is completed, and that the finished wire has no platinum leakage defects.

[0018] This invention employs a technique different from conventional hot-dip plating (where a low-melting-point metal is dipped onto a high-melting-point metal), which involves hot-dip plating high-melting-point platinum onto low-melting-point nickel. This technique is based on the fact that although platinum's melting point is 317°C higher than nickel's, nickel's heat of fusion is 1192.50 J / g, while platinum's is only 138.46 J / g, and the platinum-nickel interface has good wetting properties.

[0019] In summary, compared with the prior art, the present invention has the following advantages:

[0020] This invention proposes a method for rapidly preparing ultra-long platinum-nickel composite wires. This method can prepare ultra-long platinum-nickel composite wires with different platinum layer thicknesses. The platinum layer thickness of the composite wire is uniform and firmly bonded to the nickel layer, without delamination or platinum leakage defects. Moreover, the production efficiency is high, meeting the rapid production requirements and performance indicators of platinum-nickel composite wires. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the preparation method.

[0022] Figure 2 The images show scanning electron microscope (SEM) images of the surface and longitudinal section of the platinum-nickel composite wire prepared in Example 1.

[0023] Figure 3 The image shows scanning electron microscope (SEM) images of the surface and longitudinal section of the platinum-nickel composite wire prepared in Example 3. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. However, the following embodiments are illustrative of the invention and are not intended to limit the scope thereof. All other embodiments obtained by those skilled in the art based on the scope of the invention with some modifications and without innovative effort are also within the scope of protection of the present invention.

[0025] According to an embodiment of the present invention, a method for rapidly preparing ultra-long platinum-nickel composite wires is provided, the preparation method of which can be found in [reference needed]. Figure 1 The preparation method includes the following steps:

[0026] (1) Nickel is melted in a medium-frequency melting furnace and cast into ingots. The ingots are then machined, extruded and drawn into wires.

[0027] (2) The surface of the nickel wire is oxidized and then subjected to hydrogen reduction annealing.

[0028] (3) After heating the platinum in a medium-frequency melting furnace until it melts, immerse one end of the nickel wire into the platinum liquid, keep the nickel wire part submerged in the platinum liquid while quickly winding up the nickel wire so that the surface of the nickel wire is plated with a platinum layer.

[0029] (4) Repeat step (3) to immerse the nickel wire surface in platinum layer until the platinum layer on the nickel wire surface reaches the required thickness before drawing.

[0030] The present invention will be further described below with reference to embodiments.

[0031] Example 1

[0032] Prepare a platinum-nickel 30 / 70 (30% platinum by mass) composite wire with a finished length of 10,000 m and a diameter of 0.20 mm.

[0033] (1) Weigh 4500g of nickel according to the theoretical weight of 2374.2g of nickel in the finished platinum-nickel composite wire. Place the nickel in a medium frequency furnace and melt it with argon gas to cast it into a cylindrical ingot. Remove impurities from the surface of the cylindrical ingot by turning. Extrude and draw it into a processed hard nickel wire with a diameter of 3.0mm.

[0034] (2) First, the nickel wire is oxidized under atmospheric conditions and 500℃ for 20s. Then, the oxidized nickel wire is reduced under hydrogen atmosphere and 410℃ for 10min.

[0035] (3) Weigh 2500g of platinum and put it into the medium frequency furnace to heat to 1790±10℃ and keep it warm. Turn on the argon ring nozzle (0.3MPa gas pressure) and spray the gas into the composite wire at a distance of 6mm from the surface of the platinum liquid. Immerse one end of the nickel wire into the platinum liquid and keep the length of the nickel wire immersed in the platinum liquid 150mm. At the same time, wind up the nickel wire at a speed of 300mm / s.

[0036] (4) The diameter of the platinum-nickel composite wire was measured to be 3.097 mm for the first time. The platinum layer was deposited again in step (3), and the diameter of the platinum-nickel composite wire was 3.211 mm.

[0037] (5) Repeat step (3) again to deposit the platinum layer. The winding speed is 330 mm / s. The diameter of the platinum-nickel composite wire is measured to be 3.264 mm (which meets the theoretical diameter of 3.256 mm).

[0038] (6) The platinum-nickel composite wire was processed to a diameter of 0.20 mm by multiple conventional drawing and annealing processes. After inspection, the platinum layer was uniform and firmly bonded to the nickel layer, with no platinum leakage defects.

[0039] like Figure 1 As shown, the platinum-nickel composite wire prepared in this embodiment has a smooth surface, uniform platinum layer thickness, no platinum-nickel delamination, and no platinum leakage points.

[0040] Example 2

[0041] Prepare a platinum-nickel 30 / 70 (30% platinum by mass) composite wire with a finished length of 20,000 m and a diameter of 0.20 mm.

[0042] (1) Weigh 9000g of nickel according to the theoretical weight of 4748.4g of nickel in the finished platinum-nickel composite wire. Divide the nickel into two equal parts and put them into an intermediate frequency furnace to melt and cast into two cylindrical ingots. Remove impurities from the surface of the cylindrical ingots by turning, and extrude and draw them into hardened nickel wires with a diameter of 3.0mm. Connect the two nickel wires together into one.

[0043] (2) First, the nickel wire is oxidized under atmospheric conditions and 500℃ for 20s. Then, the oxidized nickel wire is reduced under hydrogen atmosphere and 410℃ for 10min.

[0044] (3) Weigh 3500g of platinum and put it into the medium frequency furnace to heat to 1790±10℃ and keep it warm. Turn on the argon ring nozzle (0.3MPa gas pressure) and concentrate the gas to spray 6mm away from the surface of the platinum liquid. Immerse one end of the nickel wire into the platinum liquid and keep the length of the nickel wire immersed in the platinum liquid 150mm. At the same time, wind up the nickel wire at a speed of 300mm / s.

[0045] (4) The diameter of the platinum-nickel composite wire was measured to be 3.125 mm for the first time. The platinum layer was deposited again in step (3), and the diameter of the platinum-nickel composite wire was 3.201 mm.

[0046] (5) Repeat step (3) to deposit the platinum layer again, with a winding speed of 380 mm / s. The diameter of the platinum-nickel composite wire was measured to be 3.252 mm (which meets the theoretical diameter of 3.256 mm).

[0047] (6) The platinum-nickel composite wire was processed to a diameter of 0.20 mm by multiple conventional drawing and annealing processes. After inspection, the platinum layer was uniform and firmly bonded to the nickel layer, with no platinum leakage defects.

[0048] Example 3

[0049] Prepare a platinum-nickel 20 / 80 (30% platinum by mass) composite wire with a finished length of 10,000 m and a diameter of 0.20 mm.

[0050] (1) Weigh 4600g of nickel according to the theoretical weight of 2534.0g of nickel in the finished platinum-nickel composite wire. Place the nickel in a medium frequency furnace and melt it with argon gas to cast it into a cylindrical ingot. Remove impurities from the surface of the cylindrical ingot by turning. Extrude and draw it into a processed hard nickel wire with a diameter of 2.0mm.

[0051] (2) First, the nickel wire is oxidized under atmospheric conditions and 500℃ for 15s. Then, the oxidized nickel wire is reduced under hydrogen atmosphere and 400℃ for 10min.

[0052] (3) Weigh 2500g of platinum and put it into a medium frequency furnace to heat to 1790±10℃ and keep it warm. Turn on the argon ring nozzle (0.35MPa gas pressure) and spray the gas into the composite wire at a distance of 6mm from the surface of the platinum liquid. Immerse one end of the nickel wire into the platinum liquid and keep the length of the nickel wire immersed in the platinum liquid 130mm. At the same time, wind up the nickel wire at a speed of 320mm / s. Measure the diameter of the platinum-nickel composite wire to be 2.049mm.

[0053] (4) Repeat the platinum plating process in step (3), with a winding speed of 340 mm / s. The diameter of the platinum-nickel composite wire reaches 2.078 mm. Repeat the platinum plating process in step (3) again, with a winding speed of 330 mm / s. The diameter of the platinum-nickel composite wire is measured to be 2.105 mm (meeting the theoretical diameter of 2.101 mm).

[0054] The platinum-nickel composite wire was processed to a diameter of 0.20 mm through multiple conventional drawing and annealing processes. After inspection, the platinum layer was found to be uniform and firmly bonded to the nickel layer, with no platinum leakage defects.

[0055] like Figure 2 As shown, the platinum-nickel composite wire prepared in this embodiment has a smooth surface, uniform platinum layer thickness, no platinum-nickel delamination, and no platinum leakage points.

Claims

1. A method for rapidly preparing ultra-long platinum-nickel composite wires, characterized in that, Includes the following steps: (1) The nickel is melted in a medium-frequency melting furnace and cast into a billet. The billet is then machined, extruded and drawn into nickel wire. The nickel wire is in a machined hard state and has a diameter of 1.5~3.0 mm. (2) The surface of the nickel wire is oxidized and then subjected to hydrogen reduction annealing to obtain porous nickel; the oxidation process is atmospheric atmosphere, 500±15℃ for 10~20s, and the reduction annealing process is hydrogen atmosphere, 400~415℃ for 10~15min. (3) After heating the platinum in a medium-frequency melting furnace until it melts, immerse one end of the nickel wire into the platinum liquid. While keeping the nickel wire part submerged in the platinum liquid, quickly coil the nickel wire to make the surface of the nickel wire coated with a platinum layer to obtain a platinum-nickel composite wire. The length of the nickel wire immersed in the platinum liquid is 100~180mm, and the coiling speed of the nickel wire is 250~450mm / s. (4) Repeat step (3) to immerse the nickel wire surface in platinum layer until the platinum layer on the nickel wire surface reaches the required thickness, and then perform conventional drawing process to obtain the finished platinum-nickel composite wire.

2. The method for rapidly preparing ultra-long platinum-nickel composite wire according to claim 1, characterized in that, The temperature of the platinum solution in step (3) is 1772~1800℃.

3. The method for rapidly preparing ultra-long platinum-nickel composite wire according to claim 1, characterized in that, In step (3), the nickel wire with a platinum coating on its surface passes vertically through the center of an annular argon nozzle with a diameter of 12 mm in the direction of the coil. The gas pressure at the nozzle is 0.25~0.4 MPa, and the gas is concentrated and sprayed onto the composite wire at a distance of 5~10 mm from the surface of the platinum liquid.

4. The method for rapidly preparing ultra-long platinum-nickel composite wire according to claim 1, characterized in that, Step (4) Platinum layer thickness is determined by measuring the diameter of the composite wire. When the platinum layer thickness meets the requirements, the diameter Φ of the platinum-nickel composite wire is... Pt / Ni satisfy: In the formula: Φ Ni - Nickel wire diameter, W Ni - Actual weight of nickel wire, W Pt - Theoretical weight of platinum layer.

5. The method for rapidly preparing ultra-long platinum-nickel composite wire according to any one of claims 1-4, characterized in that, The weight ratio of the platinum layer to the nickel layer in the platinum-nickel composite wire is between 8:92 and 32:

68.

6. The method for rapid preparation of ultra-long platinum-nickel composite wire according to any one of claims 1-4, characterized in that, The finished platinum-nickel composite wire has a diameter of 0.10~1.2mm.

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