A short process manufacturing line and method for platinum and platinum-based alloy rods or wires

Abstract

The application provides a short-process preparation pipeline and method of platinum and platinum-based alloy rod or wire, the pipeline comprising: a vacuum induction melting furnace for melting prepared materials into an alloy melt in a vacuum environment; a tundish comprising a composite crucible; a continuous casting device comprising a crystallizer; a continuous rolling device comprising a rough rolling unit and a finishing rolling unit receiving the rough rolling unit; a guiding input device guiding the casting blank output by the continuous casting device into the rough rolling unit of the continuous rolling device; a continuous drawing device located downstream of the continuous rolling device and closely adjacent to the continuous drawing device; and a central PLC control system receiving data transmitted by the liquid level sensor and adjusting the pouring speed of the vacuum induction melting furnace according to the data. The short-process preparation of platinum and platinum-based alloy rod or wire can solve the problems of long production cycle, high energy consumption and high loss of noble metal in the existing preparation process of platinum and platinum-based alloy rod or wire.

Description

Technical Field

[0001] This invention belongs to the field of precious metal material processing, specifically a short-process preparation line and method for platinum and platinum-based alloy rods or wires. Background Technology

[0002] Platinum and platinum-based alloys (such as Pt-Rh alloys, Pt-Au alloys, and Pt-Ir alloys) are widely used in high-end fields such as aerospace, glass and fiberglass manufacturing, thermocouple temperature measurement, and medical implants due to their excellent high-temperature stability, corrosion resistance, thermoelectric properties, and mechanical properties. According to the national recommended standard "Terminology of Precious Metals and Their Alloys" (GB T 17684-2008), platinum and platinum-based alloys are solid products with a uniform cross-section (circular or elliptical) along their entire length, manufactured through turning or cold extrusion into nozzles of various specifications. Various precious metal bonding wires used in semiconductor bonding are produced by gradually drawing rods or wires into ultra-fine wires of the required specifications using a drawing die. As the core finished product forms of platinum and platinum-based alloys, the advancement and rationality of their manufacturing processes directly affect production efficiency and precious metal utilization, while also determining the dimensional accuracy, microstructure uniformity, and overall performance of the products.

[0003] Currently, the industrial production of platinum and platinum-based alloy rods / wires mostly employs traditional long-process technologies, with core pathways such as... Figure 2 As shown, the process involves 10 steps: "material preparation → induction melting → casting gold ingots → forging → surface treatment (sandblasting or surface milling) → plate rolling → strip shearing → deburring → die rolling → drawing → annealing → redrawing and annealing → finishing and polishing → finished product inspection." This process is cumbersome, loosely connected, lengthy, requires a large amount of equipment, and involves a high metal turnover. Therefore, it exhibits the following shortcomings in the production of platinum and platinum alloy bars / wires:

[0004] (1) High precious metal loss and low yield. The yield of platinum bars / wires processed by traditional processes is low and the processing loss rate is high. According to statistics, the yield of finished bars from raw materials is about 75%. In order to prevent the material from being contaminated by base metals, the surface of gold ingots is milled or sandblasted after hot forging. The utilization rate of raw materials is reduced due to the fact that the scraps on both sides of the plate after rolling and shearing cannot be used to draw bars. The long machining process also increases the material loss rate.

[0005] (2) Redundancy in the process leads to low production efficiency and high energy consumption. In the traditional process, the ingots after melting need to be homogenized and annealed separately to eliminate dendrite segregation. After each subsequent plastic processing, intermediate annealing is required to eliminate work hardening. The annealing process alone accounts for more than 30% of the total production cycle. At the same time, the multi-process transfer process increases material loss and time costs. The industry average processing cycle is 25% longer than the international advanced level, the capacity utilization rate is low, and the overall energy consumption is 30% higher than the international standard, which is contrary to the concept of green and low-carbon production.

[0006] (3) The connection between multiple processes can easily lead to quality problems. During the repeated heating, cooling and transportation processes, the alloy is prone to secondary oxidation, generating brittle and hard oxides, which can cause cracks and wire breakage in subsequent processing. At the same time, the parameter fluctuations between processes are difficult to control precisely, which can easily cause product size deviations and uneven structure, affecting thermoelectric performance and mechanical stability, making it difficult to meet the precision preparation requirements of ultra-fine wires and high rhodium content alloys.

[0007] While existing technologies have attempted optimizations for single processes, such as using rapid forging or optimizing annealing parameters to shorten holding time, none of these have broken through the limitations of traditional long processes and cannot fundamentally solve the core problems of process redundancy, high losses, and low efficiency. For small-sized precision bars / wires, existing optimization schemes lack versatility and struggle to balance dimensional accuracy and microstructure uniformity. Summary of the Invention

[0008] This invention provides a short-process production line for the preparation of platinum and platinum-based alloy rods or wires, which can solve the problems of long production cycle, high energy consumption and high loss of precious metals in the existing platinum and platinum-based alloy rod or wire preparation process.

[0009] The short-process production line for preparing platinum and platinum-based alloy rods or wires of the present invention includes:

[0010] A vacuum induction melting furnace is used to melt prepared materials into an alloy melt in a vacuum environment.

[0011] The intermediate batch includes a composite crucible, the bottom of which has a tapered nozzle that is wider at the top and narrower at the bottom. The intermediate batch also includes a liquid level sensor for real-time monitoring of the liquid level inside the crystallizer.

[0012] A continuous casting apparatus includes a crystallizer. The inlet of the crystallizer is provided with a funnel-shaped receiving cavity that is larger at the top and smaller at the bottom, coaxial with the conical guide nozzle. A flexible sealing ring is provided between the funnel-shaped receiving cavity and the conical guide nozzle to form a semi-closed protective cavity. The continuous casting apparatus also includes a liquid level sensor for real-time monitoring of the liquid level in the crystallizer. The alloy melt is formed into a billet through the continuous casting apparatus.

[0013] A continuous rolling apparatus includes a roughing mill and a finishing mill that receives the billets from the roughing mill. A first induction heating coil is provided on the path of the billet from the roughing mill to the finishing mill, and a second induction heating coil, a thermometer for real-time detection of the billet temperature, and an air-cooling mechanism are sequentially provided on the path of the billet exiting the finishing mill.

[0014] The guide input device guides the billet output from the continuous casting device into the roughing mill of the continuous rolling device;

[0015] A continuous drawing device is located downstream of and adjacent to the continuous rolling device. The continuous drawing device includes a first-pass drawing die for receiving the bar billet from the finishing mill and a second-pass drawing die for receiving the drawn billet from the first-pass drawing die. An intermediate induction heating device and a drawing air cooling mechanism are sequentially arranged along the path of the bar from the first-pass drawing die to the second-pass drawing die. The continuous drawing device also includes a winding device for receiving the bar or wire from the second-pass drawing die.

[0016] The central PLC control system receives data from the liquid level sensor and adjusts the tilting speed of the vacuum induction melting furnace according to the data, so that the liquid level fluctuation in the composite crucible is kept within a set range. The central PLC control system receives the measured temperature data from the thermometer and synchronously feeds it back to the heating power supply of the second induction heating coil, and dynamically adjusts the output power of the second induction heating coil to control the temperature fluctuation range of the billet within a set range. The central PLC control system sets the reduction rate and controls the conveying speed of the first and second stretching dies according to the set reduction rate.

[0017] Preferably, the guiding conveying device includes a plurality of guide wheels for guiding the billet output from the crystallizer, at least one guide wheel being driven to rotate by a motor equipped with an encoder, the motor being connected to the central PLC control system, and the rotation speed being adjusted under the control of the central PLC control system.

[0018] Preferably, the composite crucible includes an outer crucible, an inner crucible, and a graphite ring located between the outer crucible and the inner crucible.

[0019] Preferably, the outer wall of the crystallizer is provided with a water-cooling jacket.

[0020] Preferably, the outlet of the crystallizer is equipped with a continuous casting air cooling mechanism.

[0021] Preferably, the continuous casting apparatus further includes a vibrator for driving the crystallizer to vibrate.

[0022] Preferably, the thermometer is a dual-color infrared thermometer.

[0023] Preferably, the frequency of the first induction heating coil is 10kHz - 20kHz, and the frequency of the second induction heating coil is 50kHz to 100kHz.

[0024] This invention also provides a short-process preparation method for platinum and platinum-based alloy rods or wires, utilizing the above-mentioned preparation line to prepare platinum and platinum-based alloy rods or wires, including the following steps:

[0025] S1. Alloy composition design and batching: Weigh platinum and alloying element raw materials according to the proportions;

[0026] S2. Vacuum induction refining: The weighed raw materials are placed in a vacuum induction melting furnace and melted under vacuum or protective atmosphere;

[0027] S3. Tundish preheating and flow stabilization: Turn on the induction heating of the tundish, and after preheating, transfer the melt into the tundish. Monitor the liquid level in the tundish in real time and control the change in liquid level within the set range.

[0028] S4. Continuous casting: The molten material continuously enters the crystallizer from the tundish in a laminar flow state and solidifies into a cast billet;

[0029] S5. Continuous rolling: The bar billets output from the crystallizer are guided into the roughing mill for roughing and then into the finishing mill for finishing. The bar billets are heated to above the recrystallization temperature for the first time during the process of entering the finishing mill from the roughing mill. They are heated a second time when they are output from the finishing mill. The temperature of the bar billets after the second heating is controlled within the set range.

[0030] S6. Continuous drawing and collection of finished products: The finishing mill conveys the finished billet to the first drawing die for the first drawing. The first drawing die conveys the drawn billet after the first drawing to the second drawing die for the second drawing. During the process of the drawn billet being conveyed from the first drawing die to the second drawing die, it is heated and cooled in sequence. The second drawing die conveys the bar or wire formed after the second drawing to the winding machine for collection.

[0031] In steps S5 and S6, the rotational speed compensation of each level of conveyor wheel is calculated, and the rotational speed of each level of conveyor wheel is controlled to prevent the wire from piling up between devices or being overstretched.

[0032] Preferably, a strengthening element or strengthening agent is added in step S1. The strengthening element is selected from one or more of zirconium, hafnium, scandium, yttrium, lanthanum, cerium, and erbium; the strengthening agent is selected from one or more of boron, calcium boride, titanium boride, and zirconium boride.

[0033] Preferably, in step S3, the rate of change of the liquid level is controlled to be less than 2 mm / s.

[0034] Preferably, in step S5, the temperature fluctuation range of the billet is controlled to be within ±5℃ of the set value.

[0035] The beneficial effects of this invention are as follows: This invention adopts a short-process design that combines continuous casting with continuous rolling and continuous drawing, eliminating redundant forging, milling, and shearing processes, thus increasing the yield by 10%-15%. Through precise control, the precious metal loss rate is strictly limited to within 0.5%, which is about 30% lower than traditional processes, resulting in extremely high economic benefits. Simultaneously, the production line of this invention significantly optimizes the production process, achieving efficient and green production. This invention achieves continuous production from smelting to finished product through equipment linkage control, utilizing the synergistic effect of rolling residual heat and induction heating to complete dynamic recrystallization within seconds. Therefore, this short-process design not only significantly reduces the production cycle but also simplifies equipment layout, reduces manpower input, and lowers energy consumption, highly aligning with the green and low-carbon production concepts of modern manufacturing. Attached Figure Description

[0036] Figure 1 : A schematic diagram of the structure of the short-process preparation line for platinum and platinum-based alloy rods or wires of the present invention.

[0037] Figure 2 Flowchart of traditional platinum and platinum-based alloy rod / wire preparation process.

[0038] Figure 3 : A schematic flowchart of the short-process preparation method of platinum and platinum-based alloy rods or wires of the present invention.

[0039] Figure label:

[0040] 1. Vacuum induction melting furnace; 11. Melting crucible; 12. Secondary feeding device;

[0041] 2. Tundish; 21. Tundish crucible; 22. Tundish nozzle;

[0042] 3 Continuous casting device, 31 Crystallizer, 32 Water cooling jacket, 33 Continuous casting air cooling mechanism;

[0043] 4 Continuous rolling unit, 41 Roughing mill, 42 Finishing mill, 43 First induction heating coil, 44 Second induction heating coil, 45 Dual-color infrared thermometer;

[0044] 5. Guiding device;

[0045] 6 Continuous drawing device, 61 First drawing die, 62 Second drawing die, 63 Intermediate induction heating device, 64 Drawing air cooling mechanism, 65 Winding device;

[0046] 7. Alloy melt. Detailed Implementation

[0047] This invention provides a short-process production line for the manufacture of platinum and platinum-based alloy rods or wires, such as... Figure 1 As shown, the system includes: a vacuum induction melting furnace 1, a tundish 2, a continuous casting device 3, a continuous rolling device 4, a guiding device 5, a continuous drawing device 6, and a central PLC control system (not shown in the figure). The vacuum induction melting furnace 1 includes a melting crucible 11, used to melt prepared materials into an alloy melt 7 under vacuum. The tundish 2 includes a tundish crucible 21, a spiral tubular coil surrounding the tundish crucible 21, and a heating power supply for the coil. In this embodiment, the tundish crucible 21 is a composite crucible. The bottom of the composite crucible has a tapered nozzle that is wider at the top and narrower at the bottom. The composite crucible is heat-resistant and anti-adhesive. The tapered nozzle can pressurize the melt, helping the flowing molten metal to enter the crystallizer 31 smoothly, evenly, and steadily. By reducing turbulence and eddies, it helps prevent the entrapment of gas and inclusions, thereby reducing defects such as internal porosity and surface cracks in the cast billet. The tundish 2 also includes a level sensor for real-time monitoring of the liquid level inside the crystallizer 31.

[0048] The continuous casting apparatus 3 includes a crystallizer 31. The inlet of the crystallizer 31 has a funnel-shaped receiving cavity (not shown in the figure) that is coaxial with the conical guide nozzle, wider at the top and narrower at the bottom. This funnel-shaped receiving cavity buffers the impact force of the molten metal from the conical guide nozzle of the tundish 2, allowing the liquid flow to be buffered and pressure-equalized before entering the mold cavity of the crystallizer 31 in a more stable state. This results in a more uniform flow field and a more even distribution of the molten metal within the crystallizer 31, which is beneficial for the consistency of the billet structure. A high-temperature resistant flexible sealing ring (not shown in the figure) forms a semi-closed protective cavity between the funnel-shaped receiving cavity and the conical guide nozzle, compensating for assembly errors and thermal expansion deformation. Through the closed-loop buffered docking structure and the control of the protective atmosphere, this process effectively blocks external air, preventing secondary oxidation of the platinum alloy melt 7. The final wire produced has extremely high dimensional accuracy, with the error controlled within ±0.01mm. It not only fully meets the needs of high-end applications such as glass fiber spinnerets, welding wires, and thermocouples, but also provides a transferable technical path for the preparation of similar precious metal alloys.

[0049] An annular liquid collection tank (not shown in the figure) is provided on the outer side of the upper opening of the crystallizer 31 to prevent leakage of high-temperature melt. This structure adopts an assembly form with the upper part fixed and the lower part floating. The continuous casting device 3 also includes a liquid level sensor (not shown in the figure) for real-time monitoring of the liquid level in the crystallizer 31. The alloy melt 7 is directly formed into a billet through the continuous casting device 3, thus eliminating the following processes in the traditional process: casting the alloy melt 7 into gold ingots, then forging the gold ingots, and then sandblasting or surface milling the surface of the forged gold ingots, rolling the gold ingots into plates, cutting them into strips, etc. This not only greatly saves the process, but also reduces the processing losses caused by surface treatment, cutting into strips, deburring and other processes.

[0050] The guiding device 5 includes multiple guide wheels that guide the billet output from the crystallizer. At least one guide wheel is driven to rotate by a motor equipped with an encoder. The motor is connected to the central PLC control system, and its rotation speed is adjusted under the control of the central PLC control system to match the guiding speed of the billet with the continuous casting drawing speed and the roughing mill entry speed. The guiding device 5 guides the billet output from the continuous casting device 3 into the roughing mill 41 of the continuous rolling device 4, thus directly connecting the casting process and the rolling process without any other processes in between, forming a "continuous casting and rolling" process. This design eliminates all intermediate steps in the traditional process, such as billet removal, cooling, inspection, and reheating, and eliminates the process of reheating the billet after cooling. This not only shortens the production cycle but also directly utilizes the high-temperature residual heat of the billet for rolling, greatly reducing production energy consumption. At the same time, it avoids surface oxidation, scratches, and other losses caused by the billet during transportation, storage, and secondary heating, thereby improving metal yield. The guiding device 5 includes:

[0051] like Figure 1 As shown, the continuous rolling apparatus 4 includes a roughing mill 41 and a finishing mill 42 that receives the billets from the roughing mill 41. The roughing mill 41 is a two-high or four-high continuous rolling mill, and the roughing reduction rate is controlled between 30% and 50%. A first induction heating coil 43 is installed on the path of the billet from the roughing mill 41 to the finishing mill 42. A second induction heating coil 44, a thermometer (not shown in the figure) for real-time detection of the billet temperature, and an air-cooling mechanism (not shown in the figure) are sequentially installed on the path of the billet starting from the finishing mill 42. In this embodiment, the thermometer is a dual-color infrared thermometer 45. With this configuration, rolling is achieved continuously, without interruption between roughing and finishing. The billet is heated on the path from the roughing mill 41 to the finishing mill 42, and the billet is heated on the path after finishing, without requiring additional time. Heating is completed during the transport journey, further shortening the production cycle.

[0052] The continuous drawing device 6 is located downstream of and adjacent to the continuous rolling device 4. The continuous drawing device 6 includes a first-pass drawing die 61 that receives the bar billet from the finishing mill 42 and a second-pass drawing die 62 that receives the wire rod from the first-pass drawing die 61. After the first drawing, the bar billet forms a drawn billet. An intermediate induction heating device 63 and a drawing air-cooling mechanism 64 are sequentially arranged along the path of the drawn billet from the first-pass drawing die 61 to the second-pass drawing die 62. The intermediate induction heating device 63 heats the drawn billet, causing it to rapidly recover its plasticity after stretching hardening. The drawing air-cooling mechanism 64 uses an atomizing air-cooling mechanism to rapidly reduce the temperature of the drawn billet from the annealed state to below 150°C. The continuous drawing device 6 also includes a winding device 65 that receives the finished bar or wire rod from the second-pass drawing die 62.

[0053] The continuous drawing device 6 itself forms a continuous drawing process. Furthermore, in this process, heating and air cooling occur during the transport of the drawn billet from the first drawing die 61 to the second drawing die 62, requiring no additional time. Simultaneously, the continuous drawing device 6 is seamlessly connected to the continuous rolling device 4, allowing the drawing process to directly utilize the residual heat from the rolling exit, eliminating the significant energy consumption associated with cooling, coiling, transport, rewinding, and reheating in traditional processes. Moreover, the intermediate induction heating only requires "supplementary heating" rather than "full heating," resulting in a significantly lower overall energy consumption compared to traditional processes.

[0054] The central PLC control system receives data from the liquid level sensor and adjusts the tilting speed of the vacuum induction melting furnace 1 accordingly. This keeps the liquid level fluctuation within the composite crucible within a set range, ensuring stable static pressure and laminar flow as the melt enters the crystallizer 31. This guarantees the continuity of the continuous casting process and the uniformity of the billet cross-section. The central PLC control system also receives measured temperature data from the thermometer and synchronously feeds it back to the heating power supply of the second induction heating coil 44. It dynamically adjusts the output power of the second induction heating coil 44 to control the billet temperature fluctuation within a set range. This prevents incomplete recrystallization due to excessively low temperatures and coarse grains due to excessively high temperatures, which damage mechanical properties. Furthermore, it ensures that the entire coil of wire undergoes the same temperature regime from beginning to end, guaranteeing uniformity in microstructure and hardness and eliminating the head-to-tail temperature difference problem present in traditional furnace annealing.

[0055] The central PLC control system sets the reduction rate and controls the conveying speed of the first and second stretching dies according to the set reduction rate. The central PLC control system controls the conveying speed of the stretching dies in the following ways:

[0056] Parameter settings: The operator inputs the target area reduction rate r and the first pass baseline speed V through the human-machine interface. 拉1 .

[0057] Feedforward velocity calculation: Based on the principle of equal metal flow rate per second Q = A × V, the PLC automatically calculates the target linear velocity V of the second pass. 拉 2 = V 拉 1 / (1 - r), and convert the linear velocity into the speed command for each drive motor.

[0058] Real-time feedback fine-tuning: The system reads the tension sensor values ​​placed between two passes in real time. The PLC has a built-in PID controller, which adjusts the tension based on the tension deviation e = T. target - T actual Calculate the compensation amount ΔV 拉 This is then superimposed on the speed command of the second pass, forming V. 拉 2 final = V 拉 2 +ΔV 拉 .

[0059] Cascaded collaborative control: The speed of the first pass is used as the master command. When the speed of the upstream finishing mill changes, the PLC synchronously adjusts the V. 拉 1 The speed of the downstream second pass and the speed of the final coiled product are automatically derived from the actual speed of the previous stage to ensure that the speed of the entire line is synchronized and to prevent material accumulation or excessive stretching.

[0060] For continuous rolling mills, the final exit speed Vroll can be determined first. n This speed can be the baseline speed V1 of the first pass, or it can be added to or subtracted from this speed, and then the speeds of the previous passes can be calculated in reverse. Assume the final diameter is D. n The final velocity is V n Then the theoretical linear velocity of any i-th wire is: V i =V n (D) n / D i ) 2 ,

[0061] In practical process design, to establish stable inter-pass tension and absorb speed margins that absorb process fluctuations, it is generally desirable for the traction speed of the next pass to be slightly higher than the theoretically calculated material speed. This establishes a certain back tension between the two molds, and a lead ratio is set on the theoretical linear velocity between each transfer wheel, i.e., speed compensation is increased: S i =(T i -V i ) / T i Where S i For the lead rate, T iV is the linear velocity of the roll surface. i This represents the theoretical linear velocity for material transport. For platinum / platinum-rhodium alloys, the lead rate is set to 0.3%–3%.

[0062] This invention employs a short-process design that combines continuous casting with continuous rolling and continuous drawing, eliminating redundant forging, milling, and shearing steps, thereby increasing the yield by 10%-15%. Through precise control, the precious metal loss rate is strictly limited to within 0.5%, which is about 30% lower than traditional processes, resulting in extremely high economic benefits.

[0063] This invention significantly optimizes the production process, achieving efficient and green manufacturing. Traditional processes are cumbersome and loosely connected, with the annealing process alone accounting for over 30% of the total production cycle, resulting in high overall energy consumption. This invention, through equipment linkage control, achieves continuous production from smelting to finished product. Utilizing the synergistic effect of residual heat from rolling combined with induction heating, dynamic recrystallization can be completed within seconds. This short-process design not only significantly reduces the production cycle but also simplifies equipment layout and reduces manpower input, highly aligning with the green and low-carbon production concepts of modern manufacturing.

[0064] Preferably, the composite crucible comprises an outer crucible, an inner crucible, and a graphite ring located between the outer and inner crucibles. The outer crucible can be made of zirconium oxide, alumina, or calcium oxide, and the inner crucible can also be made of zirconium oxide, alumina, or calcium oxide. Zirconia crucibles are preferred for both the inner and outer crucibles. The purpose of the intermediate graphite ring is to indirectly heat the inner crucible by induction heating through graphite when there is no metal or molten metal in the inner crucible, thereby achieving preheating and heat preservation of the inner crucible.

[0065] The heating principle is as follows: The composite crucible is indirectly heated using medium-frequency induction graphite. When a medium-frequency current is applied to the coil, an alternating magnetic field is generated. Under the influence of this magnetic field, the graphite ring induces a potential, producing a ring current. This current, under its own magnetic field, concentrates on the outer layer of the graphite ring (i.e., the skin effect), giving the outer graphite a very high current density, thus generating a concentrated and powerful heating effect. When the graphite ring reaches a certain temperature, the metal charge will naturally be indirectly heated and melted. The target temperature for heating the inner crucible is determined by the melt temperature in the melting crucible 11 of the vacuum induction melting furnace 1. A higher melting point for the alloy means a higher solidification temperature, thus increasing the preheating temperature of the tundish 2. Preheating the tundish crucible 21 prevents the alloy melt 7 from solidifying prematurely and clogging the nozzle when transferred from the melting crucible 11 to the tundish 2, or from solidifying directly in the tundish crucible 21. Based on the melting point of the platinum-based alloy, the preheating temperature of the tundish crucible 21 is maintained between 1300°C and 1800°C. This suitable temperature value is limited by both the alloy melting point and the overheating temperature of the alloy melt 7 during transfer casting.

[0066] In this embodiment, the outer wall of the crystallizer 31 is equipped with a water-cooling jacket, which can uniformly cool the melt and solidify it into a rod shape. The outlet of the crystallizer 31 is equipped with a continuous casting air-cooling mechanism 33 for cooling the cast rod. In this embodiment, the continuous casting air-cooling mechanism 33 is an annular multi-hole air nozzle. High-pressure pure compressed air is used to spray the pulled-out billet from all directions. By adjusting the air volume, the billet temperature is rapidly reduced from the high-heat state after crystallization to 300℃-750℃, preventing precious metal contamination caused by hot working, and maintaining a uniform temperature gradient during the conveying process to prevent excessive temperature difference between the center and the surface from causing cracks.

[0067] The continuous casting apparatus 3 also includes a vibrator that drives the crystallizer 31 to vibrate. The tundish crucible 21 remains stationary, and the crystallizer 31 can perform micro-amplitude reciprocating motion under pulse vibration conditions of 60-120 times / minute. Through controllable periodic micro-amplitude vibration, the adhesion between the platinum alloy melt 7 and the inner wall of the crystallizer 31 is effectively broken, preventing the high-temperature melt from sticking to the vessel wall, adhering to the wall, and local solidification. This significantly improves the melt demolding and forming state, ultimately ensuring that the surface of the rod-shaped solid metal is smooth, uniform, free of scratches and scratches, meeting the requirements for high-precision forming and surface quality.

[0068] The first induction heating coil 43 operates at a frequency of 10kHz-20kHz, and its heat penetration depth must cover more than 80% of the bar cross-section. Utilizing the synergistic effect of the residual heat from rolling combined with the induction heating of the first induction heating coil 43, the metal rapidly heats up to above the recrystallization temperature within 3-5 seconds, efficiently completing dynamic recrystallization and ensuring a uniformly structured and highly ductile billet for subsequent rolling processes. The second induction heating coil 44 operates at a frequency of 50kHz-100kHz. The second induction heating coil 44 primarily performs directional annealing on the surface hardened layer formed after finishing rolling, effectively eliminating microscopic distortion energy and residual rolling stress within the metal.

[0069] This invention also provides a short-process method for preparing platinum and platinum-based alloy rods or wires, utilizing the preparation line described above to prepare platinum and platinum-based alloy rods or wires, comprising the following steps:

[0070] S1. Alloy Composition Design and Batching: Precious metal elements such as platinum (Pt), rhodium (Rh), iridium (Ir), palladium (Pd), and gold (Au), meeting purity requirements, are proportioned according to design specifications. If platinum or platinum-based alloy rods / wires require further design as solid solution-strengthened or dispersion-strengthened materials, a certain proportion of strengthening elements such as zirconium (Zr), hafnium (Hf), scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), and erbium (Er) needs to be added to the matrix material. Alternatively, a certain amount of boron or borides, such as calcium boride, zirconium boride, and titanium boride, can be added to the matrix. Adding appropriate amounts of active elements to platinum or the platinum matrix allows some or all of the active elements to be oxidized into corresponding oxides during subsequent high-temperature heat treatment or high-temperature use, resulting in dispersion strengthening. The addition of boron or borides achieves both solid solution strengthening and dispersion strengthening, thereby improving the material's room temperature and high-temperature mechanical properties.

[0071] S2. Vacuum Induction Refining: The precious metal raw materials prepared in step S1 are placed into the melting crucible 11 in the vacuum induction melting furnace 1. Strengthening elements (Zr, Hf, Sc, Y, La, Ce, Er, etc.) and / or strengthening agents (boron, calcium boride, titanium boride, zirconium boride, etc.) are placed into the secondary feeding device 12 in the induction melting furnace. The melting crucible 11 is a zirconium oxide, alumina, or calcium oxide crucible, with zirconium oxide crucibles with added stabilizers preferred. The specific operation is as follows:

[0072] ① According to the designed alloy composition, after accurate weighing, the metal is placed into the melting crucible 11 of the vacuum induction melting furnace 1 and energized to start induction heating.

[0073] ② After the platinum or platinum-based alloy material described in step ① has been completely melted, close the furnace lid and evacuate the furnace body;

[0074] ③ When the vacuum degree in step ② is ≤100Pa, close the vacuum valve and fill the furnace with protective gas until the furnace pressure reaches 6×10⁻⁶ Pa. 4 Pa ~ 10×10 4 When Pa is reached, the protective gas valve should be closed.

[0075] ④ Open the vacuum valve and evacuate the furnace body again. When the vacuum degree is ≤100Pa, close the vacuum valve and fill the furnace body with protective gas again until the furnace pressure reaches atmospheric pressure. This will obtain a platinum or platinum-based alloy melt that meets the requirements.

[0076] ⑤ If strengthening elements or agents need to be added, they should be placed in the secondary feeding device 12 beforehand. After completing step ④, the secondary feeding device 12 is rotated to add the strengthening elements or agents to the high-temperature platinum or platinum-based alloy melt 7 in the melting crucible 11. After the strengthening elements or agents are added to the molten pool for 10s to 120s, they are evenly distributed in the matrix under the action of strong electromagnetic stirring. This completes the vacuum induction refining process.

[0077] S3. Tundish Preheating and Flow Stabilization: Simultaneously with starting step S2, turn on the induction heating power supply for tundish crucible 21, adjust the heating power, and begin heating tundish crucible 21. The target temperature for heating the inner crucible is determined by the melt temperature in the upper melting crucible 11. A higher melting point of the alloy being melted means a higher solidification temperature, thus increasing the preheating temperature of tundish 2. The purpose of preheating tundish crucible 21 is to prevent premature solidification and blockage of the nozzle due to excessively rapid temperature drop when the alloy melt 7 is transferred from melting crucible 11 to tundish 2, or to prevent direct solidification within tundish crucible 21. Based on the melting point of the platinum-based alloy, the preheating temperature of tundish crucible 21 is maintained between 1300℃ and 1800℃. This suitable temperature value is limited by both the alloy melting point and the overheating temperature of the alloy melt 7 during transfer. The preheating temperature of tundish crucible 21 is measured and controlled by a temperature measuring device within the melting furnace. The refined alloy melt 7 from step S2 is slowly poured into the intermediate ladle crucible 21. A laser liquid level sensor is used to monitor the liquid level in the intermediate ladle 2 in real time. By adjusting the pouring speed of the melting furnace, the liquid level fluctuation is kept less than 2 mm / s to ensure that the inlet pressure of the crystallizer 31 is stable.

[0078] S4. Continuous casting: The molten material continuously enters the crystallizer 31 from the tundish 2 in a laminar flow state and solidifies into a rod-shaped billet. Specifically, the molten material flows downstream to the tundish nozzle 22 and enters the high thermal conductivity dispersion-strengthened copper crystallizer 31, which can also be a graphite crystallizer. The outer layer of the crystallizer 31 is equipped with a spiral circulating water cooling jacket 32. The tundish crucible 21 and the crystallizer 31 adopt a coaxial, centering, and sealed buffer docking structure. The bottom of the tundish crucible 21 is equipped with a high-temperature resistant and anti-adhesion conical guide nozzle, and the upper end of the crystallizer 31 is equipped with a corresponding trumpet-shaped receiving cavity. The two are strictly coaxially assembled through a radial positioning sleeve. A high-temperature resistant flexible sealing ring is provided between the guide nozzle and the receiving cavity to form a semi-sealed protective cavity, which can effectively block the outside air to prevent secondary oxidation of the platinum alloy melt 7, and at the same time compensate for assembly errors and thermal expansion deformation. A short-range expansion buffer zone is provided below the receiving cavity to allow the melt to enter the forming area of ​​the crystallizer 31 in a stable laminar flow state, eliminating eddies, splashes and air entrapment. An annular liquid collection groove is provided on the outer side of the upper opening of the crystallizer 31 to prevent high-temperature melt leakage. This structure adopts an assembly form with the upper fixed and the lower floating. The tundish crucible 21 remains stationary, while the crystallizer 31 can perform micro-amplitude reciprocating motion under pulse vibration conditions of 60 to 120 times / minute. By controlling periodic micro-vibration, the adhesion between the platinum alloy melt 7 and the inner wall of the crystallizer 31 is effectively broken, preventing the high-temperature melt from sticking to the vessel wall, adhering to the wall, and solidifying locally. This significantly improves the melt demolding and forming state, ultimately ensuring that the surface of the rod-shaped solid metal is smooth, uniform, free of scratches and scratches, meeting the requirements for high-precision forming and surface quality.

[0079] A ring-shaped multi-hole air nozzle is installed at the outlet of crystallizer 31. High-pressure, pure compressed air is used to spray the pulled-out billet from all directions. By adjusting the air volume, the billet temperature is rapidly reduced from the high-heat state after crystallization to 300℃-750℃, which can prevent precious metal contamination caused by hot working and maintain a uniform temperature gradient during the conveying process, preventing excessive temperature difference between the center and the surface from causing cracks.

[0080] S5. Continuous Rolling: The billet enters a two- or four-high continuous rolling mill via guide rollers. The roughing reduction rate is controlled at 30%–50%. Immediately after leaving the roughing mill, the rolled piece enters the first induction heating coil 43. Medium-frequency induction heating (10kHz–20kHz) is used, and the heating depth must cover more than 80% of the billet cross-section. Utilizing the synergistic effect of residual rolling heat and induction heating, the metal is rapidly heated to above the recrystallization temperature within 3–5 seconds, efficiently completing dynamic recrystallization and providing a uniformly structured and highly ductile billet for subsequent rolling processes.

[0081] The finishing mill 42 performs precision reduction rolling on the bar billets, with the processing rate precisely controlled between 15% and 25%. The finished bar billets then enter the second set of high-frequency induction heating coils, with the working frequency set between 50kHz and 100kHz. This high-frequency induction heating mainly targets the surface hardened layer formed after finishing rolling to carry out directional annealing treatment, effectively eliminating the microscopic distortion energy and rolling residual stress inside the metal. A dual-color infrared thermometer 45 is equipped on-site, which can accurately detect the wire temperature in real time and synchronously feed the measured temperature data back to the induction heating power supply, dynamically adjusting the output power to strictly control the temperature fluctuation range of the bar billets within ±5℃, ensuring stable and uniform microstructure during the annealing process. Finally, the wire is cooled by an air-cooling mechanism.

[0082] S6. Continuous Drawing and Finished Product Collection: After lubrication, the billet enters the first drawing die 61. Then, the billet is heated by an intermediate induction heating device 63, which rapidly restores its plasticity after stretching hardening. Atomized air cooling is then used to quickly reduce the wire temperature from the annealed state to below 150°C. The entire line speed is synchronized by a central PLC control system. The billet then enters the second drawing die 62, typically a polycrystalline diamond die, to obtain the final finished product size, and then enters the winding machine 65.

[0083] In step S6, the central PLC control system automatically calculates the speed compensation of each level of conveyor rollers based on the stretching rate and controls the speed of each level of conveyor rollers to prevent the wire from piling up or being overstretched between processes.

[0084] The following describes an embodiment of the short-process preparation method for platinum and platinum-based alloy rods or wires according to the present invention. In the present invention: finished products with a diameter d > 3 mm are referred to as rods, and finished products with a diameter 0.3 mm ≤ d ≤ 3 mm are referred to as wires.

[0085] Example 1 uses a short-process technology of vacuum induction melting-continuous casting-online rolling-drawing to prepare Pt gold wire with a diameter of 1 mm, which is mainly used for glass fiber sprue assembly processing and thermocouple manufacturing.

[0086] Platinum with a purity of not less than 99.99% was selected as the raw material, with a total loading of 10 kg. The raw material was cleaned on the surface before being loaded into the furnace. After being cleaned with acetone, it was placed in a vacuum drying oven and dried at 120°C for 2 hours to remove oil and adsorbed moisture.

[0087] Vacuum induction melting is performed. The prepared raw materials are loaded into the zirconia melting crucible 11 and melted in the vacuum induction melting furnace 1. The furnace body is first evacuated to below 100 Pa, and then high-purity argon gas is introduced to a pressure of 1 × 10⁻⁶ Pa. 4Pa is used for protection, and the vacuuming and purging operations are repeated twice to reduce residual gas. The furnace temperature is raised to about 2000°C by induction heating to completely melt the metal. After the melt is formed, electromagnetic stirring is maintained for about 20 seconds to ensure that the composition is fully and evenly distributed, thereby obtaining a homogeneous platinum melt.

[0088] After melting, the melt is poured into the tundish crucible 21 for continuous casting. The preheating temperature of the tundish 2 is controlled at 1500°C to prevent the liquid from solidifying too quickly. The melt enters the dispersion-strengthened copper crystallizer 31 through the tundish nozzle 22 for continuous solidification and forming. The inner diameter of the crystallizer 31 is set to 6mm, the circulating cooling water flow rate is 6L / min, the billet pulling speed is controlled at 110mm / min, and high-pressure air cooling is applied at the outlet of the crystallizer 31 to finally obtain a platinum bar billet with a diameter of about 6mm.

[0089] The billet then enters the online rolling system for hot rolling. First, it is rough rolled on a two-roll roughing mill 41, reducing the billet diameter from 6 mm to approximately 3 mm, with the roughing reduction rate controlled at around 50%. Immediately after leaving the roughing mill, the billet enters the first set of online induction heating coils for reheating. The induction heating frequency is set to 12 kHz, and the temperature is maintained at approximately 1150°C for about 5 seconds. By utilizing the synergistic effect of the residual heat from rolling and induction heating, the material undergoes dynamic recrystallization to eliminate the as-cast structure.

[0090] The billet then enters the finishing mill 42 for finishing rolling, further reducing the diameter to approximately 1.8 mm. The finished material then enters the second set of online induction heating coils for online annealing. The annealing temperature is controlled at approximately 950°C, with a holding time of about 25 seconds, and the power is dynamically adjusted using a dual-color infrared thermometer 45. A fan is then used for rapid cooling, reducing the material temperature to below 250°C to eliminate the surface hardened layer and restore the material's plasticity.

[0091] After annealing, the billet enters the cold drawing process and is continuously drawn through multiple drawing dies. Between drawing passes, the billet is rapidly restored to plasticity by intermediate induction heating and cooled by atomized air cooling. Finally, the billet is drawn into a finished wire with a diameter of 1.00mm±0.01mm and collected by winding machine 65.

[0092] Material balance calculations were performed for the processing in this embodiment. The initial feed was 10.000 kg. After a short process including vacuum melting, casting, continuous casting and rolling, and inspection, 9.955 kg of wire with the required dimensions and appearance was finally obtained. 38 g of head and tail materials, sampled residue, and recyclable waste material in the equipment were collected, while 7 g of non-recyclable precious metals were lost. Based on the ratio of the finished wire mass to the initial feed mass, the yield rate in this embodiment was 99.6%. Based on the ratio of the non-recyclable precious metal mass to the initial feed mass, the loss rate in this embodiment was 0.07%. Performance testing showed that the Pt wire had a room temperature Vickers hardness of 75 HV, a tensile strength of 180 MPa, and an elongation of approximately 37%. Microscopic observation showed that the grain size was approximately 31 μm, with a uniform structure and no obvious segregation defects.

[0093] Example 2 uses a short-process manufacturing method—vacuum induction melting, continuous casting, online rolling, and drawing—to produce PtRh5 alloy wire with a diameter of 3 mm. This wire is mainly used for processing glass fiber sprue assemblies and manufacturing high-temperature structural components.

[0094] First, the alloy was prepared. A PtRh5 alloy was prepared according to the following mass percentages: 95.0 wt% Pt and 5.0 wt% Rh. Platinum with a purity of not less than 99.99% and rhodium with a purity of not less than 99.95% were selected as raw materials, with a total charge of 10 kg. Before loading into the furnace, the raw materials underwent surface cleaning treatment. After washing with acetone, they were placed in a vacuum drying oven and dried at 120°C for 2 hours to remove oil and adsorbed moisture.

[0095] Vacuum induction melting is then performed. The prepared raw materials are loaded into a zirconia melting crucible 11 and melted in a vacuum induction melting furnace 1. The furnace body is first evacuated to below 100 Pa, and then filled with high-purity argon gas to 1×10⁻⁶ Pa. 4 Pa is used for protection, and the vacuuming and purging operations are repeated twice to reduce residual gas. The furnace temperature is raised to about 2000℃ by induction heating to completely melt the metal. After the melt is formed, electromagnetic stirring is maintained for about 70 s to ensure that the rhodium element is fully and uniformly distributed in the platinum matrix, thereby obtaining a PtRh5 alloy melt with uniform composition 7.

[0096] After melting, the alloy melt 7 is poured into the tundish crucible 21 for continuous casting. The preheating temperature of the tundish crucible 21 is controlled at 1500℃ to prevent the alloy liquid from solidifying too quickly. The melt enters the dispersion-strengthened copper crystallizer 31 through the tundish nozzle 22 for continuous solidification and forming. The inner diameter of the crystallizer 31 is set to 10 mm, the circulating cooling water flow rate is 11 L / min, and the billet pulling speed is controlled at 90 mm / min to obtain a PtRh5 alloy billet with a diameter of approximately 10 mm.

[0097] The billet then enters the online rolling system for hot rolling. First, it undergoes rough rolling on a two-roll roughing mill (41) to reduce the billet diameter from 10 mm to approximately 5 mm, with a roughing surface reduction rate controlled at around 50%. After leaving the roughing mill, the rolled piece (bar) enters a medium-frequency induction heating coil for reheating. The induction heating frequency is set to 12 kHz, and the temperature is maintained at approximately 1150 ℃ for about 5 seconds to allow dynamic recrystallization of the material, eliminating the as-cast structure.

[0098] The billet then enters the finishing mill 42 for finishing rolling, further reducing the diameter of the billet to approximately 3.8 mm. After finishing rolling, the billet enters a high-frequency induction heating coil for online annealing. The annealing temperature is controlled at around 950 ℃, and the holding time is about 25 s. Then, a fan is used for rapid cooling to reduce the material temperature to below 250 ℃ in order to restore the material's plasticity.

[0099] After annealing, the billet enters the cold drawing process. First, a two-pass drawing process is performed using a cemented carbide drawing die to draw the 3.8 mm diameter billet to 3.0 mm. The drawing speed is controlled at 10 m / min, and graphite lubricant is used for lubrication during the drawing process. Finally, a PtRh5 wire with a diameter of 3.00 mm ± 0.02 mm is obtained.

[0100] Performance testing revealed that the PtRh5 wire had a room temperature Vickers hardness of 111 HV, a tensile strength of 355 MPa, and an elongation of approximately 22%. Microscopic observation showed that the material had a grain size of approximately 22 μm, a uniform structure, and no obvious segregation defects.

[0101] Material balance calculations were performed on the processing in this embodiment. The initial feed was 10.000 kg. After a short process including vacuum melting, casting, continuous casting and rolling, and inspection, 9.957 kg of wire with the required dimensions and appearance was finally obtained. 39 g of head and tail materials, sampled residues, and recyclable waste materials in the equipment were collected, and 4 g of non-recyclable precious metals were lost. Calculated based on the ratio of the finished wire mass to the initial feed mass, the yield rate of this embodiment was 99.6%. Calculated based on the ratio of the non-recyclable precious metal mass to the initial feed mass, the loss rate of this embodiment was 0.04%. Example 3 uses a short process of vacuum induction melting—continuous casting—online rolling—drawing to prepare PtRh10 alloy rods with a diameter of 4 mm, mainly used for glass fiber spindle assembly processing and high-temperature structural component manufacturing.

[0102] First, the alloy was prepared. A PtRh10 alloy was prepared according to the following mass percentages: 90.0 wt% Pt and 10.0 wt% Rh. Platinum with a purity of not less than 99.99% and rhodium with a purity of not less than 99.95% were selected as raw materials, with a total charge of 10 kg. Before loading into the furnace, the raw materials underwent surface cleaning treatment. After washing with acetone, they were placed in a vacuum drying oven and dried at 120°C for 2 hours to remove oil and adsorbed moisture.

[0103] Vacuum induction melting is then performed. The prepared raw materials are loaded into a zirconia melting crucible 11 and melted in a vacuum induction melting furnace 1. The furnace body is first evacuated to below 100 Pa, and then filled with high-purity argon gas to 1×10⁻⁶ Pa. 4 Pa is used for protection, and the vacuuming and purging operations are repeated twice to reduce residual gas. The furnace temperature is raised to about 2100°C by induction heating to completely melt the metal. After the melt is formed, electromagnetic stirring is maintained for about 100 seconds to ensure that the rhodium element is fully and uniformly distributed in the platinum matrix, thereby obtaining a PtRh10 alloy melt with uniform composition 7.

[0104] After melting, the alloy melt 7 is poured into the tundish crucible 21 for continuous casting. The preheating temperature of the tundish crucible 21 is controlled at 1500℃ to prevent the alloy liquid from solidifying too quickly. The melt enters the dispersion-strengthened copper crystallizer 31 through the tundish nozzle 22 for continuous solidification and forming. The inner diameter of the crystallizer 31 is set to 12 mm, the circulating cooling water flow rate is 14 L / min, and the billet pulling speed is controlled at 70 mm / min to obtain a PtRh10 alloy billet with a diameter of approximately 12 mm.

[0105] The billet then enters the online rolling system for hot rolling. First, it undergoes rough rolling on a two-roll roughing mill (41) to reduce the billet diameter from 12 mm to approximately 6 mm, with a roughing surface reduction rate controlled at around 50%. After leaving the roughing mill, the billet enters a medium-frequency induction heating coil for reheating. The induction heating frequency is set to 12 kHz, and the temperature is maintained at approximately 1150 °C for about 10 seconds to allow dynamic recrystallization of the material, eliminating the as-cast structure.

[0106] The billet then enters the finishing mill 42 for finishing rolling, further reducing the diameter of the billet to approximately 4.8 mm. After finishing rolling, the billet enters a high-frequency induction heating coil for online annealing. The annealing temperature is controlled at around 950℃, and the holding time is about 25 seconds. Then, a fan is used for rapid cooling to reduce the material temperature to below 250℃ in order to restore the material's plasticity.

[0107] After annealing, the billet enters the cold drawing process. First, a two-pass drawing process is performed using a cemented carbide drawing die to draw the 4.8 mm diameter billet to 4 mm. The drawing speed is controlled at 8 m / min, and graphite lubricant is used for lubrication during the drawing process. The final product is a PtRh10 billet with a diameter of 4.00 mm ± 0.02 mm.

[0108] Material balance calculations were performed for the processing in this embodiment. The initial feed was 10.000 kg. After short-process steps including vacuum melting, casting, continuous casting and rolling, and inspection, 9.963 kg of wire with the required dimensions and appearance was finally obtained. 32 g of head and tail materials, sampled residue, and recyclable waste material in the equipment were collected, and 5 g of non-recyclable precious metals were lost. Based on the ratio of the finished wire mass to the initial feed mass, the yield rate in this embodiment was 99.6%. Based on the ratio of the non-recyclable precious metal mass to the initial feed mass, the loss rate in this embodiment was 0.05%. Performance testing showed that the PtRh10 wire had a room temperature Vickers hardness of 132 HV, a tensile strength of 417 MPa, and an elongation of approximately 17%. Microscopic observation showed that the grain size was approximately 24 μm, with a uniform structure and no obvious segregation defects.

[0109] In the comparative example, a traditional long-process manufacturing procedure was used to produce PtRh5 alloy wire with a diameter of 3 mm, consisting of: batching → induction melting → casting gold ingots → forging → surface treatment (sandblasting or surface milling) → rolling → shearing → deburring → die rolling → drawing → annealing → redrawing and annealing → finishing and polishing → finished product inspection. This specification of wire is mainly used for processing glass fiber sprue assemblies and manufacturing high-temperature structural components.

[0110] First, the alloy was prepared. A PtRh5 alloy was prepared according to the following mass percentages: 95.0 wt% Pt and 5.0 wt% Rh. Platinum with a purity of not less than 99.99% and rhodium with a purity of not less than 99.95% were selected as raw materials, with a total charge of 10 kg. Before loading into the furnace, the raw materials underwent surface cleaning treatment. After washing with acetone, they were placed in a vacuum drying oven and dried at 120°C for 2 hours to remove oil and adsorbed moisture.

[0111] Vacuum induction melting is then performed. The prepared raw materials are loaded into the zirconia melting crucible 11 and melted in the vacuum induction melting furnace 1. The furnace body is first evacuated to below 100 Pa, and then high-purity argon gas is introduced to 1×10⁻⁶ Pa. 4Pa was used for protection, and the vacuuming and purging process was repeated twice to reduce residual gas. The furnace temperature was raised to approximately 2000°C by induction heating to completely melt the metal. After the melt was formed, electromagnetic stirring was maintained for about 70 seconds to ensure that the rhodium element was fully and uniformly distributed in the platinum matrix, thereby obtaining a homogeneous PtRh5 alloy melt 7. The melt was then poured into an 80mm×40mm×200mm water-cooled copper mold, and the gold ingot was removed after being naturally cooled to room temperature in air.

[0112] The gold ingots then enter the forging process, first being heated to 1400°C in a medium-frequency induction furnace and then forged in multiple passes using an air hammer. The initial forging temperature is controlled above 1250°C. Because the impurity layer and microcracks generated on the surface during forging and cooling will affect the quality of the finished product, the forging billet needs to undergo surface treatment. A 1mm thick metal layer is removed from the surface by mechanical milling to ensure that there are no obvious defects on the surface before it is sent to the rolling mill.

[0113] The processed billets are rolled into 7mm thick plates using a rolling mill. A two-roll roughing mill is then used to gradually roll the gold ingots to a thickness of approximately 6.5mm. During rolling, the maximum single rolling amount is strictly controlled below 1.0mm, and the lateral feed must be adjusted in real time to prevent lateral bending of the plate. The rolled plates undergo a leveling process to ensure flatness and eliminate the impact of bending on subsequent shearing. Next, a strip shearing process is performed using a hydraulic shearing machine. The shearing gap is adjusted to 0.4–0.6mm, and the baffle spacing is set to approximately 8mm. The rolled edges and layers on both sides of the plate are removed. Trial shearing and fine-tuning ensure that each strip weighs approximately 650g. After the cut strips are weighed and confirmed by welding personnel, the edges are trimmed using argon arc welding to remove burrs generated during shearing.

[0114] In the drawing preparation stage, the strip is first tapered to approximately 50mm at one end using a tapering mill. The drawing process is performed using an offline drawing machine. An initial die is selected based on the shearing dimensions, and drawing passes are progressively thinner with a 0.4mm interval. When the material cannot pass through the drawing die due to work hardening or other reasons, the tapering mill is used again to tape the front end to an even finer specification. During this process, due to the lack of an online annealing system, internal stress accumulates as deformation increases, resulting in significant work hardening. After drawing to the finished size, inspection is performed. The outer diameter of the first five bars is measured to ensure a tolerance of 3.0±0.03mm. If the tolerance is exceeded, it is corrected by adjusting the clamp tightness. The qualified bars are then sheared to a fixed length of approximately 470mm using a shearing machine. Finally, offline heat treatment is performed. The sheared finished bars are placed in an annealing furnace, and an annealing temperature of 1150℃ is set based on a 5% rhodium content. After holding at this temperature for 30 minutes, they are removed and allowed to cool naturally.

[0115] Performance testing revealed that the PtRh5 wire had a room temperature Vickers hardness of 115 HV, a tensile strength of 356 MPa, and an elongation of approximately 22%. Microscopic observation showed that the material had a grain size of approximately 23 μm, a uniform structure, and no obvious segregation defects.

[0116] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Various modifications or equivalent substitutions made by those skilled in the art to the present invention within its spirit and scope of protection also fall within the scope of protection of the present invention.

Claims

1. A short-process production line for manufacturing platinum and platinum-based alloy rods or wires, characterized in that, include: A vacuum induction melting furnace is used to melt prepared materials into an alloy melt in a vacuum environment. The intermediate batch includes a composite crucible, the bottom of which has a tapered nozzle that is wider at the top and narrower at the bottom. The intermediate batch also includes a liquid level sensor for real-time monitoring of the liquid level inside the crystallizer. A continuous casting apparatus includes a crystallizer. The inlet of the crystallizer is provided with a funnel-shaped receiving cavity that is larger at the top and smaller at the bottom, coaxial with the conical guide nozzle. A flexible sealing ring is provided between the funnel-shaped receiving cavity and the conical guide nozzle to form a semi-closed protective cavity. The continuous casting apparatus also includes a liquid level sensor for real-time monitoring of the liquid level in the crystallizer. The alloy melt is formed into a billet through the continuous casting apparatus. A continuous rolling apparatus includes a roughing mill and a finishing mill that receives the billets from the roughing mill. A first induction heating coil is provided on the path of the billet from the roughing mill to the finishing mill, and a second induction heating coil, a thermometer for real-time detection of the billet temperature, and an air-cooling mechanism are sequentially provided on the path of the billet exiting the finishing mill. The guide input device guides the billet output from the continuous casting device into the roughing mill of the continuous rolling device; A continuous drawing device is located downstream of and adjacent to the continuous rolling device. The continuous drawing device includes a first-pass drawing die for receiving the bar billet from the finishing mill and a second-pass drawing die for receiving the drawn billet from the first-pass drawing die. An intermediate induction heating device and a drawing air cooling mechanism are sequentially arranged along the path of the bar from the first-pass drawing die to the second-pass drawing die. The continuous drawing device also includes a winding device for receiving the bar or wire from the second-pass drawing die. The central PLC control system receives data from the liquid level sensor and adjusts the tilting speed of the vacuum induction melting furnace according to the data, so that the liquid level fluctuation in the composite crucible is kept within a set range. The central PLC control system receives the measured temperature data from the thermometer and synchronously feeds it back to the heating power supply of the second induction heating coil, and dynamically adjusts the output power of the second induction heating coil to control the temperature fluctuation range of the billet within a set range. The central PLC control system sets the reduction rate and controls the conveying speed of the first and second stretching dies according to the set reduction rate.

2. The assembly line according to claim 1, characterized in that, The guiding and conveying device includes multiple guide wheels for guiding the billet output from the crystallizer. At least one guide wheel is driven to rotate by a motor equipped with an encoder. The motor is connected to the central PLC control system, and the rotation speed is adjusted under the control of the central PLC control system.

3. The assembly line according to claim 1, characterized in that, The composite crucible includes an outer crucible, an inner crucible, and a graphite ring located between the outer and inner crucibles.

4. The assembly line according to claim 1, characterized in that, The crystallizer is equipped with a water-cooling jacket on its outer wall.

5. The assembly line according to claim 1, characterized in that, The outlet of the crystallizer is equipped with a continuous casting air cooling mechanism.

6. The assembly line according to claim 1, characterized in that, The continuous casting apparatus also includes a vibrator for driving the crystallizer to vibrate.

7. The assembly line according to claim 1, characterized in that, The thermometer is a dual-color infrared thermometer.

8. The assembly line according to claim 1, characterized in that, The frequency of the first induction heating coil is 10kHz-20kHz, and the frequency of the second induction heating coil is 50kHz-100kHz.

9. A short-process preparation method for platinum and platinum-based alloy rods or wires, characterized in that, The preparation of platinum and platinum-based alloy rods or wires using the production line according to any one of claims 1-9 includes the following steps: S1. Alloy composition design and batching: Weigh platinum and alloying element raw materials according to the proportions; S2. Vacuum induction refining: The weighed raw materials are placed in a vacuum induction melting furnace and melted under vacuum or protective atmosphere; S3. Tundish preheating and flow stabilization: Turn on the induction heating of the tundish, and after preheating, transfer the melt into the tundish. Monitor the liquid level in the tundish in real time and control the change in liquid level within the set range. S4. Continuous casting: The molten material continuously enters the crystallizer from the tundish in a laminar flow state and solidifies into a cast billet; S5. Continuous rolling: The bar billets output from the crystallizer are guided into the roughing mill for roughing and then into the finishing mill for finishing. The bar billets are heated to above the recrystallization temperature for the first time during the process of entering the finishing mill from the roughing mill. They are heated a second time when they are output from the finishing mill. The temperature of the bar billets after the second heating is controlled within the set range. S6. Continuous drawing and collection of finished products: The finishing mill conveys the finished billet to the first drawing die for the first drawing. The first drawing die conveys the drawn billet after the first drawing to the second drawing die for the second drawing. During the process of the drawn billet being conveyed from the first drawing die to the second drawing die, it is heated and cooled in sequence. The second drawing die conveys the bar or wire formed after the second drawing to the winding machine for collection. In steps S5 and S6, the rotational speed compensation of each level of conveyor wheel is calculated, and the rotational speed of each level of conveyor wheel is controlled to prevent the wire from piling up between devices or being overstretched.

10. The preparation method according to claim 9, characterized in that, In step S1, a strengthening element or a strengthening agent is added. The strengthening element is selected from one or more of zirconium, hafnium, scandium, yttrium, lanthanum, cerium, and erbium. The strengthening agent is selected from one or more of boron, calcium boride, titanium boride, and zirconium boride.

11. The preparation method according to claim 9, characterized in that, In step S3, the rate of change of the liquid level is controlled to be less than 2 mm / s.

12. The preparation method according to claim 9, characterized in that, In step S5, the temperature fluctuation range of the billet is controlled to be within ±5℃ of the set value.

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