A rapidly solidified nickel-based alloy wire and a process for making the same

Abstract

This invention relates to the field of nickel-based alloy wire technology, specifically disclosing a rapidly solidified nickel-based alloy wire and its preparation process. The process includes: preparing a grain boundary pinning agent preform containing hafnium hydride powder, and generating hafnium diboride nanoclusters in situ through controlled reaction sintering; melting and refining a nickel-based master alloy, adding the grain boundary pinning agent after cooling, and dispersing and suspending the nanoclusters in the melt under ultrasonic-assisted electromagnetic stirring; spraying the melt onto the surface of a high-speed rotating cooling roller for rapid solidification to form a wire; and performing online heat setting on the wire. The wire obtained by this invention exhibits excellent dimensional stability and elastic modulus thermal cycling stability under medium-temperature conditions due to the effective pinning of grain boundaries by nanoparticles.

Description

Technical Field

[0001] This invention belongs to the field of nickel-based alloy wire technology, specifically relating to a rapidly solidified nickel-based alloy wire and its preparation process. Background Technology

[0002] Rapidly solidified nickel-based alloys utilize extremely high cooling rates to force a large amount of strengthening elements into the nickel matrix, forming a highly supersaturated solid solution. This material, after being drawn into wires, possesses an extremely fine grain structure and high strain hardening capacity, making it a crucial material for manufacturing precision force-measuring springs for aero-engine systems, core components of high-temperature pressure sensors, and high-performance compensating wires. These precision components are typically installed near the final stage of aero-engine compressors or the electronics compartment of deep-well drilling instruments, operating for extended periods within a temperature range of 300°C to 500°C.

[0003] Within this specific mid-temperature service range, the metastable characteristics imparted by rapid solidification processes to materials exhibit significant microstructural instability. Due to the accumulation of substantial residual stress and lattice distortion energy within rapidly solidified wires, when the ambient temperature rises above 300°C, the solute atoms forced into solidification within the lattice acquire a certain diffusion kinetic energy. These atoms begin to migrate short-range and microscopically aggregate from the supersaturated matrix towards grain boundaries or dislocations. While this atomic-level rearrangement does not lead to macroscopic fracture, it causes minute changes in the alloy's lattice constant, macroscopically manifesting as spontaneous elongation or shortening of the wire dimensions on the order of a few ten-thousandths.

[0004] This minute dimensional deviation directly causes a drift in the elastic modulus of the precision sensing spring, resulting in zero-point residual and linearity errors when the sensor calculates force. For control valve assemblies with precise clearance fits, this irregular change in wire size can also disrupt the original thermal expansion matching balance, increasing frictional resistance and even causing moving parts to jam. The current common practice is to pre-release energy through long-term high-temperature aging treatment; however, while this method eliminates instability, it causes the originally fine grains to coarsen, significantly diminishing the advantages of high strength and long fatigue life brought about by rapid solidification.

[0005] Furthermore, during thermal cycling, the internal chemical composition uniformity of rapidly solidified wires fluctuates due to the dispersed precipitation of metastable phases. This fluctuation alters the resistivity temperature coefficient of the alloy wire, causing the accuracy of transmitted electrical signals to decrease over time, especially for compensation wires used in signal transmission. Summary of the Invention

[0006] The purpose of this invention is to provide a rapidly solidified nickel-based alloy wire and its preparation process to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, according to one aspect of the present invention, a rapidly solidified nickel-based alloy wire is provided, comprising, by weight percentage:

[0008] Grain boundary pinning agent: 3.0%-5.0%; Chromium: 18.0%-20.0%; Molybdenum: 4.0%-6.0%; Aluminum: 2.0%-3.0%; Titanium: 0.5%-1.0%; Niobium: 1.0%-2.0%; Balance: Nickel and unavoidable impurities;

[0009] The grain boundary pinning agent is a preform containing nanoscale hafnium diboride precursor clusters, and the preparation method of the grain boundary pinning agent includes the following steps:

[0010] P1. Nickel powder, amorphous boron powder, and sponge zirconium fragments are mixed in proportion and placed in a planetary ball mill. High-energy ball milling activation is carried out under inert gas protection to obtain primary mixed powder.

[0011] P2. Add hafnium hydride powder to the primary mixed powder and continue ball milling for 1-2 hours to obtain composite powder;

[0012] P3. The composite powder is heated at 350°C. -450 High-density preforms are produced by cold pressing under pressure to form high-density preforms.

[0013] P4. Place the precast block in a vacuum with a degree higher than... The process involves segmented reaction sintering under the following conditions: First, the hafnium hydride powder is held at 580℃-620℃ for 2-3 hours to induce in-situ decomposition and release of active hafnium atoms. Then, the temperature is raised to 1000℃-1100℃ and held for 3-5 hours to allow the active hafnium atoms to combine in-situ with the amorphous boron powder to generate nanoscale hafnium diboride precursor clusters.

[0014] In this invention, the grain boundary pinning agent refers to a composite intermediate material in which a nickel-based powder is used as a carrier and a nano-scale hafnium diboride precursor cluster is generated inside it through in-situ reaction sintering. The nano-scale hafnium diboride precursor cluster is the effective functional component for achieving grain boundary pinning.

[0015] Preferably, the raw material composition of the grain boundary pinning agent includes, by weight percentage: nickel powder: 80%-85%; amorphous boron powder: 2%-3%; sponge zirconium: 10%-12%; hafnium hydride: 3%-5%.

[0016] Preferably, the raw material composition of the grain boundary pinning agent further includes antimony powder, the amount of antimony powder added is 0.1%–0.2%, and the antimony powder is activated by high-energy ball milling together with nickel powder, amorphous boron powder and sponge zirconium fragments in step P1.

[0017] Preferably, the microstructure of the filament contains nanoscale hafnium diboride precursor clusters dispersed at the grain boundaries of the nickel matrix, and the average particle size of the nanoscale hafnium diboride precursor clusters is less than 100 nm.

[0018] Preferably, the nickel powder has a particle size of 45μm-75μm, and the hafnium hydride powder has the following molecular formula: .

[0019] According to another aspect of the present invention, a process for preparing rapidly solidified nickel-based alloy wire is provided, comprising the following steps:

[0020] S1. Place the raw materials, except for the grain boundary pinning agent, into a vacuum induction melting furnace and melt and refine them at 1500℃-1580℃;

[0021] S2. Adjust the melt temperature to 1420℃-1460℃, add the grain boundary pinning agent, and start ultrasonic-assisted electromagnetic stirring to suspend the nanoscale hafnium diboride precursor cluster in the melt;

[0022] S3. The melt is sprayed onto the surface of a high-speed rotating cooling roller for rapid solidification, forming a filament;

[0023] S4. The wire material undergoes heat setting treatment via an online infrared heating tunnel.

[0024] Preferably, the ultrasonic power of the ultrasonic-assisted electromagnetic stirring in step S2 is 800W-1200W, and the electromagnetic stirring frequency is 15Hz-25Hz.

[0025] Preferably, the linear velocity of the high-speed rotating cooling roller in step S3 is 30m / s-35m / s, and the cooling rate for rapid solidification is... .

[0026] Preferably, the outlet temperature of the online infrared heating tunnel in step S4 is controlled at 480℃-520℃, and the residence time of the wire in the tunnel is 1.5s-2.5s.

[0027] Preferably, the cooling roller is a water-cooled copper roller, and the interior of the online infrared heating tunnel is filled with an argon or nitrogen protective atmosphere.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] (1) By mixing and sintering nickel powder, boron powder, zirconium powder and hafnium hydride powder, highly active hafnium atoms are generated by the in-situ decomposition of hafnium hydride during the sintering process. These atoms then react with boron to generate a large number of hafnium diboride precursor clusters with a diameter of less than 100 nanometers in the nickel-based carrier, thus obtaining a highly efficient grain boundary pinning agent. After the pinning agent is added to the alloy melt and rapidly solidified into wire, these high-melting-point nanoclusters are precisely embedded at the grain boundaries of the wire, as if a large number of "nanoanchors" are driven into the atomic layers, locking the migration channels of atoms. This microscopic locking mechanism prevents spontaneous microscopic rearrangement of the internal atoms when the wire is used for a long time in a medium-temperature environment of 300℃ to 500℃, thereby controlling the macroscopic dimensional change rate of the wire to within 0.005%. When made into pressure sensor elements for aircraft engines or deep well drilling instruments, the sensor can maintain a stable zero-point output for a long time, solving the signal deviation problem caused by the minute dimensional drift of materials in precision measuring instruments.

[0030] (2) A trace amount of antimony powder was introduced for surface modification during the preparation of the grain boundary pinning agent. Combined with ultrasonic-assisted electromagnetic stirring during melting, the hafnium diboride nanoclusters can remain in a suspended state without melting or agglomeration in the high-temperature melt above 1500℃, and act as heterogeneous nuclei during instantaneous solidification. This distribution characteristic effectively suppresses the grain coarsening tendency of the filament in subsequent online heat treatment and actual working temperature range, and fully preserves the ultrafine grain strengthening effect brought about by the rapid solidification process. The filament obtained in this way has extremely high modulus stability. After undergoing more than 100,000 high-temperature thermal cycles, its elastic modulus decay rate is less than 0.2%. After being processed into a precision compensation spring for high-end gas turbines, the supporting force of the spring can be maintained constant for a long time, avoiding the opening and closing failure or structural jamming of key mechanical components due to material elastic failure, and significantly improving the service reliability of the power system under complex working conditions. Attached Figure Description

[0031] Figure 1 This is a transmission electron microscope (TEM) image of the filament material prepared in Embodiment 1 of the present invention;

[0032] Figure 2 This is a transmission electron microscope (TEM) image of the wire material prepared in Comparative Example 3 of this invention;

[0033] Figure 3 This is a transmission electron microscope (TEM) image of the wire material prepared in Comparative Example 4 of this invention. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are preferred embodiments of the present invention and should not be considered as excluding other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] In the claims and description of this invention, the terms "comprising," "having," and variations thereof are used to mean "including but not limited to."

[0036] The performance advantages of the wire material of this invention stem from its special component ratio and precisely controlled microstructure. The addition of elements such as chromium, molybdenum, and niobium to the matrix aims to construct a nickel matrix with high oxidation resistance and strong solid solution strengthening effect. Among them, chromium can form a continuous and dense oxide protective film at high temperature; molybdenum and niobium, as elements with large atomic radii, generate an elastic strain field by compressing the crystal lattice, effectively hindering dislocation movement.

[0037] The key to this technology lies in the introduction of a grain boundary pinning agent and its in-situ reaction process. In this invention, the "grain boundary pinning agent" refers to a composite intermediate material using nickel-based powder as a carrier, through which nanoscale hafnium diboride precursor clusters are generated in-situ via sintering. These nanoscale hafnium diboride precursor clusters are the effective functional component of the grain boundary pinning agent, dispersing at the grain boundaries of the nickel-based alloy during subsequent alloy melting and rapid solidification, thereby achieving grain boundary pinning. The preparation of this pinning agent begins with the mechanical activation of nickel powder, amorphous boron powder, sponge zirconium fragments, and trace amounts of antimony powder through high-energy ball milling. This process not only achieves mixing of components at the micron or even nanometer scale but also accumulates a large amount of deformation energy within the powder through intense impact, providing a kinetic basis for subsequent chemical reactions. The subsequent addition of hafnium hydride powder for short-time ball milling ensures uniform distribution of the hydride while preventing ineffective decomposition during the initial high-temperature activation stage.

[0038] In the subsequent segmented vacuum sintering, temperature control is crucial for the chemical reaction. The first stage maintains a temperature of 580℃-620℃, taking advantage of the thermal instability of hafnium hydride. Within this temperature range, hafnium hydride undergoes in-situ decomposition. This step is extremely valuable: on the one hand, the released hydrogen gas acts as a strong reducing agent, which can remove residual oxygen on the powder surface in situ and improve the purity of the matrix; on the other hand, the hafnium atoms that have just undergone dehydrogenation are in a highly reactive transient state and have a very strong tendency to react.

[0039] When the temperature is further increased to 1000℃-1100℃, these highly reactive hafnium atoms rapidly capture surrounding boron atoms, undergoing an in-situ combination reaction to generate hafnium diboride (Hb). ) nanoclusters. Because they are generated in situ in a solid matrix, these hafnium diboride ( The precursor clusters are limited to a particle size of less than 100 nm. These nanoclusters have extremely high thermal stability and do not easily melt completely even at the high temperatures of thousands of degrees during subsequent melting, but exist in the form of suspended particles.

[0040] During the alloy smelting stage, the melt temperature is precisely adjusted to 1420℃-1460℃ before adding the grain boundary pinning agent. This is to utilize the relatively low melt energy at this temperature to prevent long-range diffusion and dissolution of the nanoclusters. At this time, ultrasonic power of 800W-1200W and electromagnetic stirring are used to physically disperse the agglomerates through the cavitation effect generated by the ultrasound in the melt, ensuring that these "nanopikes" are in a monomeric dispersed state in the liquid nickel.

[0041] The subsequent rapid solidification process is crucial for microstructure shaping. This is achieved using water-cooled copper rollers. The extremely high cooling rate instantly "freezes" the dispersed distribution in the liquid state into the solid filament. In this near-instantaneous solidification process, nanoscale hafnium diboride (… Clusters tend to aggregate at grain boundaries, acting as a physical barrier.

[0042] Finally, the wire undergoes online heat setting in an infrared heating tunnel with an exit temperature of 480℃-520℃. This temperature range matches the wire's future service temperature range (300℃-500℃), aiming to release the macroscopic quenching stress generated by rapid solidification within a controllable time, while guiding the microstructure to undergo final stabilization adjustments. The wire prepared using this process has its internal grain boundaries bounded by high-hardness hafnium diboride (HBD). The nanophase is firmly anchored, and even if atoms acquire thermal activation energy when in service at medium temperatures, they cannot cross the dislocation walls formed by the nanoclusters, thus fundamentally suppressing the microscopic rearrangement and macroscopic size drift of the material.

[0043] Example 1

[0044] This embodiment provides a rapidly solidified nickel-based alloy wire and its preparation process.

[0045] 1. Preparation of grain boundary pinning agents:

[0046] Prepare the following raw materials by weight percentage: 82.4% nickel powder, 2.5% amorphous boron powder, 11.0% sponge zirconium fragments, 4.0% hafnium hydride powder, and 0.1% antimony powder.

[0047] The specific preparation steps are as follows:

[0048] (1) The nickel powder (particle size 50 μm), amorphous boron powder, sponge zirconium fragments and antimony powder in the above proportions were mixed and placed in a planetary ball mill. Under argon protection, the mixture was ball-milled at a speed of 450 r / min for 10 h to obtain a primary mixed powder with uniform structure and high active surface area.

[0049] (2) Add the measured amount of hafnium hydride powder to the ball mill jar and continue ball milling for 1.5 hours to make the hafnium hydride particles uniformly embedded in the surface of the primary mixed powder to obtain composite powder.

[0050] (3) The composite powder is placed in a steel mold and cold-pressed under a pressure of 400MPa to form a high-density cylindrical preform with a diameter of 30mm.

[0051] (4) Place the precast blocks in a vacuum environment. Segmented reaction sintering is carried out in a vacuum sintering furnace:

[0052] First stage: Increase the temperature to 600℃ at a rate of 8℃ / min, hold for 2.5h, and induce in-situ decomposition of hafnium hydride: The released hydrogen gas is used to clean the particle interface;

[0053] Second stage: Continue heating to 1050℃ and hold for 4 hours. At this time, the active hafnium atoms fully combine with the amorphous boron powder to generate hafnium diboride precursor clusters with an average particle size of about 60 nm in situ within the nickel matrix.

[0054] 2. Preparation of the final alloy wire:

[0055] Prepare the following raw materials by weight percentage:

[0056] The grain boundary pinning agent prepared above contains 4.0% chromium, 19.0% molybdenum, 5.0% aluminum, 2.5% titanium, 1.5% niobium, and the balance is nickel.

[0057] The specific preparation process is as follows:

[0058] (1) Master alloy melting: Nickel, chromium, molybdenum, aluminum, titanium and niobium raw materials, excluding grain boundary pinning agents, are placed in a vacuum induction melting furnace. The temperature is raised to 1550℃ for melting, and refined for 20 minutes to remove gases and low melting point impurities.

[0059] (2) Addition of grain boundary pinning agent: Adjust the melt temperature to 1440℃ and add the previously prepared bulk grain boundary pinning agent. At the same time, start ultrasonic-assisted electromagnetic stirring, setting the ultrasonic power to 1000W and the electromagnetic stirring frequency to 20Hz. Stir for 5 minutes to ensure that the hafnium diboride precursor cluster is uniformly suspended in the melt in a partially molten state.

[0060] (3) Melt drawing: The molten metal is propelled through a nozzle onto the edge of a high-speed rotating water-cooled copper roller using pressure. The linear velocity of the water-cooled copper roller is set to 32 m / s, causing the molten metal to move at approximately... The rapid cooling rate causes solidification, forming microfilaments with a diameter of approximately 60 μm.

[0061] (4) Online processing: After the microfilaments fly out of the cooling rollers, they directly enter the online infrared heating tunnel filled with argon gas protection. The tunnel power is adjusted to stabilize the microfilament outlet temperature at 500℃, and the residence time of the microfilaments in the tunnel is 2.0s, completing the heat setting process.

[0062] Example 2

[0063] This embodiment provides a rapidly solidified nickel-based alloy wire and its preparation process.

[0064] 1. Preparation of grain boundary pinning agents:

[0065] Prepare the following raw materials by weight percentage: 85.0% nickel powder, 2.0% amorphous boron powder, 10.0% sponge zirconium fragments, and 3.0% hafnium hydride powder.

[0066] The specific preparation steps are as follows:

[0067] (1) The nickel powder, amorphous boron powder and sponge zirconium fragments in the above proportions were mixed and placed in a planetary ball mill. Under argon protection, high-energy ball milling was carried out at a speed of 400 r / min for 12 h.

[0068] (2) Add the measured amount of hafnium hydride powder to the ball mill jar and continue ball milling for 1.0 h.

[0069] (3) The composite powder is placed in a steel mold and cold-pressed under a pressure of 350MPa to form a preform.

[0070] (4) Place the precast blocks in a vacuum environment. Segmented reaction sintering is carried out in a vacuum sintering furnace:

[0071] First stage: Increase the temperature to 580℃ at a rate of 5℃ / min and hold for 3.0h;

[0072] Second stage: Continue heating to 1000℃ and hold for 5.0h. At this lower sintering temperature, hafnium diboride nanoclusters grow more slowly, which is beneficial for maintaining a finer initial particle size.

[0073] 2. Preparation of the final alloy wire:

[0074] Prepare the following raw materials by weight percentage: 3.0% of the grain boundary pinning agent prepared above, 18.0% of chromium, 4.0% of molybdenum, 2.0% of aluminum, 0.5% of titanium, 1.0% of niobium, with the balance being nickel.

[0075] The specific preparation process is as follows:

[0076] (1) Master alloy melting: Place the raw materials, except for the grain boundary pinning agent, into a vacuum induction melting furnace. Heat to 1500℃ for melting and refine for 30 minutes.

[0077] (2) Addition of grain boundary pinning agent: Adjust the melt temperature to 1420℃ and add the previously prepared bulk grain boundary pinning agent. At the same time, start ultrasonic-assisted electromagnetic stirring, setting the ultrasonic power to 800W and the electromagnetic stirring frequency to 15Hz. Stir for 8 minutes.

[0078] (3) Melt drawing: Molten metal is injected under pressure onto the edge of a high-speed rotating water-cooled copper roller. The linear velocity of the water-cooled copper roller is set to 30 m / s, causing the melt to move at approximately... The cooling rate causes rapid solidification.

[0079] (4) Online processing: The steps are exactly the same as in Example 1, except that the tunnel power is adjusted to stabilize the microfilament outlet temperature at 480°C and the residence time of the microfilament in the tunnel is 2.5s.

[0080] Example 3

[0081] This embodiment provides a rapidly solidified nickel-based alloy wire and its preparation process.

[0082] 1. Preparation of grain boundary pinning agents:

[0083] Prepare the following raw materials by weight percentage: 80.0% nickel powder, 2.8% amorphous boron powder, 12.0% sponge zirconium fragments, 5.0% hafnium hydride powder, and 0.2% antimony powder.

[0084] The specific preparation steps are as follows:

[0085] (1) Mix the powders in the above proportions and place them in a planetary ball mill. Under argon protection, perform high-energy ball milling at a speed of 500 r / min for 8 hours.

[0086] (2) The steps are exactly the same as in Example 1.

[0087] (3) The composite powder was cold-pressed under a pressure of 450 MPa.

[0088] (4) Place the precast blocks in a vacuum environment with a vacuum level higher than 100°C. In a vacuum sintering furnace:

[0089] Phase 1: Heat to 620℃ and hold for 2.0 hours;

[0090] Second stage: Heat to 1100℃ and keep warm for 3.0 hours.

[0091] 2. Preparation of the final alloy wire:

[0092] Prepare the following raw materials by weight percentage: 5.0% of the grain boundary pinning agent prepared above, 20.0% of chromium, 6.0% of molybdenum, 3.0% of aluminum, 1.0% of titanium, 2.0% of niobium, with the balance being nickel.

[0093] The specific preparation process is as follows:

[0094] (1) Master alloy smelting: Heat to 1580℃ for melting and refining.

[0095] (2) Addition of grain boundary pinning agent: Adjust the melt temperature to 1460℃ and add the grain boundary pinning agent. Start the ultrasonic-assisted electromagnetic stirring with a power of 1200W and a frequency of 25Hz. Stir for 3 minutes.

[0096] (3) Melt drawing: The linear speed of the water-cooled copper roller is 35 m / s, and the cooling rate reaches approximately... .

[0097] (4) Online processing: The outlet temperature is stabilized at 520℃ and the residence time is 1.5s.

[0098] Example 4

[0099] This embodiment provides a rapidly solidified nickel-based alloy wire and its preparation process.

[0100] 1. Preparation of grain boundary pinning agents:

[0101] By weight percentage: nickel powder 83.5%, amorphous boron powder 3.0%, sponge zirconium fragments 10.3%, hafnium hydride powder 3.0%, antimony powder 0.2%.

[0102] (1) The steps are exactly the same as in Example 1.

[0103] (2) The steps are exactly the same as in Example 1.

[0104] (3) The steps are exactly the same as in Example 1.

[0105] (4) The steps are exactly the same as in Example 1.

[0106] 2. Preparation of the final alloy wire:

[0107] By weight percentage: 4.5% grain boundary pinning agent, 18.5% chromium, 5.5% molybdenum, 2.2% aluminum, 0.9% titanium, 1.8% niobium, with the balance being nickel.

[0108] (1) The steps are exactly the same as in Example 1.

[0109] (2) The steps are exactly the same as in Example 1.

[0110] (3) The steps are exactly the same as in Example 1.

[0111] (4) The steps are exactly the same as in Example 1.

[0112] Comparative Example 1

[0113] This comparative example provides a nickel-based alloy wire and its preparation process as a control group.

[0114] 1. Preparation of grain boundary pinning agent: None.

[0115] 2. Preparation of the final alloy wire:

[0116] By weight percentage: chromium 19.0%, molybdenum 5.0%, aluminum 2.5%, titanium 0.8%, niobium 1.5%, balance nickel.

[0117] (1) Master alloy smelting: The steps are exactly the same as in Example 1.

[0118] (2) Addition step: Do not add grain boundary pinning agent. Proceed directly to the next step.

[0119] (3) Melt drawing: The steps are exactly the same as in Example 1.

[0120] (4) Online processing: The steps are exactly the same as in Example 1.

[0121] Comparative Example 2

[0122] This comparative example provides a nickel-based alloy wire and its preparation process as a control group.

[0123] 1. Preparation of grain boundary pinning agent: None.

[0124] 2. Preparation of the final alloy wire:

[0125] The raw material composition is exactly the same as that in Example 1 by weight percentage.

[0126] The preparation process steps are as follows:

[0127] (1) Master alloy smelting: The steps are exactly the same as in Example 1.

[0128] (2) Component addition: Adjust the melt temperature to 1440℃, and directly add nickel powder, amorphous boron powder, sponge zirconium fragments, metallic hafnium powder (without using hafnium hydride) and antimony powder to the melt. The total amount of each component added is equal to the total amount of each component contained in the grain boundary pinning agent in Example 1. After addition, turn on ultrasonic-assisted electromagnetic stirring, with parameters exactly the same as in Example 1.

[0129] (3) Melt drawing: The steps are exactly the same as in Example 1.

[0130] (4) Online processing: The steps are exactly the same as in Example 1.

[0131] Comparative Example 3

[0132] This comparative example provides a nickel-based alloy wire and its preparation process as a control group.

[0133] 1. Preparation of grain boundary pinning agents:

[0134] Prepare the following raw materials by weight percentage: 82.4% nickel powder, 2.5% amorphous boron powder, 11.0% sponge zirconium fragments, 4.0% metallic hafnium powder, and 0.1% antimony powder.

[0135] The preparation steps are as follows:

[0136] (1) High-energy ball milling activation: The steps are exactly the same as in Example 1.

[0137] (2) Addition of ingredients: Add metal hafnium powder to the primary mixed powder and continue ball milling for 1.5 hours.

[0138] (3) Cold pressing: The steps are exactly the same as in Example 1.

[0139] (4) Segmented vacuum sintering: The steps are exactly the same as in Example 1.

[0140] 2. Preparation of the final alloy wire:

[0141] The intermediate alloy containing hafnium metal prepared above was used as an additive, and the proportions of the remaining components and the preparation process steps (1) to (4) were exactly the same as in Example 1.

[0142] Comparative Example 4

[0143] This comparative example provides a nickel-based alloy wire and its preparation process as a control group.

[0144] 1. Preparation of grain boundary pinning agent: The steps are exactly the same as in Example 1.

[0145] 2. Preparation of the final alloy wire: The raw material composition is exactly the same as in Example 1.

[0146] The preparation process steps are as follows:

[0147] (1) Master alloy smelting: The steps are exactly the same as in Example 1.

[0148] (2) Addition of grain boundary pinning agent: Adjust the melt temperature to 1440℃ and add the same grain boundary pinning agent as in Example 1. Do not turn on ultrasonic-assisted stirring, use only conventional electromagnetic stirring at a frequency of 20Hz, and extend the stirring time to 15min to compensate for the dispersion effect as much as possible.

[0149] (3) Melt drawing: The steps are exactly the same as in Example 1.

[0150] (4) Online processing: The steps are exactly the same as in Example 1.

[0151] To verify the effectiveness of this invention, the preparation and testing methods of the test samples are as follows: Rapidly solidified nickel-based alloy wires prepared in Examples 1, 2, 3, and 4, as well as Comparative Examples 1, 2, 3, and 4, were selected, and 500mm length segments were cut as standard samples. Based on the corresponding preparation processes for each scheme, it was ensured that all samples were in the same heat-setting state. The test samples corresponding to each process scheme were sequentially labeled as S-NSW001 to S-NSW008 (where S-NSW001-004 correspond to Examples 1 to 4, and S-NSW005-008 correspond to Comparative Examples 1 to 4). Subsequently, the following performance tests were performed on all grouped samples.

[0152] All performance tests of this invention were conducted in accordance with the relevant Chinese national standards (GB / T), the specific standards of which are as follows:

[0153] 1. Mid-temperature dimensional stability test

[0154] This test was conducted in accordance with the relevant technical requirements of GB / T2039 "Metallic Materials - Uniaxial Tensile Creep Test Method" and GB / T4339 "Metallic Materials - Determination of Thermal Expansion Characteristic Parameters". The wire sample was placed in a vacuum constant temperature environment at 450°C for 1000 hours. The length change before and after the holding time was measured and recorded using a high-precision laser interferometer. The quantitative index is the dimensional change rate (i.e., the ratio of the length change to the original length). The smaller the value of this index, the less microscopic migration of atoms at the grain boundaries occurs after thermal excitation, and the more balanced the microstructure is. In practical applications, an extremely low dimensional change rate ensures that precision pressure sensors or dislocation components made from this wire do not experience zero-point drift under long-term high-temperature service conditions, thus guaranteeing the authenticity and reliability of the measurement data. This is a core indicator for determining whether a material can be used in precision measuring instruments.

[0155] 2. Elastic modulus thermal cycling stability test

[0156] This test was conducted in accordance with GB / T22315 "Test Method for Elastic Modulus and Poisson's Ratio of Metallic Materials". The wire samples were subjected to 100,000 rapid high-frequency thermal cycling tests between 25℃ and 500℃. The elastic modulus values ​​before and after cycling were measured using a dynamic thermodynamic analyzer, and the quantitative index is the elastic modulus decay rate. The smaller this index value, the stronger the crystal lattice stability of the material under repeated thermal shock and the stronger the resilience of the reinforcing phase. In practical applications, a low decay rate ensures that the output pressure or supporting force of precision compensating springs or elastic elements made from this wire remains constant under long-term and frequent temperature changes, preventing mechanical structure malfunctions or system failures due to material elasticity failure.

[0157] 3. Microstructure observation and phase analysis

[0158] This test was conducted in accordance with GB / T13298 "Methods for Examination of Metallic Microstructures" and GB / T18907 "Microbeam Analysis, Electron Microscopy, Transmission Electron Microscopy, Selected Area Electron Diffraction Analysis". Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) were used to sample and observe the transverse and longitudinal sections of the wire. The quantitative indicators were the average particle size and distribution uniformity of the nanoclusters. The finer the particle size (typically less than 100 nm) and the more uniformly distributed at the grain boundaries, the more successfully the hafnium diboride particles generated through the "in-situ decomposition-combination" process acted as a physical barrier. This indicator directly confirms the degree of microscopic realization of the grain boundary pinning mechanism, which is the material basis for determining whether the wire can lock dislocations at the atomic level, inhibit grain coarsening, and thus obtain extraordinary thermal stability.

[0159] 4. High-temperature creep performance test

[0160] This test was conducted in accordance with GB / T2039 "Metallic Materials - Uniaxial Tensile Creep Test Method". Under a constant temperature of 500°C, a constant tensile stress was applied to the wire specimen, and the deformation curve of the sample over time was continuously recorded. The quantitative index of this deformation is the steady-state creep rate. The lower the rate, the greater the resistance to grain boundary slip and diffusion creep under the combined effects of high temperature and stress, and the more significant the anchoring effect of the pinning relative to the grain boundaries. For fastening and supporting components in aero-engines or high-temperature power systems, an extremely low steady-state creep rate means that the parts can maintain their geometry for a long time under thermal loads without permanent plastic elongation, making it a key performance parameter for evaluating the service life and structural reliability of materials.

[0161] The performance of the test samples obtained from the above embodiments and comparative examples was tested, and the results are summarized in the table below:

[0162]

[0163] 1. Mid-temperature dimensional stability test

[0164] The data results show that the dimensional change rates of Examples 1 to 4 after storage at 450°C for 1000 hours were all extremely low. Example 3, with the highest content of grain boundary pinning agent, exhibited the strongest structural stability with a dimensional change rate of only 0.0035%. Although Example 2, with its lower pinning agent content, saw a slight increase in the change rate to 0.0068%, it was still an order of magnitude lower than the 0.085% change rate of Comparative Example 1. The comparison reveals that Comparative Example 1, without pinning agent, experienced severe atomic diffusion upon heating, leading to a significant irreversible drift in the filament length. Even in Comparative Examples 2, 3, and 4, which employed different addition processes, although the change rates were improved compared to Comparative Example 1, they remained above 0.028%. This indicates that without the in-situ generation of extremely fine nanoclusters as in the examples, it is impossible to completely block atomic migration paths at the atomic level.

[0165] 2. Elastic modulus thermal cycling stability test

[0166] After undergoing 100,000 frequent high-temperature thermal cycles, the modulus decay rates of Example 3 and Example 1 were only 0.11% and 0.15%, respectively, and even Example 2, with a slightly lower content, maintained a rate of 0.21%, indicating that the elastic properties of the materials in these examples were very stable. However, the decay rate of Comparative Example 1 reached 2.45%, indicating that the internal structure of the ordinary alloy had loosened after repeated heating. Although Comparative Example 3 used hafnium powder to attempt reinforcement, reducing the decay rate to 0.85%, the effect was still not as good as the 0.17% of Example 4. This data comparison proves that the nanophases generated by the decomposition of hafnium hydride in these examples have extremely high thermal stability, and they tightly support the metal lattice. If powder is added directly as in Comparative Example 2, or if less reactive hafnium is used as in Comparative Example 3, the reinforcing phase will fail during thermal cycling, resulting in a weakening of the material's supporting strength.

[0167] 3. Microstructure observation and phase analysis

[0168] Combined with appendix Figure 1 As can be seen, the diameter of the hafnium diboride particles in Examples 1 to 4 is effectively compressed to between 58 nm and 65 nm. Clearly visible in the images, these tiny nanoparticles are uniformly embedded along the grain boundaries like nails, ensuring that the grain boundaries remain straight even at high temperatures, without bending or migration. This nano-pinning structure is attributed to the use of highly reactive atoms generated from the in-situ decomposition of hafnium hydride in the process, enabling controlled nucleation and growth of the particles.

[0169] In stark contrast is the appendix Figure 2Because this comparative example used less reactive hafnium metal powder instead of hafnium hydride, the incomplete reaction resulted in significantly coarser particle sizes (average particle size of 180 nm, with some large particles exceeding 400 nm shown in the figure). More importantly, [the following text appears to be incomplete and requires further context]. Figure 2 The grain boundary segments between medium-sized particles exhibit a distinct wavy curvature (arc-shaped protrusion), indicating that due to the small number and excessive spacing of coarse particles, the migration of grain boundaries during heating cannot be effectively blocked, resulting in grain boundary leakage. Similarly, Comparative Example 2 also lost the nano-effect because the particles grew to 245 nm.

[0170] Furthermore, the importance of ultrasonic-assisted dispersion technology lies in the appendix. Figure 3 This was confirmed in Comparative Example 4. Although the initial particle size of individual particles in Comparative Example 4 was not very large (average 155 nm) due to the lack of ultrasonic stirring, they exhibited severe agglomeration in the melt. Figure 3 As shown, a large number of particles accumulate into giant grape-like clusters with a diameter exceeding 500 nm, causing severe distortion of the grain boundaries near the clusters. Meanwhile, large areas of grain boundaries outside the clusters become completely unprotected blank areas. This highly uneven distribution makes the material extremely prone to failure when subjected to stress, starting from the weak, unprotected grain boundaries.

[0171] 4. High-temperature creep performance test

[0172] Under tensile load at 500℃, the creep rates of Examples 1, 3, and 4 were 1.82, 1.56, and 1.95, respectively, very close to the 2.05 of the pure alloy matrix in Comparative Example 1, with fluctuations not exceeding 10%. This indicates that the addition of pinning agent did not have a negative impact on the original high-temperature strength of the nickel-based alloy. The creep rate of Example 2 was 2.45, slightly higher than that of the pure alloy, but still within the acceptable normal performance range for this type of material. This slight performance sacrifice resulted in a significant improvement in dimensional stability. However, the creep rates of Comparative Examples 2, 3, and 4 all deteriorated significantly, with values ​​exceeding 5.20. This indicates that if the particle size is too large or unevenly distributed, they not only fail to prevent grain boundary sliding but also form crack initiation points or slip channels at the grain boundaries, causing the material to be rapidly elongated under high-temperature stress.

[0173] The descriptions of the foregoing specification and embodiments are used to explain the scope of protection of the present invention, but do not constitute a limitation on the scope of protection of the present invention. Modifications, equivalent substitutions, or other improvements to the embodiments of the present invention or a portion thereof that can be obtained by those skilled in the art through logical analysis, reasoning, or limited experimentation, based on the teachings of the present invention or the foregoing embodiments, in conjunction with common knowledge, general technical knowledge, and / or existing technology, should all be included within the scope of protection of the present invention.

Claims

1. A rapidly solidifying nickel-based alloy wire, characterized in that, Its components, by weight percentage, include: Grain boundary pinning agent: 3.0%-5.0%; Chromium: 18.0%-20.0%; Molybdenum: 4.0%-6.0%; Aluminum: 2.0%-3.0%; Titanium: 0.5%-1.0%; Niobium: 1.0%-2.0%; Balance: Nickel and unavoidable impurities; The grain boundary pinning agent is a preform containing nanoscale hafnium diboride precursor clusters, and the preparation method of the grain boundary pinning agent includes the following steps: P1. Nickel powder, amorphous boron powder, and sponge zirconium fragments are mixed in proportion and placed in a planetary ball mill. High-energy ball milling activation is carried out under inert gas protection to obtain primary mixed powder. P2. Add hafnium hydride powder to the primary mixed powder and continue ball milling for 1-2 hours to obtain composite powder; P3. The composite powder is cold-pressed under a pressure of 350MPa-450MPa to form a high-density preform; P4. Place the precast block in a vacuum with a degree higher than 10. -3 Segmented reaction sintering is carried out under Pa environment: first, the temperature is held at 580℃-620℃ for 2h-3h to induce the in-situ decomposition of the hafnium hydrogenation powder to release active hafnium atoms, and then the temperature is raised to 1000℃-1100℃ and held for 3h-5h to allow the active hafnium atoms to combine with the amorphous boron powder in situ to generate nano-scale hafnium diboride precursor clusters; The preparation process of the rapidly solidified nickel-based alloy wire includes the following steps: S1. Place the raw materials, except for the grain boundary pinning agent, into a vacuum induction melting furnace and melt and refine them at 1500℃-1580℃; S2. Adjust the melt temperature to 1420℃-1460℃, add the grain boundary pinning agent, and start ultrasonic-assisted electromagnetic stirring to suspend the nanoscale hafnium diboride precursor cluster in the melt; S3. The melt is sprayed onto the surface of a high-speed rotating cooling roller for rapid solidification, forming a filament; S4. The wire material undergoes heat setting treatment via an online infrared heating tunnel.

2. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, The raw materials for preparing the grain boundary pinning agent include, by weight percentage: nickel powder: 80%-85%; amorphous boron powder: 2%-3%; sponge zirconium: 10%-12%; hafnium hydride: 3%-5%.

3. The rapidly solidified nickel-based alloy wire according to claim 2, characterized in that, The grain boundary pinning agent also includes antimony powder in its raw material composition. The amount of antimony powder added is 0.1%–0.2%, and the antimony powder is activated by high-energy ball milling together with nickel powder, amorphous boron powder and sponge zirconium fragments in step P1.

4. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, The microstructure of the filament contains nanoscale hafnium diboride precursor clusters dispersed at the grain boundaries of the nickel matrix, and the average particle size of the nanoscale hafnium diboride precursor clusters is less than 100 nm.

5. The rapidly solidified nickel-based alloy wire according to claim 2, characterized in that, The nickel powder has a particle size of 45μm-75μm, and the hafnium hydride powder has the molecular formula HfH2.

6. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, The ultrasonic power of the ultrasonic-assisted electromagnetic stirring in step S2 is 800W-1200W, and the electromagnetic stirring frequency is 15Hz-25Hz.

7. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, The linear velocity of the high-speed rotating cooling roller in step S3 is 30m / s-35m / s, and the cooling rate for rapid solidification is 10. 5 K / s-10 6 K / s.

8. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, In step S4, the outlet temperature of the online infrared heating tunnel is controlled at 480℃-520℃, and the residence time of the wire in the tunnel is 1.5s-2.5s.

9. The rapidly solidified nickel-based alloy wire according to claim 1, characterized in that, The cooling roller is a water-cooled copper roller, and the interior of the online infrared heating tunnel is filled with an argon or nitrogen protective atmosphere.

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