A precise nickel-based superalloy, preparation process and application thereof

Abstract

The application discloses a kind of precision nickel-based superalloys and preparation process and application, belong to high-precision metal material field.A kind of precision nickel-based superalloy, by weight percentage, including 16.3%~18.5%Cr, 2.5%~3.5%Al, 0.4%~0.8%Ti, 0.4%~0.8%Nb and 0.4%~0.8%Zr, the balance is Ni.On the basis of original nickel-based superalloy component, it can be improved to improve the high-temperature mechanical properties of nickel-based superalloy.The preparation process of the application adopts the combined heat treatment process of homogenization and double-stage superheating treatment and warm processing makes phase (Ni3 (Al, Ti)) and M 23 C6 type carbide precipitates at dislocation, pins dislocation and makes dislocation substructure stable, hinders dislocation movement and makes the high-temperature mechanical properties of nickel-based superalloy improve.Preparation step is easy to operate, suitable for industrial production, and excellent quality nickel-based composite material can be stably prepared.

Description

Technical Field

[0001] This invention belongs to the field of high-precision metal materials, specifically relating to a precision nickel-based high-temperature alloy and its preparation process and application. Background Technology

[0002] Precision nickel-based superalloys are a class of high-performance alloys made with nickel as the base material and by adding elements such as chromium, molybdenum, tungsten, aluminum, and titanium, with strict control over composition and processing. They not only possess the high-temperature resistance and corrosion resistance of traditional nickel-based superalloys, but also achieve excellent comprehensive properties through precise microstructure control. They are widely used in cutting-edge fields requiring high precision and reliability, and are one of the important indicators of a nation's high-end manufacturing capabilities.

[0003] The preparation of precision nickel-based superalloys typically involves steps such as smelting, casting, hot working, and heat treatment. In traditional manufacturing processes, to ensure that precision nickel-based superalloys retain good mechanical properties under extreme environments such as high temperatures, a large amount of alloying elements is often added during the preparation process to achieve solid solution strengthening or precipitation strengthening. However, certain metallic compounds formed, such as the Raglan phase (a lamellar brittle phase), can significantly affect the material properties; furthermore, the first-stage and second-stage aging processes of traditional manufacturing methods cannot meet the performance requirements of parts with complex shapes.

[0004] Patent application CN115029586A discloses a nickel-based single-crystal high-temperature alloy and its preparation method. By optimizing the composition (Cr 3.5%~5.5%, Re 4%~7.5%, etc.) and coordinating heat treatment, the alloy achieves a creep life of over 200 hours at 1140℃ / 150MPa, which is 30% higher than the second generation. However, the high Re and Ru content leads to a surge in cost, and the yield of single-crystal growth is only 60%~70%. Patent application CN117684032A discloses a preparation process for a new type of high-temperature nickel alloy with fine grain size. By integrating multiple technologies such as powder pretreatment, composition control, deformation and precise heat treatment, it solves the problem of coarse grains in traditional alloys. However, it has limitations such as a lengthy process, high dependence on high-end equipment, strict parameter control, and high raw material and energy costs.

[0005] Therefore, this invention addresses the problems existing in the preparation process of precision nickel-based superalloys by providing a precision nickel-based superalloy, its preparation process, and its application. Summary of the Invention

[0006] One of the objectives of this invention is to provide a precision nickel-based superalloy to improve the mechanical strength of nickel-based superalloys and to solve the problem that the strength and electrical conductivity of nickel-based superalloys cannot be simultaneously achieved.

[0007] The second objective of this invention is to provide a process for preparing a precision nickel-based high-temperature alloy, which is used to prepare the aforementioned precision nickel-based high-temperature alloy.

[0008] The third objective of this invention is to provide an application of precision nickel-based superalloys in the fields of aerospace and electronic power.

[0009] The objective of this invention can be achieved through the following technical solutions:

[0010] A precision nickel-based superalloy, comprising, by weight percentage, 16.3%–18.5% Cr, 2.5%–3.5% Al, 0.4%–0.8% Ti, 0.4%–0.8% Nb and 0.4%–0.8% Zr, with the balance being Ni.

[0011] A method for preparing a precision nickel-based superalloy includes the following steps:

[0012] S1: Prepare electrolytic nickel blocks, metallic chromium, aluminum ingots, titanium blocks, niobium blocks, and zirconium blocks according to the specified ratio and perform pretreatment;

[0013] S2: Using vacuum induction melting technology, pretreated raw materials are melted to obtain a molten alloy;

[0014] S3: Using horizontal continuous casting technology, the molten alloy obtained in S2 is introduced into an electromagnetic horizontal continuous casting machine through an inert gas protective channel to produce a precision nickel-based high-temperature alloy round bar ingot.

[0015] S4: The round bar ingot prepared in S3 is homogenized and then hot forged to obtain an alloy billet.

[0016] S5: The alloy billet prepared in step S4 is subjected to a combined thermomechanical treatment process of two-stage overheating and warm working, specifically including first-stage overheating, warm working, second-stage overheating and cold working, to obtain a nickel-based high-temperature alloy foil with high strength.

[0017] Furthermore, in S1, the pretreatment includes: grinding the surfaces of electrolytic nickel blocks, metallic chromium, titanium blocks, niobium blocks, and zirconium blocks to remove oxide scale, and removing the surface oxide film from aluminum ingots; then placing all raw materials in anhydrous ethanol for ultrasonic cleaning for 20-30 minutes, and then drying them in a vacuum drying oven at 115-120℃ to constant weight.

[0018] Furthermore, in step S2, the process parameters for vacuum induction melting are: vacuum degree ≤ 5 × 10⁻⁶. -3 Pa, heating rate 15-20℃ / min, melting temperature 1550-1650℃, holding time 20-30min, electromagnetic stirring is turned on during the melting process, stirring speed 200-300r / min.

[0019] Furthermore, in step S3, the inert gas is argon with a purity ≥ 99.99%; the process parameters for horizontal continuous casting are: crystallizer temperature 1100-1200℃, cooling rate 50-80℃ / min, billet pulling speed 0.5-1.0m / min; the diameter of the resulting round bar ingot is 80-120mm, and the surface roughness is ≤ Ra1.6μm.

[0020] Furthermore, in S4, the process parameters for the homogenization treatment are: temperature 1050-1200℃, holding time 3-5h, and cooling to room temperature in the furnace after treatment; the process parameters for the hot forging billet are: heating temperature 1100-1150℃, holding time 1-2h, forging ratio 4-5, air cooling after forging, to obtain an alloy billet with a thickness of 15-20mm.

[0021] Furthermore, in S5, the temperature of the first-stage overheating treatment is 900-1000℃, the holding time is 50-100h, and the furnace is cooled to room temperature after treatment; the temperature of the second-stage overheating treatment is 750-900℃, the holding time is 4-24h, and the furnace is air-cooled after treatment.

[0022] Furthermore, in S5, the warm working (deformation heat treatment) temperature is 950-1100℃, and four warm rolling passes are performed; wherein the deformation amount of the first warm rolling pass is 15%-20%, the deformation amount of the second warm rolling pass is 25%-30%, the deformation amount of the third warm rolling pass is 10%-15%, and the deformation amount of the fourth warm rolling pass is 20%-25%; after four warm rolling passes, the cumulative deformation amount is 55%-65%.

[0023] The warm rolling deformation is the deformation per pass "relative to the thickness of the previous pass" (rather than relative to the initial billet); the cumulative deformation is relative to the initial billet.

[0024] Furthermore, the cold working temperature is room temperature, the cold working deformation is >90%, and the thickness of the obtained nickel-based high-temperature alloy foil is 0.01-0.1mm, with a thickness tolerance ≤±0.005mm.

[0025] Applications of a precision nickel-based superalloy in aerospace and electronic power fields.

[0026] The beneficial effects of this invention are:

[0027] (1) This invention achieves synergistic strengthening and complementary performance of each element by precisely controlling the weight ratio of Cr, Al, Ti, Nb, Zr and Ni (16.3%~18.5%Cr, 2.5%~3.5%Al, 0.4%~0.8%Ti, 0.4%~0.8%Nb, 0.4%~0.8%Zr, balance Ni). As the core forming element of γ' phase (Ni3Al), Al can be enriched around dislocations after heat treatment and form a pinning effect, which hinders dislocation movement to strengthen the matrix. Ti and Al work together to dissolve in γ' phase to suppress dislocation climb at high temperature and enhance creep resistance. On the other hand, it increases the nucleation rate of γ' phase to achieve grain refinement and uniform dispersion precipitation of γ' phase. Nb can form γ'' phase (Ni3Nb) to provide strong aging strengthening. A small amount of Zr dissolves in γ' phase to further enhance its high-temperature structural stability. The four phases work together with the Ni matrix to form a composite strengthening system of "γ' phase + γ'' phase", which significantly improves the room temperature and high temperature strength of the alloy.

[0028] (2) The Nb used in this invention can segregate at grain boundaries, inhibiting the enrichment of harmful impurities such as sulfur and phosphorus at grain boundaries. At the same time, Zr can purify grain boundaries and inhibit high-temperature brittleness of grain boundaries. The two work together to improve the toughness of grain boundaries and the ability to resist high-temperature cracking. In addition, Zr and Ti work together to refine grains, strengthen the matrix by increasing the number of grain boundaries, and reduce the tendency of cracking during hot working by combining with the property of Nb to reduce the resistance of alloy to hot deformation, thus providing a guarantee for the molding of precision foil and other products. Cr enhances the strength of the matrix through solid solution strengthening, and at the same time forms a dense Cr2O3 oxide film, which enhances the oxidation and corrosion resistance of the alloy in high-temperature environments. The balance Ni serves as the matrix to ensure the good electrical and thermal conductivity of the alloy. Together with the strengthening elements, it achieves a balance of "high strength, creep resistance, corrosion resistance and machinability", which can meet the stringent service requirements of precision nickel-based high-temperature alloys in the fields of electronics, power, aerospace and other fields.

[0029] (3) The horizontal continuous casting technology used in this invention has significant advantages over traditional casting processes in the preparation of nickel-based superalloys. It suppresses excessive crystal growth through rapid cooling, resulting in a fine and uniform ingot grain structure; electromagnetic stirring and directional solidification greatly reduce material composition segregation; and continuous feeding and controllable solidification effectively reduce defects such as porosity and shrinkage, significantly improving alloy density and performance stability. Furthermore, this technology has continuous production capabilities, low energy consumption, high yield, and high automation, significantly improving production efficiency and reducing costs while ensuring material quality.

[0030] (4) The combined thermomechanical treatment process of dual-stage overheating and warm working adopted in this invention achieves a breakthrough improvement in alloy performance through multi-stage synergy. The first-stage overheating coarsens the γ' phase (Ni3(Al,Ti)), weakens its inhibitory effect on high-temperature performance, and significantly improves the hot working plasticity of the alloy, laying the foundation for subsequent processes; the warm working breaks up the coarsened γ' phase and distributes it evenly, while allowing some small-sized γ' phases to dissolve back into the matrix, optimizing the microstructure; the second-stage overheating promotes the re-precipitation of the dissolved γ' phase at dislocation sites, resulting in significant precipitation strengthening, and the deformed structure has high heat resistance due to the pinning of the precipitated phase, achieving work hardening; in addition, the two precipitation processes allow elements such as Al, Ti, Nb, and Zr to be fully precipitated, greatly improving the alloy's electrical conductivity. Through this combined process, the alloy's strength and electrical conductivity are synergistically optimized. Detailed Implementation

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below.

[0032] In some embodiments, a precision nickel-based superalloy comprises, by weight percentage, 16.3%–18.5% Cr, 2.5%–3.5% Al, 0.4%–0.8% Ti, 0.4%–0.8% Nb, and 0.4%–0.8% Zr, with the balance being Ni.

[0033] The composition of nickel-based alloy foil is reasonable: (1) Adding Al to the alloy can form Ni3Al strengthening phase, which can be enriched around the dislocation by appropriate heat treatment process, playing a pinning role on the dislocation, hindering the movement of the dislocation, and thus improving the strength of the material.

[0034] (2) Ti is the main forming element of the γ' phase (Ni3Al / Ti). It works with Al to improve the thermal stability of the γ' phase. On the one hand, Ti can suppress dislocation climb at high temperature and enhance the creep resistance when dissolved in the γ' phase. On the other hand, it increases the nucleation rate, thereby refining the grains and making the γ' phase uniformly dispersed and precipitated.

[0035] (3) Adding Nb to make the γ'' phase (N The formation of Nb provides a significant age-strengthening effect. Nb tends to segregate at grain boundaries, suppressing the harmful effects of impurities such as sulfur and phosphorus, improving grain boundary toughness, and achieving grain boundary strengthening. At the same time, it reduces the alloy's resistance to hot deformation and decreases the tendency for hot working cracks.

[0036] (4) The addition of Zr will cause a small amount of solid solution in the γ' phase, which will enhance its high-temperature stability. In addition, Zr can also refine the grains, purify the grain boundaries and inhibit the high-temperature brittleness of the grain boundaries.

[0037] In some embodiments, a method for preparing a precision nickel-based superalloy includes the following steps:

[0038] S1: Prepare electrolytic nickel blocks, metallic chromium, aluminum ingots, titanium blocks, niobium blocks, and zirconium blocks according to the specified ratio and perform pretreatment;

[0039] S2: Using vacuum induction melting technology, pretreated raw materials are melted to obtain a molten alloy;

[0040] S3: Using horizontal continuous casting technology, the molten alloy obtained in S2 is introduced into an electromagnetic horizontal continuous casting machine through an inert gas protective channel to produce a precision nickel-based high-temperature alloy round bar ingot.

[0041] S4: The round bar ingot prepared in S3 is homogenized and then hot forged to obtain an alloy billet.

[0042] S5: The alloy billet prepared in step S4 is subjected to a combined thermomechanical treatment process of two-stage overheating and warm working, specifically including first-stage overheating, warm working, second-stage overheating and cold working, to obtain a nickel-based high-temperature alloy foil with high strength.

[0043] Horizontal continuous casting technology offers significant advantages over traditional casting processes in the preparation of nickel-based superalloys, particularly in terms of alloy grain structure control, production efficiency, cost reduction, and improved material properties, as detailed below:

[0044] (1) Horizontal continuous casting technology has the advantage of rapid cooling, which can suppress crystal growth and make the ingot grains fine and uniform;

[0045] (2) Horizontal continuous casting technology has the advantages of electromagnetic stirring and directional solidification, which can greatly reduce material composition segregation;

[0046] (3) Horizontal continuous casting technology has the advantages of continuous feeding and controllable solidification, which can reduce the porosity and shrinkage of materials;

[0047] (4) Horizontal continuous casting technology has the advantages of continuous production, low energy consumption, high yield and high automation.

[0048] A combined thermomechanical treatment process, employing a two-stage overheating process and warm working, is used. The process consists of a first-stage overheating treatment, warm working, and a second-stage overheating treatment, as detailed below:

[0049] (1) First-stage overheating treatment: holding at a high temperature of 900-1000℃ for a long time causes the phase (Ni3(Al,Ti)) to coarsen and grow, thereby significantly weakening the role of this alloy phase in improving the high-temperature performance of nickel alloys. Through first-stage overheating treatment, the plasticity of nickel-based alloys for hot working can be significantly improved, thus preparing the alloy for subsequent hot working processes.

[0050] (2) Warm working: The billet after the first-stage heat treatment is deformed at 950-1100℃, which breaks down and evenly distributes the coarsened and grown phase (Ni3(Al,Ti)) in the first-stage heat treatment. At the same time, since the deformation temperature exceeds the solid solution temperature of the phase, some of the smaller phases (Ni3(Al,Ti)) will dissolve back into the parent phase matrix during deformation at 950-1100℃, preparing the microstructure for the subsequent second-stage heat treatment. In addition, in this process, the problem of insufficient plasticity of the material during warm working can be effectively avoided by passing multiple warm rolling passes.

[0051] (3) Secondary overheating treatment: The billet after warm working is held at 750-900℃ for 4-24h, causing the re-dissolved phase (Ni3(Al,Ti)) in the matrix to precipitate again at the dislocations generated during the warm deformation process. The re-precipitation of the precipitated phase gives the alloy a significant precipitation strengthening effect. In addition, since the microstructure of the alloy is a deformed structure generated by warm working, and this deformed structure has extremely high heat resistance due to the in-situ pinning of the precipitated phase, a significant work hardening effect is produced. Therefore, the strength of the alloy can be significantly improved through dual-stage overheating treatment and warm working.

[0052] (4) In the two-stage overheating and warm working process, the alloy undergoes two precipitation processes, so the Al, Ti, Nb and Zr elements in the alloy matrix are fully precipitated and the alloy matrix is ​​significantly purified, so the prepared nickel-based alloy has high electrical conductivity.

[0053] In some embodiments, the pretreatment in S1 includes: grinding the surfaces of electrolytic nickel blocks, metallic chromium, titanium blocks, niobium blocks, and zirconium blocks to remove oxide scale, and removing the surface oxide film from aluminum ingots; then placing all raw materials in anhydrous ethanol for ultrasonic cleaning for 20-30 minutes, and then drying them in a vacuum drying oven at 115-120℃ to constant weight.

[0054] The oxide layer on the metal surface can become an inclusion in the smelting process, leading to alloy defects. Grinding and removing it can ensure the purity of the raw materials. Ethanol dissolves oil stains, and ultrasonic cleaning enhances the cleaning process, preventing impurities from affecting the alloy's performance.

[0055] In some embodiments, in step S2, the process parameters for vacuum induction melting are: vacuum degree ≤ 5 × 10⁻⁶. - 3 The heating parameters were set at 15-20℃ / min, a melting temperature of 1550-1650℃, a holding time of 20-30min, and an electromagnetic stirrer at a speed of 200-300 r / min during the melting process. These parameters were optimized to reduce gas inclusions and oxide formation, thereby improving alloy purity.

[0056] In some embodiments, in step S3, the inert gas is argon with a purity ≥ 99.99%; the process parameters for horizontal continuous casting are: crystallizer temperature 1100-1200℃, cooling rate 50-80℃ / min, billet pulling speed 0.5-1.0m / min; the diameter of the resulting round bar ingot is 80-120mm, and the surface roughness is ≤ Ra1.6μm.

[0057] Inert gas is used to isolate the molten material from air, prevent oxidation during molten material transport and solidification, and reduce surface defects; the crystallizer and cooling system are used to control the start-up of solidification and refine the grains; the casting and cooling rates are matched to ensure that the ingot solidifies fully and has a smooth surface.

[0058] In some embodiments, in step S4, the homogenization process parameters are: temperature 1050-1200℃, holding time 3-5h, and furnace cooling to room temperature after treatment; the hot forging process parameters are: heating temperature 1100-1150℃, holding time 1-2h, forging ratio 4-5, air cooling after forging, to obtain an alloy billet with a thickness of 15-20mm.

[0059] Homogenization can activate atomic diffusion, eliminate dendritic segregation in ingots, and improve the uniformity of the microstructure; hot forging and heat preservation ensure uniform billet temperature and avoid forging cracks.

[0060] In some embodiments, in step S5, the temperature of the first-stage overheating treatment is 900-1000℃, the holding time is 50-100h, and the treatment is followed by furnace cooling to room temperature; the temperature of the second-stage overheating treatment is 750-900℃, the holding time is 4-24h, and the treatment is followed by air cooling.

[0061] First-stage overheating coarsens the γ' phase (Ni3(Al,Ti)), reducing dislocation pinning and improving the hot working plasticity of the alloy; second-stage overheating promotes the precipitation of fine γ' phases in Al and Ti at dislocation sites, achieving precipitation strengthening and improving strength.

[0062] In some embodiments, in step S5, the warm working (deformation heat treatment) temperature is 950-1100℃, and four warm rolling passes are performed; wherein the deformation amount of the first warm rolling pass is 15%-20%, the deformation amount of the second warm rolling pass is 25%-30%, the deformation amount of the third warm rolling pass is 10%-15%, and the deformation amount of the fourth warm rolling pass is 20%-25%; after four warm rolling passes, the cumulative deformation amount is 55%-65%.

[0063] The temperature is 950-1100℃, which is higher than the solid solution temperature of the γ' phase, promoting the re-dissolution of small-sized γ' phase and preparing for secondary precipitation; four-stage gradient deformation (cumulative 55%~65%) avoids cracking from single large deformation, breaks up and coarsens the γ' phase, and refines the grains.

[0064] In some embodiments, the cold working temperature is room temperature, the cold working deformation is >90%, and the thickness of the obtained nickel-based high-temperature alloy foil is 0.01-0.1 mm with a thickness tolerance ≤±0.005 mm.

[0065] With a room temperature and deformation rate of >90%, the grains are further refined through work hardening to improve the alloy strength; the thickness is 0.01-0.1mm and the tolerance is ≤±0.005mm, which is suitable for the assembly needs of high-end scenarios such as precision connectors and ensures dimensional accuracy.

[0066] In some embodiments, the application of a precision nickel-based superalloy in the aerospace and electronic power fields is specifically as follows:

[0067] In the aerospace field: miniature conductive connectors for engine hot-end components are subjected to high temperature and high frequency vibration conditions of 450-600℃ for a long time. They need to withstand high tensile strength of ≥400MPa to avoid breakage, while maintaining high conductivity to achieve stable transmission of temperature / pressure signals.

[0068] In the field of electronics and power: In high-temperature environments, the precision connector foils for new energy vehicle motors or nuclear power instruments need to be able to withstand the thermal stress generated by large currents, with a room temperature tensile strength ≥500MPa; and achieve low resistance loss, with a conductivity ≥40%IACS.

[0069] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0070] Example 1

[0071] This embodiment provides a precision nickel-based superalloy, prepared through the following steps:

[0072] S1. Raw Material Preparation and Pretreatment: Weigh the following raw materials by weight percentage: 17.2% Cr, 3.0% Al, 0.6% Ti, 0.6% Nb, 0.6% Zr, with the balance being Ni. These correspond to electrolytic nickel blocks, metallic chromium, aluminum ingots, titanium blocks, niobium blocks, and zirconium blocks, respectively. Polish the surfaces of the electrolytic nickel blocks, metallic chromium, titanium blocks, niobium blocks, and zirconium blocks to remove oxide scale. Remove the surface oxide film from the aluminum ingots. Then, ultrasonically clean all raw materials in anhydrous ethanol for 25 minutes. After cleaning, place them in a vacuum drying oven at 120℃ and dry to constant weight for later use.

[0073] S2. Vacuum Induction Melting: Add the pretreated raw materials to a vacuum induction melting furnace and evacuate the furnace to a vacuum level of ≤5×10⁻⁶. - 3Pa was heated to 1600℃ at a heating rate of 18℃ / min and held for 25min to completely melt the raw material; during the melting process, electromagnetic stirring was turned on and the stirring speed was controlled at 250r / min to ensure uniform composition and obtain molten alloy.

[0074] S3. Horizontal continuous casting: Molten alloy is introduced into an electromagnetic horizontal continuous casting machine through an argon-protected flow channel with a purity of ≥99.99%. The crystallizer temperature is controlled at 1150℃, the cooling rate is 65℃ / min, and the billet speed is 0.8m / min to produce a precision nickel-based high-temperature alloy round bar ingot with a diameter of 100mm and a surface roughness of ≤Ra1.6μm.

[0075] S4. Homogenization and Hot Forging: The round bar ingot is placed in a heating furnace and heated to 1100℃. It is held at this temperature for 4 hours for homogenization treatment. After treatment, it is cooled to room temperature with the furnace. Then, the homogenized ingot is heated to 1150℃ and held for 1.5 hours. It is then forged using a free forging process with a forging ratio of 4.5. After forging, it is air-cooled to obtain an alloy billet with a thickness of 18mm.

[0076] S5. Combined Thermomechanical Treatment and Precision Forming: The alloy billet is processed using a "two-stage overheat treatment, warm working, and cold working" process.

[0077] First-stage overheating treatment: Place the billet in a vacuum annealing furnace, heat it to 950℃, hold it for 75 hours, and then cool it to room temperature with the furnace;

[0078] Warm rolling: The treated billet is heated to 1000℃, held at that temperature for 0.75h, and then subjected to 4 passes of warm rolling. The deformation amount of each pass is relative to the thickness of the previous pass: 18% for the first pass, 28% for the second pass, 12% for the third pass, and 22% for the fourth pass. The cumulative deformation amount is 60% relative to the initial billet.

[0079] Secondary overheating treatment: The temperature of the pre-processed board is raised to 820℃, held for 12 hours, and then air-cooled;

[0080] Cold working: The sheet metal is cold rolled in multiple passes at room temperature, with a total deformation of 92%, to finally produce a precision nickel-based high-temperature alloy with a thickness of 0.05 mm and a thickness tolerance of ±0.004 mm.

[0081] The precision nickel-based superalloy prepared in this embodiment can be widely used in the aerospace field (such as conductive connectors for engine hot ends) and the electronic power field (such as high-temperature connectors for new energy vehicle motors).

[0082] Example 2

[0083] Compared with Example 1, this embodiment differs in that the Cr content is optimized to improve corrosion resistance and adapt to humid and high-temperature environments. Some step parameters are as follows:

[0084] S1. Raw material preparation and pretreatment: Weigh the raw materials according to the following weight percentages: 18.5% Cr, 2.8% Al, 0.7% Ti, 0.5% Nb, 0.5% Zr, with the balance being Ni. Pretreatment is the same as in Example 1, including ultrasonic cleaning for 30 minutes.

[0085] S2, Vacuum Induction Melting: Vacuum degree 2×10 -3 Pa, heating rate 20℃ / min, melting temperature 1650℃ (suitable for high Cr dissolution), holding temperature for 30min, stirring speed 280r / min;

[0086] S3, Horizontal continuous casting: Argon purity 99.995%, crystallizer temperature 1180℃, cooling rate 70℃ / min, billet pulling speed 0.7m / min, to produce Φ110mm ingots;

[0087] S4. Homogenization and hot forging: Homogenize at 1150℃ for 5 hours (to eliminate high Cr segregation), heat at 1150℃ for 2 hours, forging ratio 4.0, air cool after forging to obtain a 20mm thick billet.

[0088] S5, Combined Thermomechanical Treatment:

[0089] First-stage overheat treatment: 980℃ for 90 hours;

[0090] Warm rolling: Hold at 1050℃ for 1 hour, then perform 4 passes of warm rolling (deformation amounts of 20%, 30%, 15%, and 25%), with a cumulative deformation of 65%.

[0091] Secondary overheating treatment: 850℃ for 18 hours;

[0092] Cold working: 93% deformation yields a precision nickel-based high-temperature alloy with a thickness of 0.08 mm.

[0093] The precision nickel-based high-temperature alloy prepared in this embodiment is mainly used for corrosion-resistant precision connectors in nuclear power instruments.

[0094] The remaining raw materials and preparation process are the same as in Example 1.

[0095] Example 3

[0096] Compared with Example 1, this embodiment differs in that the continuous casting and heat treatment parameters are optimized to refine the grains and improve high-temperature strength. Some of the step parameters are as follows:

[0097] S1. Raw material preparation and pretreatment: Weigh the raw materials according to the following weight percentages: 16.5% Cr, 3.2% Al, 0.8% Ti, 0.7% Nb, 0.7% Zr, with the balance being Ni. Ultrasonic cleaning for 22 minutes, followed by vacuum drying at 115℃.

[0098] S2, Vacuum Induction Melting: Vacuum degree 5×10-3 Pa, heating rate 15℃ / min, melting temperature 1580℃, holding temperature 22min, stirring speed 220r / min;

[0099] S3. Horizontal continuous casting: Argon protection, crystallizer temperature 1120℃, cooling rate 80℃ / min (accelerating grain refinement), billet speed 0.5m / min, to produce Φ80mm ingots;

[0100] S4. Homogenization and hot forging: Homogenize at 1080℃ for 3 hours, heat at 1100℃ for 1 hour, forging ratio 5.0 (strengthening grain breakage), air cool after forging to obtain a 15mm thick billet.

[0101] S5, Combined Thermomechanical Treatment:

[0102] First-stage overheat treatment: 920℃ for 60 hours;

[0103] Warm rolling: 980℃ for 0.6h, 4 passes of warm rolling (deformation of 15%, 26%, 10% and 20%), with a cumulative deformation of 55%;

[0104] Secondary overheating treatment: 780℃ for 8 hours;

[0105] Cold working: 91% deformation, resulting in a foil with a thickness of 0.03mm.

[0106] The precision nickel-based superalloy prepared in this embodiment is primarily used for micro high-strength connectors in aero-engines.

[0107] The remaining raw materials and preparation process are the same as in Example 1.

[0108] Example 4

[0109] The difference between this embodiment and Embodiment 1 is that the forging and overheating parameters are adjusted to improve processing plasticity. Some of the step parameters are as follows:

[0110] S1. Raw material preparation and pretreatment: Weigh the raw materials according to the following weight percentages: 17.8% Cr, 2.5% Al, 0.5% Ti, 0.8% Nb, 0.8% Zr, with the balance being Ni. Ultrasonic cleaning for 28 minutes, followed by vacuum drying at 120℃.

[0111] S2, Vacuum induction melting vacuum degree 4×10 -3 Pa, heating rate 17℃ / min, melting temperature 1620℃, holding temperature 28min, stirring speed 260r / min;

[0112] S3, horizontal continuous casting with argon purity of 99.99%, crystallizer temperature of 1160℃, cooling rate of 55℃ / min, and billet pulling speed of 1.0m / min, to produce Φ120mm ingots;

[0113] S4. Homogenization and hot forging: Homogenize at 1120℃ and hold for 4.5h, heat at 1130℃ and hold for 1.8h, forging ratio 4.2, air cool after forging, to obtain a billet with a thickness of 17mm.

[0114] S5, Combined Thermomechanical Processing

[0115] First-level overheat treatment: 900℃ for 100 hours (extending the heat preservation time to improve plasticity);

[0116] Warm rolling: 1080℃ for 0.9h, 4 passes of warm rolling (deformation of 19%, 27%, 13% and 24%), with a cumulative deformation of 62%;

[0117] Secondary overheating treatment: 800℃ for 20 hours;

[0118] Cold working: 90% deformation, producing foil with a thickness of 0.1mm.

[0119] The precision nickel-based superalloy prepared in this embodiment is mainly used for the molding of complex-shaped electronic connectors.

[0120] The remaining raw materials and preparation process are the same as in Example 1.

[0121] Example 5

[0122] Compared with Example 1, this embodiment focuses on the precision of the foil material and optimizes cold working and dimensional control. Some step parameters are as follows:

[0123] S1. Raw material preparation and pretreatment: Weigh the raw materials according to the following weight percentages: 16.3% Cr, 3.5% Al, 0.4% Ti, 0.4% Nb, 0.4% Zr, with the balance being Ni. Ultrasonic cleaning for 20 minutes, followed by vacuum drying at 115℃.

[0124] S2, Vacuum induction melting vacuum degree 2×10 -3 Pa, heating rate 16℃ / min, melting temperature 1550℃, holding temperature 20min, stirring speed 200r / min;

[0125] S3. Horizontal continuous casting with argon purity of 99.995%, crystallizer temperature of 1100℃, cooling rate of 60℃ / min, and billet pulling speed of 0.6m / min, to produce Φ90mm ingots.

[0126] S4. Homogenization and hot forging: Homogenize at 1050℃ and hold for 3 hours, heat at 1100℃ and hold for 1 hour, forging ratio 4.0, air cool after forging, to obtain a billet with a thickness of 16mm.

[0127] S5, Combined Thermomechanical Processing

[0128] First-stage overheat treatment: 980℃ for 50 hours;

[0129] Warm rolling: Hold at 950℃ for 0.5h, 4 passes of warm rolling (deformation of 20%, 25%, 15% and 25%), with a cumulative deformation of 63%;

[0130] Secondary overheating treatment: 750℃ for 4 hours;

[0131] Cold working: 95% deformation at room temperature, producing ultra-thin foil with a thickness of 0.01mm and a tolerance of ±0.003mm.

[0132] The precision nickel-based superalloy prepared in this embodiment is primarily used for the precision packaging of miniature nuclear power detectors.

[0133] The remaining raw materials and preparation process are the same as in Example 1.

[0134] Example 6

[0135] The difference between this embodiment and Embodiment 1 lies in the optimization of Ti and Nb content and heat treatment to improve high-temperature creep resistance. The steps are as follows:

[0136] S1. Raw Material Preparation and Pretreatment: Weigh the raw materials according to the following weight percentages: 18.0% Cr, 2.7% Al, 0.8% Ti, 0.8% Nb, 0.6% Zr, with the balance being Ni. Ultrasonic cleaning for 30 minutes, followed by vacuum drying at 117℃.

[0137] S2, Vacuum induction melting vacuum degree 5×10 -3 Pa, heating rate 20℃ / min, melting temperature 1650℃, holding temperature for 30min, stirring speed 300r / min;

[0138] S3. Horizontal continuous casting with argon purity of 99.99%, crystallizer temperature of 1200℃, cooling rate of 75℃ / min, and billet pulling speed of 0.9m / min, yields Φ110mm ingots.

[0139] S4. Homogenization and hot forging: Homogenize at 1200℃ and hold for 5 hours (to promote the diffusion of Ti and Nb), heat at 1150℃ and hold for 2 hours, forging ratio 4.8, air cool after forging, to obtain a billet with a thickness of 19mm.

[0140] S5, Combined Thermomechanical Processing

[0141] First-stage overheat treatment: 1000℃ for 80 hours;

[0142] Warm rolling: Hold at 1100℃ for 1.5 hours, 4 passes of warm rolling (deformation of 17%, 30%, 14% and 23%), with a cumulative deformation of 65%;

[0143] Secondary overheating treatment: 900℃ for 24 hours;

[0144] Cold working: 94% deformation, producing foil with a thickness of 0.06mm.

[0145] The precision nickel-based high-temperature alloy prepared in this embodiment is mainly used in aerospace components that operate at high temperatures above 600°C.

[0146] The remaining raw materials and preparation process are the same as in Example 1.

[0147] Comparative Example 1

[0148] The difference between this comparative example and Example 1 is that the Al content in the alloy composition is 0.

[0149] The remaining raw materials and preparation process are the same as in Example 1.

[0150] Comparative Example 2

[0151] The difference between this comparative example and Example 1 is that the Zr content in the alloy composition is 0.

[0152] The remaining raw materials and preparation process are the same as in Example 1.

[0153] Comparative Example 3

[0154] The difference between this comparative example and Example 1 is that the Cr content in the alloy composition is 0.

[0155] The remaining raw materials and preparation process are the same as in Example 1.

[0156] Comparative Example 4

[0157] The difference between this comparative example and Example 1 is that the Ti content in the alloy composition is 0.

[0158] The remaining raw materials and preparation process are the same as in Example 1.

[0159] Comparative Example 5

[0160] The difference between this comparative example and Example 1 is that the Nb content in the alloy composition is 0.

[0161] The remaining raw materials and preparation process are the same as in Example 1.

[0162] Comparative Example 6

[0163] Compared with Example 1, the difference in this comparative example is that the "first-level overheating treatment" is removed in step S5, and "warm working, second-level overheating treatment and cold working" are performed directly.

[0164] In the preparation steps, S5 is adjusted to: direct warm working of the billet at 1000℃, secondary overheat treatment at 820℃, and cold working;

[0165] The remaining raw materials and preparation process are the same as in Example 1.

[0166] Comparative Example 7

[0167] Compared with Example 1, the difference in this comparative example is that the "secondary overheating treatment" is removed in step S5, and only the "primary overheating treatment, warm working and cold working" are performed.

[0168] In the preparation steps, S5 is adjusted to: 950℃ primary overheat treatment, 1000℃ warm working and direct cold working;

[0169] The remaining raw materials and preparation process are the same as in Example 1.

[0170] Comparative Example 8

[0171] Compared with Example 1, the difference in this comparative example is that the "homogenization treatment" is removed in step S4, and the round bar ingot is directly hot forged.

[0172] In the preparation steps, S4 is adjusted to: direct heating of round bar ingots at 1120℃ for 1.5h and forging for billet, while S5 remains unchanged;

[0173] The remaining raw materials and preparation process are the same as in Example 1.

[0174] Performance testing

[0175] The performance of the precision nickel-based superalloys prepared in Examples 1-6 and Comparative Examples 1-8 was tested, and the specific items are as follows:

[0176] 1. High-temperature mechanical properties: Referring to GB / T228.2-2015 "Metallic materials - Tensile testing - Part 2: High-temperature test method", a microcomputer-controlled electronic universal testing machine was used to conduct tensile tests at 650℃ with a loading rate of 2mm / min. Three parallel specimens were tested in each group, and the average value was used to calculate the tensile strength, yield strength and elongation.

[0177] 2. Corrosion resistance: Refer to GB / T10125-2021 "Artificial Atmosphere Corrosion Test - Salt Spray Test" and conduct a neutral salt spray test (NSS). The spray medium is 5% NaCl solution (pH 6.5-7.2), the test temperature is 35℃, and after continuous spraying for 1000h, the corrosion rate is calculated by weight loss method.

[0178] 3. Electrical conductivity: Refer to GB / T351-2019 "Methods for measuring resistivity of metallic materials", use an eddy current conductivity meter (accuracy ±0.5%IACS) to test at room temperature (25℃), select 5 evenly distributed measurement points and take the average value.

[0179] The results are shown in Table 1:

[0180] Table 1

[0181]

[0182] As shown in Table 1, Example 3 exhibits the best performance: its tensile strength at 650℃ reaches 1105.2 MPa and its yield strength is 978.6 MPa. In terms of composition, the increased Al and Ti content allows for the formation of more γ' phase (Ni3Al) and enhances its stability. The elongation decreases slightly to 16.8%, but still meets the requirements for high-strength components. Example 2 has a tensile strength of 1028.4 MPa and a yield strength of 896.5 MPa, a decrease compared to Example 1. While the increased Cr content enhances corrosion resistance, the high Cr solid solution slightly reduces the matrix plasticity. To accommodate the high Cr dissolution, the melting temperature is raised to 1650℃, which may lead to a slight volatilization of a small amount of low-melting-point elements, resulting in a minor impact on strength. Example 1 demonstrates stable performance. The baseline ratio of 17.2%Cr and 3.0%Al, combined with neutral parameters such as melting at 1600℃ and cooling at 65℃ / min, achieves a balance between tensile strength of 1052.6MPa and elongation of 18.5%, taking into account both strength and plasticity.

[0183] The corrosion resistance exhibits a pattern of "higher Cr content, lower corrosion rate": the neutral salt spray corrosion rate in Example 2 is as low as 0.08 mm / a, a decrease compared to Example 1, because the higher Cr content allows for the formation of a denser and more continuous C layer on the alloy surface. The oxide film blocks the corrosion of the substrate by the salt spray medium; the corrosion rate in Example 3 increased to 0.11 mm / a, which is higher than that in Example 1, confirming the decisive role of Cr content in corrosion resistance. The decrease in Cr content leads to a decrease in the integrity of the oxide film, and the corrosive medium can penetrate into the substrate more easily.

[0184] The conductivity showed a slight decreasing trend with the increase of the reinforcing phase content: In Example 3, due to the highest Al and Ti content, the number of γ' phases formed was the largest, and the scattering effect of γ' phase on electron conduction was enhanced, resulting in a decrease in conductivity; Although Example 2 had a high Cr content, Cr had a small effect on electron scattering, and the conductivity was only slightly lower than that of Example 1; The conductivity of all three remained in the range of 40.8%-42.3% IACS, which met the signal / energy transmission requirements of ≥38% IACS in the field of electronic power, and achieved a balance between "intensity and conductivity".

[0185] Comparative Example 1 (lacking Al) showed a tensile strength of only 731.8 MPa and a yield strength of 603.2 MPa at 650℃, a significant decrease compared to Example 1. This is because Al is a γ' phase (N Al is the only core forming element. The absence of Al leads to the complete disappearance of the γ' phase. The alloy relies only on a small amount of Ni3(Ti,Nb) phase for strengthening, and the precipitation strengthening effect is almost lost, making it unable to effectively pin dislocation movement. Its electrical conductivity of 43.1% IACS is slightly high, which is due to the lack of γ' phase scattered electrons, but at the cost of strength collapse, it has no practical application value.

[0186] In Comparative Example 3, the neutral salt spray corrosion rate surged to 0.85 mm / a, a significant increase compared to Example 1, and the high-temperature tensile strength decreased to 820.7 MPa. This is because Cr is a precursor to C. Cr is the only element in the protective oxide film. Without Cr, the alloy surface lacks an effective protective layer, leading to direct, comprehensive electrochemical corrosion. Simultaneously, the solid solution strengthening effect of Cr disappears, resulting in a decrease in matrix strength. Comparative Example 2 showed a tensile strength of 962.5 MPa and an elongation of 14.3% at 650℃, with a corrosion rate of 0.15 mm / a. Although Zr does not directly participate in the formation of the strengthening phase, it can form stable compounds with harmful impurities such as S and P to purify grain boundaries and reduce grain boundary brittleness. Without Zr, grain boundary cleanliness decreases, grain boundary slip resistance decreases, leading to a decline in strength and plasticity. Simultaneously, corrosive media easily penetrate along grain boundaries, worsening corrosion resistance. The tensile strengths of Comparative Examples 4 and 5 decreased to 880.3 MPa and 850.6 MPa, respectively, compared to Example 1. This is because Ti can dissolve in the γ' phase to inhibit dislocation climb at high temperatures, and Nb can form a γ'' phase (Ni3Nb) to supplement age-hardening. The absence of both leads to a decrease in the stability of the γ' phase and a single strengthening system, ultimately causing a decline in strength.

[0187] Comparative Example 6 exhibits a tensile strength of 870.2 MPa and an elongation of 15.5%. The core function of the first-stage overheat treatment (holding at 950℃ for 75 h) is to sufficiently coarsen the initial γ' phase, weakening its pinning of dislocations to improve the alloy's thermoplasticity and laying the foundation for subsequent warm working to break down the γ' phase. After its absence, the γ' phase is fine and unevenly distributed, resulting in high deformation resistance and insufficient microstructural fragmentation during warm working, significantly weakening the strengthening effect. Comparative Example 7 has the worst performance, with a tensile strength of 806.4 MPa, a yield strength of 720.5 MPa, and an elongation of 13.8%. After warm working, some of the coarsened γ' phase dissolves back into the matrix. The second-stage overheat treatment is a crucial step in promoting the re-precipitation of fine γ' phases from the dissolved Al and Ti elements at dislocation sites. After its absence, the re-dissolved strengthening phase cannot precipitate, relying solely on work hardening, leading to a comprehensive decline in both strength and plasticity. Comparative Example 8 exhibits a tensile strength of 810.9 MPa and an elongation of 14.2%. Homogenization treatment (holding at 1100℃ for 4 hours) can eliminate dendritic segregation in continuously cast ingots, ensuring the uniformity of microstructure during subsequent hot forging and heat treatment. Without this treatment, inhomogeneous ingot composition leads to inconsistent hot forging deformation and stress concentration within the microstructure, reducing both strength and plasticity.

[0188] In summary, the precision nickel-based superalloy composition and preparation process proposed in this invention have many advantages. In particular, compared with traditional nickel-based superalloy preparation processes, this process is highly practical and can produce precision nickel-based superalloys with stable quality and excellent performance.

[0189] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. A precision nickel-base superalloy characterized by, comprising 16.3-18.5% Cr, 2.5-3.5% Al, 0.4-0.8% Ti, 0.4-0.8% Nb and 0.4-0.8% Zr by weight percent, with the balance being Ni.

2. A method of producing a precision nickel-based superalloy, characterized by, The application relates to a preparation method of a precision nickel-based superalloy. S1: electrolytic nickel blocks, metal chromium, aluminum ingots, titanium blocks, niobium blocks and zirconium blocks are prepared according to a proportioning scheme and are pretreated; S2: a vacuum induction melting technology is used to melt the pretreated raw materials to obtain a molten alloy; S3: the molten alloy prepared in S2 is introduced into an electromagnetic horizontal continuous casting machine through an inert gas protection flow tank by using a horizontal continuous casting technology to obtain a precision nickel-based superalloy round bar ingot; S4: the round bar ingot prepared in S3 is subjected to homogenization treatment, and then is subjected to hot forging and blooming to obtain an alloy blank; S5: the alloy blank prepared in S4 is subjected to a combined thermal mechanical treatment process of two-stage overheating treatment and warm working, specifically including first-stage overheating treatment, warm working, second-stage overheating treatment and cold working, to obtain a nickel-based superalloy foil with high strength.

3. The method of claim 2, wherein the method further comprises the step of: In S1, the pretreatment includes: the electrolytic nickel blocks, the metal chromium, the titanium blocks, the niobium blocks and the zirconium blocks are respectively subjected to surface polishing to remove oxide skins, and the aluminum ingots are subjected to surface oxide film removal; then all the raw materials are ultrasonically cleaned in anhydrous ethanol for 20-30 min, and are baked in a 115-120 DEG C vacuum drying oven until constant weight.

4. The method of claim 2, wherein the method further comprises the step of: The process parameters of the vacuum induction melting in S2 are: vacuum degree ≤5×10 -3 Pa, heating rate 15-20℃ / min, melting temperature 1550-1650℃, holding time 20-30min, electromagnetic stirring is started during the melting process, stirring speed 200-300r / min.

5. The method of claim 2, wherein the method further comprises the step of: In S3, the inert gas is argon with a purity of greater than or equal to 99.99%; the process parameters of the horizontal continuous casting are as follows: a crystallizer temperature is 1100-1200 DEG C, a cooling rate is 50-80 DEG C / min, and a blank drawing speed is 0.5-1.0 m / min; the prepared round bar ingot has a diameter of 80-120 mm and a surface roughness of less than or equal to Ra1.6 mu m.

6. The method of claim 2, wherein the method further comprises the step of: In S4, the process parameters of the homogenization treatment are as follows: a temperature is 1050-1200 DEG C, a holding time is 3-5 h, and the treatment is followed by furnace cooling to room temperature; the process parameters of the hot forging and blooming are as follows: a heating temperature is 1100-1150 DEG C, a holding time is 1-2 h, a forging ratio is 4-5, and the forging is followed by air cooling to obtain an alloy blank with a thickness of 15-20 mm.

7. The method of claim 2, wherein the method further comprises the step of: In S5, the first-stage overheating treatment has a temperature of 900-1000 DEG C and a holding time of 50-100 h, and the treatment is followed by furnace cooling to room temperature; the second-stage overheating treatment has a temperature of 750-900 DEG C and a holding time of 4-24 h, and the treatment is followed by air cooling. ​ 8. The method of claim 2, wherein the method further comprises the step of: In S5, the warm working temperature is 950-1100 DEG C, and four passes of warm rolling are performed; the first pass of warm rolling has a deformation of 15%-20%, the second pass of warm rolling has a deformation of 25%-30%, the third pass of warm rolling has a deformation of 10%-15%, and the fourth pass of warm rolling has a deformation of 20%-25%; after the four passes of warm rolling, the cumulative deformation is 55%-65%. ​ 9. The method of claim 2, wherein the method further comprises the step of: The cold working temperature is room temperature, the cold working deformation is greater than 90%, the prepared nickel-based superalloy foil has a thickness of 0.01-0.1 mm, and a thickness tolerance is + / -0.005 mm. ​ 10. Use of a precision nickel-based superalloy in the aerospace and electronic power fields, characterized in that, The application relates to a precision nickel-based superalloy prepared by the preparation method of the precision nickel-based superalloy according to any one of claims 2-9.

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