Niobium alloy materials and their preparation methods

Abstract

This invention belongs to the field of metallic materials, specifically relating to a niobium alloy material, wherein, by weight percentage, the niobium alloy material is mainly composed of the following elements: tantalum 4%-8.5%, tungsten 4%-8.5%, molybdenum 1%-3%, zirconium 0.8%-2.5%, carbon 0-0.2%, with the remainder being niobium. This invention also relates to a method for preparing this niobium alloy material. The density and tensile properties at room temperature and high temperature of the niobium alloy material of this invention are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of metallic materials, specifically relating to a niobium alloy material and a method for preparing the niobium alloy material. Background Technology

[0002] The aerospace industry has an increasingly urgent need for high-temperature resistant materials, and niobium alloys have become the preferred material for hot-end components due to their excellent high-temperature strength, corrosion resistance, and low density. Traditional manufacturing processes, such as vacuum arc melting, suffer from long processing cycles and high costs, especially for C-103 alloys containing expensive elements such as Hf and Ta, which further increases costs. Studies have shown that adding solid solution strengthening elements such as Ta, W, and Mo can improve the high-temperature performance of alloys. Among them, tungsten has twice the strengthening effect of molybdenum, but excessive addition can impair plasticity and increase the brittle transition temperature. Composite strengthening can optimize performance through synergistic solid solution strengthening and carbide / oxide dispersion strengthening, but precise control of the size and distribution of precipitated phases is required.

[0003] The development of niobium alloys has gone through several stages: the Cb23 series developed in the United States in the 1950s was phased out due to insufficient machinability. In 1961, the C-103 alloy (Nb-10Hf-1Ti) became the first successfully applied niobium-tungsten alloy. Subsequent alloys such as Cb132M, although attempted for use in aero-engine blades, failed to achieve practical application due to insufficient overall performance. Current research focuses on low-cost process innovation to provide new ideas for meeting the large-scale demand for high-performance niobium alloy components in the aerospace field. Summary of the Invention

[0004] One objective of this invention relates to a niobium alloy material with significantly improved density and tensile properties at both room temperature and high temperature. Furthermore, this invention also relates to a method for preparing the niobium alloy material.

[0005] To achieve the above objectives, the first aspect of the present invention provides a niobium alloy material, wherein, by weight percentage, the niobium alloy material is mainly composed of the following elements:

[0006] Tantalum 4%-8.5% (e.g., 4%, 6%, 8%, 8.5%)

[0007] Tungsten 4%-8.5% (e.g., 4%, 6%, 8%, 8.5%)

[0008] Molybdenum 1%-3% (e.g., 2%)

[0009] Zirconium 0.8%-2.5% (e.g., 1%, 2%)

[0010] Carbon 0-0.2% (e.g., 0.1%)

[0011] The rest is niobium.

[0012] In any embodiment of the first aspect, the tensile strength of the niobium alloy material at room temperature is 550-600 MPa, preferably 560-600 MPa, more preferably 568-600 MPa, for example 569 MPa, 570 MPa, 575 MPa, 580 MPa, 590 MPa.

[0013] In any embodiment of the first aspect, the stress corresponding to 0.2% plastic deformation of the niobium alloy material at room temperature is 420-490 MPa, preferably 425-490 MPa, more preferably 429-490 MPa, for example 430 MPa, 432 MPa, 435 MPa, 440 MPa, 460 MPa, 480 MPa.

[0014] In any embodiment of the first aspect, the niobium alloy material has an elongation at break of 31%-40% at room temperature, preferably 33%-40%, more preferably 35%-40%, for example 35.6%, 36%, 37%, 38%, or 39%.

[0015] In any embodiment of the first aspect, the tensile strength of the niobium alloy material at 1600°C is 144-160 MPa, preferably 146-160 MPa, more preferably 148-160 MPa, for example 149 MPa, 150 MPa, or 155 MPa.

[0016] In any embodiment of the first aspect, the stress corresponding to 0.2% plastic deformation of the niobium alloy material at 1600°C is 135-150 MPa, preferably 140-150 MPa, more preferably 142-150 MPa, for example 142 MPa, 145 MPa, 147 MPa, 148 MPa.

[0017] In any embodiment of the first aspect, the niobium alloy material has an elongation after fracture of 35%-45% at 1600°C, preferably 36%-45%, for example 36.5%, 37%, 37.5%, 38%, or 40%.

[0018] In any embodiment of the first aspect, the tensile strength of the niobium alloy material at 1800°C is 78-100 MPa, preferably 80-100 MPa, more preferably 88-100 MPa, for example 89 MPa, 90 MPa, or 95 MPa.

[0019] In any embodiment of the first aspect, the stress corresponding to 0.2% plastic deformation of the niobium alloy material at 1800°C is 73-100 MPa, preferably 80-100 MPa, more preferably 85-100 MPa, for example 86 MPa, 88 MPa, 90 MPa, 95 MPa.

[0020] In any embodiment of the first aspect, the niobium alloy material has an elongation after fracture of 34%-50% at 1800°C, preferably 39%-50%, more preferably 40%-50%, for example 40.5%, 41%, 42%, 45%, or 48%.

[0021] In any embodiment of the first aspect, the density of the niobium alloy material is 96%-100%, preferably 99%-100%, more preferably 99.8%-100%, for example 99.9%.

[0022] A second aspect of the present invention provides a method for preparing the niobium alloy material of the first aspect of the present invention, comprising the following steps:

[0023] A mixture is obtained by mixing tantalum source, tungsten source, molybdenum source, zirconium source and niobium source;

[0024] The mixture is shaped and sintered to obtain a shaped product;

[0025] The molded article is melted at least once under vacuum conditions to obtain an alloy ingot;

[0026] The alloy ingot is homogenized and annealed at 1300℃-1600℃ (e.g., 1400℃, 1500℃) for 80min-110min (e.g., 85min, 90min, 95min, 100min, 105min), and then cooled to obtain a billet.

[0027] The billet is radially forged and then rotary forged to obtain a niobium alloy material.

[0028] In any embodiment of the second aspect, the molded part is bundled before melting to ensure uniformity during the melting process and to prevent loose material from falling into the crucible and causing component segregation.

[0029] In any embodiment of the second aspect, the radial forging temperature is 1000℃-1200℃ (e.g., 1050℃, 1100℃, 1150℃), and the time is 10-30min (e.g., 15min, 20min, 25min).

[0030] In any embodiment of the second aspect, the number of radial forging hammers is 4-6, for example, 4 or 5.

[0031] In any embodiment of the second aspect, the hammering force of the radial forging is 150-300N, for example 200N or 250N.

[0032] In any embodiment of the second aspect, the hammering frequency of the radial forging is 40-60 times / min, for example 45 times / min, 50 times / min, or 55 times / min.

[0033] In any embodiment of the second aspect, during the radial forging process, the rotational speed of the billet is 10 r / min to 30 r / min, for example, 15 r / min, 20 r / min, or 25 r / min.

[0034] In any embodiment of the second aspect, during the radial forging process, the axial feeding speed of the billet is 2-6 mm / s, for example, 3 mm / s or 5 mm / s.

[0035] In any embodiment of the second aspect, the forging temperature is 1000℃-1200℃ (e.g., 1050℃, 1100℃, 1150℃), and the time is 80-100min (e.g., 80min, 85min, 90min, 95min).

[0036] In any embodiment of the second aspect, the number of hammers in the rotary forging is 4-6, for example, 4 or 5.

[0037] In any embodiment of the second aspect, the hammering force of the rotary forging is 200-300kN, for example, 200kN, 250kN, or 280kN.

[0038] In any embodiment of the second aspect, the hammering frequency of the rotary forging is 30-80 times / min, for example 40 times / min, 45 times / min, 50 times / min, 55 times / min, 60 times / min, 65 times / min, 70 times / min, or 75 times / min.

[0039] In any embodiment of the second aspect, the rotational speed of the rotary forging hammer is 10-30 rpm, for example, 15 r / min, 20 r / min, or 25 r / min.

[0040] In any embodiment of the second aspect, during the rotary forging process, the axial feeding speed of the billet is 1-10 mm / s, for example, 2 mm / s, 5 mm / s, 6 mm / s, 7 mm / s, or 8 mm / s.

[0041] In any embodiment of the second aspect, cold isostatic pressing is used.

[0042] In any embodiment of the second aspect, the static pressure of the cold isostatic pressing is 200MPa-260MPa (e.g., 220MPa, 230MPa, 250MPa), and the holding time of the cold isostatic pressing is 20s-30s (e.g., 25s).

[0043] In any embodiment of the second aspect, the fluid medium for cold isostatic pressing is hydraulic oil or glycerin.

[0044] In any embodiment of the second aspect, the niobium source is niobium powder, which is prepared by the following steps:

[0045] Niobium oxide is mixed with carbon materials to obtain a mixture;

[0046] The mixture is subjected to carbonization, sintering, hydrogenation, sieving, dehydrogenation, and cooling to obtain the niobium powder.

[0047] In any embodiment of the second aspect, the step of preparing the niobium powder includes one or more of the following features:

[0048] The niobium oxide is niobium pentoxide;

[0049] The carbon material is carbon black and / or graphite;

[0050] The weight ratio of the niobium oxide to the carbon material is 1:0.2-1:0.5, for example, 1:0.3 or 1:0.4;

[0051] The mixing time is 7-9 hours, for example, 7 hours or 8 hours;

[0052] Mixed by ball milling;

[0053] The carbonization treatment is carried out at a temperature of 1400℃-1600℃ (e.g., 1500℃) for 2-5 hours (e.g., 3 hours) and at a heating rate of 10-40℃ / min (e.g., 20℃ / min).

[0054] The carbonization process is carried out in a hydrogen atmosphere;

[0055] The sintering temperature is 1750℃-1950℃ (e.g., 1800℃, 1850℃, 1900℃), and the time is 8-12h (e.g., 9h, 10h, 10.5h, 11h).

[0056] The sintering is performed under vacuum; optionally, the vacuum level is ≤10. -1 Pa, for example, 10 -2 Pa;

[0057] The hydrogenation process is carried out at a hydrogen pressure of 0.04-0.2 MPa (e.g., 0.04 MPa, 0.06 MPa), a temperature of 800℃-1000℃ (e.g., 850℃, 900℃, 950℃), and a time of 3-5 hours (e.g., 4 hours).

[0058] Pass the sample through a 100-200 mesh sieve before dehydrogenation treatment, for example, a 180 mesh sieve;

[0059] The equipment for the dehydrogenation process is a hydrogenation degassing furnace;

[0060] The dehydrogenation treatment is performed at a temperature of 900℃-1000℃ (e.g., 950℃) for 2-5 hours (e.g., 4 hours).

[0061] In any embodiment of the second aspect, in the step of preparing the molded article, the sintering temperature is 1800℃-2100℃ (e.g., 1830℃, 1850℃, 1900℃, 1950℃, 2000℃), and the time is 9h-15h (e.g., 10h, 11h, 12h, 13h, 14h).

[0062] In any embodiment of the second aspect, in the step of preparing the molded article, the sintering heating rate is 200℃ / h-400℃ / h, for example 300℃ / h.

[0063] In any embodiment of the second aspect, in the step of preparing the molded article, the sintering is performed at ≤10 -2 Performed under vacuum conditions, for example, 10 Pa. -3 Pa.

[0064] In any embodiment of the second aspect, the melting is performed twice.

[0065] In any embodiment of the second aspect, the power of the first smelting is 350-380KW, for example 355KW, 360KW, 365KW, 370KW, or 375KW.

[0066] In any embodiment of the second aspect, the melting speed of the first melting is 75-100 kg / h, for example 80 kg / h, 86 kg / h, 90 kg / h, 95 kg / h, or 98 kg / h.

[0067] In any embodiment of the second aspect, the first smelting is ≤4×10 -4 Performed at a vacuum level of mbar, for example, 4×10 -5 mbar.

[0068] In any embodiment of the second aspect, the power of the second melting is 360-385KW, for example 365KW, 370KW, 375KW, or 380KW.

[0069] In any embodiment of the second aspect, the melting rate of the second melting is 75-90 kg / h, for example 80 kg / h or 85 kg / h.

[0070] In any embodiment of the second aspect, the second melting is ≤2×10 -4 Performed at a vacuum level of mbar, for example, 2×10 -5 mbar.

[0071] In any embodiment of the second aspect, the total weight of tantalum, tungsten, molybdenum, zirconium, niobium, and carbon in the mixture is taken as 100% as a basis, and the mixture contains the following elements by weight percentage:

[0072] Tantalum 4%-8.5% (e.g., 4%, 6%, 8%, 8.5%)

[0073] Tungsten 4%-8.5% (e.g., 4%, 6%, 8%, 8.5%)

[0074] Molybdenum 1%-3% (e.g., 2%)

[0075] Zirconium 0.8%-2.5% (e.g., 1%, 2%)

[0076] Carbon 0-0.2% (e.g., 0.1%)

[0077] The rest is niobium.

[0078] In any embodiment of the second aspect, before mixing, the tantalum source, the tungsten source, the molybdenum source, the zirconium source and the niobium source are each passed through a 100-300 mesh sieve, for example, a 200 mesh sieve.

[0079] In this invention, Rm refers to the tensile strength of the material, that is, the maximum stress per unit area that the material can withstand before tensile fracture.

[0080] In this invention, Rp0.2 refers to the stress when the material undergoes 0.2% plastic deformation, and is used to measure the material's ability to resist minor plastic deformation.

[0081] In this invention, A refers to the elongation after fracture of the material, which is the percentage of the total plastic deformation to the original gauge length after the material sample fractures.

[0082] The beneficial effects achieved by this invention are as follows:

[0083] 1. The density and tensile properties at room temperature and high temperature of the niobium alloy material of the present invention are improved.

[0084] 2. This invention uses a specific ratio of metal elements to improve the density of the alloy material and its tensile properties at room temperature and high temperature, as well as its comprehensive properties such as corrosion resistance, through the synergistic effect of solid solution strengthening and dispersion strengthening.

[0085] 3. The preparation method of this invention comprehensively adopts homogenization annealing, radial forging and rotary forging, which reduces problems such as alloy microstructure segregation and uneven element distribution, and improves the density, room temperature tensile properties and high temperature tensile properties of niobium alloy materials.

[0086] 4. The preparation method of the present invention can effectively avoid the generation of infusible blocks during the smelting process, reduce the impurity content in the material, and improve the purity of the material. Detailed Implementation

[0087] The embodiments of the present invention will now be clearly and completely described in conjunction with examples. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0088] Example 1

[0089] (1) Niobium pentoxide (Nb2O5) and carbon black were mixed by ball milling at a mass ratio of 1:0.3 for 7 hours; the mixture was then carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20℃ / min, a holding temperature of 1500℃, a holding time of 3 hours, and a hydrogen atmosphere; the carbonized mixture was then sintered at a temperature of 1900℃ for 10 hours and a vacuum degree of 10. -2 Pa; The sintered material was hydrogenated at 950°C for 4 hours in a hydrogen atmosphere of 0.04 MPa; The hydrogenated material was ball-milled and passed through a 180-mesh sieve; Then the sieved material was dehydrogenated using a hydrogenation degassing furnace at 950°C for 4 hours. After natural cooling, high-purity niobium powder was obtained.

[0090] (2) High-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder and zirconium hydride powder (based on the weight of zirconium element) with a purity of 99.9% and all passing through a 200-mesh sieve were put into a vacuum mixer in a weight ratio of 80:8:8:2:2 and mixed at room temperature for 8 hours at 60 rpm to obtain a mixture.

[0091] (3) The mixture is placed into a 20mm×20mm×500mm graphite mold for cold isostatic pressing. The fluid medium for cold isostatic pressing is hydraulic oil, the static pressure is 220MPa, and the holding time is 25s to obtain pre-bonded strips.

[0092] (4) The pre-bonded strips are placed in a vacuum hot-pressing sintering furnace for sintering. The heating rate is 300℃ / h, the sintering temperature is 1830℃, the sintering time is 12 hours, and the sintering vacuum degree is 10. -3 Pa, after sintering, is cooled in the furnace to obtain alloy bars;

[0093] (5) Bundle the alloy strips and place them in a vacuum electron beam furnace for two melting processes: During the first melting process, the melting power of the vacuum electron beam furnace is set to 375KW, the melting speed is controlled at 86kg / h, and the vacuum degree inside the furnace reaches 4×10 -5 mbar; During the second melting, the vacuum electron beam furnace also used a melting power of 375KW, the melting speed was adjusted to 80kg / h, and the vacuum degree inside the furnace reached 2×10 -5 mbar yields alloy ingots;

[0094] (6) Heat the alloy ingot to 1400℃ and hold for 90 min for homogenization annealing, then cool it in the furnace.

[0095] (7) The alloy ingot after homogenization and annealing is radially forged. The radial forging temperature is 1020℃ and the time is 20min. The radial forging uses 4 hammers, the hammering force is 200N and the hammering frequency is 45 times / min. During the radial forging process, the rotation speed of the alloy ingot is 15r / min and the axial feeding speed is 5mm / s. The alloy ingot is forged from Φ153×260mm to Φ85×700mm to obtain the billet.

[0096] (8) The radially forged billet is rotary forged at a temperature of 1100℃ for 90 minutes. The rotary forging uses 4 hammers with a hammering force of 250kN, a hammering frequency of 50 times / min, and a hammer rotation speed of 20rpm. The billet is fed at a speed of 3mm / s. The billet is forged to Φ55×1650mm to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder being niobium.

[0097] Example 2

[0098] (1) Niobium pentoxide and carbon black were mixed by ball milling at a mass ratio of 1:0.3 for 8 hours. The mixture was then carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20℃ / min, a holding temperature of 1500℃, a holding time of 3 hours, and a hydrogen atmosphere. The carbonized mixture was then sintered at 1800℃ for 11 hours under a vacuum of 10. -2 Pa; The sintered material was hydrogenated at 950°C for 4 hours in a hydrogen atmosphere of 0.04 MPa; The hydrogenated material was ball-milled and passed through a 180-mesh sieve; Then the sieved material was dehydrogenated using a hydrogenation degassing furnace at 950°C for 4 hours. After natural cooling, high-purity niobium powder was obtained.

[0099] (4) The pre-bonded strips are placed in a vacuum hot-pressing sintering furnace for sintering. The heating rate is 300℃ / h, the sintering temperature is 1900℃, the sintering time is 12 hours, and the vacuum degree of sintering is 10. -3 Pa, after sintering, is cooled in the furnace to obtain alloy bars;

[0100] (5) Bundle the alloy strips and place them in a vacuum electron beam furnace for two melting processes: During the first melting process, the melting power of the vacuum electron beam furnace is set to 370KW, the melting speed is controlled at 80kg / h, and the vacuum degree inside the furnace reaches 4×10 -5 mbar; During the second melting, the vacuum electron beam furnace used a melting power of 380KW, a melting speed of 80kg / h, and a vacuum degree of 2×10 mbar inside the furnace. -5 mbar yields alloy ingots;

[0101] Steps (2)-(3) and (6)-(8) are the same as in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder is niobium.

[0102] Example 3

[0103] (1) Niobium pentoxide (Nb2O5) and carbon black were mixed by ball milling at a mass ratio of 1:0.3 for 7 hours; the mixture was then carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20℃ / min, a holding temperature of 1500℃, a holding time of 3 hours, and a hydrogen atmosphere; the carbonized mixture was then sintered at a temperature of 1850℃ for 10.5 hours and a vacuum degree of 10. -2 Pa; The sintered material was hydrogenated at 950°C for 4 hours in a hydrogen atmosphere of 0.04 MPa; The hydrogenated material was ball-milled and passed through a 180-mesh sieve; Then the sieved material was dehydrogenated using a hydrogenation degassing furnace at 950°C for 4 hours. After natural cooling, high-purity niobium powder was obtained.

[0104] (4) The pre-bonded strips are placed in a vacuum hot-pressing sintering furnace for sintering. The heating rate is 300℃ / h, the sintering temperature is 1950℃, the sintering time is 10 hours, and the sintering vacuum degree is 10. -3 Pa, after sintering, is cooled in the furnace to obtain alloy bars;

[0105] (5) Bundle the alloy strips and place them in a vacuum electron beam furnace for two melting processes: During the first melting process, the melting power of the vacuum electron beam furnace is set to 360KW, the melting speed is controlled at 80kg / h, and the vacuum degree inside the furnace reaches 4×10 -5mbar; During the second melting, the vacuum electron beam furnace also used a melting power of 375KW, the melting speed was adjusted to 80kg / h, and the vacuum degree inside the furnace reached 2×10 -5 mbar yields alloy ingots;

[0106] Steps (2)-(3) and (6)-(8) are the same as in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder is niobium.

[0107] Example 4

[0108] (1) Niobium pentoxide (Nb2O5) and carbon black were mixed by ball milling at a mass ratio of 1:0.3 for 7 hours; the mixture was then carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20℃ / min, a holding temperature of 1500℃, a holding time of 3 hours, and a hydrogen atmosphere; the carbonized mixture was then sintered at a temperature of 1850℃ for 10.5 hours and a vacuum degree of 10. -2 Pa; The sintered material was hydrogenated at 950°C for 4 hours in a hydrogen atmosphere of 0.04 MPa; The hydrogenated material was ball-milled and passed through a 180-mesh sieve; Then the sieved material was dehydrogenated using a hydrogenation degassing furnace at 950°C for 4 hours. After natural cooling, high-purity niobium powder was obtained.

[0109] (4) The pre-bonded strips are placed in a vacuum hot-pressing sintering furnace for sintering. The heating rate is 300℃ / h, the sintering temperature is 2000℃, the sintering time is 10 hours, and the sintering vacuum degree is 10. -3 Pa, after sintering, is cooled in the furnace to obtain alloy bars;

[0110] (5) Bundle the alloy strips and place them in a vacuum electron beam furnace for two melting processes: During the first melting process, the melting power of the vacuum electron beam furnace is set to 360KW, the melting speed is controlled at 80kg / h, and the vacuum degree inside the furnace reaches 4×10 -5 mbar; During the second melting, the vacuum electron beam furnace also used a melting power of 380KW, the melting speed was adjusted to 85kg / h, and the vacuum degree inside the furnace reached 2×10 -5 mbar yields alloy ingots;

[0111] Steps (2)-(3) and (6)-(8) are the same as in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder is niobium.

[0112] Example 5

[0113] (6) Heat the alloy ingot to 1500℃ and hold for 90 min for homogenization annealing, then cool it in the furnace.

[0114] Steps (1)-(5) and (7)-(8) are the same as in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder is niobium.

[0115] Example 6

[0116] Steps (1)-(6) are the same as in Example 1;

[0117] (7) The alloy ingot after homogenization and annealing is radially forged. The radial forging temperature is 1100℃ and the time is 15min. The radial forging uses 4 hammers, the hammering force is 200N and the hammering frequency is 45 times / min. During the radial forging process, the rotation speed of the alloy ingot is 20r / min and the axial feeding speed is 5mm / s. The alloy ingot is forged from Φ153×260mm to Φ85×700mm to obtain the billet.

[0118] (8) The radially forged billet is rotary forged at a temperature of 1100℃ for 90 minutes. The rotary forging uses 4 hammers with a hammering force of 250kN, a hammering frequency of 35 times / min, and a hammer rotation speed of 20rpm. The billet is fed at a speed of 3mm / s. The billet is forged to Φ55×1650mm to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder being niobium.

[0119] Example 7

[0120] Steps (1) to (7) are the same as in Example 1;

[0121] (8) The radially forged billet is rotary forged at a temperature of 1100℃ for 85 minutes. The rotary forging uses 4 hammers with a hammering force of 250kN, a hammering frequency of 40 times / min, and a hammer rotation speed of 20rpm. The billet is fed at a speed of 3mm / s. The billet is forged to Φ55×1650mm to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder being niobium.

[0122] Comparative Example 1

[0123] High-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder, and zirconium hydride powder (based on zirconium element weight) with a purity of 99.9% and all passing through a 200-mesh sieve were placed in a vacuum mixer at a mass ratio of 81.5:8:8:2:0.5 and mixed at room temperature at 60 rpm for 8 hours to obtain a mixture.

[0124] The remaining steps are the same as in Example 1, to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 8% tungsten, 2% molybdenum, 0.5% zirconium, 0.1% carbon, and the remainder being niobium.

[0125] Comparative Example 2

[0126] High-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder, and zirconium hydride powder (based on zirconium element weight) with a purity of 99.9% and all passing through a 200-mesh sieve were placed in a vacuum mixer in a weight ratio of 79:8:8:2:3 and mixed at 60 rpm for 8 hours at room temperature to obtain a mixture.

[0127] The remaining steps are the same as in Example 1, to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 8% tungsten, 2% molybdenum, 3% zirconium, 0.1% carbon, and the remainder being niobium.

[0128] Comparative Example 3

[0129] High-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder and zirconium hydride powder (based on zirconium element weight) were placed in a vacuum mixer in a weight ratio of 79:9:8:2:2 and mixed at 60 rpm for 8 hours at room temperature to obtain a mixture.

[0130] The remaining steps are the same as in Example 1, resulting in a niobium-tantalum-tungsten alloy material containing 9% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder being niobium.

[0131] Comparative Example 4

[0132] High-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder and zirconium hydride powder (based on zirconium element weight) were placed in a vacuum mixer in a weight ratio of 79:8:9:2:2 and mixed at 60 rpm for 8 hours at room temperature to obtain a mixture.

[0133] The remaining steps are the same as in Example 1, to obtain a niobium-tantalum-tungsten alloy material containing 8% tantalum, 9% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder being niobium.

[0134] Comparative Example 5

[0135] The alloy ingot was heated to 1200℃ and held for 90 minutes for homogenization annealing, and then cooled in the furnace.

[0136] The remaining steps are the same as in Example 1, and the niobium-tantalum-tungsten alloy material is obtained.

[0137] Comparative Example 6

[0138] The homogenized annealed alloy ingot was radially forged at a temperature of 900℃ for 20 minutes. Four hammers were used for radial forging, with a hammering force of 200N and a hammering frequency of 45 times / min. During the radial forging process, the rotation speed of the alloy ingot was 15r / min and the axial feeding speed was 5mm / s. The alloy ingot was forged from Φ153×260mm to Φ85×700mm to obtain the billet.

[0139] The remaining steps are the same as in Example 1, and the niobium-tantalum-tungsten alloy material is obtained.

[0140] Comparative Example 7

[0141] The radially forged billet was then subjected to rotary forging at a temperature of 700℃ for 90 minutes. Four hammers were used for rotary forging, with a hammering force of 250 kN, a hammering frequency of 50 times / min, and a hammer rotation speed of 20 rpm. The billet was fed at a speed of 3 mm / s. The billet was forged to Φ55×1650 mm to obtain a niobium-tantalum-tungsten alloy material. The remaining steps were the same as in Example 1.

[0142] Test case

[0143] (1) Testing of the purity of metal powder:

[0144] The metal powder was digested in a nitric acid-hydrogen peroxide solution (volume ratio 4:1) under microwave treatment for 12 hours, cooled and dried, and then diluted to 25 mL with 2% nitric acid solution to obtain the sample. The sample was analyzed by ICP-MS, and the purity of the metal powder was calculated based on the test results and the external standard method.

[0145] (2) Testing of the proportions of each element in niobium-tantalum-tungsten alloy materials:

[0146] The alloy material was polished to remove the oxide surface, and then ultrasonically cleaned with ethanol and deionized water in sequence. A sample with a diameter of 16 mm and a thickness of 2 mm was taken and analyzed by glow discharge mass spectrometry. The proportion of each element in the alloy material was determined according to the national standard GB / T 42272-2022 "Method for compositional analysis of metallic materials by glow discharge mass spectrometry".

[0147] (3) Density test of niobium-tantalum-tungsten alloy materials:

[0148] Density testing employs Archimedes' displacement method, which is suitable for sintered metals or hard alloys. The specific steps are as follows:

[0149] Sample preparation: Cut the alloy material into regular small pieces, polish the surface smooth, and use ultrasonic cleaning to remove dirt.

[0150] Dry weight measurement (m1): Weigh the sample in air.

[0151] Wet weight measurement (m2): Immerse the sample in deionized water, suspend it on the balance hook to eliminate the influence of air bubbles, and measure its buoyancy after the liquid level stabilizes.

[0152]

[0153] Where ρ 水 The density of water at the test temperature.

[0154] Theoretical density calculation: The theoretical density is calculated based on the weighted average of the alloy composition ratio. Density = Actual density / Theoretical density.

[0155] (4) Tensile properties of niobium-tantalum-tungsten alloy materials at room temperature and high temperature:

[0156] The room temperature tensile properties of niobium-tantalum-tungsten alloy materials were tested according to the national standard GB / T 228.1-2010 "Metallic materials, tensile testing - Part 1: Room temperature test method". The high temperature tensile properties of niobium-tantalum-tungsten alloy materials were tested according to the national standard GB / T 228.2-2015 "Metallic materials, tensile testing - Part 2: High temperature test method".

[0157] The elemental composition, density, tensile strength Rm, and stress Rp corresponding to 0.2% plastic deformation of the alloy material. 0.2 The results of the elongation after fracture (A) are shown in the table below.

[0158] Table 1 Test results of Examples 1-7

[0159]

[0160] As can be seen from the table above, the alloy material of the present invention has high density and high tensile properties at room temperature, 1600℃ and 1800℃.

[0161] Table 2 Test results of Example 1 and Comparative Examples 1-4

[0162]

[0163] As shown in Table 2:

[0164] Compared with the low zirconium content in the alloy material of Comparative Example 1, the high tantalum content in the alloy material of Comparative Example 3, or the high tungsten content in the alloy material of Comparative Example 4, the alloy material of the present invention has significantly improved density and tensile properties at room temperature, 1600℃, and 1800℃.

[0165] Compared to the alloy material in Comparative Example 2, which had an excessively high zirconium content, the alloy material of this invention exhibits significantly improved density, tensile strength and elongation at room temperature, and elongation at 1600°C. Furthermore, it shows significantly improved Rp at 1800°C. 0.2 The elongation after fracture is significantly improved.

[0166] Table 3 Test results of Examples 1, 5-7 and Comparative Examples 5-7

[0167]

[0168] As shown in Table 3:

[0169] Compared with the low homogenization annealing temperature of Comparative Example 5, the tensile properties of the alloy materials in Examples 1 and 5 of the present invention are significantly improved at room temperature, 1600°C and 1800°C.

[0170] Compared with the excessively low radial forging temperature of Comparative Example 6, the alloy materials of Examples 1 and 6 of the present invention have significantly improved density and tensile properties at room temperature, 1600°C and 1800°C.

[0171] Compared with the excessively low forging temperature of Comparative Example 7, the alloy materials of Examples 1 and 7 of the present invention have significantly improved density and tensile properties at room temperature, 1600°C and 1800°C.

[0172] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A niobium alloy material, wherein, The niobium alloy material is mainly composed of the following elements by weight percentage: Tantalum 4% - 8.5% Tungsten 4% - 8.5% Molybdenum 1% - 3% Zirconium 0.8% - 2.5% Carbon 0 - 0.2% The rest are niobium; Furthermore, the niobium alloy material has a tensile strength of 550-600 MPa at room temperature; a tensile strength of 144-160 MPa at 1600℃; and a tensile strength of 78-100 MPa at 1800℃.

2. The niobium alloy material of claim 1, wherein, The niobium alloy material has a tensile strength of 560-600 MPa at room temperature; and / or, The niobium alloy material exhibits a stress of 420-490 MPa corresponding to 0.2% plastic deformation at room temperature; and / or, The niobium alloy material has an elongation at break of 31% - 40% at room temperature.

3. The niobium alloy material of claim 1, wherein, The niobium alloy material has a tensile strength of 568-600 MPa at room temperature; and / or, The niobium alloy material exhibits a stress of 425-490 MPa corresponding to 0.2% plastic deformation at room temperature; and / or, The niobium alloy material has an elongation at break of 33% - 40% at room temperature.

4. The niobium alloy material according to claim 1, wherein, The niobium alloy material exhibits a stress of 429-490 MPa corresponding to 0.2% plastic deformation at room temperature; and / or, The niobium alloy material has an elongation at break of 35% - 40% at room temperature.

5. The niobium alloy material according to claim 1, wherein, The niobium alloy material has a tensile strength of 146–160 MPa at 1600 °C; and / or, The niobium alloy material exhibits a stress of 135-150 MPa corresponding to 0.2% plastic deformation at 1600 °C; and / or, The niobium alloy material has an elongation after fracture of 35% - 45% at 1600 °C.

6. The niobium alloy material of claim 1, wherein, The niobium alloy material has a tensile strength of 148-160 MPa at 1600 °C; and / or, The niobium alloy material exhibits a stress of 140-150 MPa corresponding to 0.2% plastic deformation at 1600 °C; and / or, The niobium alloy material has an elongation after fracture of 36% - 45% at 1600 °C.

7. The niobium alloy material of claim 1, wherein, The stress corresponding to 0.2% plastic deformation in the niobium alloy material at 1600 °C is 142-150 MPa.

8. The niobium alloy material of claim 1, wherein, The niobium alloy material has a tensile strength of 80-100 MPa at 1800 °C; and / or, The niobium alloy material exhibits a stress of 73-100 MPa corresponding to 0.2% plastic deformation at 1800 °C; and / or, The niobium alloy material has an elongation after fracture of 34% - 50% at 1800 °C.

9. The niobium alloy material of claim 1, wherein, The niobium alloy material has a tensile strength of 88-100 MPa at 1800 °C; and / or, The niobium alloy material exhibits a stress of 80-100 MPa corresponding to 0.2% plastic deformation at 1800 °C; and / or, The niobium alloy material has an elongation after fracture of 39% - 50% at 1800 °C.

10. The niobium alloy material according to claim 1, wherein, The niobium alloy material exhibits a stress of 85-100 MPa corresponding to 0.2% plastic deformation at 1800 °C; and / or, The niobium alloy material has an elongation after fracture of 40% - 50% at 1800 °C.

11. The niobium alloy material of any one of claims 1 to 10, wherein, The density of the niobium alloy material is 96%–100%.

12. The niobium alloy material of any one of claims 1 to 10, wherein, The density of the niobium alloy material is 99%-100%.

13. The niobium alloy material of any one of claims 1 to 10, wherein, The density of the niobium alloy material is 99.8%-100%.

14. A method for preparing the niobium alloy material according to any one of claims 1 to 13, comprising the following steps: A mixture is obtained by mixing tantalum source, tungsten source, molybdenum source, zirconium source and niobium source; The mixture is shaped and sintered to obtain a shaped product; The molded article is melted at least once under vacuum conditions to obtain an alloy ingot; The alloy ingot was homogenized and annealed at 1300 ℃ - 1600 ℃ for 80 - 110 minutes, then cooled to obtain a billet. The billet is subjected to radial forging and rotary forging to obtain niobium alloy material; wherein the radial forging temperature is 1000℃ - 1200℃ and the time is 10-30 minutes; the rotary forging temperature is 1000℃ - 1200℃ and the time is 80-100 minutes.

15. The method of claim 14, wherein, The conditions for radial forging include one or more of the following: 1) The number of radially forged hammers is 4-6; 2) The hammering force for radial forging is 150-300N; 3) The hammering frequency for radial forging is 40-60 times / min; 4) During the radial forging process, the rotational speed of the billet is 10 r / min - 30 r / min; 5) During the radial forging process, the axial feeding speed of the billet is 2-6 mm / s.

16. The method of claim 14, wherein, The conditions for rotary forging include one or more of the following: A) The number of hammers in the rotary forging process is 4-6; B) The hammering force of the rotary forging is 200-300 kN; C) The hammering frequency of the rotary forging is 30-80 times / min; D) The rotational speed of the hammer in the rotary forging process is 10-30 rpm; E) During the rotary forging process, the axial feeding speed of the billet is 1-10 mm / s.

17. The method of claim 14, wherein, Formed by cold isostatic pressing.

18. The method of claim 17, wherein, The static pressure of the cold isostatic pressing is 200 MPa - 260 MPa, and the holding time of the cold isostatic pressing is 20s - 30s.

19. The method of claim 14, wherein, The niobium source is niobium powder, which is prepared through the following steps: Niobium oxide is mixed with carbon materials to obtain a mixture; The mixture is subjected to carbonization, sintering, hydrogenation, sieving, dehydrogenation, and cooling to obtain the niobium powder.

20. The method according to claim 19, wherein, The steps for preparing the niobium powder include one or more of the following features: The niobium oxide is niobium pentoxide; The carbon material is carbon black and / or graphite; The weight ratio of niobium oxide to carbon material is 1:0.2 - 1:0.5; The mixing time is 7-9 hours; The carbonization treatment is carried out at a temperature of 1400 ℃-1600 ℃ for 2-5 hours, with a heating rate of 10-40 ℃ / min. The carbonization process is carried out in a hydrogen atmosphere; The sintering temperature is 1750 ℃ ​​- 1950 ℃, and the time is 8 - 12 hours; The sintering is performed under vacuum; The hydrogenation process is carried out at a hydrogen pressure of 0.02 - 0.2 MPa, a temperature of 800 ℃ - 1000 ℃, and a time of 3 - 5 hours. The dehydrogenation treatment is carried out at a temperature of 900℃ - 1000℃ for 2 - 5 hours.

21. The method according to any one of claims 14 to 20, characterized in that... One or more of the following: a) In the step of preparing the molded article, the sintering temperature is 1800 ℃ - 2100 ℃, and the time is 9 - 15 hours; b) In the step of preparing the molded article, the sintering heating rate is 200℃ / h - 400℃ / h; c) In the step of preparing the molded article, the sintering is carried out at ≤10 -2 The procedure was carried out under Pa vacuum conditions; d) The melting process is performed twice; e) The power of the first smelting is 350-380 KW; f) The melting rate for the first melting is 75-100 kg / h; g) The first smelting is ≤4×10 -4 Performed under a vacuum of mbar; h) The power of the second smelting is 360-385 KW; i) The melting rate for the second melting is 75-90 kg / h; j) the second melting is performed at a vacuum of < 2 x 10 -4 mbar. k) Taking the total weight of tantalum, tungsten, molybdenum, zirconium, niobium, and carbon in the mixture as a 100% basis, the mixture contains the following elements by weight percentage: Tantalum 4% - 8.5% Tungsten 4% - 8.5% Molybdenum 1% - 3% Zirconium 0.8% - 2.5% Carbon 0 - 0.2% The rest are niobium; l) Before mixing, the tantalum source, the tungsten source, the molybdenum source, the zirconium source and the niobium source are each passed through a 100-300 mesh sieve.

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