Niobium alloy material and preparation method thereof

Abstract

The invention belongs to the field of metal materials, and particularly relates to a niobium alloy material which mainly comprises the following elements in percentage by weight: 4%-8.5% of tantalum, 4%-8.5% of tungsten, 1%-3% of molybdenum, 0.8%-2.5% of zirconium, 0-0.2% of carbon and the balance of niobium. The invention further relates to a method for preparing the niobium alloy material. The compactness of the niobium alloy material and the tensile property at the room temperature and the high temperature are obviously improved.

Description

Technical Field

[0001] The present invention belongs to the field of metal materials, and in particular relates to a niobium alloy material and a method for preparing the niobium alloy material. Background Art

[0002] The demand for high-temperature resistant materials in the aerospace field is becoming increasingly urgent. Niobium alloys have become the preferred material for hot-end components due to their excellent high-temperature strength, corrosion resistance and low density. Traditional preparation processes such as vacuum arc melting have problems with long processing cycles and high costs. In particular, C-103 alloys containing expensive elements such as Hf and Ta increase costs. Studies have shown that the high-temperature performance of alloys can be improved by adding solid solution strengthening elements such as Ta, W, and Mo. Among them, the strengthening effect of tungsten is twice that of molybdenum, but excessive addition will damage plasticity and increase the brittle transition temperature. Composite strengthening can optimize performance through synergistic solid solution strengthening and carbide / oxide dispersion strengthening, but the size and distribution of the precipitated phases must be precisely controlled.

[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 processing performance. In 1961, C-103 alloy (Nb-10Hf-1Ti) became the first successfully applied niobium-tungsten alloy. Subsequent alloys such as Cb132M, though attempted for use in aircraft engine blades, failed due to insufficient overall performance. Current research is shifting towards low-cost process innovations, providing new approaches to meeting the large-scale demand for high-performance niobium alloy components in the aerospace industry. Summary of the Invention

[0004] One of the objects of the present invention is to provide a niobium alloy material having significantly improved density and tensile properties at room temperature and high temperature. Furthermore, the present invention also relates to a method for preparing the niobium alloy material.

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

[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 remainder 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, such as 569 MPa, 570 MPa, 575 MPa, 580 MPa, or 590 MPa.

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

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

[0015] In any embodiment of the first aspect, the niobium alloy material has a tensile strength at 1600° C. of 144-160 MPa, preferably 146-160 MPa, more preferably 148-160 MPa, such as 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, such as 142 MPa, 145 MPa, 147 MPa, or 148 MPa.

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

[0018] In any embodiment of the first aspect, the niobium alloy material has a tensile strength at 1800° C. of 78-100 MPa, preferably 80-100 MPa, more preferably 88-100 MPa, such as 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, such as 86 MPa, 88 MPa, 90 MPa, or 95 MPa.

[0020] In any embodiment of the first aspect, the niobium alloy material has an elongation after fracture at 1800° C. of 34%-50%, preferably 39%-50%, more preferably 40%-50%, such as 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] mixing a tantalum source, a tungsten source, a molybdenum source, a zirconium source, and a niobium source to obtain a mixture;

[0024] forming and sintering the mixture to obtain a formed object;

[0025] melting the formed object at least once under vacuum conditions to obtain an alloy ingot;

[0026] homogenizing annealing the alloy ingot at 1300° C.-1600° C. (e.g., 1400° C., 1500° C.) for 80 min-110 min (e.g., 85 min, 90 min, 95 min, 100 min, 105 min), and cooling to obtain a billet;

[0027] The blank is subjected to radial forging and rotary forging to obtain a niobium alloy material.

[0028] In any embodiment of the second aspect, the formed objects are bundled before smelting to ensure uniformity during the melting process and to prevent loose materials from falling into the crucible and causing component segregation.

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

[0030] In any embodiment of the second aspect, the number of radially forged hammer heads 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, 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 rotation speed of the blank is 10 r / min-30 r / min, for example, 15 r / min, 20 r / min, 25 r / min.

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

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

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

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

[0038] In any embodiment of the second aspect, the hammering frequency of the rotary swaging 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, 75 times / min.

[0039] In any embodiment of the second aspect, the rotation speed of the hammer head during rotary forging is 10-30 rpm, such as 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 blank 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, the forming is performed by cold isostatic pressing.

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

[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, and the niobium powder is prepared by the following steps:

[0045] mixing niobium oxide with carbon material to obtain a mixed material;

[0046] The mixed material is subjected to carbonization treatment, sintering, hydrogenation treatment, sieving, dehydrogenation treatment, 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, 1:0.4;

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

[0052] Mixing by ball milling;

[0053] The carbonization treatment temperature is 1400° C.-1600° C. (e.g., 1500° C.), the time is 2-5 hours (e.g., 3 hours), and the heating rate is 10-40° C. / min (e.g., 20° C. / min);

[0054] The carbonization treatment is carried out under a hydrogen atmosphere;

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

[0056] The sintering is carried out under vacuum; optionally, the vacuum degree is ≤10 -1 Pa, for example 10 -2 Pa;

[0057] The hydrogen pressure of the hydrogenation treatment is 0.04-0.2 MPa (e.g., 0.04 MPa, 0.06 MPa), the temperature is 800° C.-1000° C. (e.g., 850° C., 900° C., 950° C.), and the time is 3-5 hours (e.g., 4 hours);

[0058] Before dehydrogenation treatment, pass through a 100-200 mesh sieve, such as a 180 mesh sieve;

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

[0060] The dehydrogenation treatment is performed at a temperature of 900° C. to 1000° C. (eg, 950° C.) and for a time of 2 to 5 hours (eg, 4 hours).

[0061] In any embodiment of the second aspect, in the step of preparing the molded object, the sintering temperature is 1800°C-2100°C (for example, 1830°C, 1850°C, 1900°C, 1950°C, 2000°C), and the sintering time is 9h-15h (for example, 10 hours, 11 hours, 12 hours, 13 hours, 14 hours).

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

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

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

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

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

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

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

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

[0070] In any embodiment of the second aspect, the second smelting is less than 2×10 -4 mbar vacuum, for example 2×10 -5 mbar.

[0071] In any embodiment of the second aspect, taking the total weight of the tantalum element, tungsten element, molybdenum element, zirconium element, niobium element and carbon element in the mixture as 100%, the mixture comprises the following elements in terms of 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 remainder 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 respectively passed through a 100-300 mesh sieve, such as a 200 mesh sieve.

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

[0080] In the present 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 slight plastic deformation.

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

[0082] The beneficial effects achieved by the present invention are:

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

[0084] 2. The present invention adopts a specific proportion of metal elements, and through the synergistic effect of solid solution strengthening and dispersion strengthening, it improves the density of the alloy material and the tensile properties at room temperature and high temperature, and improves the comprehensive properties such as corrosion resistance.

[0085] 3. The preparation method of the present invention adopts a combination of homogenization annealing, radial forging and rotary forging to reduce problems such as alloy structure segregation and uneven element distribution, and improve the density, room temperature tensile properties and high temperature tensile properties of the niobium alloy material.

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

[0087] The embodiments of the present invention will be clearly and completely described below with reference to the examples. Obviously, the examples described are only some of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. All other embodiments obtained by ordinary technicians in this field based on the examples in the present invention without making any creative efforts 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 carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20°C / min, a holding temperature of 1500°C, a holding time of 3 hours, and a hydrogen atmosphere; the carbonized mixture was sintered at a temperature of 1900°C, a holding time of 10 hours, and a vacuum degree of 10 -2 The sintered material was hydrogenated in a 0.04 MPa hydrogen atmosphere at 950°C for 4 hours. The hydrogenated material was ball milled and passed through a 180-mesh sieve. The sieved material was then dehydrogenated in a hydrogenation degassing furnace at 950°C for 4 hours. After cooling naturally, high-purity niobium powder was obtained.

[0090] (2) placing high-purity niobium powder, tantalum powder, tungsten powder, molybdenum powder, and zirconium hydride powder (calculated by weight of zirconium element) with a purity of 99.9% and all passing a 200-mesh sieve in a weight ratio of 80:8:8:2:2 into a vacuum mixer at 60 rpm at room temperature for 8 hours to obtain a mixed material;

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

[0092] (4) Place the pre-sintered bar into a vacuum hot pressing sintering furnace for sintering at a heating rate of 300°C / h, a sintering temperature of 1830°C, a sintering time of 12 hours, and a sintering vacuum degree of 10 -3 Pa, after sintering is completed, the furnace is cooled to obtain alloy bars;

[0093] (5) The alloy bars were bundled and placed in a vacuum electron beam furnace for two smeltings. During the first smelting, the smelting power of the vacuum electron beam furnace was set to 375 kW, the smelting speed was controlled at 86 kg / h, and the vacuum degree in the furnace reached 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 in the furnace reached 2×10 -5 mbar, and obtain alloy ingot;

[0094] (6) heating the alloy ingot to 1400°C and holding it for 90 minutes for homogenization annealing, and then cooling it in the furnace;

[0095] (7) The alloy ingot after homogenization annealing was subjected to radial forging at a temperature of 1020°C and a time of 20 min. The number of hammers used in the radial forging was 4, the hammering force was 200 N, and the hammering frequency was 45 times / min. During the radial forging process, the rotation speed of the alloy ingot was 15 r / min and the axial feeding speed was 5 mm / s. The alloy ingot was forged from Φ153×260 mm to Φ85×700 mm to obtain a billet;

[0096] (8) The radially forged billet is rotary forged at a temperature of 1100°C and a time of 90 min. Four hammers are used for rotary forging, with a hammering force of 250 kN, a hammering frequency of 50 times / min, a hammering speed of 20 rpm, and a billet feeding speed of 3 mm / s. The billet is forged to Φ55×1650 mm 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 carbonized in a graphite resistance furnace (3000A / 25V) at a heating rate of 20°C / min, a holding temperature of 1500°C, a holding time of 3 hours, and a hydrogen atmosphere. The carbonized mixture was sintered at 1800°C for 11 hours and a vacuum degree of 10 -2 The sintered material was hydrogenated in a 0.04 MPa hydrogen atmosphere at 950°C for 4 hours. The hydrogenated material was ball milled and passed through a 180-mesh sieve. The sieved material was then dehydrogenated in a hydrogenation degassing furnace at 950°C for 4 hours. After cooling naturally, high-purity niobium powder was obtained.

[0099] (4) Place the pre-bonded bar into a vacuum hot pressing sintering furnace for sintering at a heating rate of 300°C / h, a sintering temperature of 1900°C, a sintering time of 12 hours, and a sintering vacuum degree of 10 -3 Pa, after sintering is completed, the furnace is cooled to obtain alloy bars;

[0100] (5) The alloy bars were bundled and placed in a vacuum electron beam furnace for two smeltings. During the first smelting, the smelting power of the vacuum electron beam furnace was set to 370 kW, the smelting speed was controlled at 80 kg / h, and the vacuum degree in the furnace reached 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 -5 mbar, and obtain alloy ingot;

[0101] Steps (2)-(3) and (6)-(8) are the same as those 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 rest 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 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 sintered at a temperature of 1850℃, a holding time of 10.5 hours, and a vacuum degree of 10 -2 The sintered material was hydrogenated in a 0.04 MPa hydrogen atmosphere at 950°C for 4 hours. The hydrogenated material was ball milled and passed through a 180-mesh sieve. The sieved material was then dehydrogenated in a hydrogenation degassing furnace at 950°C for 4 hours. After cooling naturally, high-purity niobium powder was obtained.

[0104] (4) Place the pre-sintered bar into a vacuum hot pressing sintering furnace for sintering at a heating rate of 300°C / h, a sintering temperature of 1950°C, a sintering time of 10 hours, and a sintering vacuum degree of 10 -3 Pa, after sintering is completed, the furnace is cooled to obtain alloy bars;

[0105] (5) The alloy bars were bundled and placed in a vacuum electron beam furnace for two smeltings. During the first smelting, the smelting power of the vacuum electron beam furnace was set to 360 kW, the smelting speed was controlled at 80 kg / h, and the vacuum degree in the furnace reached 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 in the furnace reached 2×10 -5 mbar, and obtain alloy ingot;

[0106] Steps (2)-(3) and (6)-(8) are the same as those 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 rest 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 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 sintered at a temperature of 1850℃, a holding time of 10.5 hours, and a vacuum degree of 10 -2 The sintered material was hydrogenated in a 0.04 MPa hydrogen atmosphere at 950°C for 4 hours. The hydrogenated material was ball milled and passed through a 180-mesh sieve. The sieved material was then dehydrogenated in a hydrogenation degassing furnace at 950°C for 4 hours. After cooling naturally, high-purity niobium powder was obtained.

[0109] (4) Place the pre-sintered bar into a vacuum hot pressing sintering furnace for sintering at a heating rate of 300°C / h, a sintering temperature of 2000°C, a sintering time of 10 hours, and a sintering vacuum degree of 10 -3 Pa, after sintering is completed, the furnace is cooled to obtain alloy bars;

[0110] (5) The alloy bars were bundled and placed in a vacuum electron beam furnace for two smeltings. During the first smelting, the smelting power of the vacuum electron beam furnace was set to 360 kW, the smelting speed was controlled at 80 kg / h, and the vacuum degree in the furnace reached 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 in the furnace reached 2×10 -5 mbar, and obtain alloy ingot;

[0111] Steps (2)-(3) and (6)-(8) are the same as those 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 rest is niobium.

[0112] Example 5

[0113] (6) heating the alloy ingot to 1500°C and holding it for 90 minutes for homogenization annealing, and then cooling it in the furnace;

[0114] Steps (1)-(5) and (7)-(8) are the same as those 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 rest is niobium.

[0115] Example 6

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

[0117] (7) The alloy ingot after homogenization annealing was subjected to radial forging at a temperature of 1100°C and a time of 15 min. The number of hammers used in the radial forging was 4, the hammering force was 200 N, and the hammering frequency was 45 times / min. During the radial forging process, the rotation speed of the alloy ingot was 20 r / min and the axial feeding speed was 5 mm / s. The alloy ingot was forged from Φ153×260 mm to Φ85×700 mm to obtain a billet;

[0118] (8) The radially forged billet is rotary forged at a temperature of 1100°C and a time of 90 min. The number of hammers used in the rotary forging is 4, the hammering force is 250 kN, the hammering frequency is 35 times / min, the hammering speed is 20 rpm, and the billet feeding speed is 3 mm / s. The billet is forged to Φ55×1650 mm to obtain a niobium-tantalum-tungsten alloy material, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the rest is 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°C and a time of 85 min. Four hammers are used for rotary forging, with a hammering force of 250 kN, a hammering frequency of 40 times / min, a hammering speed of 20 rpm, and a billet feeding speed of 3 mm / s. The billet is forged to Φ55×1650 mm 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 (calculated by weight of zirconium element), all of which have a purity of 99.9% and have passed a 200-mesh sieve, are placed in a vacuum mixer at a mass ratio of 81.5:8:8:2:0.5 and mixed at 60 rpm at room temperature for 8 hours to obtain a mixed material;

[0124] The remaining steps are the same as those in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 0.5% zirconium, 0.1% carbon, and the remainder is niobium.

[0125] Comparative Example 2

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

[0127] The remaining steps are the same as those in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 8% tungsten, 2% molybdenum, 3% zirconium, 0.1% carbon, and the remainder is niobium.

[0128] Comparative Example 3

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

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

[0131] Comparative Example 4

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

[0133] The remaining steps are the same as those in Example 1, and a niobium-tantalum-tungsten alloy material is obtained, which contains 8% tantalum, 9% tungsten, 2% molybdenum, 2% zirconium, 0.1% carbon, and the remainder is niobium.

[0134] Comparative Example 5

[0135] The alloy ingot was heated to 1200°C and kept at this temperature for 90 min for homogenization annealing, and then cooled in the furnace;

[0136] The remaining steps are the same as those in Example 1 to obtain a niobium-tantalum-tungsten alloy material.

[0137] Comparative Example 6

[0138] The alloy ingot after homogenization annealing was subjected to radial forging at a temperature of 900° C. and a time of 20 min. The number of hammers used in the radial forging was 4, the hammering force was 200 N, and the hammering frequency was 45 times / min. During the radial forging process, the rotation speed of the alloy ingot was 15 r / min, and the axial feeding speed was 5 mm / s. The alloy ingot was forged from Φ153×260 mm to Φ85×700 mm to obtain a billet.

[0139] The remaining steps are the same as those in Example 1 to obtain a niobium-tantalum-tungsten alloy material.

[0140] Comparative Example 7

[0141] The radially forged billet was rotary forged at a temperature of 700°C for 90 min, with four hammers, a hammering force of 250 kN, a hammering frequency of 50 times / min, a hammer speed of 20 rpm, and a billet feeding 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 those in Example 1.

[0142] Test Case

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

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

[0145] (2) Test of the ratio of each element in niobium-tantalum-tungsten alloy material:

[0146] The alloy material was polished to remove the oxidized surface, and 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 the sample was tested by glow discharge mass spectrometry. The proportion of each element in the alloy material was measured according to the national standard GB / T 42272-2022 "Method for Composition Analysis of Metal Materials by Glow Discharge Mass Spectrometry".

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

[0148] The density test uses the Archimedes drainage method, which is applicable to sintered metal or cemented carbide materials. The specific steps are as follows:

[0149] Sample preparation: The alloy material was cut into regular small pieces, the surface was polished smooth, and the dirt was removed by ultrasonic cleaning.

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

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

[0152]

[0153] where ρ 水 is the density of water at the test temperature.

[0154] Theoretical density calculation: Theoretical density is calculated based on the weighted ratio of alloy components. Density = actual density / theoretical density.

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

[0156] Room temperature tensile testing of niobium, tantalum, and tungsten alloys is conducted in accordance with the national standard GB / T 228.1-2010, "Tensile testing of metallic materials - Part 1: Room temperature test methods." Elevated temperature tensile testing of niobium, tantalum, and tungsten alloys is conducted in accordance with the national standard GB / T 228.2-2015, "Tensile testing of metallic materials - Part 2: Elevated temperature test methods."

[0157] Element ratio, 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 break A are shown in the table below.

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

[0159]

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

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

[0162]

[0163] From Table 2 we can see that:

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

[0165] Compared with the alloy material of comparative example 2 in which the zirconium content is too high, the density of the alloy material of the present invention is significantly improved, the tensile strength and elongation at room temperature are significantly improved, the elongation at 1600℃ is significantly improved, and the Rp at 1800℃ is 0.2 and elongation at break are significantly improved.

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

[0167]

[0168] From Table 3 we can see that:

[0169] Compared with comparative example 5 in which the homogenization annealing temperature is too low, the tensile properties of the alloy materials of examples 1 and 5 of the present invention at room temperature, 1600° C. and 1800° C. are significantly improved.

[0170] Compared with comparative example 6 in which the radial forging temperature is too low, the density of the alloy materials in examples 1 and 6 of the present invention is significantly improved, and the tensile properties at room temperature, 1600° C. and 1800° C. are significantly improved.

[0171] Compared with comparative example 7 in which the swaging temperature is too low, the density of the alloy materials in examples 1 and 7 of the present invention is significantly improved, and the tensile properties at room temperature, 1600° C. and 1800° C. are significantly improved.

[0172] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A niobium alloy material, wherein: The niobium alloy material is mainly composed of the following elements in terms of weight percentage: Tantalum 4%-8.5% Tungsten 4%-8.5% Molybdenum 1%-3% Zirconium 0.8%-2.5% Carbon 0-0.2% The remainder is niobium.

2. The niobium alloy material according to claim 1, wherein: The niobium alloy material has a tensile strength of 550-600 MPa at room temperature, preferably 560-600 MPa, more preferably 568-600 MPa; and / or, 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; and / or, The elongation after fracture of the niobium alloy material at room temperature is 31%-40%, preferably 33%-40%, more preferably 35%-40%.

3. The niobium alloy material according to claim 1 or 2, wherein: The niobium alloy material has a tensile strength at 1600° C. of 144-160 MPa, preferably 146-160 MPa, more preferably 148-160 MPa; and / or, 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; and / or, The niobium alloy material has an elongation after fracture at 1600° C. of 35%-45%, preferably 36%-45%.

4. The niobium alloy material according to any one of claims 1 to 3, wherein: The niobium alloy material has a tensile strength at 1800° C. of 78-100 MPa, preferably 80-100 MPa, more preferably 88-100 MPa; and / or, 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; and / or, The niobium alloy material has an elongation after fracture at 1800° C. of 34%-50%, preferably 39%-50%, and more preferably 40%-50%.

5. The niobium alloy material according to any one of claims 1 to 4, wherein: The density of the niobium alloy material is 96%-100%, preferably 99%-100%, and more preferably 99.8%-100%.

6. A method for preparing the niobium alloy material according to any one of claims 1 to 5, comprising the following steps: mixing a tantalum source, a tungsten source, a molybdenum source, a zirconium source, and a niobium source to obtain a mixture; forming and sintering the mixture to obtain a formed object; melting the formed object at least once under vacuum conditions to obtain an alloy ingot; homogenizing annealing the alloy ingot at 1300° C.-1600° C. for 80-110 minutes, and cooling to obtain a billet; The blank is subjected to radial forging and rotary forging to obtain a niobium alloy material.

7. The method according to claim 6, wherein: The radial forging conditions include one or more of the following: 1) The radial forging temperature is 1000° C.-1200° C., and the time is 10-30 minutes; 2) The number of radial forging hammers is 4-6; 3) The hammering force of the radial forging is 150-300N; 4) The hammering frequency of the radial forging is 40-60 times / min; 5) During the radial forging process, the rotation speed of the blank is 10 rpm to 30 rpm; 6) During the radial forging process, the axial feeding speed of the blank is 2-6 mm / s.

8. The method according to claim 6 or 7, wherein: The conditions for swaging include one or more of the following: A) the swaging temperature is 1000° C.-1200° C., and the swaging time is 80-100 minutes; B) the number of hammer heads for rotary forging is 4-6; C) the hammering force of the rotary forging is 200-300kN; D) the hammering frequency of the rotary swaging is 30-80 times / min; E) the hammer speed of the rotary forging is 10-30 rpm; F) During the rotary forging process, the axial feeding speed of the blank is 1-10 mm / s.

9. The method according to any one of claims 6 to 8, wherein: Formed by cold isostatic pressing; Optionally, 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.

10. The method according to any one of claims 6 to 9, wherein: The niobium source is niobium powder, which is prepared by the following steps: mixing niobium oxide with carbon material to obtain a mixed material; Carburizing, sintering, hydrogenating, screening, dehydrogenating, and cooling the mixed material to obtain the niobium powder; Optionally, the steps of 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 the niobium oxide to the carbon material is 1:0.2-1:0.5; The mixing time is 7-9 hours; The carbonization treatment temperature is 1400-1600°C, the time is 2-5 hours, and the heating rate is 10-40°C / min; The carbonization treatment is carried out under a hydrogen atmosphere; The sintering temperature is 1750°C-1950°C and the sintering time is 8-12 hours; The sintering is carried out under vacuum; The hydrogen pressure of the hydrogenation treatment is 0.02-0.2 MPa, the temperature is 800°C-1000°C, and the time is 3-5 hours; The dehydrogenation treatment is carried out at a temperature of 900° C. to 1000° C. and for a time of 2 to 5 hours.

11. The method according to any one of claims 6 to 10, characterized in that One or more of the following: a) in the step of preparing the molded article, the sintering temperature is 1800° C.-2100° C. and the sintering time is 9-15 hours; b) in the step of preparing the molded object, the sintering heating rate is 200° C. / h-400° C. / h; c) In the step of preparing the molded object, the sintering temperature is ≤10 -2 Pa vacuum conditions; d) the smelting is performed twice; e) The power of the first smelting is 350-380KW; f) The melting rate of the first melting is 75-100 kg / h; g) The first melting is ≤4×10 -4 mbar vacuum; h) The power of the second smelting is 360-385KW; i) The melting speed of the second melting is 75-90kg / h; j) The second melting is ≤2×10 -4 mbar vacuum; k) Taking the total weight of tantalum, tungsten, molybdenum, zirconium, niobium and carbon in the mixture as 100%, the mixture comprises the following elements in percentage by weight: Tantalum 4%-8.5% Tungsten 4%-8.5% Molybdenum 1%-3% Zirconium 0.8%-2.5% Carbon 0-0.2% The rest is niobium; l) Before mixing, the tantalum source, the tungsten source, the molybdenum source, the zirconium source and the niobium source are respectively passed through a 100-300 mesh sieve.

Images