Tungsten alloy wire, preparation method therefor, and use thereof in cutting of semiconductor material

Abstract

The present application relates to the technical field of tungsten alloy materials, and in particular to a tungsten alloy wire, a preparation method therefor, and a use thereof in cutting of a semiconductor material. The tungsten alloy is composed of the following elements in percentage by mass: 0.4-1.1 wt% of L, 0.001-0.25 wt% of Z, and the balance of tungsten and inevitable impurities, wherein L is one or more than two of lanthanum, cerium, praseodymium, neodymium, gadolinium and erbium, and Z comprises oxygen and carbon. The wire diameter of the wire is 20-60 μm, the wire contains linear L or a compound of L along the wire axis direction, and the radial average width D of L or the compound of L is smaller than or equal to 5 nm. According to the present application, the linear L element is doped between tungsten base bodies, and the radial average width of L is controlled to be smaller than or equal to 5 nm, so that the wire has the tensile strength of 5000 MPa or above under the wire diameter of 20-60 μm, and the machining performance of the tungsten alloy wire is enhanced.

Description

A tungsten alloy wire and its preparation method and its application in semiconductor material cutting

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on December 26, 2023, with application number 2023118259397 and invention name “A tungsten alloy wire, its preparation method and application”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of tungsten alloy materials, and in particular to a tungsten alloy wire, a preparation method thereof, and an application thereof in cutting semiconductor materials. Background Art

[0003] Tungsten-based alloy is an alloy material made of refractory metal tungsten as the hard phase and nickel, iron, copper or silver as the bonding phase through powder metallurgy or injection molding technology. Due to its excellent thermal, mechanical, electrical and chemical properties, it is widely used in automotive, medical, aerospace, military, defense and other fields.

[0004] In order to further improve the comprehensive mechanical properties of tungsten alloy wire, the existing method is to dope rare earth elements or rare earth compounds into the tungsten matrix as a second phase dispersion strengthening tungsten material. However, during the high-temperature sintering and recrystallization annealing process, a solid-liquid phase transition easily occurs, and more second-phase particles will merge and grow during the transition process. In addition, the current pressure processing process will cause the second-phase particles to break due to uneven forging or drawing deformation, which cannot effectively improve the strength of the tungsten matrix. More cracks will form at the junction of the second-phase particles and the tungsten wire, causing wire breakage, and also limiting the diameter size of the tungsten wire for deep processing.

[0005] For example, Chinese patent document CN113186438A discloses an alloy wire, its preparation method, and application, in which the lanthanum oxide content is 0.1wt% to 2.0wt%. The tensile strength of the alloy wire can reach 4800MPa below 40μm. However, due to the large amount of rare earth oxide added, the wire defects increase sharply, and the proportion of wire breakage failures during the preparation process increases significantly. At the same time, due to the aggregation of rare earth second phases, the alloy wire has excessive deformation resistance, resulting in a decrease in strength gain after wire thinning and deterioration in processing performance, making it impossible to meet engineering requirements. Summary of the Invention

[0006] In order to solve the problem in the prior art that the introduction of a second phase causes a large number of cracks and breakages in a tungsten alloy wire, the present application provides a tungsten alloy wire, wherein the tungsten alloy is composed of the following elements in mass fractions: L 0.4-1.1wt%, Z 0.001-0.25wt%, and the balance being tungsten and unavoidable impurities;

[0007] Wherein, the L is one or more of lanthanum, cerium, praseodymium, neodymium, gadolinium, and erbium; the Z includes oxygen and carbon; the wire diameter is 20 to 60 μm, and the wire contains linear L or a compound of L along the wire axis, and the radial average width D of the L or the compound of L is ≤5 nm.

[0008] For example, L represents lanthanum, or cerium, or praseodymium, or lanthanum and cerium, or lanthanum and neodymium, or lanthanum and praseodymium, or lanthanum and gadolinium, or cerium and praseodymium, or cerium and neodymium, or praseodymium and gadolinium, or praseodymium and erbium, or neodymium and gadolinium, or lanthanum, cerium and praseodymium, or lanthanum, cerium and erbium, or lanthanum, praseodymium and neodymium, or cerium, praseodymium and neodymium, or praseodymium, neodymium, gadolinium and erbium, etc.;

[0009] For another example, the mass percentage of L is 0.4% to 1.1%, or 0.4% to 1.0%, or 0.4% to 0.8%, or 0.4% to 0.6%, or 0.4% to 0.5%, or 1.0% to 1.1%, or 0.8% to 1.1%. Of course, it can also be 0.4%, 0.41%, 0.5%, 0.55%, 0.6%, 0.8%, 0.86%, 1.0%, 1.05%, etc.;

[0010] The mass percentage of Z is 0.001% to 0.25%, or 0.001% to 0.05%, or 0.001% to 0.1%, or 0.001% to 0.2%, or 0.005% to 0.1%, or 0.1% to 0.25%, or 0.1% to 0.2%, or 0.05% to 0.2%. Of course, it can also be 0.0009%, 0.001%, 0.005%, 0.01%, 0.015%, 0.02%, 0.05%, 0.1%, 0.15%, 0.2%, etc.

[0011] The wire diameter is 20-60 μm, such as 20 μm, 28 μm, 30 μm, 38 μm, 40 μm, 48 μm, 50 μm, 55 μm, 58 μm, 60 μm, etc. The tungsten alloy wire may be uniform or not completely uniform, and may also have a difference of several percentages such as 1% depending on the location;

[0012] It should be noted that “linear” means that the size of L or the compound of L in the wire along the axial direction of the wire is much larger than the size along the radial direction of the wire.

[0013] The compound of L may be an oxide, such as lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, gadolinium oxide, erbium oxide, etc. Of course, it may also be a compound in other forms, such as a carbide of L.

[0014] In some embodiments, in the wire, the radial average width of the tungsten grains is ≤80 nm; preferably, the number of L or L compounds in the wire / the number of tungsten grains=γ, 3≤γ≤10.

[0015] Preferably, the number of surface defects of the wire is ≤10 per 100 meters;

[0016] Preferably, the dislocation density in the wire is ≥5*10 9 / mm 2 .

[0017] In order to ensure the final strength of the tungsten alloy wire, it is necessary to ensure that the wire has good comprehensive mechanical properties and good processing feasibility. The ratio γ of the number of L or L compounds in the wire to the number of tungsten grains is between 3 and 10. If γ is less than 3, the breaking force of the wire cannot be met. If γ is greater than 10, the processing performance of the wire will deteriorate sharply, resulting in a sharp increase in cracks in the wire and serious wire breakage.

[0018] Preferably, when the wire diameter is greater than 50 μm and ≤ 60 μm, the radial average width D of the compound of L or L is ≤ 5 nm, and the tensile strength of the wire is ≥ 5000 MPa; when the wire diameter is greater than 40 μm and ≤ 50 μm, the radial average width D of the compound of L or L is ≤ 4 nm, and the tensile strength of the wire is ≥ 5500 MPa; when the wire diameter is greater than 30 μm and ≤ 40 μm, the radial average width D of the compound of L or L is ≤ 3 nm, and the tensile strength of the wire is ≥ 6000 MPa; when the wire diameter is greater than 20 μm and ≤ 30 μm, the radial average width D of the compound of L or L is ≤ 2 nm, and the tensile strength of the wire is ≥ 7000 MPa.

[0019] The present application also provides a method for preparing the above-mentioned tungsten alloy wire, which includes wet doping, powdering, pressing, sintering, blanking and pressure processing.

[0020] In some embodiments, the wet doping process is: blue tungsten powder is evenly dispersed in deionized water to obtain a blue tungsten suspension, nano-scale compound powder of L is evenly dispersed in an alkaline solution with a pH greater than 11 to form a second suspension, and then the solution containing the Z element and the second suspension are sprayed into the blue tungsten suspension in sequence, and doped blue tungsten powder is obtained after heating and drying.

[0021] The nano-scale compound powder of L is preferably uniformly dispersed in an alkaline solution with a pH greater than 11, and then stirred at a high speed of 1000 to 2000 r / min by a stirring device;

[0022] Preferably, the solution containing element Z is a salt solution of element Z or a suspension of a compound containing element Z;

[0023] The solution of element Z is preferably diluted to a volume ratio of 1:20 or more;

[0024] The preferred drying method is rapid vacuum heating and drying.

[0025] By preparing a suspension of L element compounds, fine particles are directly and evenly doped into the blue tungsten powder, and the fine particles are used as heterogeneous crystal nuclei to co-crystallize and precipitate with tungsten particles. The tungsten alloy powder that can be prepared has a more uniform dispersion distribution. This method no longer requires the use of the element's acid salt form, and the range of dispersed particles that can be prepared is wider, resulting in more stable and reliable tungsten material performance.

[0026] In some embodiments, the preparation method of the blue tungsten powder is: feeding ammonium paratungstate into a reduction furnace, and reducing it at 400-600°C under hydrogen and nitrogen protection to obtain blue tungsten powder, wherein the thickness of the ammonium paratungstate powder layer is less than 10mm, the hydrogen flow rate in the reduction furnace is 20-40L / min, the nitrogen flow rate is 80-160L / min, the oxygen index of the blue tungsten powder is 2.85±0.05, and the ammonium tungsten bronze phase component is greater than 80%.

[0027] Blue tungsten powder is produced using a hydrogen-nitrogen mixed gas as a reducing protective medium. The performance of the discharged blue tungsten powder is controlled by the thickness of the material layer and the size and flow direction of the hydrogen gas. The oxygen index of the blue tungsten is 2.85±0.05, and the blue tungsten with an ammonium tungsten bronze phase ratio of more than 80% is doped. The blue tungsten has coarse particles and many surface cracks, which are conducive to the entry of rare earth solution, improve the doping effectiveness, and thus improve the uniformity of the second phase distribution in the tungsten wire, and improve the comprehensive mechanical properties and processing performance of the tungsten wire.

[0028] In some embodiments, the powder making process is: reducing the doped blue tungsten powder to obtain alloy powder A with a particle size of 1.5 to 2.6 μm and alloy powder B with a particle size of 3.8 to 4.5 μm, respectively, and then mixing alloy powder A and alloy powder B to obtain a mixed powder;

[0029] Preferably, the reduction method of the alloy powder A is: reducing the doped blue tungsten powder once in a hydrogen reduction furnace at 500-800°C, and then reducing it twice in a hydrogen reduction furnace at 700-1000°C to obtain alloy powder A with a particle size of 1.5-2.6 μm.

[0030] Preferably, the alloy powder B is reduced by reducing the doped blue tungsten powder in a hydrogen reduction furnace at 700-1100° C. to obtain alloy powder B with a particle size of 3.8-4.5 μm.

[0031] Preferably, the alloy powder A and alloy powder B are mixed in a mass ratio of 1:(1-2).

[0032] The fine-grained tungsten alloy powder prepared by two reductions is mixed in a certain proportion with the coarse-grained tungsten alloy powder prepared by one high-temperature reduction. This not only avoids the local uneven doping of the coarse-grained powder during the reduction process, but also effectively inhibits the agglomeration and enrichment of the fine-grained powder after reduction, so that the subsequent alloy powder doping is microscopically uneven, resulting in defects in the subsequent pressure processing process and reducing the risk of wire breakage.

[0033] In some embodiments, the sintering process is as follows: the pre-sintered billet obtained by pressing is sintered by electricity, and the sintering is carried out in two stages. The first sintering is carried out at a current intensity of 60% of the tungsten bar melting current for 30 to 45 minutes and then cooled. The second sintering is carried out at a current intensity of 90% to 92% of the tungsten bar melting current for 40 to 80 minutes, and the density is 18.6 g / cm 3 The above sintered billets.

[0034] Preferably, the second sintering is carried out in a hydrogen atmosphere, wherein the purity of the hydrogen is >99.5%.

[0035] The use of two-stage high-temperature sintering is different from the traditional single-stage high-temperature sintering and the combined sintering mode of electric sintering and medium-frequency indirect sintering. The density of the billet obtained by conventional single-stage electric sintering and vertical melting combined with medium-frequency sintering can only reach 17.2-18.4g / cm 3 , basically below 92% of the theoretical density, and the uniformity of its edge and core structure varies greatly, that is, the tungsten wire fiber size consistency is poor, which leads to uneven processing structure during the subsequent tungsten alloy material processing, making the wire easy to break. The present application fully volatilizes the impurity elements in the tungsten billet and closes the surface gaps of the tungsten billet through the first electric sintering, and improves the hydrogen purity and billet density in the second electric high-temperature sintering, obtaining a uniform billet with a density of more than 96%, improving the billet structure consistency, improving the subsequent tungsten alloy wire fiber consistency, and improving the winding performance of the tungsten alloy wire.

[0036] In some embodiments, the pressure processing process is: the alloy rod obtained by the blanking is recrystallized and annealed, and then forged into a tungsten rod with a diameter of 2.5 to 4.0 mm through a multi-pass continuous rotary forging device, and the tungsten rod is roughly drawn through drawing dies of different specifications, and the drawing passes are repeated multiple times with a compression ratio of 35% to 60% to obtain a tungsten alloy thick wire with a diameter of 0.3 to 0.5 mm.

[0037] The tungsten alloy wire is processed with a large compression ratio of 35% to 60%. The obtained wire fiber is more developed, which is conducive to the linearization of L element and its compounds during the processing, thereby improving the breaking force of the wire.

[0038] In some embodiments, during the press working, the alloy rod obtained by the blanking is heated to 2000-2600° C. by a medium / high frequency induction coil for recrystallization annealing.

[0039] In some embodiments, the tungsten alloy wire is annealed at a temperature of 1300°C to 1800°C after being drawn to a diameter of 0.3 to 0.5 mm. After annealing, the tungsten alloy wire is cooled in an oxygen atmosphere and then repeatedly drawn multiple times to produce tungsten alloy wires of varying diameters. When the tungsten alloy wire is drawn below 0.3 mm, annealing is discontinued. The annealed and cooled wire is then drawn through drawing dies of varying sizes, and the drawing process is repeated multiple times until the desired diameter is achieved.

[0040] By oxygen cooling the wire after annealing, the content and thickness of the oxide layer on the surface of the tungsten alloy wire can be increased, which can effectively improve the wire lubrication layer, thereby improving the drawing conditions and ensuring the feasibility of wire drawing with a large compression ratio, thereby greatly reducing the probability of wire breakage.

[0041] The present application also provides an application of the above-mentioned tungsten alloy wire in the fields of cutting, cut-resistant protection, cables, screen printing, ropes or textiles.

[0042] The present application also provides an application of the above-mentioned tungsten alloy wire in cutting semiconductor materials.

[0043] Compared with the existing technology, the tungsten alloy wire provided by this application has the following advantages:

[0044] The present application uses one or more rare earth elements / rare earth compounds as the second phase to strengthen the tungsten material. By controlling the L element to be doped in a linear form between the tungsten matrix and making the radial average width of L less than 5nm, the cracks and wire breaks caused by the second phase particles during subsequent pressure processing are greatly reduced, which is beneficial to ensuring the mechanical strength of the tungsten alloy wire. The wire can have a tensile strength of more than 5000MPa at a wire diameter of 20 to 60μm, and at a wire diameter of 60μm, while enhancing the processing performance of the tungsten alloy wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0046] FIG1 is a schematic diagram showing the radial average width measurement of L or a compound of L provided in the present application. DETAILED DESCRIPTION

[0047] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] The present application provides a tungsten alloy wire, wherein the tungsten alloy is composed of the following elements in mass fractions:

[0049] L 0.4-1.1wt%, Z 0.001-0.25wt%, the balance being tungsten and unavoidable impurities;

[0050] Wherein, L is one or more of lanthanum, cerium, praseodymium, neodymium, gadolinium, and erbium;

[0051] Said Z comprises oxygen and carbon;

[0052] The wire has a diameter of 20 to 60 μm. In the wire, linear L or a compound of L is present along the wire axis, and the radial average width D of the L or the compound of L is ≤5 nm.

[0053] It is understood that unavoidable impurities are other elements introduced during the preparation process.

[0054] The radial average width of tungsten grains is ≤80nm;

[0055] The number of L or the compound of L in the wire / the number of tungsten grains=γ, 3≤γ≤10.

[0056] When the wire diameter is greater than 50 μm and less than or equal to 60 μm, the radial average width D of L or the compound of L is less than or equal to 5 nm, and the tensile strength of the wire is greater than or equal to 5000 MPa;

[0057] When the wire diameter is greater than 40 μm and less than or equal to 50 μm, the radial average width D of L or the compound of L is less than or equal to 4 nm, and the tensile strength of the wire is greater than or equal to 5500 MPa;

[0058] When the wire diameter is greater than 30 μm and ≤ 40 μm, the radial average width D of L or the compound of L is ≤ 3 nm, and the tensile strength of the wire is ≥ 6000 MPa;

[0059] When the wire diameter is ≥20 μm and ≤30 μm, the radial average width D of L or the compound of L is ≤2 nm, and the tensile strength of the wire is ≥7000 MPa;

[0060] The number of surface defects of the wire is ≤10 per 100 meters;

[0061] The dislocation density in the wire is ≥5*10 9 / mm 2 .

[0062] The present application provides a method for preparing tungsten alloy wire, including wet doping, powdering, pressing, sintering, blanking and pressure processing.

[0063] The wet doping process is as follows: blue tungsten powder is uniformly dispersed in deionized water to obtain a blue tungsten suspension; nano-scale compound powder of L is uniformly dispersed in an alkaline solution with a pH greater than 11 to form a second suspension; a solution containing the Z element and the second suspension are then sprayed into the blue tungsten suspension in sequence; and after spraying, rapid vacuum heating and drying are performed to obtain doped blue tungsten powder.

[0064] The preparation method of the blue tungsten powder comprises: feeding ammonium paratungstate into a reduction furnace, and reducing the ammonium paratungstate powder at 400-600° C. under the protection of hydrogen and nitrogen to obtain the blue tungsten powder, wherein the thickness of the ammonium paratungstate powder layer is less than 10 mm, the hydrogen flow rate in the reduction furnace is 20-40 L / min, the nitrogen flow rate is 80-160 L / min, the oxygen index of the blue tungsten powder is 2.85±0.05, and the ammonium tungsten bronze phase component is greater than 80%;

[0065] The powder making process comprises: reducing the doped blue tungsten powder in a hydrogen reduction furnace at 500-800° C. for a primary reduction, and then reducing the doped blue tungsten powder in a hydrogen reduction furnace at 700-1000° C. for a secondary reduction to obtain alloy powder A with a particle size of 1.5-2.6 μm;

[0066] Reducing the doped blue tungsten powder in a hydrogen reduction furnace at 700-1100° C. to obtain alloy powder B with a particle size of 3.8-4.5 μm;

[0067] Alloy powder A and alloy powder B are mixed in a mass ratio of 1:(1-2) to obtain a mixed powder;

[0068] The sintering is as follows: the pre-sintered blank obtained by pressing is sintered by electricity, and the sintering is carried out in two stages. The first sintering is carried out at a current intensity of 60% of the tungsten bar melting current for 30 to 45 minutes and then cooled. The second sintering is carried out at a current intensity of 90% to 92% of the tungsten bar melting current for 40 to 80 minutes to obtain a density of 18.6 g / cm 3 The above sintered billets;

[0069] The second sintering is preferably carried out in a hydrogen atmosphere, wherein the hydrogen purity is greater than 99.5%;

[0070] The press working comprises: heating the alloy rod obtained by the blanking to 2000-2600° C. by a medium / high frequency induction coil for recrystallization annealing, and then forging the alloy rod into a tungsten rod with a diameter of 2.5-4.0 mm by a multi-pass continuous rotary forging device;

[0071] The tungsten rod is roughly drawn through drawing dies of different specifications, and the drawing process is repeated multiple times with a compression ratio of 35% to 60% to obtain a tungsten alloy thick wire with a diameter of 0.3 to 0.5 mm;

[0072] The tungsten alloy wire needs to be annealed when it is drawn to a diameter of 0.3-0.5 mm, and the annealing temperature is 1300-1800° C. After annealing, the tungsten alloy wire is cooled in an oxygen environment.

[0073] The annealed wire is drawn through wire drawing dies of different specifications, and the drawing process is repeated multiple times to reach the required wire diameter.

[0074] In addition, the pressing and blanking steps in the above steps are preferably, but not limited to, implemented in the following manner:

[0075] Pressing: The mixed powder is pressed into a green compact with a single weight of 1.5 to 6 kg at a pressure of 140 to 240 MPa by isostatic pressing. The green compact is then pre-sintered at 1200 to 1400°C for 10 to 30 minutes in a hydrogen atmosphere to increase the green compact strength.

[0076] Coiling: The sintered billets with a diameter of 15 to 25 mm are continuously rolled at 1600 to 1700° C. using a multi-roll rolling mill to cobble into alloy rods with a diameter of 8.0 to 12.0 mm.

[0077] The preparation method also includes an electrolytic cleaning post-processing step to facilitate subsequent electroplating operations.

[0078] To this end, the present application provides the elemental composition of tungsten alloys according to the embodiments and comparative examples shown in Table 1 below:

[0079] Table 1 (unit: wt%)

[0080] Here, “-” indicates that the corresponding element is not added.

[0081] Example 1.1

[0082] This embodiment is a tungsten alloy wire prepared according to the present application, and its material element composition includes: 0.4wt% lanthanum, 0.4wt% cerium, 0.01wt% carbon, 0.16wt% oxygen, and the balance is tungsten and unavoidable impurities;

[0083] The preparation steps are as follows:

[0084] Step 1, preparation of blue tungsten: ammonium paratungstate powder is reduced with hydrogen in a reverse hydrogen continuous reduction furnace at 400°C, 450°C, 500°C, and 560°C. The thickness of the ammonium paratungstate powder layer is 8mm, the hydrogen flow rate is 30L / min, and the nitrogen flow rate is 140L / min. Blue tungsten powder is obtained, and its oxygen index is 2.87, and the ammonium tungsten bronze phase composition is 82%;

[0085] Step 2, wet doping: the blue tungsten powder obtained in step 1 is uniformly dispersed in deionized water to obtain a blue tungsten suspension, wherein the volume ratio of the blue tungsten powder to the deionized water is 1:15; an appropriate amount of carbon powder and deionized water are mixed at a mass ratio of 1:20 to obtain a first suspension, an appropriate amount of nano-powders of lanthanum oxide and cerium oxide are uniformly dispersed in a sodium hydroxide solution with a pH of 13, and stirred at a high speed of 1500 r / min in a high-speed emulsification equipment to form a second suspension, and then the first suspension and the second suspension are sprayed into the blue tungsten suspension in sequence through a vacuum pipe. After the spraying is completed, the blue tungsten powder is quickly heated and dried in a vacuum to obtain the doped blue tungsten powder; the remaining steps are the same as those in Example 1.1.

[0086] Step 3, powder preparation: The doped blue tungsten powder obtained in step 2 is reduced in a three-temperature zone hydrogen reduction furnace at 500°C, 650°C, and 750°C, and then reduced in a four-temperature zone hydrogen reduction furnace at 700°C, 810°C, 870°C, and 920°C to obtain alloy powder A with a particle size of 2.0 μm;

[0087] The doped blue tungsten powder obtained in step 2 was reduced in a four-temperature zone hydrogen reduction furnace at 720°C, 820°C, 870°C, and 950°C to obtain alloy powder B with a particle size of 4.1 μm;

[0088] Alloy powder A and alloy powder B were placed in a high-energy powder mixer at a ratio of 1:1.5 and mixed for 120 minutes to obtain a mixed powder with a particle size of 3.0 μm.

[0089] Step 4, pressing: isostatically pressing the mixed powder obtained in step 3 at a pressure of 160 MPa to form a green compact weighing 3 kg, and pre-sintering the green compact at 1300° C. in a hydrogen atmosphere for 20 minutes to obtain a pre-sintered green compact bar;

[0090] Step 5, sintering: The pre-sintered billet obtained in step 4 is sintered by electricity. The sintering is carried out in two stages. The first sintering is carried out at a current intensity of 60% of the tungsten bar's melting current for 40 minutes, then the temperature is lowered, the vertical melting cover is purged and dried, and the second sintering is carried out at a current intensity of 91% of the tungsten bar's melting current for 60 minutes to obtain a density of 18.68 g / cm 3 Sintered billets;

[0091] Step 6, blanking: using a multi-roll rolling mill to continuously roll the 20 mm diameter sintered billet into an 8.0 mm alloy rod at a heating temperature of 1600°C;

[0092] Step 7, press working: The alloy rod obtained in step 6 is heated to 2400° C. by a high-frequency induction coil for recrystallization annealing, and then forged into a tungsten rod with a diameter of 3.0 mm by a multi-pass continuous rotary forging device;

[0093] Step 8: Roughly draw the tungsten rod through drawing dies of different specifications, repeat the drawing process multiple times with a compression ratio of 35% to 60%, and obtain a tungsten alloy thick wire with a diameter of 0.5 mm;

[0094] Step 9, annealing: annealing the tungsten alloy wire obtained in step 8 when the wire is processed to φ0.5 mm. After annealing, the tungsten alloy wire is cooled in an oxygen environment. The annealing temperature is 1600° C. when the wire is φ0.5 mm.

[0095] Step 10: Drawing the annealed wire obtained in step 9 through wire drawing dies of different specifications, repeatedly drawing the wires to diameters of 58 μm, 48 μm, 38 μm, 28 μm, and 20 μm, respectively;

[0096] Step 11, electrolytic cleaning: The tungsten alloy wire obtained in step 10 is first electrolyzed in a 22wt% potassium hydroxide solution, which includes 12 sets of AC electrolytic sheets, and then sequentially electrolyzed in 6 sets of 6wt% potassium hydroxide solution, which includes 5 sets of DC electrolytic sheets. The electrolysis speed is 180m / min. After electrolysis, the surface is cleaned with deionized water to obtain white thin tungsten wires of different wire diameters.

[0097] Example 1.2

[0098] The difference between this embodiment and embodiment 1.1 is that the material element composition includes 0.2wt% lanthanum, 0.2wt% cerium, 0.01wt% carbon, 0.08wt% oxygen, and the balance is tungsten and unavoidable impurities; the remaining preparation steps are the same as embodiment 1.1.

[0099] Example 1.3

[0100] The difference between this embodiment and embodiment 1.1 is that the material element composition includes 0.55wt% lanthanum, 0.55wt% cerium, 0.03wt% carbon, 0.22wt% oxygen, and the balance is tungsten and unavoidable impurities; the remaining preparation steps are the same as embodiment 1.1.

[0101] Comparative Example 1.1

[0102] The material element composition includes: 0.8wt% lanthanum, 0.138wt% oxygen, and the balance is tungsten and unavoidable impurities;

[0103] The preparation steps are as follows:

[0104] Step 1: Doping: Evenly dope an appropriate amount of lanthanum nitrate solution into the blue tungsten powder. After sufficient stirring, dry it at 80°C for 4 hours and then at 120°C.

[0105] Step 2, reduction: the material obtained in step 1 is reduced into alloy powder of appropriate particle size in a four-temperature zone reduction furnace;

[0106] Step 3: Mixing: Place the materials obtained in step 2 into a powder mixer according to different particle sizes. Mix at a speed of 8 rpm for 80 minutes.

[0107] Step 4, powder pressing: using isostatic pressing to press the powders of different particle sizes into green compacts weighing 3.0 kg at a pressure of 200 MPa, and pre-sintering the green compacts at low temperature in a hydrogen atmosphere to increase the green compact strength;

[0108] Step 5: High temperature sintering: Perform high temperature sintering to obtain a density of 18.10 g / cm 3 Sintered billets;

[0109] Step 6, blanking: using a multi-roll rolling mill to continuously roll the 23.0 mm diameter sintered billet into 8.0 mm alloy rods at a heating temperature of 1650° C.;

[0110] Step 7: Press processing: Use multiple passes of rotary forging. Then, use drawing dies of different specifications for drawing. After repeated drawing, alloy wires with diameters of 58μm, 48μm, 38μm, 28μm, and 20μm are produced.

[0111] Comparative Example 1.2

[0112] The material element composition includes: 0.8wt% cerium, 0.183wt% oxygen, and the balance is tungsten and unavoidable impurities;

[0113] The preparation steps are as follows:

[0114] Step 1: Doping: Evenly dope an appropriate amount of lanthanum nitrate solution into the blue tungsten powder. After sufficient stirring, dry it at 80°C for 4 hours and then at 120°C.

[0115] Step 2, reduction: the material obtained in step 1 is reduced into alloy powder of appropriate particle size in a four-temperature zone reduction furnace;

[0116] Step 3: Mixing: Place the materials obtained in step 2 into a powder mixer according to different particle sizes. Mix at 8 rpm for 80 minutes.

[0117] Step 4, powder pressing: using isostatic pressing to press the powders of different particle sizes into green compacts weighing 3.0 kg at a pressure of 200 MPa, and pre-sintering the green compacts at low temperature in a hydrogen atmosphere to increase the green compact strength;

[0118] Step 5: High temperature sintering: Perform high temperature sintering to obtain a density of 18.10 g / cm 3 Sintered billets;

[0119] Step 6, blanking: using a multi-roll rolling mill to continuously roll the 23.0 mm diameter sintered billet into 8.0 mm alloy rods at a heating temperature of 1650° C.;

[0120] Step 7: Press processing: Use multiple passes of rotary forging. Then, use drawing dies of different specifications for drawing. After repeated drawing, alloy wires with diameters of 58μm, 48μm, 38μm, 28μm, and 20μm are produced.

[0121] Comparative Example 1.3 (Z element content exceeds 0.25 wt%)

[0122] The difference from Example 1.1 is that its material element composition includes 0.4wt% cerium, 0.4wt% lanthanum, 0.1wt% carbon, 0.16wt% oxygen, and the balance is tungsten and unavoidable impurities; its preparation steps are the same as Example 1.1.

[0123] Comparative Example 1.4 (Total content of L element second phase exceeds 1.1 wt%)

[0124] The difference from Example 1.1 is that the material element composition includes 0.6wt% cerium, 0.6wt% lanthanum, 0.01wt% carbon, 0.24wt% oxygen, and the balance is tungsten and unavoidable impurities; the remaining preparation steps are the same as Example 1.1.

[0125] Comparative Example 2.1 (using deionized water as the solvent for element L)

[0126] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.1 and Example 1.1 is:

[0127] The blue tungsten powder obtained in step 1 is uniformly dispersed in deionized water to obtain a blue tungsten suspension, wherein the volume ratio of the blue tungsten powder to the deionized water is 1:15; an appropriate amount of carbon powder and deionized water are mixed at a mass ratio of 1:20 to obtain a first suspension; an appropriate amount of crystalline powders of lanthanum nitrate and cerium nitrate are uniformly dispersed in deionized water, and stirred at a high speed of 1500 r / min in a high-speed emulsifying equipment to form a second suspension; the first suspension and the second suspension are then added to the blue tungsten suspension in turn, and the mixture is fully stirred and dried to obtain doped blue tungsten; the stirring speed is 40 r / min, and the drying temperature is 160°C; the remaining steps are the same as in Example 1.1.

[0128] The remaining steps are the same as in Example 1.1.

[0129] Comparative Example 2.2 (Alloy powder prepared by single reduction)

[0130] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.2 and Example 1.1 is:

[0131] Step 3, powder preparation: reducing the doped blue tungsten powder obtained in step 2 in a four-temperature zone hydrogen reduction furnace at 650° C., 750° C., 850° C., and 930° C. at a reduction rate of 20 min / boat to obtain an alloy powder with a particle size of 3.0 μm;

[0132] The remaining steps are the same as in Example 1.1.

[0133] Comparative Example 2.3 (using conventional drawing pass compression ratio of 10% to 30%)

[0134] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.3 and Example 1.1 is:

[0135] Step 8: Roughly draw the tungsten rod through drawing dies of different specifications, repeat the drawing process multiple times with a compression ratio of 10% to 30%, and obtain a tungsten alloy thick wire with a diameter of 0.5 mm;

[0136] The remaining steps are the same as in Example 1.1.

[0137] Comparative Example 2.4.1 (Cooling in air after annealing)

[0138] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.4.1 and Example 1.1 is:

[0139] Step 9, annealing: annealing the tungsten alloy wire obtained in step 8 when the wire is processed to φ0.5 mm, and cooling the tungsten alloy wire in air after annealing, wherein the annealing temperature is 1600° C. when the wire is φ0.5 mm;

[0140] The remaining steps are the same as in Example 1.1.

[0141] Comparative Example 2.4.2 (Cooling in air after annealing)

[0142] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.4.2 and Example 1.1 is:

[0143] Step 9, annealing: annealing the tungsten alloy wire obtained in step 8 when the wire is processed to φ0.5 mm, and cooling the tungsten alloy wire in air after annealing, wherein the annealing temperature is 1650° C. when the wire is φ0.5 mm;

[0144] The remaining steps are the same as in Example 1.1.

[0145] Comparative Example 2.4.3 (Cooling in air after annealing)

[0146] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.4.3 and Example 1.1 is:

[0147] Step 9, annealing: annealing the tungsten alloy wire obtained in step 8 when the wire is processed to φ0.5 mm, and cooling the tungsten alloy wire in air after annealing, wherein the annealing temperature is 1700° C. when the wire is φ0.5 mm;

[0148] The remaining steps are the same as in Example 1.1.

[0149] Comparative Example 2.4.4 (Cooling in air after annealing)

[0150] The material element composition is the same as that of Example 1.1. The difference between Comparative Example 2.4.4 and Example 1.1 is:

[0151] Step 9, annealing: annealing the tungsten alloy wire obtained in step 8 when the wire is processed to φ0.5 mm, and cooling the tungsten alloy wire in air after annealing, wherein the annealing temperature is 1550° C. when the wire is φ0.5 mm;

[0152] The remaining steps are the same as in Example 1.1.

[0153] Microstructure and performance testing

[0154] The tungsten alloy wires obtained in the examples and comparative examples were subjected to a tensile strength test and characterized using a transmission electron microscope. The γ value was calculated. The test results are shown in Table 2-3.

[0155] The tungsten alloy wires obtained in the examples and comparative examples were cut into thin slices along the axial direction of the tungsten alloy wires using a focused ion beam cutting device. The thin slices were placed in a high-resolution transmission electron microscope and characterized using different modes. The number of linear second phases, the number of tungsten grains, and the grain boundary angles of the tungsten grains in the sample slices were observed, and the γ value and the proportion of tungsten grains with a grain boundary angle ≤15° were calculated.

[0156] The calculation formula of γ value is:

[0157] γ = the number of linear second phases / the number of tungsten grains.

[0158] Ratio of tungsten grains with a grain boundary angle of ≤15°=number of tungsten grains with a grain boundary angle of ≤15° / (number of tungsten grains with a grain boundary angle of ≤15°+number of grain boundary angles>15°)*100%.

[0159] The tensile strength test method is as follows: a standard tensile testing machine is used to clamp a 200mm long tungsten wire, and one end is loaded at a constant speed to obtain the breaking force data;

[0160] The tensile strength is calculated by the following formula:

[0161] σ=F / S,

[0162] Where, F is the breaking force, N; S is the original cross-sectional area, mm;

[0163] Table 2

[0164] Among them, “ / ” means there is no corresponding data.

[0165] The number of surface defects, the average diameter of tungsten grains, the radial average width of L or L compounds, and the dislocation density of the tungsten alloy wires obtained in the examples and comparative examples were measured. The measurement results are shown in Table 3.

[0166] The method for measuring the number of surface defects is as follows: the obtained tungsten alloy wire is subjected to surface defect detection by an eddy current flaw detector, and a flaw signal depth exceeding 15% of the diameter is defined as a defect;

[0167] The radial average width of tungsten grains is measured as follows: a thin slice is cut along the axial direction of the wire using a focused ion beam cutting device, the slice is placed in a scanning electron microscope with an EBSD (electrolyte backscatter diffractometer), the morphology of the tungsten grains of the sample to be tested is collected, and the width of the upper and lower grain boundaries is measured using conventional measurement software to obtain the radial width of the tungsten grains. The average value of the measured widths of multiple tungsten grains is the radial average width of the tungsten grains.

[0168] The radial average width measurement method of L or L compounds is as follows: as shown in FIG1 , a thin slice is cut out along the axial direction of the tungsten alloy wire 1 using a focused ion beam cutting device, the thin slice is placed in a high-resolution transmission electron microscope, the morphology is first observed in bright and dark field modes, a position with obvious morphological contrast is selected, a surface scan is performed, and a line scan is performed perpendicular to the axial position of the tungsten alloy wire to obtain element distribution and element composition information, and the position with obvious morphological contrast and obvious element distribution in the detection sample (i.e., the position of the second phase element aggregation area) is photographed by a transmission electron microscope to obtain a high-resolution image of the second phase, and the high-resolution image is Fourier transformed to obtain a lattice diffraction spectrum. The obtained second-phase diffraction spectrum, combined with the second-phase elemental composition information, is used to calibrate the phase corresponding to each diffraction spectrum. By comparing the phase cards, the structure of the L or L compound phase is confirmed. The software then measures the width of the L or L compound. In Figure 1, 10 represents the tungsten matrix, and 20 represents L or L compound. The average value of the widths of multiple L measurements is calculated, which is the radial average width of the L or L compound. It should be understood that for ease of explanation, Figure 1 captures a partial cross-section of the tungsten alloy wire sheet, not the entire sheet.

[0169] The dislocation density test method is as follows: use a focused ion beam cutting device to cut a thin slice along the axial direction of the tungsten alloy wire, place the slice in a high-resolution transmission electron microscope to directly observe the lattice pattern, obtain the dislocation, and calculate the number of dislocation lines passing through the unit cross-sectional area to obtain the dislocation density.

[0170] Table 3

[0171] Among them, “ / ” means there is no corresponding data.

[0172] From the test results in Table 2 and Table 3, we can see that:

[0173] The tungsten alloy wire provided in the embodiment of the present application has a tensile strength of more than 5000 MPa at a wire diameter of 20 to 60 μm, and as the wire diameter decreases, its tensile strength increases accordingly. At 28 μm, its tensile strength can reach more than 7000 MPa, and the number of surface defects of the wire is less than 10 / 100 meters; at 28 μm, L or L compounds exist in a linear form, and their radial average width is less than 4 nm, the radial average width of the tungsten grains is less than 80 nm, and the dislocation density in the wire is greater than 5*10 9 / mm 2 , the number of L or L compounds in the wire / the number of tungsten grains = γ, 3≤γ≤10;

[0174] From the comparison results of Comparative Examples 1.1 and 1.2 with Example 1.1, it can be seen that:

[0175] The tungsten alloy wire preparation method provided in this application can effectively improve the tensile strength of the wire compared to the existing process. The reason is that the single L element second phase merges and grows during the high-temperature sintering and recrystallization annealing process, resulting in a wider radial average width of the L element, and more cracks and wire breaks caused by the second phase particles during the subsequent pressure processing, affecting the mechanical strength and processing performance of the tungsten alloy wire. With the rapid increase in cracks, the wire breakage during the wire drawing process increases significantly. From the data in Table 3, it can be seen that with the significant increase in the number of surface defects on the wire, the wire processing performance deteriorates, and the average number of meters of wire per coil decreases sharply.

[0176] From the comparison results of Comparative Example 1.3 and Example 1.1, it can be seen that:

[0177] When the Z element content in the tungsten alloy component exceeds 0.25wt%, the Z element forms a solid solution with W, which effectively increases the lattice distortion of tungsten and improves the deformation rate of the tungsten wire, thereby improving the tensile strength of the tungsten wire. However, the introduction of too much Z element will cause the dislocation density of the tungsten alloy wire to increase significantly during the deformation process, resulting in the tungsten alloy wire's work hardening increasing too quickly, making it difficult to refine the wire to below 60μm.

[0178] From the comparison results of Comparative Example 1.4 and Example 1.1, it can be seen that:

[0179] When the total content of the two L element second phases in the tungsten alloy component exceeds 1.1wt%, the amount of second phases in the tungsten alloy wire is too much, and the ratio γ of the amount of second phases to the number of tungsten grains is too high, resulting in insufficient bonding between the grains of the tungsten alloy wire. At the same time, the increase in the amount of second phases will greatly increase the difficulty of dislocation slip, resulting in increased difficulty in processing the tungsten alloy wire and inability to process it to below 60μm.

[0180] From the comparison results of Comparative Example 2.1 and Example 1.1, it can be seen that:

[0181] Compared with the embodiment of the present application, when deionized water is used as the solvent for the L element in the wet doping step, the tungsten grain size and the average radial width of L also increase at the same wire diameter level. The reason is that the dispersion of the L element compound in the doping process is insufficient, resulting in local enrichment of the L element during the nucleation of the tungsten powder in the subsequent reduction process. After high-temperature sintering, these L element compounds swallow each other and grow, resulting in a significant reduction in the strengthening and refinement effect of the actual tungsten grains, and a significant increase in the number of surface defects in the obtained tungsten alloy wire.

[0182] From the comparison results of Comparative Example 2.2 and Example 1.1, it can be seen that:

[0183] When the alloy powder is prepared by single reduction in the powder making step, the average radial width of L is significantly increased, resulting in the tensile strength of the wire being much lower than that in Example 1.1, and the number of surface defects of the prepared tungsten alloy wire is significantly increased. The reason is that the tungsten alloy powder prepared by high-temperature single reduction is prone to local uneven doping during the reduction process, or agglomeration and enrichment after reduction, which makes the subsequent alloy powder doping microscopically uneven, resulting in defects in the subsequent pressure processing process and the risk of wire breakage.

[0184] From the comparison results of Comparative Example 2.3 and Example 1.1, it can be seen that:

[0185] When a conventional drawing pass compression ratio of 10% to 30% is used in the pressure processing step, the average radial width of L in the wires of various specifications produced is large, and the average width of the tungsten grains is greatly increased, resulting in more cracks and wire breaks caused by second-phase particles in the subsequent pressure processing process, which in turn affects the tensile strength.

[0186] It is explained that this application adopts a large compression ratio of 35% to 60% for tungsten alloy wire processing, and the obtained wire fibers are more developed, which is conducive to the linearization of L elements and their compounds during the processing process. At the same time, the deformation degree of tungsten grain boundaries is faster, thereby improving the tensile strength of the wire.

[0187] The number of surface defects and the average length of the tungsten alloy wires obtained in Example and Comparative Examples 2.4.1-2.4.4 were measured. The measurement results are shown in Table 4.

[0188] Table 4

[0189] From the comparison results of Comparative Examples 2.4.1-2.4.4 and Example 1.1, it can be seen that:

[0190] When the surface oxide percentage of the wire during the annealing step is less than 1% by mass, the tungsten alloy wire undergoes multiple drawing processes after annealing, resulting in a significant increase in the surface hardening rate of the wire due to insufficient surface lubrication. This leads to a significant increase in the number of surface defects, ultimately preventing the product from being stably produced to the required length. The surface oxide percentage of the tungsten alloy wire in this application is greater than or equal to 1%.

[0191] Finally, it should be noted that:

[0192] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A tungsten alloy wire, characterized in that: The tungsten alloy is composed of the following elements by mass fraction: L 0.4 - 1.1 wt%, Z 0.001 - 0.25 wt%, and the balance is tungsten and inevitable impurities; Among them, the L is one or more of lanthanum, cerium, praseodymium, neodymium, gadolinium, and erbium; The Z includes oxygen and carbon; The wire diameter of the wire is 20 - 60 μm. In the wire, there is a linear L or a compound of L along the axis direction of the spool, and the radial average width D of the L or the compound of L ≤ 5 nm.

2. The tungsten alloy wire according to claim 1, characterized in that: In the wire, the radial average width of tungsten grains ≤ 80 nm; The number of L or the compound of L / the number of tungsten grains in the wire = γ, 3 ≤ γ ≤ 10.

3. The tungsten alloy wire according to claim 1, characterized in that: The dislocation density in the wire ≥ 5*10 9 / mm 2 .

4. The tungsten alloy wire according to claim 1, characterized in that: When the wire diameter of the wire > 50 μm and ≤ 60 μm, the radial average width D of the L or the compound of L ≤ 5 nm, and the tensile strength of the wire ≥ 5000 MPa; When the wire diameter of the wire > 40 μm and ≤ 50 μm, the radial average width D of the L or the compound of L ≤ 4 nm, and the tensile strength of the wire ≥ 5500 MPa; When the wire diameter of the wire > 30 μm and ≤ 40 μm, the radial average width D of the L or the compound of L ≤ 3 nm, and the tensile strength of the wire ≥ 6000 MPa; When the wire diameter of the wire ≥ 20 μm and ≤ 30 μm, the radial average width D of the L or the compound of L ≤ 2 nm, and the tensile strength of the wire ≥ 7000 MPa; The number of surface defects of the wire ≤ 10 per 100 meters.

5. A method for preparing a tungsten alloy wire according to any one of claims 1-4, characterized in that: It includes wet doping, powder making, pressing, sintering, cogging, and pressure processing.

6. The preparation method of the tungsten alloy wire according to claim 5, characterized in that: The wet doping process is as follows: uniformly disperse blue tungsten powder in deionized water to obtain a blue tungsten suspension, uniformly disperse the nano - level compound powder of L in an alkaline solution with pH > 11 to form a second suspension, then sequentially spray the solution containing element Z and the second suspension onto the blue tungsten suspension, and obtain doped blue tungsten powder after heating and drying; The powder making process is as follows: reduce the doped blue tungsten powder to obtain alloy powder A with a particle size of 1.5 - 2.6 μm and alloy powder B with a particle size of 3.8 - 4.5 μm respectively, and then mix alloy powder A and alloy powder B to obtain a mixed powder; The sintering process is as follows: The pre-sintered blank bar obtained by pressing is subjected to electric sintering. The sintering is carried out in two stages. After the first sintering at a current intensity of 60% of the tungsten bar fusing current for 30 - 45 minutes, the temperature is decreased. The second sintering is carried out at a current intensity of 90% - 92% of the tungsten bar fusing current for 40 - 80 minutes to obtain a sintered blank bar with a density of 18.6 g / cm 3 or more; The pressure processing process is as follows: perform recrystallization annealing on the alloy rod obtained by cogging, and then forge it to a tungsten rod with a diameter of 2.5 - 4.0 mm through a multi - pass continuous rotary forging device. The tungsten rod is subjected to rough drawing through wire drawing dies of different specifications, and the drawing pass reduction ratio is repeated 35% - 60% for multiple times to obtain a tungsten alloy thick wire with a diameter of 0.3 - 0.5 mm.

7. The preparation method of the tungsten alloy wire according to claim 6, characterized in that: During the wet doping process, the preparation method of the blue tungsten powder is as follows: Ammonium paratungstate is fed into a reduction furnace and reduced under the protection of hydrogen and nitrogen at 400-600 °C to obtain blue tungsten powder. Among them, the thickness of the ammonium paratungstate powder layer is <10 mm, the hydrogen flow rate in the reduction furnace is 20-40 L / min, the nitrogen flow rate is 80-160 L / min, the oxygen index of the blue tungsten powder is 2.85±0.05, and the ammonium tungsten bronze phase composition is >80%; During the powder making process, the reduction method of alloy powder A is as follows: The doped blue tungsten powder is first reduced in a hydrogen reduction furnace at 500-800 °C and then further reduced in a hydrogen reduction furnace to obtain alloy powder A with a particle size of 1.5-2.6 μm; The reduction method of alloy powder B is as follows: The doped blue tungsten powder is reduced in a hydrogen reduction furnace at 700-1100 °C to obtain alloy powder B with a particle size of 3.8-4.5 μm; Alloy powder A and alloy powder B are mixed evenly according to a mass ratio of 1:(1-2).

8. The preparation method of the tungsten alloy wire according to claim 6, characterized in that: During the hot working process, the alloy rod obtained by cogging is heated to 2000-2600 °C by a medium / high frequency induction coil for recrystallization annealing; When the tungsten alloy wire is drawn to a diameter of 0.3-0.5 mm, annealing treatment is required, and the annealing temperature is 1300-1800 °C. After annealing, the tungsten alloy wire is cooled in an oxygen environment, and after annealing, drawing is repeated multiple times to obtain tungsten alloy wires with different diameter specifications.

9. Application of a tungsten alloy wire according to any one of claims 1-4 in the fields of cutting, cutting-resistant protection, cables, screen printing, ropes or textiles.

10. Application of a tungsten alloy wire according to any one of claims 1-4 in the cutting of semiconductor materials.

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