Ultrathin high-strength multi-component composite reinforced tungsten filament and preparation method thereof

Abstract

The invention relates to an ultrafine high-strength multi-component composite reinforced tungsten filament and a preparation method thereof, the tungsten filament comprises W, rare earth oxide (any one of La2O3, Y2O3 and CeO2) and alloy elements (Al, Si, K and Zr), the content of the rare earth oxide in the tungsten filament is 0.1-1.0 wt%, and the content of Al in the alloy elements is 0.025-0.05 wt%, the content of Si is 0.1-0.2 wt%, the content of K is 0.28-0.56 wt%, the content of Zr is 0.1-0.5 wt%, and the balance is W. The wire diameter of the tungsten filament is 28-30 [mu] m; the tensile strength of the tungsten filament is more than 7100 MPa, and the length of a single tungsten filament is more than 150 thousand meters. According to the tungsten wire, through multi-phase composite doping, the purpose of synergistic strengthening such as nano-particle dispersion strengthening, fine grain strengthening and grain boundary strengthening is achieved, and the superfine high-strength tungsten alloy wire with good toughness can be obtained.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of tungsten alloy wires, in particular to an ultra-fine high-strength multi-component composite reinforced tungsten wire and a preparation method thereof. Background Art

[0002] Photovoltaic silicon wafers are developing towards larger sizes and thinner slices, which has led to thinner diamond wires. Thinning is the key to reducing silicon consumption and cost.

[0003] At present, the existing high-carbon steel wire has a limit size of 38-40μm, and its breaking force is relatively small, which cannot meet the needs of industrial development. The ordinary doped tungsten wire busbar developed later has higher strength and can temporarily meet the use needs. The minimum wire diameter reaches 35 microns, the breaking force is 6N, and the tensile strength can reach 5500MPa. However, the rapid development of the photovoltaic industry requires further cost reduction and higher requirements for the performance of tungsten wire. On the one hand, the wire diameter continues to be reduced (≤30μm), and on the other hand, the strength continues to be maintained while the diameter is thin (≥7000Mpa). At the same time, the single length is required to exceed 150,000 meters. The currently disclosed forms of reinforcing phase addition in tungsten wire mainly include solid-solid and solid-liquid doping. A few components that use liquid-liquid doping cannot achieve complete liquid phase mixing. The Chinese invention patent with application number 202110482229.3 discloses an alloy wire and its preparation method and application. The raw material blue tungsten is insoluble in water. The solid phase addition cannot make the components evenly distributed. The particle size of the strengthening phase is easy to agglomerate and grow, which affects the strengthening effect. Although a tungsten wire with a wire diameter of 25μm can be produced, its average tensile strength is 5262MP. The Chinese invention patent with application number 202110687610.3 discloses an alloy wire and its preparation method and application. The added strengthening phase is zirconium oxide, but it is mainly distributed at the grain boundary of the tungsten main phase (matrix phase). If the strengthening phase is distributed too much and unevenly at the grain boundary, the performance of the material will deteriorate. In addition, the alloy wire also adds some metal elements potassium, rhenium, molybdenum, iron, and cobalt, but the specific role of adding metal elements is not explained in the article. It is estimated that it can play a partial solid solution strengthening effect. The existing preparation process of tungsten wire is unevenly doped, the length is insufficient and easy to break, and the strength does not meet the standard. Through the above analysis, optimizing the composition of tungsten alloy and improving the preparation technology are the key to obtaining high-performance tungsten wire. The development of ultra-long and ultra-fine tungsten wire with high strength and low wire breakage rate has become an important development trend for diamond wires used in the photovoltaic industry. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide an ultrafine high-strength multi-component composite reinforced tungsten wire and a preparation method thereof, wherein a tungsten alloy powder is prepared by a wet chemical method combined with a calcination reduction process, and then an ultrafine high-strength and tough tungsten wire is obtained through processes such as pressing and sintering, blanking, intermediate treatment, multi-pass rotary forging, multi-mode wire drawing and electrolytic polishing. The prepared tungsten wire has a wire diameter of less than 30 μm, a tensile strength of more than 7100 MPa, and a single wire of more than 150,000 meters.

[0005] A method for preparing an ultra-fine high-strength multi-component composite reinforced tungsten wire specifically comprises the following steps:

[0006] (1) Liquid-liquid doping

[0007] According to the raw material ratio, a certain amount of ammonium metatungstate, rare earth element nitrate, potassium silicate and aluminum nitrate are weighed and dissolved in water to form a solution, and then the obtained ammonium metatungstate solution, rare earth element nitrate solution, potassium silicate solution and aluminum nitrate solution are fully mixed, and then placed at 100-120°C for heating and co-precipitation, and stirred continuously during the heating process until solid precipitates and the liquid evaporates completely to obtain a precursor powder;

[0008] (2) Calcination reduction

[0009] The precursor powder is calcined in a muffle furnace at 500-550°C for 4-4.5 hours, and then the calcined product is subjected to a two-stage reduction to obtain doped W powder;

[0010] (3) Mechanical ball milling

[0011] The Zr element is proportioned according to the content in the finally obtained multi-component composite reinforced tungsten wire, and a quantitatively proportioned ZrH2 powder (wherein the ZrH2 powder will decompose at high temperature) is weighed, and the ZrH2 powder is mixed with the doped W powder obtained in step (2) by mechanical ball milling for 8-12 hours, and a vacuum environment is maintained during the mixing process, and finally a mixed tungsten alloy powder containing nano rare earth oxides and alloy elements (specifically including Al, Si, K, and Zr) is obtained;

[0012] (4) pressing and sintering to obtain a tungsten alloy sintered blank;

[0013] (5) hot isostatic pressing to obtain a sintered blank after hot isostatic pressing;

[0014] (6) rolling and blanking to obtain a tungsten alloy rod;

[0015] (7) a first intermediate treatment to obtain a tungsten rod after the first intermediate treatment;

[0016] (8) performing multiple rotary forging to obtain a tungsten alloy rod after rotary forging;

[0017] (9) a second intermediate treatment to obtain a tungsten rod after the second intermediate treatment;

[0018] (10) Single-mode wire drawing and multi-mode wire drawing

[0019] The tungsten rod obtained by the second intermediate treatment in step (9) is drawn to a diameter of 0.65-0.67 mm by single-mode drawing under natural gas flame heating, the heating temperature is 750-800° C., the mold temperature is 650-700° C., and the drawing speed is 20-30 m / min. After stress relief annealing at 1100° C.-1200° C. for 30-60 min, the tungsten rod is drawn to a diameter of 0.18-0.29 mm by multi-mode drawing with the same parameters as the single-mode drawing process (i.e., heating temperature, mold temperature, and drawing speed). The above-mentioned drawing and annealing processes are both heated by natural gas flames and argon is introduced as a protective gas to prevent oxidation. At the same time, graphite powder is applied around the tungsten wire as a lubricant;

[0020] (11) Third intermediate processing

[0021] The tungsten wire obtained in step (10) is subjected to recrystallization annealing to eliminate work hardening and residual stress, the annealing temperature is 1500-1700° C., and the annealing holding time is 40-60 min;

[0022] (12) Wire drawing

[0023] The tungsten wire is drawn multiple times by electric furnace heating, and argon gas is introduced to prevent oxidation. The heating temperature is 500-600℃, the drawing die temperature is 350-600℃, and the drawing speed is 60-80m / min. Finally, a tungsten wire with a diameter of 30-32μm is obtained.

[0024] (13) Electrolytic polishing

[0025] The graphite emulsion and the oxide layer attached to the surface of the tungsten wire are removed by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire.

[0026] Furthermore, the rare earth element nitrate in step (1) includes any one of lanthanum nitrate, yttrium nitrate and cerium nitrate; wherein the concentration of the ammonium metatungstate solution is 0.1-1 mol / L, the concentration of the rare earth element nitrate solution is 0.001-0.01 mol / L, the concentration of the potassium silicate solution is 0.5-2 mol / L, and the concentration of the aluminum nitrate solution is 0.1-1 mol / L.

[0027] Furthermore, the raw material ratio in step (1) specifically refers to the amount of raw materials calculated based on the content of each component of the ultrafine high-strength multi-component composite reinforced tungsten wire, wherein the rare earth oxide in the ultrafine high-strength multi-component composite reinforced tungsten wire is derived from rare earth element nitrate, Al is derived from aluminum nitrate, Si and K are both derived from potassium silicate, Zr is derived from zirconium hydride powder, and W is derived from ammonium metatungstate. The content of each component of the ultrafine high-strength multi-component composite reinforced tungsten wire is as follows: rare earth oxide content is 0.1-1.0wt.%, Al content is 0.025-0.05wt.%, Si content is 0.1-0.2wt.%, K content is 0.28-0.56wt.%, Zr content is 0.1-0.5wt.%, and the rest is W.

[0028] Furthermore, the two-stage reduction in step (2) is specifically to first reduce at 650°C-700°C for 2h, and then reduce at 900°C-920°C for 4h, and the particle size of the obtained doped W powder is 1.0-2.5μm;

[0029] Further, step (4) specifically comprises cold isostatic pressing the mixed tungsten alloy powder under a pressure of 200MPa-240Mpa into a cylindrical tungsten alloy billet with a diameter of 20-25mm, the holding time of the cold isostatic pressing being 18-20min, and then placing the mixed tungsten alloy powder in a medium frequency induction sintering furnace, and performing three-stage heating + heat preservation to obtain a tungsten alloy sintered billet; the three-stage heating + heat preservation specifically comprises: placing the pressed billet obtained by cold isostatic pressing in a medium frequency induction sintering furnace, first heating to 1000-1200°C, heating at a rate of 5-10°C / min, and heat preservation for 0.5-1h; then heating to 1800-2000°C at a rate of 10-20°C / min, heat preservation for 0.5-1h, and finally heating to 2500-2600°C at a rate of 10-20°C / min, heat preservation for 4-5h, to obtain a tungsten alloy sintered billet;

[0030] Furthermore, step (5) specifically includes placing the tungsten alloy sintered blank in a sheath, and then placing the sheath in a hot isostatic pressing device, and treating it at high temperature and high pressure for 1-3 hours, and finally obtaining a sintered blank after hot isostatic pressing;

[0031] Furthermore, in step (5), the high temperature specifically refers to 1200-1400° C., and the high pressure specifically refers to 150-200 MPa; the tungsten alloy sintered blank further eliminates internal pores under the combined action of high temperature and high pressure, so that the material reaches a higher density; the relative density of the sintered blank after hot isostatic pressing is 98.5-99.5%.

[0032] Furthermore, step (6) specifically comprises rolling the sintered billet after hot isostatic pressing with a three-roller Y-type rolling mill, the billet opening temperature being 1500-1700° C., and preparing a tungsten alloy rod with a diameter of 8.0-11 mm by continuous rolling, and the end surface deformation of each pass being 17-20%;

[0033] Furthermore, step (7) specifically straightens and rounds the tungsten alloy rod obtained above to obtain a tungsten rod with a diameter of 8-9 mm, and then uses natural gas heating to recrystallize and anneal the tungsten rod at 1600-1800° C., and introduces argon gas during the annealing process to prevent oxidation (natural gas consumes oxygen during combustion to form a certain reducing atmosphere, which can also prevent the surface oxidation of the tungsten rod during the annealing process). After that, the tungsten rod after the first intermediate treatment is obtained, and the holding time of the recrystallization annealing is 40-60 minutes;

[0034] Furthermore, step (8) specifically comprises rotary forging the tungsten rod obtained by the first intermediate treatment in step (7) under a natural gas or hydrogen atmosphere, wherein the rotary forging temperature is 1500-1600° C., the forging frequency is 9000-10000 times / min, the single end face shrinkage deformation is 10-15%, and the rotary forging obtains a tungsten alloy rod with an end face diameter of 5 mm;

[0035] Furthermore, step (9) specifically comprises chain-pulling the tungsten alloy rod with an end diameter of 5 mm obtained in step (8) to a diameter of 3 mm at a drawing temperature of 1400° C.-1500° C., and winding the rod around a disc to form a circle with a diameter of 300 mm.

[0036] The present invention also provides an ultra-fine high-strength multi-component composite reinforced tungsten wire obtained according to the above preparation method.

[0037] Furthermore, the composition of the ultrafine high-strength multi-component composite reinforced tungsten wire includes rare earth oxides, alloy elements and tungsten, the alloy elements include Al, Si, K, and Zr, and the content of each component is as follows: rare earth oxide content is 0.1-1.0wt.%, Al content is 0.025-0.05wt.%, Si content is 0.1-0.2wt.%, K content is 0.28-0.56wt.%, Zr content is 0.1-0.5wt.%, and the rest is W.

[0038] Furthermore, the rare earth oxide includes one of La2O3, Y2O3, and CeO2.

[0039] Furthermore, the diameter of the ultra-fine high-strength multi-component composite reinforced tungsten wire is 28-30 μm, the tensile strength is above 7100 MPa, and a single wire is above 150,000 meters.

[0040] In the present invention, tungsten and lanthanum oxide are completely liquid-liquid doped, the required raw materials can be completely dissolved in water, and the purpose of synergistic strengthening such as second phase dispersion strengthening, fine grain strengthening, solid solution strengthening and grain boundary purification is achieved by adding elements Al, Si, K and Zr. Soluble salts of tungsten and lanthanum oxide are used as raw materials, and lanthanum elements are introduced by liquid-liquid (aqueous solution of ammonium metatungstate and rare earth salt) doping, so that rare earths can be dispersed in the tungsten matrix.

[0041] The present invention uses liquid phase and solid phase to add elements such as Al, Si, K, and Zr respectively, so that they play different roles in the preparation and performance improvement of tungsten wire. Al, Si, and K are traditional added elements in the preparation process of tungsten wire, which can improve recrystallization behavior, refine grains, form potassium bubbles to improve toughness, etc. The present invention adopts liquid-liquid doping to make the distribution of each element in the tungsten wire more uniform. Adding trace Zr elements by mechanical ball milling can absorb impurity oxygen elements in tungsten and generate ZrO2, thereby reducing the segregation of impurity oxygen and playing a purification role. The generated fine zirconium oxide particles can also play a role of dispersion strengthening, and finally improve the toughness of tungsten alloy together.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The multi-component composite reinforced tungsten wire prepared by the present invention not only has an ultra-fine wire diameter, but also achieves strength improvement through the synergistic effects of second phase dispersion strengthening, fine grain strengthening, solid solution strengthening and grain boundary purification; the dispersion strengthening is synergistically achieved through the pinning effect of dispersed and fine-sized nano-oxide particles and potassium bubbles on crystal dislocations; the fine grain strengthening is achieved by suppressing the grain boundary migration of the tungsten matrix through the nano-dispersed phase, thereby refining the grain size; the grain boundary purification is achieved by adding Zr elements to combine with impurity elements such as oxygen present in the tungsten alloy interface to generate ZrO2.

[0044] (2) The present invention adopts liquid-liquid mixing to obtain a tungsten alloy precursor, and prepares a multiphase reinforced tungsten alloy powder with fine and uniform particle size, high sphericity, and high sintering activation through the precursor, which effectively reduces the sintering temperature and improves the sintering density.

[0045] (3) The multi-component composite reinforced tungsten wire prepared by the present invention has a length of more than 150 km, has good performance, a wire diameter specification of 28-30 μm, good dimensional accuracy, a wire diameter tolerance of ±0.5 μm, a tensile strength of ≥7100 MPa, and high cutting accuracy, meeting the production requirements of diamond wire for photovoltaic silicon wafer cutting. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1These are SEM images of the multi-component composite reinforced tungsten wires prepared in Examples 1-4, respectively, wherein Figure (a) corresponds to Example 1, Figure (b) corresponds to Example 2, Figure (c) corresponds to Example 3, and Figure (d) corresponds to Example 4.

[0047] Figure 2 It is the cross-sectional microstructure of the tungsten alloy drawn to Φ3mm prepared in Example 1, wherein Figure (a) is the microstructure and strengthening phase distribution of the tungsten alloy, and Figure (b) is the enlarged microstructure of the cross-sectional view of the tungsten alloy.

[0048] Figure 3 This is a surface scanning energy spectrum diagram of the cross section of the tungsten alloy drawn to Φ3mm prepared in Example 1.

[0049] Figure 4 This is a longitudinal section microstructure diagram of the tungsten alloy drawn to Φ30.55μm prepared in Example 1.

[0050] Figure 5 This is a scanning energy spectrum of the longitudinal section of the tungsten alloy drawn to Φ30.55μm prepared in Example 1. DETAILED DESCRIPTION

[0051] In order to better understand the content of the present invention, the present invention will be further described below in conjunction with specific embodiments and drawings. The following embodiments are implemented based on the technology of the present invention, and detailed implementation methods and operating steps are given, but the protection scope of the present invention is not limited to the following embodiments.

[0052] Embodiment 1:

[0053] (1) According to the La2O3 content of 0.5wt.%, Al content of 0.03wt.%, Si content of 0.1wt.%, K content of 0.28wt.%, and W content of 98.59wt.% in the multi-component composite reinforced tungsten wire, the raw materials ammonium metatungstate, lanthanum nitrate, potassium silicate, and aluminum nitrate are calculated and weighed according to the above ratio, and the ammonium metatungstate, lanthanum nitrate, potassium silicate, and aluminum nitrate are respectively mixed and dissolved with distilled water to obtain a clear solution, wherein the concentration of the ammonium metatungstate solution is 0.5mol / L, and the concentration of the lanthanum nitrate solution is 0. The concentration of the ammonium metatungstate solution is 0.01 mol / L, the concentration of the potassium silicate solution is 0.5 mol / L, and the concentration of the aluminum nitrate solution is 1 mol / L; then the ammonium metatungstate solution, lanthanum nitrate solution, potassium silicate solution, and aluminum nitrate solution are mixed, that is, liquid-liquid doping is performed, and the various doping phases are fully stirred for 4 hours to achieve uniform mixing, and then placed in a container at 110°C for heating and co-precipitation, and stirred continuously until solids are precipitated (the purpose of continuous stirring here is to keep the various doping phases mixed uniformly and prevent segregation during evaporation), and finally the liquid is completely evaporated to obtain a mixed precursor powder;

[0054] (2) Calcination reduction

[0055] The mixed precursor powder was calcined in a muffle furnace at 550°C for 4 hours, and then the calcined product was subjected to a two-stage reduction to obtain a doped W powder, the particle size of the doped W powder was 2 μm, and the two-stage reduction was specifically reduced at 700°C for 2 hours and then at 900°C for 4 hours;

[0056] (3) Mechanical ball milling

[0057] According to the Zr element content of the final multi-component composite reinforced tungsten wire being 0.5wt.%, weigh the quantitatively proportioned ZrH2 powder, mix it with the doped W powder obtained in step (2) by mechanical ball milling for 8h, and maintain a vacuum environment during the mixing process to finally obtain a mixed tungsten alloy powder containing nano-La2O3 and alloy elements (specifically including Al, Si, K, and Zr);

[0058] (4) Pressing and sintering

[0059] The mixed tungsten alloy powder was cold isostatically pressed at 220 MPa into a cylindrical tungsten alloy billet with a diameter of 22 mm, and the holding time was 20 min. Then, the medium frequency induction sintering method was adopted. Specifically, the pressed billet was placed in a medium frequency induction furnace, first heated to 1200°C, with a heating rate of 10°C / min, and kept warm for 1 h; then heated to 1800°C at a heating rate of 20°C / min, kept warm for 1 h, and finally heated to 2500°C at 20°C / min, and kept warm for 5 h to obtain a tungsten alloy sintered billet;

[0060] (5) Hot isostatic pressing

[0061] The tungsten alloy sintered blank is placed in a can, and then the can is placed in a hot isostatic pressing device, and processed for 2 hours at a temperature of 1300°C and a pressure of 180MPa, which can further eliminate the internal pores and finally obtain a sintered blank after hot isostatic pressing. After testing, the density of the sintered blank reaches 98.9%;

[0062] (6) Rolling and blanking

[0063] The sintered billet after hot isostatic pressing was rolled and opened by a three-roller Y-type rolling mill at a temperature of 1700°C. A tungsten alloy rod with a diameter of 10 mm was prepared by continuous rolling, and the end deformation of each pass was 20%.

[0064] (7) First intermediate processing

[0065] The tungsten alloy rod prepared above was straightened and rounded to obtain a tungsten rod with a diameter of 9 mm, and then the tungsten rod was recrystallized and annealed at 1700°C by heating with natural gas (specifically, the tungsten rod was placed in an annealing furnace, and the natural gas flame sprayed from the burner burned in the furnace, and the tungsten rod absorbed heat through heat transfer). Argon was introduced during the annealing process to prevent oxidation, and the holding time was 55 minutes;

[0066] (8) Multi-pass rotary forging

[0067] The tungsten rod obtained after the first intermediate treatment in step (7) is rotary forged in a natural gas atmosphere, the rotary forging temperature is 1600° C., the forging frequency is 9500 times / min, the single end face shrinkage deformation is 15%, and the rotary forging obtains a tungsten alloy rod with an end face diameter of 5 mm;

[0068] (9) Second intermediate processing

[0069] The tungsten alloy rod with an end diameter of 5 mm obtained in step (8) is chain-pulled to a diameter of 3 mm at a drawing temperature of 1500° C. and wound around a disk with a diameter of 300 mm;

[0070] (10) Single-mode and multi-mode drawing

[0071] The tungsten rod obtained by the second intermediate treatment in step (9) is drawn to a diameter of 0.67 mm by single-mode drawing, with a heating temperature of 750° C., a mold temperature of 650° C., and a drawing speed of 25 m / min. After stress relief annealing at 1100° C. for 30 min, the tungsten rod is drawn to a diameter of 0.20 mm by multi-mode drawing with the same parameters (i.e., a heating temperature of 750° C., a mold temperature of 650° C., and a drawing speed of 25 m / min). The above-mentioned drawing and annealing processes are both heated by a natural gas flame and argon is introduced as a protective gas. Graphite powder is applied around the tungsten wire as a lubricant.

[0072] (11) Intermediate treatment: the tungsten wire obtained in step (10) is subjected to recrystallization annealing to eliminate work hardening and residual stress. The annealing temperature is 1700° C. and the holding time is 55 min.

[0073] (12) Wire drawing: multiple multi-mode wire drawing is performed by heating in an electric furnace, wherein the heating temperature is 550°C, the drawing die temperature is 500°C, the drawing speed is 70 m / min, and argon gas is introduced during the wire drawing process, and finally a tungsten wire with a diameter of 30.55 μm is obtained.

[0074] (13) Electrolytic polishing: The graphite emulsion and the oxide layer attached to the surface of the tungsten wire are removed by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire with a diameter of 29.12 μm.

[0075] According to the performance test, the tensile strength of the multi-component composite reinforced tungsten wire prepared in this embodiment is 7328 MPa, and the length of a single wire is 155 km.

[0076] Embodiment 2:

[0077] (1) According to the La2O3 content of 1.0wt.%, Al content of 0.04wt.%, Si content of 0.15wt.%, K content of 0.42wt.%, and W content of 98.09wt.% in the multi-component composite reinforced tungsten wire, the raw materials ammonium metatungstate, lanthanum nitrate, potassium silicate, and aluminum nitrate are calculated and weighed according to the above ratio, and the ammonium metatungstate, lanthanum nitrate, potassium silicate, and aluminum nitrate are respectively mixed with distilled water and dissolved to obtain a clear solution, wherein the ammonium metatungstate solution The concentration of the ammonium metatungstate solution is 1 mol / L, the concentration of the lanthanum nitrate solution is 0.01 mol / L, the concentration of the potassium silicate solution is 1 mol / L, and the concentration of the aluminum nitrate solution is 1 mol / L; the ammonium metatungstate solution, lanthanum nitrate solution, potassium silicate solution, and aluminum nitrate solution are mixed, that is, liquid-liquid doping is performed, and the various doping phases are fully stirred for 2 hours to achieve uniform mixing, and then placed in a container at 110°C for heating and co-precipitation, and stirred continuously until solids are precipitated, and finally the liquid is completely evaporated to obtain a mixed precursor powder;

[0078] (2) Calcination reduction

[0079] The precursor powder was calcined in a muffle furnace at 530°C for 4.5 hours, and then the calcined product was subjected to a two-stage reduction to obtain a doped W powder, the particle size of the doped W powder was 1.96 μm, and the two-stage reduction was specifically carried out at 700°C for 2 hours and then at 920°C for 4 hours;

[0080] (3) Mechanical ball milling

[0081] According to the Zr element content of the final multi-component composite reinforced tungsten wire being 0.3wt.%, weigh the quantitatively proportioned ZrH2 powder, mix it with the doped W powder obtained in step (2) by mechanical ball milling for 8h, and maintain a vacuum environment during the mixing process to finally obtain a mixed tungsten alloy powder containing nano-La2O3 and alloy elements (specifically including Al, Si, K, and Zr);

[0082] (4) Pressing and sintering

[0083] The mixed tungsten alloy powder was cold isostatically pressed at 240Mpa into a cylindrical tungsten alloy billet with a diameter of 22mm, and the holding time was 20min. Then, the medium frequency induction sintering method was adopted, and the pressed billet was placed in a medium frequency induction furnace, firstly heated to 1200℃, with a heating rate of 10℃ / min, and kept warm for 0.5h; then heated to 2000℃ at a heating rate of 20℃ / min, kept warm for 1h, and finally heated to 2550℃ at a heating rate of 10℃ / min, and kept warm for 5h to obtain a tungsten alloy sintered billet;

[0084] (5) Hot isostatic pressing

[0085] The tungsten alloy sintered blank is placed in a can, and then the can is placed in a hot isostatic pressing device, and processed for 2 hours at a temperature of 1250°C and a pressure of 200MPa, which can further eliminate the internal pores and finally obtain a sintered blank after hot isostatic pressing. After testing, the density of the sintered blank reaches 99.0%;

[0086] (6) Rolling and blanking

[0087] The sintered billet after hot isostatic pressing was rolled and opened by a three-roller Y-type rolling mill at a temperature of 1680°C. A tungsten alloy rod with a diameter of 9.8 mm was prepared by continuous rolling, and the end deformation of each pass was 19%.

[0088] (7) First intermediate processing

[0089] The tungsten alloy rod prepared above was straightened and rounded to obtain a tungsten rod with a diameter of 9 mm, and then the tungsten rod was recrystallized and annealed at 1650°C by heating with natural gas. Argon was introduced during the annealing process to prevent oxidation, and the holding time was 60 minutes.

[0090] (8) Multi-pass rotary forging

[0091] The tungsten rod obtained after the first intermediate treatment in step (7) is rotary forged in a natural gas atmosphere, the rotary forging temperature is 1550° C., the forging frequency is 9800 times / min, the single end face shrinkage deformation is 13%, and the rotary forging obtains a tungsten alloy rod with an end face diameter of 5 mm;

[0092] (9) Second intermediate processing

[0093] The tungsten alloy rod with an end diameter of 5 mm obtained in step (8) is chain-pulled to a diameter of 3 mm at a drawing temperature of 1480° C. and wound around a disk with a diameter of 300 mm;

[0094] (10) Multi-mode wire drawing

[0095] The tungsten rod obtained by the second intermediate treatment in step (9) is drawn to a diameter of 0.65 mm by single-mode drawing, the drawing temperature is 780° C., the mold temperature is 660° C., and the drawing speed is 20 m / min. After stress relief annealing at 1100° C. for 45 min, the tungsten rod is drawn to a diameter of 0.25 mm by multi-mode drawing with the same parameters (i.e., the drawing temperature is 780° C., the mold temperature is 660° C., and the drawing speed is 20 m / min). The above-mentioned drawing and annealing processes are both heated by natural gas flames and argon is introduced as a protective gas. Graphite powder is applied around the tungsten wire as a lubricant.

[0096] (11) intermediate treatment, subjecting the tungsten wire obtained in step (10) to recrystallization annealing to eliminate work hardening and residual stress, the annealing temperature is 1680° C., and the holding time is 60 min;

[0097] (12) Wire drawing: multiple multi-mode wire drawing is performed by heating in an electric furnace, wherein the heating temperature is 600°C, the drawing die temperature is 550°C, the drawing speed is 75 m / min, and argon gas is introduced during the wire drawing process, and finally a tungsten wire with a diameter of 30.08 μm is obtained.

[0098] (13) Electrolytic polishing: The graphite emulsion and the oxide layer attached to the surface of the tungsten wire are removed by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire with a diameter of 29.03 μm.

[0099] According to the performance test, the tensile strength of the multi-component composite reinforced tungsten wire prepared in this embodiment is 7455 MPa, and the length of a single wire is 160 km.

[0100] Embodiment 3:

[0101] (1) According to the Y2O3 content of 0.5wt.%, Al content of 0.035wt.%, Si content of 0.12wt.%, K content of 0.33wt.%, and W content of 98.515wt.% in the multi-component composite reinforced tungsten wire, the raw materials ammonium metatungstate, yttrium nitrate, potassium silicate, and aluminum nitrate are calculated and weighed according to the above ratio, and the ammonium metatungstate, yttrium nitrate, potassium silicate, and aluminum nitrate are respectively mixed with distilled water and dissolved to obtain a clear solution, wherein the metatungstate The concentration of the ammonium solution is 0.6 mol / L, the concentration of the lanthanum nitrate solution is 0.008 mol / L, the concentration of the potassium silicate solution is 2 mol / L, and the concentration of the aluminum nitrate solution is 1 mol / L. Then the above ammonium metatungstate solution, yttrium nitrate solution, potassium silicate solution, and aluminum nitrate solution are mixed, that is, liquid-liquid doping is performed, and the various doping phases are fully stirred for 2 hours to achieve uniform mixing, and then placed in a 100°C container for heating and co-precipitation, and the heating process is continuously stirred, and finally the liquid is completely evaporated to obtain a mixed precursor powder;

[0102] (2) Calcination reduction

[0103] The precursor powder was calcined in a muffle furnace at 550°C for 4 hours, and then the calcined product was subjected to a two-stage reduction to obtain a doped W powder, the particle size of the doped W powder was 2.02 μm, and the two-stage reduction was specifically carried out at 680°C for 2 hours and then at 920°C for 4 hours;

[0104] (3) Mechanical ball milling

[0105] According to the Zr element content of the final multi-component composite reinforced tungsten wire being 0.5wt.%, weigh the quantitatively proportioned ZrH2 powder, mix it with the doped W powder obtained in step (2) by mechanical ball milling for 10 hours, and maintain a vacuum environment during the mixing process to finally obtain a mixed tungsten alloy powder containing nano Y2O3 and alloy elements (specifically including Al, Si, K, and Zr);

[0106] (4) Pressing and sintering

[0107] The mixed tungsten alloy powder was cold isostatically pressed at 240Mpa into a cylindrical tungsten alloy billet with a diameter of 24mm, and the holding time was 20min. Then, the medium frequency induction sintering method was adopted, and the pressed billet was placed in a medium frequency induction furnace, firstly heated to 1200℃, with a heating rate of 10℃ / min, and kept warm for 0.5h; then heated to 1800℃ at a heating rate of 20℃ / min, kept warm for 1h, and finally heated to 2500℃ at 20℃ / min, and kept warm for 5h to obtain a tungsten alloy sintered billet;

[0108] (5) Hot isostatic pressing

[0109] The tungsten alloy sintered blank is placed in a can, and then the can is placed in a hot isostatic pressing device, and processed for 3 hours at a temperature of 1350°C and a pressure of 200MPa, which can further eliminate the internal pores and finally obtain a sintered blank after hot isostatic pressing. After testing, the density of the sintered blank reaches 99.2%;

[0110] (6) Rolling and blanking

[0111] The sintered billet after hot isostatic pressing was rolled and opened by a three-roller Y-type rolling mill at a temperature of 1680°C. A tungsten alloy rod with a diameter of 10.2 mm was prepared by continuous rolling, and the end deformation of each pass was 20%.

[0112] (7) First intermediate processing

[0113] The tungsten alloy rod prepared above was straightened and rounded to obtain a tungsten rod with a diameter of 9 mm, and then the tungsten rod was recrystallized and annealed at 1700°C by burning natural gas heating. Argon was introduced during the annealing process to prevent oxidation, and the holding time was 60 minutes.

[0114] (8) Multi-pass rotary forging

[0115] The tungsten rod obtained after the first intermediate treatment in step (7) is rotary forged in a natural gas atmosphere, the rotary forging temperature is 1600° C., the forging frequency is 10,000 times / min, the single end face shrinkage deformation is 15%, and the rotary forging obtains a tungsten alloy rod with an end face diameter of 5 mm;

[0116] (9) Second intermediate processing

[0117] The tungsten alloy rod with an end diameter of 5 mm obtained in step (8) is chain-pulled to a diameter of 3 mm at a drawing temperature of 1500° C. and wound around a disk with a diameter of 300 mm;

[0118] (10) Single-mode and multi-mode drawing

[0119] The tungsten rod obtained by the second intermediate treatment in step (9) is drawn to a diameter of 0.67 mm by single-mode drawing, the drawing temperature is 800° C., the mold temperature is 700° C., and the drawing speed is 30 m / min. After stress relief annealing at 1150° C. for 45 min, the tungsten rod is drawn to a diameter of 0.27 mm by multi-mode drawing with the same parameters (i.e., the drawing temperature is 800° C., the mold temperature is 700° C., and the drawing speed is 30 m / min). The above-mentioned drawing and annealing processes are both heated by natural gas flames and argon is introduced as a protective gas. Graphite powder is applied around the tungsten wire as a lubricant.

[0120] (11) intermediate treatment, subjecting the tungsten wire obtained in step (10) to recrystallization annealing to eliminate work hardening and residual stress, the annealing temperature is 1700° C., and the holding time is 60 min;

[0121] (12) Wire drawing: multiple multi-mode wire drawing is performed by heating in an electric furnace, wherein the heating temperature is 600°C, the drawing die temperature is 600°C, the drawing speed is 80 m / min, and argon gas is introduced during the wire drawing process, and finally a tungsten wire with a diameter of 31.08 μm is obtained.

[0122] (13) Electrolytic polishing: The graphite emulsion and the oxide layer attached to the surface of the tungsten wire are removed by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire with a diameter of 28.63 μm.

[0123] According to the performance test, the tensile strength of the multi-component composite reinforced tungsten wire prepared in this embodiment is 7229 MPa, and the length of a single wire is 163 km.

[0124] Embodiment 4:

[0125] (1) According to the CeO2 content of 1.0wt.%, Al content of 0.035wt.%, Si content of 0.2wt.%, K content of 0.56wt.%, and W content of 97.955wt.% in the multi-component composite reinforced tungsten wire, the raw materials are proportioned, and the raw materials ammonium metatungstate, cerium nitrate, potassium silicate, and aluminum nitrate are calculated and weighed according to the above proportions, and the ammonium metatungstate, cerium nitrate, potassium silicate, and aluminum nitrate are respectively mixed with distilled water and dissolved to obtain a clear solution, wherein the ammonium metatungstate solution The concentration of lanthanum nitrate solution is 0.5mol / L, the concentration of potassium silicate solution is 0.5mol / L, the concentration of aluminum nitrate solution is 0.8mol / L, and then the ammonium metatungstate solution, cerium nitrate solution, potassium silicate solution and aluminum nitrate solution are mixed, that is, liquid-liquid doping is performed, and the various doping phases are fully stirred for 2.5h to achieve uniform mixing, and then placed in a container at 110°C for heating and co-precipitation, and stirred continuously during the heating process to finally obtain a mixed precursor powder;

[0126] (2) Calcination reduction

[0127] The precursor powder was calcined in a muffle furnace at 550°C for 4 hours, and then the calcined product was subjected to a two-stage reduction to obtain a doped W powder, the particle size of the doped W powder was 1.88 μm, and the two-stage reduction was specifically carried out at 700°C for 2 hours and then at 900°C for 4 hours;

[0128] (3) Mechanical ball milling

[0129] According to the Zr element content of the final multi-component composite reinforced tungsten wire being 0.25wt.%, weigh the quantitatively proportioned ZrH2 powder, mix it with the doped W powder obtained in step (2) by mechanical ball milling for 10 hours, and maintain a vacuum environment during the mixing process to finally obtain a mixed tungsten alloy powder containing nano-CeO2 and alloy elements (specifically including Al, Si, K, and Zr);

[0130] (4) Pressing and sintering

[0131] The mixed tungsten alloy powder was cold isostatically pressed at 220Mpa into a cylindrical tungsten alloy billet with a diameter of 20mm, and the holding time was 25min. Then, the medium frequency induction sintering method was adopted. The pressed billet was placed in a medium frequency induction furnace, first heated to 1100℃, with a heating rate of 10℃ / min, and kept warm for 0.5h; then heated to 1800℃ at a heating rate of 20℃ / min, kept warm for 1h, and finally heated to 2550℃ at 10℃ / min, and kept warm for 4.5h to obtain a tungsten alloy sintered billet;

[0132] (5) Hot isostatic pressing

[0133] The tungsten alloy sintered blank is placed in a can, and then the can is placed in a hot isostatic pressing device, and processed for 2 hours at a temperature of 1400°C and a pressure of 190MPa, which can further eliminate the internal pores and finally obtain a sintered blank after hot isostatic pressing. After testing, the density of the sintered blank reaches 98.8%;

[0134] (6) Rolling and blanking

[0135] The sintered billet after hot isostatic pressing was rolled and opened by a three-roller Y-type rolling mill at a temperature of 1700°C. Tungsten alloy rods with a diameter of 10.5 mm were prepared by continuous rolling, and the end deformation of each pass was 18%.

[0136] (7) First intermediate processing

[0137] The tungsten alloy rod prepared above was straightened and rounded to obtain a tungsten rod with a diameter of 9 mm, and then the tungsten rod was recrystallized and annealed at 1750°C by heating with natural gas. Argon was introduced during the annealing process to prevent oxidation, and the holding time was 60 minutes.

[0138] (8) Multi-pass rotary forging

[0139] The tungsten rod obtained after the first intermediate treatment in step (7) is rotary forged in a natural gas atmosphere, the rotary forging temperature is 1600° C., the forging frequency is 10,000 times / min, the single end face shrinkage deformation is 15%, and a 5 mm tungsten alloy rod is obtained by rotary forging;

[0140] (9) Second intermediate processing

[0141] The 5 mm tungsten alloy rod obtained in step (8) is chain-pulled to a diameter of 3 mm at a drawing temperature of 1450° C. and wound around a disc with a diameter of 300 mm;

[0142] (10) Single-mode and multi-mode drawing

[0143] The tungsten rod obtained by the second intermediate treatment in step (9) is drawn to a diameter of 0.66 mm by single-mode drawing, with a heating temperature of 760° C., a mold temperature of 670° C., and a drawing speed of 25 m / min. After stress relief annealing at 1200° C. for 60 min, the tungsten rod is drawn to a diameter of 0.28 mm by multi-mode drawing with the same parameters (i.e., a heating temperature of 760° C., a mold temperature of 670° C., and a drawing speed of 25 m / min). The above-mentioned drawing and annealing processes are both heated by a natural gas flame and argon is introduced as a protective gas. Graphite powder is applied around the tungsten wire as a lubricant.

[0144] (11) intermediate treatment, subjecting the tungsten wire obtained in step (10) to recrystallization annealing to eliminate work hardening and residual stress, the annealing temperature is 1650° C., and the holding time is 60 min;

[0145] (12) Wire drawing, using electric furnace heating to draw multiple times by multi-die drawing, wherein the heating temperature is 600° C., the drawing die temperature is 550° C., and the drawing speed is 75 m / min, and finally a tungsten wire with a diameter of 31.88 μm is obtained;

[0146] (13) electrolytic polishing, wherein the graphite emulsion and the oxide layer attached to the surface of the tungsten wire are removed by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire with a diameter of 29.56 μm;

[0147] According to the performance test, the tensile strength of the multi-component composite reinforced tungsten wire prepared in this embodiment is 7176 MPa, and the length of a single wire is 158 km.

[0148] The multi-component composite reinforced tungsten wires prepared in Examples 1-4 were randomly sampled for analysis and testing. The SEM images of the tungsten wire surfaces were as follows: Figure 1 The performance comparison is shown in Table 1.

[0149] Table 1 Basic dimensions and properties of multi-component composite reinforced tungsten wires prepared in Examples 1-4

[0150]

[0151]

[0152] As shown in Table 1, the multi-component composite reinforced tungsten wire prepared by the method of the present invention has an extremely fine wire diameter and has typical characteristics such as high yield rate of wire drawing and high tensile strength. When an appropriate amount of lanthanum oxide or yttrium oxide or cerium oxide, silicon, aluminum, potassium and zirconium elements mentioned in the present invention are added, combined with sintering, drawing and annealing processes, a high-strength and tough tungsten wire with a length of more than 155 km and a tensile strength of 7455 MPa can be prepared.

[0153] from Figure 2 and Figure 3 It can be seen that the oxides in the tungsten alloy material involved in the present invention are mainly distributed in the grains of the matrix phase, and a few are distributed at the grain boundaries. Compared with the strengthening phase at the grain boundaries, the intracrystalline dispersed strengthening phase can be more evenly distributed inside the entire grain, so that the movement of dislocations at any position in the grain will be hindered. This strengthening effect can be reflected in the entire grain, which is beneficial to the overall improvement of material strength.

[0154] from Figure 4 and Figure 5 It can be seen that the lanthanum oxide particles in the prepared Φ30μm tungsten wire are still nanoscale, but have been elongated. After the fibrous reinforcement phase is elongated, the dislocation needs to bypass a longer reinforcement phase path to continue moving, which requires additional energy, thereby improving the yield strength and tensile strength of the material.

[0155] Table 2 is a comparison of tungsten wire preparation processes and performance in other published invention patents.

[0156] Table 2

[0157]

[0158]

[0159] The above is only an embodiment of the present invention, and does not limit the present invention in any form. The present invention can also have other forms of embodiments according to the above structures and functions, which are not listed one by one. Therefore, any simple modification, equivalent change and modification made by any technician familiar with the profession to the above embodiment according to the technical essence of the present invention without departing from the scope of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An ultra-fine high-strength multi-component composite reinforced tungsten wire, characterized in that: The composition of the ultrafine high-strength multi-component composite reinforced tungsten wire includes rare earth oxide, alloy elements and tungsten, the alloy elements include Al, Si, K, and Zr, and the content of each component is as follows: the rare earth oxide content is 0.1-1.0wt.%, the Al content is 0.025-0.05wt.%, the Si content is 0.1-0.2wt.%, the K content is 0.28-0.56wt.%, the Zr content is 0.1-0.5wt.%, and the rest is W.

2. The ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 1, characterized in that: The ultra-fine high-strength multi-component composite reinforced tungsten wire has a diameter of 28-30 μm, a tensile strength of more than 7100 MPa, and a single wire is more than 150,000 meters.

3. The ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 1, characterized in that: The rare earth oxide includes one of La2O3, Y2O3 and CeO2.

4. A method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire as claimed in claim 1, characterized in that: The specific steps include: (1) Liquid-liquid doping According to the raw material ratio, a certain amount of ammonium metatungstate, rare earth element nitrate, potassium silicate and aluminum nitrate are weighed and dissolved in water to form a solution, and then the obtained ammonium metatungstate solution, rare earth element nitrate solution, potassium silicate solution and aluminum nitrate solution are fully mixed, and then heated at 100-120°C for coprecipitation, and stirred continuously during the heating process until solid precipitates and the liquid evaporates completely to obtain a precursor powder; (2) Calcination reduction The precursor powder is calcined in a muffle furnace at 500-550°C for 4-4.5 hours, and then the calcined product is subjected to a two-stage reduction to obtain doped W powder; (3) Mechanical ball milling Weigh ZrH2 powder according to the raw material ratio, and mix it with the doped W powder obtained in step (2) by mechanical ball milling in a vacuum environment for 8-12 hours to finally obtain a mixed tungsten alloy powder containing nano rare earth oxides and alloying elements; (4) pressing and sintering to obtain a tungsten alloy sintered blank; (5) hot isostatic pressing to obtain a sintered blank after hot isostatic pressing; (6) rolling and blanking to obtain a tungsten alloy rod; (7) a first intermediate treatment to obtain a tungsten rod after the first intermediate treatment; (8) performing multiple rotary forging to obtain a tungsten alloy rod after rotary forging; (9) a second intermediate treatment to obtain a tungsten rod after the second intermediate treatment; (10) Single-mode wire drawing and multi-mode wire drawing; (11) a third intermediate treatment to obtain a tungsten wire after the third intermediate treatment; (12) drawing to obtain tungsten wire; (13) Electrolytic polishing is performed to finally obtain ultrafine high-strength multi-component composite reinforced tungsten wire.

5. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 4, characterized in that: The rare earth element nitrate in step (1) includes any one of lanthanum nitrate, yttrium nitrate and cerium nitrate; wherein the concentration of ammonium metatungstate solution is 0.1-1 mol / L, the concentration of rare earth element nitrate solution is 0.001-0.01 mol / L, the concentration of potassium silicate solution is 0.5-2 mol / L, and the concentration of aluminum nitrate solution is 0.1-1 mol / L; the raw material ratio specifically refers to the amount of raw materials calculated according to the content of each component of the ultrafine high-strength multi-component composite reinforced tungsten wire, wherein the rare earth oxide in the ultrafine high-strength multi-component composite reinforced tungsten wire is derived from rare earth element nitrate, Al is derived from aluminum nitrate, Si and K are both derived from potassium silicate, Zr is derived from zirconium hydride powder, and W is derived from ammonium metatungstate.

6. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 4, characterized in that: The two-stage reduction in step (2) is specifically to first reduce at 650°C-700°C for 2h and then reduce at 900°C-920°C for 4h; the particle size of the obtained doped W powder is 1.0-2.5μm.

7. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 4, characterized in that: Step (4) pressing and sintering is specifically to cold isostatically press the mixed tungsten alloy powder into a cylindrical tungsten alloy billet with a diameter of 20 to 25 mm under a pressure of 200 MPa to 240 MPa, the holding time of the cold isostatic pressing is 18 to 20 min, and then place it in a medium frequency induction sintering furnace, and perform three stages of heating + heat preservation to obtain a tungsten alloy sintered billet; the three stages of heating + heat preservation are specifically as follows: placing the pressed billet in a medium frequency induction sintering furnace, first heating to 1000 to 1200° C., the heating rate is 5 to 10° C. / min, and the temperature is kept for 0.5 to 1 h; then heating to 1800 to 2000° C. at a heating rate of 10 to 20° C. / min, and the temperature is kept for 0.5 to 1 h; finally heating to 2500 to 2600° C. at a heating rate of 10 to 20° C. / min, and the temperature is kept for 4 to 5 h, to obtain a tungsten alloy sintered billet; Step (5) specifically includes placing the tungsten alloy sintered blank obtained in step (4) in a sheath, and then placing the sheath in a hot isostatic pressing device, and treating it under high temperature and high pressure for 1-3 hours, and finally obtaining a sintered blank after hot isostatic pressing; Step (6) specifically comprises rolling the sintered billet after hot isostatic pressing in step (5) with a three-roller Y-type rolling mill, the billet opening temperature being 1500-1700° C., and preparing a tungsten alloy rod with a diameter of 8.0-11 mm by continuous rolling, and the end surface deformation of each pass being 17-20%; Step (7) specifically straightens and rounds the tungsten alloy rod obtained in step (6) to obtain a tungsten rod with a diameter of 8-9 mm, and then uses natural gas heating to recrystallize and anneal the tungsten rod at 1600-1800° C., argon is introduced during the recrystallization annealing process, and the holding time of the recrystallization annealing is 40-60 minutes.

8. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 4, characterized in that: Step (8) specifically comprises rotary forging the tungsten rod obtained by the first intermediate treatment in step (7) under a natural gas or hydrogen atmosphere, wherein the rotary forging temperature is 1500-1600° C., the forging frequency is 9000-10000 times / min, the single end face shrinkage deformation is 10-15%, and the rotary forging obtains a tungsten alloy rod with an end face diameter of 5 mm; Step (9) specifically comprises chain-pulling the tungsten alloy rod with an end diameter of 5 mm obtained in step (8) to a diameter of 3 mm at a drawing temperature of 1400° C.-1500° C., and winding the rod around a disk to form a circle with a diameter of 300 mm. Step (10) specifically comprises: drawing the tungsten rod obtained by the second intermediate treatment in step (9) to a diameter of 0.65-0.67 mm by single-mode drawing under natural gas flame heating, the heating temperature is 750-800° C., the mold temperature is 650-700° C., the drawing speed is 20-30 m / min, and after stress relief annealing at 1100° C.-1200° C. for 30-60 min, the tungsten rod is drawn to a diameter of 0.18-0.29 mm by multi-mode drawing with the same parameters as the single-mode drawing process. The above-mentioned drawing and annealing processes are both heated by natural gas flame and argon gas is introduced, and graphite powder is applied around the tungsten wire as a lubricant; Step (11) specifically comprises subjecting the tungsten wire obtained in step (10) to recrystallization annealing to eliminate work hardening and residual stress, the annealing temperature being 1500-1700° C., and the annealing holding time being 40-60 min.

9. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 4, characterized in that: Step (12) specifically comprises heating in an electric furnace by multiple multi-mode drawing, introducing argon gas to prevent oxidation during the drawing process, wherein the heating temperature is 500° C.-600° C., the drawing die temperature is 350-600° C., and the drawing speed is 60-80 m / min, and finally a tungsten wire with a diameter of 30-32 μm is obtained; Step (13) specifically involves removing the graphite emulsion and the oxide layer attached to the surface of the tungsten wire prepared in step (12) by electrolytic polishing to obtain a multi-component composite reinforced tungsten wire.

10. The method for preparing the ultra-fine high-strength multi-component composite reinforced tungsten wire according to claim 7, characterized in that: In step (5), the high temperature specifically refers to 1200-1400° C., and the high pressure specifically refers to 150-200 MPa; the relative density of the sintered blank after hot isostatic pressing is 98.5-99.5%; and the holding time of recrystallization annealing in step (7) is 40-60 min.

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