Tungsten-cerium alloy wire and preparation method thereof

Abstract

The invention belongs to the technical field of tungsten material manufacturing, and particularly relates to a tungsten-cerium alloy wire and a preparation method thereof.The preparation method comprises the steps that a cerium-containing solution and ammonium paratungstate are mixed through a spray mixing method and dried, and a mixture is obtained; the mixture is calcined at the temperature lower than or equal to 900 DEG C and reduced in the hydrogen atmosphere at the temperature of 800-1050 DEG C, and cerium-containing tungsten powder is obtained; the cerium-containing tungsten powder is subjected to isostatic pressing forming, sintered for 1-1.5 h at the temperature of 1500-1600 DEG C in the hydrogen atmosphere and then sintered for 5-8 h at the temperature of 2300-2450 DEG C, and a tungsten rod is obtained; and the tungsten rod is subjected to rolling, electric pulse treatment, forging and wire drawing treatment, and the tungsten-cerium alloy wire with the diameter being 20-28 microns is obtained. The cerium element is uniformly distributed in the alloy wire through solid-liquid cerium doping; through the two-stage sintering process, the compactness and the mechanical property of the tungsten rod are improved; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and shows low edge breakage rate, low wire breakage rate and long service life in silicon nitride ceramic substrate cutting.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of tungsten material manufacturing, in particular to a tungsten-cerium alloy wire and a preparation method thereof. BACKGROUND

[0002] With the demand explosion of new energy and semiconductor industry chain, the third generation of semiconductor is developing rapidly. Silicon nitride (Si3N4) ceramic substrate is rapidly penetrating into multiple high-tech fields due to its excellent comprehensive performance. Some enterprises have begun to use silicon nitride substrate to package third-generation semiconductor devices, and silicon nitride substrate will usher in a golden development period.

[0003] At present, the diamond wire used for cutting silicon nitride ceramic substrate usually uses high-strength high-carbon steel wire or nickel-plated steel wire as the base material. Although the high-carbon steel wire or nickel-plated steel wire has low cost and mature technology, its mechanical properties have significant defects in the application process. First, the hardness of silicon nitride ceramic is extremely high (HV10 ≈ 16-18 GPa), and high tension is needed to maintain stability during cutting. The tensile strength of high-carbon steel wire (usually ≤ 3500 MPa) is prone to fatigue fracture under long-term high load, resulting in cutting interruption and yield reduction. Second, the rigidity of high-carbon steel wire is low, and it is prone to vibration during high-speed cutting, resulting in micro-collapse edge or oblique cutting of the cut, which affects the size accuracy and subsequent packaging performance of the silicon nitride ceramic substrate. Third, the toughness of high-carbon steel wire is low, and it is prone to brittle fracture during repeated cutting of hard materials, resulting in short service life. SUMMARY

[0004] In view of the problems of low tensile strength, low toughness, high wire breakage rate and low cutting precision of high-carbon steel wire, which lead to cutting edge collapse, etc., the application provides a tungsten-cerium alloy wire and a preparation method thereof. The tungsten-cerium alloy wire is prepared by a solid-liquid cerium-doped mixing method and a sintering process to obtain a tungsten-cerium alloy with uniform distribution of cerium elements. The tungsten-cerium alloy wire has excellent comprehensive performance, and the phenomenon of edge collapse or oblique cutting is significantly reduced during cutting of the silicon nitride ceramic substrate. The service life of the tungsten-cerium alloy wire is also significantly improved compared with that of the high-carbon steel wire.

[0005] According to a first aspect of the application, the application provides a preparation method of a tungsten-cerium alloy wire, comprising the following steps: S1, mixing a cerium-containing solution with ammonium paratungstate by a spray mixing method, and drying to obtain a mixed material; S2, calcining the mixed material to obtain an oxide composite powder, and the calcination temperature is ≤ 900 ℃; S3, reducing the oxide composite powder in a hydrogen atmosphere to obtain a cerium-containing tungsten powder, and the reduction temperature is 800-1050 ℃ and the time is 3-3.5 h; S4, isostatic pressing the cerium-containing tungsten powder to obtain a compact; S5, segmentally sintering the compact in a hydrogen atmosphere to obtain a tungsten rod, the segmentally sintering comprising a first stage sintering and a second stage sintering, wherein the first stage sintering is at a temperature of 1500-1600℃ for 1-1.5h, and the second stage sintering is at a temperature of 2300-2450℃ for 5-8h; S6, rolling, electric pulse processing, forging and wire drawing processing the tungsten rod to obtain a tungsten-cerium alloy wire with a diameter of 20-28μm.

[0006] In the above technical solution, the spraying mixing method is used in step S1 to uniformly disperse the cerium-containing solution in ammonium paratungstate (APT), so that the cerium element can be highly uniformly distributed in the tungsten matrix. In step S2, the mixture is calcined to obtain an oxide composite powder comprising cerium oxide and tungsten oxide, wherein the cerium oxide is obtained by oxidation of the cerium element, and the tungsten oxide is obtained by thermal decomposition of APT; the tungsten oxide obtained by calcination at a temperature ≤900℃ has a small particle size, and the tungsten powder after reduction has a small particle size, which can inhibit grain boundary diffusion during sintering and cause pores in the sintered rod; if the calcination temperature is too high, the crystal form of tungsten oxide will be difficult to control, thereby changing the properties of the tungsten powder. In step S3, the tungsten oxide in the oxide composite powder is reduced to tungsten powder using hydrogen, and the reduction temperature is 800-1050℃ and the time is 3-3.5h; if the temperature is too low or the time is too short, the tungsten oxide cannot be fully reduced, resulting in impure tungsten powder, which will increase the brittleness during the subsequent preparation of alloy wires; if the temperature is too high or the time is too long, unnecessary consumption will be increased. In step S5, the compact prepared in step S4 is subjected to two-stage sintering in a hydrogen atmosphere, the first stage is at a relatively low temperature (1500-1600℃) to reduce the tungsten oxide formed during the preparation of the compact, thereby reducing the oxygen content in the tungsten rod, and the second stage is at a high temperature (2300-2450℃) for densification sintering to improve the density and mechanical properties. In step S6, the tungsten rod is prepared into a tungsten-cerium alloy wire that meets the conditions by combining rolling, electric pulse processing, forging and wire drawing processing, and the electric pulse processing can reduce the internal stress of the tungsten rod.

[0007] Further, in step S1, a soluble cerium salt is used to prepare the cerium-containing solution, the mass fraction of cerium element in the cerium-containing solution is 6.5%-10%, and the mass ratio of the cerium-containing solution to the ammonium paratungstate is 0.24:1-0.36:1. If the content of cerium element is low, it cannot inhibit the excessive growth of tungsten grains during annealing, which will increase the brittleness of the tungsten-cerium alloy wire; if the content of cerium element is high, the recrystallization of tungsten grains during annealing will be excessively inhibited, and the tensile strength after deformation will be reduced; therefore, by adjusting the content of cerium element within the optimal range, a tungsten-cerium alloy wire with high tensile strength can be obtained.

[0008] Further, the soluble cerium salt comprises Ce(NO3)3·6H2O, and the cerium-containing solution comprises a cerium nitrate solution.

[0009] Further, in the step S1, the temperature for drying is 70-90℃.

[0010] Further, in the step S2, the calcination comprises a first-stage calcination, a second-stage calcination and a third-stage calcination, wherein the temperature for the first-stage calcination is 200-220℃, the time is 1.5-2h, the temperature for the second-stage calcination is 350-400℃, the time is 2-2.5h, and the temperature for the third-stage calcination is 750-900℃, the time is 3-4h. The first-stage calcination is mainly for removing the crystal water; in the second-stage calcination, the cerium element is fully oxidized into cerium oxide; in the third-stage calcination, the APT is decomposed into tungsten oxide, at this time, the cerium oxide obtained in the second-stage calcination is distributed at the grain boundaries of the tungsten grains, forming a pinning effect, thereby inhibiting the growth of the tungsten grains; thus, the size of the tungsten grains can be adjusted by the three-stage calcination.

[0011] Further, in the step S3, the flow rate of hydrogen in the hydrogen atmosphere is 20-28L / min.

[0012] Further, in the step S4, the pressure for isostatic pressing is 170-200MPa.

[0013] Further, in the step S5, the flow rate of hydrogen in the hydrogen atmosphere is 3-5L / min.

[0014] Further, in the step S6, the temperature for rolling is 1400-1800℃; the temperature for the electric pulse treatment is 700-900℃, and the time is 23-26s; the feeding speed for forging is 1.2-3m / min, and the speed of forging is 1500-2400times / min.

[0015] Further, in the step S5, the diameter of the tungsten rod is 19.5±0.3mm; in the step S6, the diameter of the tungsten rod after rolling is 9±0.2mm; in the step S6, the diameter of the tungsten rod after forging is 3.6±0.2mm.

[0016] According to a second aspect of the present application, the present application provides a tungsten-cerium alloy wire obtained by the above-mentioned method for preparing a tungsten-cerium alloy wire.

[0017] Further, the tungsten-cerium alloy wire has a tensile strength of ≥4800 MPa and an elongation of 3-15%.

[0018] Further, the tungsten-cerium alloy wire has a tensile strength of ≥6500 MPa and an elongation of 8-15%.

[0019] The application provides a tungsten-cerium alloy wire and a preparation method thereof, and has the following beneficial effects: the uniform distribution of cerium elements in the alloy wire is realized by solid-liquid cerium mixing, and the problems of uneven distribution of cerium and easy agglomeration in the traditional mechanical mixing method are overcome; the oxygen content in the tungsten rod is significantly reduced, and the density and mechanical properties are improved by using a two-stage sintering process; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and exhibits low edge collapse rate, low wire breakage rate and long service life in the cutting of silicon nitride ceramic substrates. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared for Example 1.

[0022] Figure 2 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared for Example 2.

[0023] Figure 3 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared for Comparative Example 2.

[0024] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0026] According to a first aspect of the present application, the present application provides a preparation method of a tungsten-cerium alloy wire, comprising the following steps: S1, mixing a cerium-containing solution and ammonium paratungstate by using a spray mixing method, and drying to obtain a mixture; Preferably, a soluble cerium salt is used to prepare the cerium-containing solution, the mass fraction of cerium in the cerium-containing solution is 6.5% to 10%, the mass ratio of the cerium-containing solution to ammonium paratungstate is 0.24:1 to 0.36:1, and the drying temperature is 70 to 90℃. Specifically, the mass fraction of cerium in the cerium-containing solution can be any one of 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, and 10% or a range between any two of them, and the mass ratio of the cerium-containing solution to ammonium paratungstate can be any one of 0.24:1, 0.27:1, 0.30:1, 0.33:1, and 0.36:1 or a range between any two of them.

[0027] S2, calcining the mixture to obtain an oxide composite powder, the calcining temperature being ≤900℃; Preferably, the calcining includes first-stage calcining, second-stage calcining, and third-stage calcining, wherein the first-stage calcining temperature is 200 to 220℃, the time is 1.5 to 2h, the second-stage calcining temperature is 350 to 400℃, the time is 2 to 2.5h, and the third-stage calcining temperature is 750 to 900℃, the time is 3 to 4h. Specifically, the first-stage calcining temperature can be any one of 200℃, 205℃, 210℃, 215℃, and 220℃ or a range between any two of them, the time can be any one of 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, and 2h or a range between any two of them, the second-stage calcining temperature can be any one of 350℃, 360℃, 370℃, 380℃, 390℃, and 400℃ or a range between any two of them, the time can be any one of 2h, 2.1h, 2.2h, 2.3h, 2.4h, and 2.5h or a range between any two of them, the third-stage calcining temperature can be any one of 750℃, 780℃, 820℃, 850℃, 880℃, and 900℃ or a range between any two of them, and the time can be any one of 3h, 3.2h, 3.4h, 3.6h, 3.8h, and 4h or a range between any two of them.

[0028] S3, reducing the oxide composite powder in a hydrogen atmosphere with a flow rate of 20 to 28L / min to obtain a cerium-containing tungsten powder, the reduction temperature being 800 to 1050℃, and the time being 3 to 3.5h. Specifically, the temperature of the reduction can be any one of 800℃, 850℃, 900℃, 950℃, 1000℃, 1050℃ or a range between any two of them, the time can be any one of 3h, 3.1h, 3.2h, 3.3h, 3.4h, 3.5h or a range between any two of them, and the flow rate of hydrogen can be any one of 20L / min, 22L / min, 24L / min, 26L / min, 28L / min or a range between any two of them.

[0029] S4, isostatic pressing of the cerium-containing tungsten powder at a pressure of 170-200MPa to obtain a compact; Specifically, the pressure can be any one of 170MPa, 180MPa, 190MPa, 200MPa or a range between any two of them.

[0030] S5, the compact is subjected to staged sintering in a hydrogen atmosphere with a flow rate of 3-5L / min to obtain a tungsten rod with a diameter of 19.5±0.3mm, the staged sintering comprising first-stage sintering and second-stage sintering, wherein the temperature of the first-stage sintering is 1500-1600℃, and the time is 1-1.5h, the temperature of the second-stage sintering is 2300-2450℃, and the time is 5-8h; Specifically, the temperature of the first-stage sintering can be any one of 1500℃, 1520℃, 1540℃, 1560℃, 1580℃, 1600℃ or a range between any two of them, the time can be any one of 1h, 1.1h, 1.2h, 1.3h, 1.4h, 1.5h or a range between any two of them, the temperature of the second-stage sintering can be any one of 2300℃, 2350℃, 2400℃, 2450℃ or a range between any two of them, the time can be any one of 5h, 6h, 7h, 8h or a range between any two of them, the flow rate of hydrogen can be any one of 3L / min, 3.5L / min, 4L / min, 4.5L / min, 5L / min or a range between any two of them, and the diameter of the tungsten rod can be any one of 19.2mm, 19.4mm, 19.5mm, 19.7mm, 19.8mm or a range between any two of them.

[0031] S6, the tungsten rod is subjected to rolling at a temperature of 1400-1800℃, the diameter of the tungsten rod after rolling is 9±0.2mm; then the tungsten rod is subjected to electric pulse treatment at a temperature of 700-900℃ for 23-26s; then the tungsten rod is subjected to forging, the feeding speed during forging is 1.2-3m / min, the forging speed is 1500-2400times / min, and the diameter of the tungsten rod after forging is 3.6±0.2mm; finally, the tungsten rod is subjected to wire drawing to obtain a tungsten-cerium alloy wire with a diameter of 20-28μm; Specifically, the temperature for rolling can be any one of 1400℃, 1500℃, 1600℃, 1700℃, 1800℃ or a range between any two of them, the diameter of the tungsten rod after rolling can be any one of 8.8mm, 8.8mm, 9.0mm, 9.1mm, 9.2mm or a range between any two of them; the temperature for electric pulse treatment can be any one of 700℃, 750℃, 800℃, 850℃, 900℃ or a range between any two of them; the feeding speed during forging can be any one of 1.2m / min, 1.5m / min, 2m / min, 2.5m / min, 3m / min or a range between any two of them, the speed of forging can be any one of 1500 times / min, 1800 times / min, 2000 times / min, 2200 times / min, 2400 times / min or a range between any two of them, the diameter of the tungsten rod after forging can be any one of 3.4mm, 3.6mm, 3.6mm, 3.7mm, 3.8mm or a range between any two of them; the diameter of the tungsten-cerium alloy wire can be any one of 20μm, 22μm, 24μm, 26μm, 28μm or a range between any two of them.

[0032] According to the second aspect of the present application, the present application provides a tungsten-cerium alloy wire obtained by the above-mentioned method for preparing a tungsten-cerium alloy wire.

[0033] Preferably, the tensile strength of the tungsten-cerium alloy wire is ≥4800MPa, and the elongation is 3%~15%.

[0034] More preferably, the tensile strength of the tungsten-cerium alloy wire is ≥6500MPa, and the elongation is 8%~15%.

[0035] Preferably, the fatigue life of the tungsten-cerium alloy wire is more than 30000 times when tested by a fatigue testing machine at 4000MPa.

[0036] More preferably, the fatigue life of the tungsten-cerium alloy wire is more than 60000 times when tested by a fatigue testing machine at 4000MPa.

[0037] The technical solutions of the present application are further described below in combination with specific examples.

[0038] Example 1 A method for preparing a tungsten-cerium alloy wire, comprising the following steps: S1, a cerium-containing solution with a cerium element mass fraction of 6.5% is prepared by using Ce(NO3)3·6H2O, the cerium-containing solution and ammonium paratungstate are mixed by a spray mixing method at a mass ratio of 0.24:1, and then dried at 80℃ to obtain a mixed material; S2, the mixed material is subjected to staged calcination, wherein the temperature of the first stage calcination is 210 DEG C, the time is 1.5 h, the temperature of the second stage calcination is 350 DEG C, the time is 2 h, the temperature of the third stage calcination is 750 DEG C, and the time is 4 h, to obtain an oxide composite powder; S3, the oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain a cerium-containing tungsten powder, the reduction temperature is 1050 DEG C, and the time is 3 h; S4, the cerium-containing tungsten powder is isostatically pressed at a pressure of 200 MPa to obtain a compact; S5, the compact is subjected to staged sintering in a hydrogen atmosphere with a flow rate of 5 L / min to obtain a tungsten rod with a diameter of 19.7 mm, wherein the temperature of the first stage sintering is 1500 DEG C, the time is 1.5 h, the temperature of the second stage sintering is 2300 DEG C, and the time is 7 h; S6, the tungsten rod is rolled at a temperature of 1600 DEG C, the diameter of the tungsten rod after rolling is 9.2 mm; then the tungsten rod is subjected to electric pulse treatment at a temperature of 900 DEG C for 23 s; then the tungsten rod is forged, the feeding speed during forging is 2.3 m / min, the forging speed is 2000 times / min, and the diameter of the tungsten rod after forging is 3.6 mm; finally, the tungsten rod is subjected to wire drawing treatment to obtain a tungsten-cerium alloy wire with a diameter of 28.4 μm.

[0039] The tungsten-cerium alloy wire prepared in the embodiment is detected, and the cross-sectional microstructure is as shown in FIG. 1. Figure 1 It can be seen that the microstructure is uniform, the tensile strength is 6545 MPa, the elongation is 11%, and the tungsten-cerium alloy wire is broken after 75760 times of 4000 MPa fatigue resistance test.

[0040] Embodiment 2 A preparation method of a tungsten-cerium alloy wire, comprising the following steps: S1, a cerium-containing solution with a cerium element mass fraction of 6.5% is prepared by using Ce(NO3)3·6H2O, the cerium-containing solution and ammonium paratungstate are mixed in a mass ratio of 0.36:1 by using a spray mixing method, and then dried at 80 DEG C to obtain a mixed material; S2, the mixed material is subjected to staged calcination, wherein the temperature of the first stage calcination is 200 DEG C, the time is 2 h, the temperature of the second stage calcination is 380 DEG C, the time is 2 h, the temperature of the third stage calcination is 900 DEG C, and the time is 3.5 h, to obtain an oxide composite powder; S3, the oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 24 L / min to obtain a cerium-containing tungsten powder, the reduction temperature is 800 DEG C, and the time is 3.5 h; S4, the cerium-containing tungsten powder is isostatically pressed at a pressure of 170 MPa to obtain a compact; S5, the green compact is subjected to staged sintering in a hydrogen atmosphere with a flow rate of 4 L / min to obtain a tungsten rod with a diameter of 19.5 mm, wherein the temperature of the first stage sintering is 1550℃, and the time is 1.5 h, and the temperature of the second stage sintering is 2450℃, and the time is 5 h; S6, the tungsten rod is subjected to rolling at a temperature of 1800℃, and the diameter of the tungsten rod after rolling is 8.8 mm; then the tungsten rod is subjected to electric pulse treatment at a temperature of 700℃ for 25 s; then the tungsten rod is subjected to forging, and the feeding speed during forging is 3 m / min, and the forging speed is 2400 times / min, and the diameter of the tungsten rod after forging is 3.8 mm; finally, the tungsten rod is subjected to wire drawing treatment to obtain a tungsten-cerium alloy wire with a diameter of 25.7 μm.

[0041] The tungsten-cerium alloy wire prepared in the embodiment is detected, and the cross-sectional microstructure is as shown in FIG. 1, and it can be seen that the microstructure is uniform, the tensile strength is 6710 MPa, the elongation is 8%, and the 4000 MPa fatigue resistance test is broken after 67360 times. Figure 2

[0042] Embodiment 3 A preparation method of a tungsten-cerium alloy wire, comprising the following steps: S1, a cerium-containing solution with a cerium element mass fraction of 6.5% is prepared by using Ce(NO3)3·6H2O, the cerium-containing solution and ammonium paratungstate are mixed in a mass ratio of 0.30:1 by using a spray mixing method, and then dried at 80℃ to obtain a mixed material; S2, the mixed material is subjected to staged calcination, wherein the temperature of the first stage calcination is 220℃, and the time is 2 h, the temperature of the second stage calcination is 400℃, and the time is 2.5 h, and the temperature of the third stage calcination is 830℃, and the time is 3 h, to obtain an oxide composite powder; S3, the oxide composite powder is subjected to reduction in a hydrogen atmosphere with a flow rate of 20 L / min to obtain a cerium-containing tungsten powder, and the reduction temperature is 900℃, and the time is 3.5 h; S4, the cerium-containing tungsten powder is subjected to isostatic pressing forming under a pressure of 185 MPa to obtain a green compact; S5, the green compact is subjected to staged sintering in a hydrogen atmosphere with a flow rate of 3 L / min to obtain a tungsten rod with a diameter of 19.2 mm, wherein the temperature of the first stage sintering is 1600℃, and the time is 1 h, and the temperature of the second stage sintering is 2400℃, and the time is 8 h; ​S6, rolling the tungsten rod at a temperature of 1400℃, the diameter of the tungsten rod after rolling is 9.0mm; then performing electric pulse treatment on the tungsten rod at a temperature of 800℃ for 26s; then performing forging on the tungsten rod, the feeding speed during forging is 1.2m / min, the forging speed is 1500 times / min, the diameter of the tungsten rod after forging is 3.4mm; finally performing wire drawing treatment on the tungsten rod, and a tungsten-cerium alloy wire with a diameter of 22.9μm is obtained.

[0043] The tungsten-cerium alloy wire prepared in this embodiment is detected, the microstructure is uniform, the tensile strength is 6880MPa, the elongation is 15%, and the wire is broken after 63140 times of 4000MPa fatigue resistance test.

[0044] Example 4 A preparation method of a tungsten-cerium alloy wire, comprising the following steps: S1, preparing a cerium-containing solution with a cerium element mass fraction of 6.5% by using Ce(NO3)3·6H2O, mixing the cerium-containing solution and ammonium paratungstate by using a spraying mixing method, and then drying at 80℃ to obtain a mixed material; S2, performing sectional calcination on the mixed material, wherein the first stage calcination temperature is 210℃, the time is 1.5h, the second stage calcination temperature is 400℃, the time is 2h, and the third stage calcination temperature is 900℃, the time is 3.5h, to obtain an oxide composite powder; S3, reducing the oxide composite powder in a hydrogen atmosphere with a flow rate of 28L / min to obtain a cerium-containing tungsten powder, the reduction temperature is 950℃, and the time is 3h; S4, performing isostatic pressing on the cerium-containing tungsten powder under a pressure of 190MPa to obtain a compact; S5, performing sectional sintering on the compact in a hydrogen atmosphere with a flow rate of 4L / min to obtain a tungsten rod with a diameter of 19.8mm, wherein the first stage sintering temperature is 1600℃, the time is 1h, and the second stage sintering temperature is 2350℃, the time is 8h; S6, rolling the tungsten rod at a temperature of 1500℃, the diameter of the tungsten rod after rolling is 9.1mm; then performing electric pulse treatment on the tungsten rod at a temperature of 800℃ for 26s; then performing forging on the tungsten rod, the feeding speed during forging is 2.5m / min, the forging speed is 1800 times / min, the diameter of the tungsten rod after forging is 3.8mm; finally performing wire drawing treatment on the tungsten rod, and a tungsten-cerium alloy wire with a diameter of 28.1μm is obtained.

[0045] The tungsten-cerium alloy wire prepared in this embodiment is detected, the microstructure is uniform, the tensile strength is 6516MPa, the elongation is 8%, and the wire is broken after 73682 times of 4000MPa fatigue resistance test.

[0046] Example 5 A preparation method of tungsten-cerium alloy wire, comprising the following steps: S1, a cerium-containing solution with a cerium element mass fraction of 6.5% is prepared by using Ce(NO3)3·6H2O, the cerium-containing solution and ammonium paratungstate are mixed in a mass ratio of 0.15:1 by using a spray mixing method, and then dried at 80℃ to obtain a mixed material; S2, the mixed material is subjected to staged calcination, wherein the temperature of the first stage calcination is 210℃, the time is 1.5h, the temperature of the second stage calcination is 350℃, the time is 2h, and the temperature of the third stage calcination is 750℃, the time is 4h, to obtain an oxide composite powder; S3, the oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28L / min to obtain a cerium-containing tungsten powder, and the reduction temperature is 1050℃, the time is 3h; S4, the cerium-containing tungsten powder is isostatically pressed at a pressure of 200MPa to obtain a green compact; S5, the green compact is subjected to staged sintering in a hydrogen atmosphere with a flow rate of 5L / min to obtain a tungsten rod with a diameter of 19.7mm, wherein the temperature of the first stage sintering is 1500℃, the time is 1.5h, the temperature of the second stage sintering is 2300℃, and the time is 7h; S6, the tungsten rod is rolled at a temperature of 1600℃, and the diameter of the tungsten rod after rolling is 9.2mm; then the tungsten rod is subjected to electric pulse treatment at a temperature of 900℃ for 23s; then the tungsten rod is forged, the feeding speed during forging is 2.3m / min, the forging speed is 2000 times / min, and the diameter of the tungsten rod after forging is 3.6mm; finally, the tungsten rod is subjected to wire drawing treatment to obtain a tungsten-cerium alloy wire with a diameter of 28.4μm.

[0047] The tungsten-cerium alloy wire prepared in this embodiment is detected, the microstructure is uniform, the tensile strength is 5248MPa, the elongation is 3%, and the 4000MPa fatigue resistance test is broken after 36285 times.

[0048] Example 6 A preparation method of tungsten-cerium alloy wire, comprising the following steps: S1, a cerium-containing solution with a cerium element mass fraction of 6.5% is prepared by using Ce(NO3)3·6H2O, the cerium-containing solution and ammonium paratungstate are mixed in a mass ratio of 0.15:1 by using a spray mixing method, and then dried at 80℃ to obtain a mixed material; S2, the mixed material is calcined at 900℃ for 3.5 hours to obtain an oxide composite powder; S3, the oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain a cerium-containing tungsten powder, the reduction temperature is 1050°C, and the time is 3 h; S4, the cerium-containing tungsten powder is isostatic pressed under a pressure of 200 MPa to obtain a compact; S5, the compact is sintered in a hydrogen atmosphere with a flow rate of 5 L / min in a step-by-step manner to obtain a tungsten rod with a diameter of 19.7 mm, wherein the first-stage sintering temperature is 1500°C, the time is 1.5 h, the second-stage sintering temperature is 2300°C, and the time is 7 h; S6, the tungsten rod is rolled at a temperature of 1600°C, the diameter of the tungsten rod after rolling is 9.2 mm; then the tungsten rod is subjected to electric pulse treatment at a temperature of 900°C for 23 s; then the tungsten rod is forged, the feeding speed is 2.3 m / min, the forging speed is 2000 times / min, and the diameter of the tungsten rod after forging is 3.6 mm; finally, the tungsten rod is subjected to wire drawing treatment to obtain a tungsten-cerium alloy wire with a diameter of 28.4 μm.

[0049] The tungsten-cerium alloy wire prepared in the embodiment is detected, the microstructure is uneven (cerium and tungsten form a second phase during calcination), the tensile strength is 4868 MPa, the elongation is 5%, and the tungsten-cerium alloy wire is broken after 31735 times of 4000 MPa fatigue resistance test.

[0050] Comparative Example 1 The comparative example is consistent with the embodiment 1 except that the reduction temperature in step S3 is 500°C, and the time is 5 h; due to the too low reduction temperature, the tungsten oxide cannot be completely reduced, the obtained tungsten powder is impure, the brittleness is increased, and the forging and drawing processes are frequently broken, so that the tungsten-cerium alloy wire cannot be prepared.

[0051] Comparative Example 2 The comparative example is consistent with the embodiment 1 except that step S5 does not use step-by-step sintering, but only sintering at a temperature of 2400°C for 9 h; the obtained tungsten rod has a high oxygen content, and the wire breaking rate is high during drawing (7 out of 10 wires are broken during drawing), and the cross-sectional microstructure of the tungsten-cerium alloy wire prepared in the comparative example is as shown in Figure 3 , it can be seen that the microstructure has pores.

[0052] Comparative Example 3 The comparative example is consistent with the embodiment 1 except that the third-stage calcination temperature in step S2 is 1000°C, and the time is 2 h; the forging and drawing processes are frequently broken, so that the tungsten-cerium alloy wire cannot be prepared.

[0053] Comparative Example 4 The comparative example is consistent with example 1 except that the temperature of the second stage sintering in step S5 is 2200°C and the time is 8h; after rolling, the tungsten rod has more cracks, and the deformation and drawing process frequently breaks, so that the tungsten-cerium alloy wire cannot be prepared.

[0054] Comparative example 5 The comparative example is consistent with example 1 except that Ce(NO3)3·6H2O solid is mixed with APT ammonium paratungstate solution to prepare the mixture in step S1; the forging and drawing process frequently breaks, so that the tungsten alloy wire cannot be prepared.

[0055] The application provides a tungsten-cerium alloy wire and a preparation method thereof, and has the beneficial effects that: the uniform distribution of cerium elements in the alloy wire is realized by solid-liquid cerium mixing, and the problems of uneven distribution and easy agglomeration of cerium in the traditional mechanical mixing method are overcome; the oxygen content in the tungsten rod is significantly reduced, and the density and mechanical properties are improved by using the two-stage sintering process; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and has low edge collapse rate, low broken line rate and high service life in the cutting of silicon nitride ceramic substrates.

[0056] The above only describes the preferred embodiments of the application, and does not limit the patent scope of the application, and any equivalent structural transformation or direct / indirect application in other related technical fields based on the inventive concept of the application and the content of the specification of the application is included in the patent protection scope of the application.

Claims

1. A method of producing a tungsten-cerium alloy wire, characterized by, The method comprises the following steps: S1, mixing a cerium-containing solution and ammonium paratungstate by a spray mixing method, and drying to obtain a mixture; S2, calcining the mixture to obtain an oxide composite powder, wherein the calcining temperature is ≤900℃; S3, reducing the oxide composite powder in a hydrogen atmosphere to obtain a cerium-containing tungsten powder, wherein the reducing temperature is 800-1050℃, and the time is 3-3.5h; S4, isostatic pressing the cerium-containing tungsten powder to obtain a compact; S5, segmentally sintering the compact in a hydrogen atmosphere to obtain a tungsten rod, wherein the segmental sintering comprises first-stage sintering and second-stage sintering, wherein the first-stage sintering temperature is 1500-1600℃, and the time is 1-1.5h, and the second-stage sintering temperature is 2300-2450℃, and the time is 5-8h; S6, rolling, electric pulse treatment, forging and wire drawing treatment of the tungsten rod to obtain a tungsten-cerium alloy wire with a diameter of 20-28μm.

2. The method of claim 1, wherein the tungsten-cerium alloy wire is prepared by a process comprising: In the step S1, the cerium-containing solution is prepared by using a soluble cerium salt, the mass fraction of cerium in the cerium-containing solution is 6.5%-10%, and the mass ratio of the cerium-containing solution to the ammonium paratungstate is 0.24:1-0.36:

1.

3. The method of claim 1, wherein the tungsten-cerium alloy wire is prepared by a process comprising: In the step S2, the calcining comprises first-stage calcining, second-stage calcining and third-stage calcining, wherein the first-stage calcining temperature is 200-220℃, and the time is 1.5-2h, the second-stage calcining temperature is 350-400℃, and the time is 2-2.5h, and the third-stage calcining temperature is 750-900℃, and the time is 3-4h.

4. The method of claim 1, wherein the tungsten-cerium alloy wire is prepared by a process comprising: In the step S3, the hydrogen flow rate in the hydrogen atmosphere is 20-28L / min.

5. The method of claim 1, wherein the tungsten-cerium alloy wire is prepared by a process comprising: In the step S4, the pressure during the isostatic pressing is 170-200MPa.

6. The method of claim 1, wherein the tungsten-cerium alloy wire is prepared by a process comprising: In the step S5, the hydrogen flow rate in the hydrogen atmosphere is 3-5L / min.

7. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In the step S6, the rolling temperature is 1400-1800℃; The electric pulse treatment temperature is 700-900℃, and the time is 23-26s; The feeding speed during the forging is 1.2-3m / min, and the forging speed is 1500-2400times / min.

8. The method of claim 7, wherein the tungsten cerium alloy wire is prepared by a process comprising: In the step S5, the diameter of the tungsten rod is 19.5±0.3mm; In the step S6, the diameter of the tungsten rod after the rolling is 9±0.2mm; In the step S6, the diameter of the tungsten rod after the forging is 3.6±0.2mm.

9. A tungsten-cerium alloy wire, characterized by, The tungsten-cerium alloy wire is prepared by the method in any one of claims 1-8.

10. The tungsten-cerium alloy wire of claim 9, wherein The tensile strength of the tungsten-cerium alloy wire is ≥4800MPa, and the elongation rate is 3%-15%.

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