AgCuTi alloy powder and preparation method thereof

Abstract

The invention relates to the technical field of alloy powder materials, and provides AgCuTi alloy powder and a preparation method thereof. According to the method, an alloy electrode bar is prepared in advance by adopting a powder metallurgy method (mechanical powder mixing, cold isostatic pressing forming and vacuum sintering), and then AgCuTi alloy powder is prepared by adopting a rotating electrode atomization method, so that the use of a smelting crucible and a heat preservation crucible in the powder atomization process is avoided, and the Ti element loss and pollution caused by the reaction of the crucible and an active element are completely eradicated; meanwhile, the AgCuTi alloy powder prepared through the method is uniform in component distribution, high in sphericity degree, low in oxygen content, high in fluidity, good in welding performance, high in purity and few in defects such as hollow powder and satellite powder, the brazing performance and mechanical performance of the alloy powder can be effectively improved, and wide application prospects are achieved.

Description

Technical Field

[0001] This invention relates to the field of alloy powder materials technology, and in particular to an AgCuTi alloy powder and its preparation method. Background Technology

[0002] Silver-copper-titanium alloys are commonly used brazing materials in high-end fields such as aerospace and electronics due to their excellent thermal and electrical conductivity, high-temperature stability, and brazing wettability. Traditional silver-copper-titanium alloys are mostly available in the form of wires and foils, which suffer from poor adhesion and numerous welding blind spots when brazing complex-shaped parts. However, alloy powders, with their good flowability and formability, can achieve precise brazing of complex structures through processes such as powder metallurgy and laser cladding, and are gradually becoming an extremely important application form.

[0003] Currently, silver-copper-titanium alloy powders are mainly prepared using mechanical mixing or smelting-atomization powder preparation. However, mechanical mixing results in powders with extremely poor uniformity, making alloying difficult. Smelting-atomization, on the other hand, suffers from high Ti reactivity, readily chemically bonding with the crucible, leading to a reduction in Ti content and making precise control of alloy element content challenging. Furthermore, Ti tends to segregate in the powder, resulting in low powder sphericity and high oxygen content.

[0004] In summary, current silver-copper-titanium alloy powders suffer from uneven composition distribution, low sphericity, and high oxygen content. These issues can easily lead to insufficient powder flowability and wettability during welding, an increase in brittle phases and welding defects, significantly reducing joint strength and making it difficult to meet welding requirements. Summary of the Invention

[0005] In view of this, the present invention provides an AgCuTi alloy powder and a method for preparing the same. The AgCuTi alloy powder prepared by the present invention has a uniform composition distribution, high sphericity, low oxygen content, and good flowability, which can effectively improve the brazing performance and mechanical properties of the alloy powder.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution: A method for preparing AgCuTi alloy powder includes the following steps: Ag powder, Cu powder and Ti powder are ball-milled and mixed to obtain a mixed powder; The mixed powder was subjected to reduction annealing and cold isostatic pressing in sequence to obtain a rod-shaped blank. The rod-shaped billet is sequentially subjected to vacuum sintering, machining and cleaning to obtain alloy electrode rods; The alloy electrode rod is subjected to rotary electrode atomization to obtain the AgCuTi alloy powder.

[0007] Preferably, the purity of the Ag powder is ≥99.99%, the purity of the Cu powder is ≥99.95%, the purity of the Ti powder is ≥99.9%, and the particle size of the Ag powder, Cu powder, and Ti powder is -200 mesh. The ball milling method is high-energy ball milling; the ball milling conditions include: time of 6 to 12 hours, ball-to-material ratio of 5 to 20:1, and rotation speed of 200 to 300 r / min.

[0008] Preferably, the atmosphere for the reduction annealing is hydrogen; the temperature for the reduction annealing is 200~300℃, and the annealing time is 60~120min.

[0009] Preferably, the pressure of the cold isostatic pressing is 200~300MPa, and the molding time is 30~60s.

[0010] Preferably, the vacuum degree of the vacuum sintering is 6×10⁻⁶. -3 Below Pa; the vacuum sintering procedure is as follows: heat to 200-300°C at a heating rate of 7-10°C per minute, hold for 30-60 minutes, then heat to 400-500°C at a heating rate of 4-6°C per minute, hold for 1-2 hours, then heat to 700-750°C at a heating rate of 2-3°C per minute, hold for 2-3 hours, and finally cool to room temperature with the furnace.

[0011] Preferably, the machining is turning, and the straightness fluctuation of the turned bar is less than 0.1 mm, the straightness is less than 0.025 mm, the perpendicularity is less than 0.15 mm, and the surface roughness is less than Ra 1.6 micrometers.

[0012] Preferably, the diameter of the alloy electrode rod is [missing information]. 40~80mm.

[0013] Preferably, the conditions for the rotating electrode atomization include: a rotation speed of 12000~18000 r / min, an arc flame length of 40~60 mm, a plasma arc current intensity of 1000~1200 A, and a feed speed of 0.5~1 mm / s; the rotating electrode atomization is carried out under inert gas protection.

[0014] The present invention also provides AgCuTi alloy powder prepared by the preparation method described above, comprising the following mass fractions: Cu 22%~32%, Ti 2%~7%, and the balance being Ag.

[0015] Preferably, the AgCuTi alloy powder has a sphericity greater than 95% and an oxygen content less than 220 ppm.

[0016] This invention provides a method for preparing AgCuTi alloy powder, comprising the following steps: ball milling Ag powder, Cu powder and Ti powder to obtain a mixed powder; sequentially subjecting the mixed powder to reduction annealing and cold isostatic pressing to obtain a rod-shaped billet; sequentially subjecting the rod-shaped billet to vacuum sintering, machining and cleaning to obtain an alloy electrode rod; and subjecting the alloy electrode rod to rotary electrode atomization to obtain the AgCuTi alloy powder. This invention employs a powder metallurgy method (mechanical powder mixing + cold isostatic pressing + vacuum sintering) to pre-prepare alloy electrode rods, and then prepares AgCuTi alloy powder using a rotating electrode atomization method. This avoids the use of melting crucibles and heat-preserving crucibles during powder atomization, eliminating Ti element loss and contamination caused by the reaction between the crucible and active elements, and improving the compositional uniformity and alloying degree of the alloy powder. Simultaneously, the AgCuTi alloy powder prepared by this invention exhibits uniform compositional distribution, high sphericity, low oxygen content, high fluidity, good weldability, and high purity with few defects such as hollow powder and satellite powder. It can be used for the production of high-quality active brazing powder and alloy powders for additive manufacturing. In summary, the AgCuTi alloy powder prepared by this invention solves the problems of uneven compositional distribution, low sphericity, high oxygen content, and poor fluidity in existing AgCuTi powders, effectively improving the brazing performance and mechanical properties of the alloy powder. Furthermore, the preparation process is stable and controllable, showing broad application prospects. Attached Figure Description

[0017] Figure 1 A process flow diagram of the preparation method of AgCuTi alloy powder provided by the present invention; Figure 2 The image shows the SEM morphology of the AgCuTi alloy bar obtained in Example 1. Figure 3 The image shows the wetting of the AgCuTi alloy powder obtained in Example 1 on 95% alumina ceramic. Detailed Implementation

[0018] This invention provides a method for preparing AgCuTi alloy powder, comprising the following steps: Ag powder, Cu powder and Ti powder are ball-milled and mixed to obtain a mixed powder; The mixed powder was subjected to reduction annealing and cold isostatic pressing in sequence to obtain a rod-shaped blank. The rod-shaped billet is sequentially subjected to vacuum sintering, machining and cleaning to obtain alloy electrode rods; The alloy electrode rod is subjected to rotary electrode atomization to obtain the AgCuTi alloy powder.

[0019] Figure 1 The following is a process flow diagram of the preparation method of AgCuTi alloy powder provided by the present invention, in conjunction with... Figure 1 Please provide a detailed explanation.

[0020] This invention involves ball milling Ag powder, Cu powder, and Ti powder to obtain a mixed powder. In this invention, the purity of the Ag powder is preferably ≥99.99%, the purity of the Cu powder is preferably ≥99.95%, and the purity of the Ti powder is preferably ≥99.9%. The particle size of the Ag, Cu, and Ti powders is preferably -200 mesh. The ball milling method is preferably high-energy ball milling. The ball milling conditions preferably include: a time of 6-12 hours, a ball-to-powder ratio of 5-20:1 (specifically 10:1 or 20:1), and a rotation speed of 200-300 r / min. In a specific embodiment of this invention, the ball milling is performed in a high-energy ball mill. This invention achieves uniform mixing of Ag powder, Cu powder, and Ti powder through ball milling.

[0021] After obtaining the mixed powder, the present invention sequentially performs reduction annealing and cold isostatic pressing to obtain a rod-shaped billet. In the present invention, the atmosphere of the reduction annealing is preferably hydrogen; the temperature of the reduction annealing is preferably 200~300℃, and the annealing time is preferably 60~120min; the reduction annealing is carried out in a reduction annealing furnace; after annealing, the powder is cooled to room temperature with the furnace; Cu powder and Ti powder are easily oxidized in air, and the present invention removes oxides and inclusions on the powder surface by reduction annealing; the pressure of the cold isostatic pressing is preferably 200~300MPa, and the pressing time is preferably 30~60s; the present invention preferably first fills the mixed powder into an elastic mold, compacts it, and then performs cold isostatic pressing.

[0022] After obtaining the rod-shaped billet, the present invention sequentially performs vacuum sintering, machining, and cleaning on the rod-shaped billet to obtain alloy electrode rods. In the present invention, the vacuum degree of the vacuum sintering is preferably 6 × 10⁻⁶. -3 The vacuum sintering process is preferably as follows: heating to 200-300°C at a heating rate of 7-10°C per minute (preferably 8°C per minute), holding for 30-60 minutes, then heating to 400-500°C at a heating rate of 4-6°C per minute (preferably 5°C per minute), holding for 1-2 hours, then heating to 700-750°C at a heating rate of 2-3°C per minute (preferably 2.5°C per minute), holding for 2-3 hours, and finally cooling to room temperature with the furnace; the vacuum sintering is preferably carried out in a vacuum atmosphere tube furnace.

[0023] In this invention, the machining is preferably turning, and the straightness fluctuation of the turned bar is preferably less than 0.1 mm, the straightness is preferably less than 0.025 mm, the perpendicularity is preferably less than 0.15 mm, and the surface roughness is preferably less than Ra 1.6 micrometers. By controlling the above parameters of the bar, this invention can meet the requirements of subsequent rotating electrode atomization.

[0024] In this invention, the cleaning is preferably performed using anhydrous ethanol ultrasonic cleaning.

[0025] In this invention, the diameter of the alloy electrode rod is preferably [missing information]. 40~80mm, specifically... 60mm.

[0026] After obtaining the alloy electrode rod, the present invention performs rotary electrode atomization on the alloy electrode rod to obtain the AgCuTi alloy powder. In the present invention, the preferred conditions for rotary electrode atomization include: a rotational speed of 12000~18000 r / min, specifically 12000 r / min, 15000 r / min, or 18000 r / min; an arc length of 40~60 mm, specifically 40 mm, 50 mm, or 60 mm; a plasma arc current intensity of 1000~1200 A, specifically 1000 A, 1100 A, or 1200 A; and a feed rate of 0.5~1 mm / s, specifically 0.5 mm / s, 0.8 mm / s, or 1 mm / s. The rotary electrode atomization is preferably performed under inert gas protection, preferably argon, and the purity of the argon is preferably greater than 99.99%. During the atomization process of the rotating electrode, the alloy electrode rod is melted by plasma arc. Under the action of high-speed rotation of the electrode rod, the droplets are separated and broken, and after cooling, AgCuTi alloy powder is obtained.

[0027] In a specific embodiment of the present invention, after the atomization of the rotating electrode is completed, the obtained powder is preferably sieved to obtain AgCuTi alloy powder, and the mesh size of the sieve used for sieving is preferably 200 mesh.

[0028] The present invention also provides AgCuTi alloy powder prepared by the preparation method described above, comprising the following mass fractions: Cu 22%~32%, Ti 2%~7%, and the balance being Ag.

[0029] In this invention, the mass fraction of Cu in the AgCuTi alloy powder is preferably 25% to 30%, and the mass fraction of Ti is preferably 2% to 5%.

[0030] In this invention, the AgCuTi alloy powder has a sphericity greater than 95%, an oxygen content less than 220 ppm, and a small error range for the elemental content of Ti.

[0031] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0032] Example 1 A method for preparing AgCuTi alloy powder, comprising the following steps: (1) Ingredients: Weigh 1360g of Ag powder, 560g of Cu powder, and 80g of Ti powder. The purity requirements of Ag powder, Cu powder, and Ti powder are 99.99wt%, 99.95wt%, and 99.99wt%, respectively, and the particle size is -200 mesh.

[0033] (2) Powder homogenization: All the powder weighed in step (1) is placed in a high-energy ball mill jar and mixed. The ball-to-powder ratio is 10:1, the rotation speed is 300 r / min, and the time is 12 h.

[0034] (3) Reduction annealing: The mixed powder obtained in step (2) is placed in a hydrogen reduction annealing furnace for reduction annealing. The annealing temperature is 300℃ and the annealing time is 120min. Then, it is cooled to room temperature with the furnace and taken out for use.

[0035] (4) Cold isostatic pressing: The powder obtained in step (3) is filled into a rubber mold and subjected to cold isostatic pressing at a pressure of 300 MPa for 30 seconds to produce a rod-shaped blank with a diameter of [missing information]. 70mm.

[0036] (5) The rod-shaped billet obtained in step (4) is placed in a vacuum tube furnace for sintering and forming, and the vacuum is drawn to 6×10. -3 Below Pa, the temperature is first increased to 200°C at a rate of 8°C per minute and held for 60 minutes; then increased to 400°C at a rate of 5°C per minute and held for 2 hours; then increased to 700°C at a rate of 2.5°C per minute and held for 3 hours; then cooled to room temperature in the furnace to obtain sintered AgCuTi alloy bars.

[0037] (6) Bar processing: The surface of the AgCuTi alloy bar obtained in step (5) is machined to make the bar straightness fluctuation less than 0.1 mm, the bar straightness less than 0.025 mm, the perpendicularity less than 0.15 mm, and the surface roughness less than Ra 1.6 micrometers. Then, ultrasonic cleaning with alcohol is used to remove impurities and oil stains from the bar surface. The diameter of the processed bar is 60mm; Figure 2 The image shows the SEM morphology of the AgCuTi alloy bar obtained in Example 1.

[0038] (7) Rotary electrode atomization powder making: The alloy electrode rod obtained in step (6) is subjected to rotary electrode atomization in a rotary electrode atomization powder making equipment. The rod is heated by a plasma arc to form droplets. Under the action of high-speed rotation, the droplets are separated and broken, and then cooled to form AgCuTi alloy powder. The rotation speed of the alloy electrode rod is 15000 r / min, the arc length is 50 mm, the plasma arc current intensity is 1100 A, the feed speed is 0.8 mm / s, and high-purity argon gas (purity greater than 99.99%) is introduced for protection during the process.

[0039] (8) The powder obtained in step (7) is sieved through a 200-mesh stainless steel sieve to obtain -200-mesh AgCuTi alloy powder, which is then weighed and vacuum packaged.

[0040] The AgCuTi alloy powder prepared in this embodiment has a sphericity greater than 96%, low defect content, oxygen content less than 200 ppm, and a wetting angle of 9.3° on 95% oxidation furnace ceramic. Figure 3 The image shows the wetting of the AgCuTi alloy powder obtained in Example 1 on 95% alumina ceramic. Composition analysis revealed that the mass percentages of Ag, Cu, and Ti were 67.81%, 28.23%, and 3.96%, respectively, with an error of less than 0.1 for Ti.

[0041] Example 2 A method for preparing AgCuTi alloy powder, comprising the following steps: (1) Ingredients: Weigh 1400g of Ag powder, 500g of Cu powder, and 100g of Ti powder. The purity of Ag powder, Cu powder, and Ti powder are 99.99wt%, 99.95wt%, and 99.99wt%, respectively, and the particle size is -200 mesh.

[0042] (2) Powder homogenization: All the powder weighed in step (1) is placed in a high-energy ball mill jar and mixed. The ball-to-powder ratio is 20:1, the rotation speed is 300 r / min, and the time is 6 h.

[0043] (3) Reduction annealing: The mixed powder obtained in step (2) is placed in a hydrogen reduction annealing furnace for reduction annealing. The annealing temperature is 300℃ and the annealing time is 120min. Then, it is cooled to room temperature with the furnace and taken out for use.

[0044] (4) Cold isostatic pressing: The powder obtained in step (3) is filled into a rubber mold and subjected to cold isostatic pressing at a pressure of 300 MPa for 30 seconds to produce a rod-shaped blank with a diameter of [missing information]. 70mm.

[0045] (5) The rod-shaped billet obtained in step (4) is placed in a vacuum tube furnace for sintering and forming, and the vacuum is drawn to 6×10. -3 Below Pa, the temperature is first increased to 200°C at a rate of 8°C per minute and held for 60 minutes; then increased to 400°C at a rate of 5°C per minute and held for 2 hours; then increased to 700°C at a rate of 2.5°C per minute and held for 3 hours; then cooled to room temperature in the furnace to obtain sintered AgCuTi alloy bars.

[0046] (6) Bar processing: The surface of the alloy bar obtained in step (5) is machined to make the bar straightness fluctuation less than 0.1 mm, the bar straightness less than 0.025 mm, the perpendicularity less than 0.15 mm, and the surface roughness less than Ra 1.6 micrometers. Then, ultrasonic cleaning with alcohol is used to remove impurities and oil stains from the bar surface. The diameter of the bar after processing is 60mm.

[0047] (7) Rotary electrode atomization powder making: The alloy rod obtained in step (6) is atomized by a rotating electrode in a rotary electrode atomization powder making device. The alloy rod is heated by a plasma arc to form droplets. Under the action of high-speed rotation, the droplets are separated and broken, and then cooled to form AgCuTi alloy powder. The electrode rod rotation speed is 15000r / min, the arc flame length is 50mm, the plasma arc current intensity is 1100A, the feed speed is 0.8mm / s, and high-purity argon gas (purity greater than 99.99%) is introduced for protection during the process.

[0048] (8) The powder obtained in step (7) is sieved through a 200-mesh stainless steel sieve to obtain -200-mesh AgCuTi alloy powder, which is then weighed and vacuum packaged.

[0049] The AgCuTi alloy powder obtained through the above steps has a sphericity greater than 96%, low defect content, oxygen content less than 200 ppm, and a wetting angle of 8.3° on the ceramic in a 95°C oxidation furnace. Composition analysis shows that the mass percentages of Ag, Cu, and Ti are 69.76%, 25.3%, and 4.94%, respectively, with a Ti element error of less than 0.1%.

[0050] Example 3 A method for preparing AgCuTi alloy powder, comprising the following steps: (1) Ingredients: Weigh 1420g of Ag powder, 530g of Cu powder, and 50g of Ti powder. The purity of Ag powder, Cu powder, and Ti powder are 99.99wt%, 99.95wt%, and 99.99wt%, respectively, and the particle size is -200 mesh.

[0051] (2) Powder homogenization: All the powder weighed in step (1) is placed in a high-energy ball mill jar and mixed. The ball-to-powder ratio is 20:1, the rotation speed is 300 r / min, and the time is 6 h.

[0052] (3) Reduction annealing: The powder obtained in step (2) is placed in a hydrogen reduction annealing furnace for reduction annealing. The annealing temperature is 300℃ and the annealing time is 120min. Then, it is cooled to room temperature with the furnace and taken out for use.

[0053] (4) Cold isostatic pressing: The mixed powder obtained in step (3) is filled into a rubber mold and subjected to cold isostatic pressing at a pressure of 300 MPa for 30 seconds to produce a rod-shaped blank with a diameter of [missing information]. 70mm.

[0054] (5) The rod-shaped billet obtained in step (4) is placed in a vacuum tube furnace for sintering and forming, and the vacuum is drawn to 6×10. -3 Below Pa, the temperature is first increased to 200°C at a rate of 8°C per minute and held for 60 minutes; then increased to 400°C at a rate of 5°C per minute and held for 2 hours; then increased to 700°C at a rate of 2.5°C per minute and held for 3 hours; then cooled to room temperature in the furnace to obtain sintered AgCuTi alloy bars.

[0055] (6) Bar processing: The surface of the alloy bar obtained in step (5) is machined to make the bar straightness fluctuation less than 0.1 mm, the bar straightness less than 0.025 mm, the perpendicularity less than 0.15 mm, and the surface roughness less than Ra 1.6 micrometers. Then, ultrasonic cleaning with alcohol is used to remove impurities and oil stains from the bar surface. The diameter of the bar after processing is 60mm.

[0056] (7) Rotary electrode atomization powder making: The alloy rod obtained in step (6) is atomized by a rotating electrode in a rotary electrode atomization powder making device. The alloy rod is heated by a plasma arc to form droplets. Under the action of high-speed rotation, the droplets are separated and broken, and then cooled to form AgCuTi alloy powder. The electrode rod rotation speed is 15000r / min, the arc flame length is 50mm, the plasma arc current intensity is 1100A, the feed speed is 0.8mm / s, and high-purity argon gas (purity greater than 99.99%) is introduced for protection during the process.

[0057] (8) The powder obtained in step (7) is sieved through a 200-mesh stainless steel sieve to obtain -200-mesh AgCuTi alloy powder, which is then weighed and vacuum packaged.

[0058] The AgCuTi alloy powder obtained through the above steps has a sphericity greater than 96%, low defect content, oxygen content less than 200 ppm, and a wetting angle of 12.4° on the ceramic of a 95°C oxidation furnace. Composition analysis shows that the mass percentages of Ag, Cu, and Ti are 71.18%, 26.33%, and 2.49%, respectively, with a Ti element error of less than 0.1%.

[0059] Example 4 A method for preparing AgCuTi alloy powder, taking AgCu28Ti4 as an example, is described below: (1) Ingredients: Weigh 1360g of Ag powder, 560g of Cu powder, and 80g of Ti powder. The purity of Ag powder, Cu powder, and Ti powder are 99.99wt%, 99.95wt%, and 99.99wt%, respectively, and the particle size is -200 mesh.

[0060] (2) Powder homogenization: All the powder weighed in step (1) is placed in a high-energy ball mill jar and mixed. The ball-to-powder ratio is 20:1, the rotation speed is 300 r / min, and the time is 6 h.

[0061] (3) Reduction annealing: The powder obtained in step (2) is placed in a hydrogen reduction annealing furnace for reduction annealing. The annealing temperature is 300℃ and the annealing time is 120min. Then, it is cooled to room temperature with the furnace and taken out for use.

[0062] (4) Cold isostatic pressing: The powder obtained in step (3) is filled into a rubber mold and subjected to cold isostatic pressing at a pressure of 300 MPa for 30 seconds to produce a rod-shaped blank with a diameter of [missing information]. 60mm.

[0063] (5) The rod-shaped billet obtained in step (4) is placed in a vacuum tube furnace for sintering and forming, and the vacuum is drawn to 6×10. -3 Below Pa, the temperature is first increased to 300°C at a heating rate of 8°C per minute and held for 30 minutes; then increased to 400°C at a heating rate of 5°C per minute and held for 1 hour; then increased to 750°C at a heating rate of 2.5°C per minute and held for 2 hours; then cooled to room temperature in the furnace to obtain sintered AgCuTi alloy rods.

[0064] (6) Bar stock processing: The surface of the bar stock obtained in step (5) is machined to make the bar stock straightness fluctuation less than 0.1 mm, the bar stock straightness less than 0.025 mm, the perpendicularity less than 0.15 mm, and the surface roughness less than Ra 1.6 micrometers. Then, ultrasonic cleaning with alcohol is used to remove impurities and oil stains from the surface of the bar stock. The diameter of the bar stock after processing is 40mm.

[0065] (7) Rotary electrode atomization powder making: The alloy rod obtained in step (6) is atomized by a rotating electrode in a rotary electrode atomization powder making device. The alloy rod forms droplets under plasma arc heating. The droplets are separated and broken under high-speed rotation, and then cooled to form AgCuTi alloy powder. The electrode rod rotation speed is 18000 r / min, the arc flame length is 40 mm, the plasma arc current intensity is 1200 A, the feed speed is 1 mm / s, and high-purity argon gas (purity greater than 99.99%) is introduced for protection during the process.

[0066] (8) The powder obtained in step (7) is sieved through a 200-mesh stainless steel sieve to obtain -200-mesh AgCuTi alloy powder, which is then weighed and vacuum packaged.

[0067] The AgCuTi alloy powder obtained through the above steps has a sphericity greater than 98%, low defect content, oxygen content less than 220 ppm, and a wetting angle of 9.7° on the ceramic of a 95° oxidation furnace. Composition analysis shows that the mass percentages of Ag, Cu, and Ti are 67.9%, 28.17%, and 3.93%, respectively, with a Ti element error of less than 0.1%.

[0068] Example 5 A method for preparing AgCuTi alloy powder, comprising the following steps: (1) Ingredients: Weigh 1360g of Ag powder, 560g of Cu powder, and 80g of Ti powder. The purity of Ag powder, Cu powder, and Ti powder are 99.99wt%, 99.95wt%, and 99.99wt%, respectively, and the particle size is -200 mesh.

[0069] (2) Powder homogenization: All the powder weighed in step (1) is placed in a high-energy ball mill jar and mixed. The ball-to-powder ratio is 20:1, the rotation speed is 300 r / min, and the time is 6 h.

[0070] (3) Reduction annealing: The powder obtained in step (2) is placed in a hydrogen reduction annealing furnace for reduction annealing. The annealing temperature is 300℃ and the annealing time is 120min. Then, it is cooled to room temperature with the furnace and taken out for use.

[0071] (4) Cold isostatic pressing: The powder obtained in step (3) is filled into a rubber mold and subjected to cold isostatic pressing at a pressure of 300 MPa for 30 seconds to produce a rod-shaped blank with a diameter of [missing information]. 90mm.

[0072] (5) The rod-shaped billet obtained in step (4) is placed in a vacuum tube furnace for sintering and forming, and the vacuum is drawn to 6×10. -3Below Pa, the temperature is first increased to 200°C at a rate of 8°C per minute and held for 60 minutes; then increased to 400°C at a rate of 5°C per minute and held for 2 hours; then increased to 700°C at a rate of 2.5°C per minute and held for 3 hours; then cooled to room temperature in the furnace to obtain sintered AgCuTi alloy bars.

[0073] (6) Bar stock processing: The surface of the bar stock obtained in step (5) is machined to make the bar stock straightness fluctuation less than 0.1 mm, the bar stock straightness less than 0.025 mm, the perpendicularity less than 0.15 mm, and the surface roughness less than Ra 1.6 micrometers. Then, ultrasonic cleaning with alcohol is used to remove impurities and oil stains from the surface of the bar stock. The diameter of the bar stock after processing is 80mm.

[0074] (7) Rotary electrode atomization powder making: The alloy rod obtained in step (6) is atomized by a rotating electrode in a rotary electrode atomization powder making device. The alloy rod is heated by a plasma arc to form droplets. Under the action of high-speed rotation, the droplets are separated and broken, and then cooled to form AgCuTi alloy powder. The electrode rod rotation speed is 12000r / min, the arc flame length is 60mm, the plasma arc current intensity is 1000A, the feed speed is 0.5mm / s, and high-purity argon gas (purity greater than 99.99%) is introduced for protection during the process.

[0075] (8) The powder obtained in step (7) is sieved through a 200-mesh stainless steel sieve to obtain -200-mesh AgCuTi alloy powder, which is then weighed and vacuum packaged.

[0076] The AgCuTi alloy powder obtained through the above steps has a sphericity greater than 95%, low defect content, oxygen content less than 200 ppm, and a wetting angle of 9.5° on the ceramic of a 95° oxidation furnace. Composition analysis shows that the mass percentages of Ag, Cu, and Ti are 67.72%, 28.31%, and 3.97%, respectively, with an error of less than 0.1 for Ti.

[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing AgCuTi alloy powder, characterized in that, Includes the following steps: Ag powder, Cu powder and Ti powder are ball-milled and mixed to obtain a mixed powder; The mixed powder was subjected to reduction annealing and cold isostatic pressing in sequence to obtain a rod-shaped blank. The rod-shaped billet is sequentially subjected to vacuum sintering, machining and cleaning to obtain alloy electrode rods; The alloy electrode rod is subjected to rotary electrode atomization to obtain the AgCuTi alloy powder.

2. The preparation method according to claim 1, characterized in that, The purity of the Ag powder is ≥99.99%, the purity of the Cu powder is ≥99.95%, and the purity of the Ti powder is ≥99.9%. The particle size of the Ag powder, Cu powder, and Ti powder is -200 mesh. The ball milling method is high-energy ball milling; the ball milling conditions include: time of 6 to 12 hours, ball-to-material ratio of 5 to 20:1, and rotation speed of 200 to 300 r / min.

3. The preparation method according to claim 1, characterized in that, The atmosphere for the reduction annealing is hydrogen; the temperature for the reduction annealing is 200~300℃, and the annealing time is 60~120min.

4. The preparation method according to claim 1, characterized in that, The cold isostatic pressing pressure is 200~300MPa, and the pressing time is 30~60s.

5. The preparation method according to claim 1, characterized in that, The vacuum degree of the vacuum sintering is 6×10⁻⁶. -3 Below Pa; the vacuum sintering procedure is as follows: heat to 200-300°C at a heating rate of 7-10°C per minute, hold for 30-60 minutes, then heat to 400-500°C at a heating rate of 4-6°C per minute, hold for 1-2 hours, then heat to 700-750°C at a heating rate of 2-3°C per minute, hold for 2-3 hours, and finally cool to room temperature with the furnace.

6. The preparation method according to claim 1, characterized in that, The machining is turning, and the straightness fluctuation of the turned bar is less than 0.1 mm, the straightness is less than 0.025 mm, the perpendicularity is less than 0.15 mm, and the surface roughness is less than Ra 1.6 micrometers.

7. The preparation method according to claim 1, characterized in that, The diameter of the alloy electrode rod is 40~80mm.

8. The preparation method according to claim 1, characterized in that, The conditions for the atomization of the rotating electrode include: a rotation speed of 12000~18000 r / min, an arc flame length of 40~60 mm, a plasma arc current intensity of 1000~1200 A, and a feed speed of 0.5~1 mm / s; the atomization of the rotating electrode is carried out under the protection of an inert gas.

9. The AgCuTi alloy powder prepared by the preparation method according to any one of claims 1 to 8, characterized in that, The composition includes the following mass fractions: Cu 22%~32%, Ti 2%~7%, with the balance being Ag.

10. The AgCuTi alloy powder according to claim 9, characterized in that, The AgCuTi alloy powder has a sphericity greater than 95% and an oxygen content less than 220 ppm.

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