Alloy-state active brazing filler metal wire and preparation method thereof

Abstract

The invention relates to an alloy-state active brazing filler metal wire and a preparation method thereof, and belongs to the field of non-ferrous metal brazing material processing. The wire comprises an active brazing filler metal wire mother alloy and an active element, the mother alloy is an Ag-based alloy or a Cu-based alloy, the active element is Ti, the active element accounts for 6-12 wt%, and the balance is the mother alloy. Spherical Ti powder is uniformly dispersed in mother alloy in a solid-liquid mixing and stirring and rapid pull casting solidification mode, an alloy bar with uniform components is vertically pulled and cast, and the active brazing filler metal wire with the diameter of 0.3 mm is obtained through cold drawing machining. The problem that an active brazing filler metal alloy state wire product cannot be formed is mainly solved, and the wire prepared through the device and the method is uniform in component, excellent in performance, high in yield, low in cost and beneficial to batch production.

Description

Technical Field

[0001] The invention relates to an alloy-state active solder wire and a preparation method thereof, which are mainly used for preparing active solder and gold-state wire products, and belong to the field of nonferrous metal brazing material processing. Background Art

[0002] Ceramics have excellent properties such as high strength, high hardness, corrosion resistance, wear resistance and good insulation performance. They show great potential in demanding application environments and are the best materials for vacuum electronic devices. They have been widely used in many fields such as aerospace, radar electronics, rail transportation, 5G communications, quantum mechanics, etc. However, due to the inherent hardness and brittleness of ceramics, they are difficult to process and manufacture. Many advanced application fields require the use of stable and reliable brazing technology to achieve connection with metals, and then achieve complementary properties with metals, in order to obtain ceramic-metal composite components that have both excellent properties of ceramics and metals, and better play the superior performance of ceramics as structural materials and electrical insulation materials.

[0003] Ceramic active direct connection technology refers to the use of metal alloys containing active elements (such as Ti, Zr, V, Nb, Hf, etc.) to directly braze ceramics and ceramics (or metals, graphite), and achieve reliable connection through metallurgical reaction at the interface between active elements and parent materials. Nowadays, with the continuous promotion of direct active connection between ceramics and metals in the field of ceramic packaging, especially the rapid development of vacuum electronic devices and IGBT power modules in recent years, more requirements are put forward for the packaging reliability of ceramics and metals. Therefore, the research on active brazing materials has become a hot topic, and active brazing materials related products have been developed one after another. According to market research, active brazing materials are mainly Ag-based alloys and Cu-based alloys containing Ti elements, and the forms are mostly powder pastes and foil strips. The preparation methods are roughly divided into single metal powder mixed paste, alloy vacuum atomization powder, pressure sintering + rolling foil strip, multi-layer composite foil strip, etc., which are basically mature and can be mass-produced.

[0004] Due to the complex structural design of vacuum electronic devices, many T-joints, shaft hole connections, and rib wall structures require wire-shaped active solder to complete brazing connections. Active solder wire products are rarely seen in the market, and there are also few reports on the preparation methods of active solder wire. The main reasons are: 1. The solid solubility of active elements such as Ti in Ag-based alloys and Cu-based alloys is limited. The traditional casting method is easy to produce Ti element segregation, resulting in ingot failure; 2. The active element Ti in the free state is easy to contact and react with the crucible, mold, etc. in the preparation process, and it is impossible to prepare active solder in the gold state; 3. The Ti element is very easy to react with oxygen, hydrogen, nitrogen and other atmospheres. General preparation methods such as non-vacuum and hot processing will lead to a decrease in product performance; 4. The Ti element is distributed in the Ag-based alloy and Cu-based alloy as needle-shaped intermetallic compounds, resulting in extremely poor plasticity of the alloy and basically unable to be processed; 5. The specific gravity of the Ti element is small, and there is a big difference in physical properties with the Ag-based alloy and Cu-based alloy, which further affects the wire forming of the alloy.

[0005] After investigation, the patent CN 102319964 B was published, which discloses an active core silver solder for brazing ceramics and its preparation method. The invention relates to the preparation technology of Ag-based alloy active solder composite wire. Through this preparation method, the outer layer of AgCuGe alloy can be processed, and the core is TiZrHf active alloy. The prepared wire has a diameter of 3 to 3.5 mm. Although this method shows that active core silver solder wire can be prepared, it is a composite wire with an active alloy in the core (melting point over 1600°C). High temperature and long time heating are required for brazing ceramics. The outer alloy needs to dissolve the active alloy in the core first, resulting in the presence of a high melting point phase in the melting point of the composite wire. A brazing temperature higher than 900°C or a brazing holding time of more than 1h is required to react metallurgically with the ceramic. This process can easily produce thermal residual stress or cracks at one end of the ceramic. If the metal end is brazed, the outer silver alloy brazing material can easily react metallurgically with the metal first, resulting in the inability to completely dissolve the active alloy in the core, forming a high melting point substance, which greatly reduces the quality of the welding weld. Secondly, the active alloy and the outer silver alloy have a large difference in density, and there are certain differences in physical processing properties. The prepared composite wire cannot be processed to a finer wire diameter and cannot meet actual engineering applications. Summary of the invention

[0006] The purpose of the present invention is to provide an alloy-state active solder wire to address the above-mentioned problems, thereby solving the problem of plastic forming of Ag-based alloy and Cu-based alloy active solder wires. The prepared solder has a moderate melting point and high production efficiency, and can realize mass production of alloy-state active solder wires, thus filling the market gap of alloy-state active solder wire products.

[0007] Another object of the present invention is to provide a method for preparing alloy-state active solder wire. The preparation method has a simple process and combines multiple technologies such as vacuum melting, powder addition, solid-liquid stirring and mixing, rapid solidification vertical casting, etc., and can be widely used in the preparation of various doped material wires such as particle reinforcement and fiber reinforcement.

[0008] The present invention first prepares active solder wire in an alloy state, and the method adopted is to evenly disperse spherical Ti powder in a master alloy by "solid-liquid mixing and stirring + rapid casting and solidification", and vertically cast an alloy rod with uniform composition. This method prepares alloy rods because Ti is wrapped in the alloy in the form of particles, and the surface of the Ti particles is metallurgically bonded with the alloy, resulting in a dense connection. During the alloy processing process, the spherical titanium powder is easy to slip along the direction of rotary forging and drawing, which can effectively improve the alloy processing plasticity. Therefore, active solder wire with a diameter of 0.3 mm can be processed by cold rotary forging and cold drawing, which meets the current complex structural design requirements of vacuum electronic devices.

[0009] To achieve the above object, the present invention adopts the following technical solutions:

[0010] An alloy-state active solder wire comprises an active solder wire master alloy and an active element, wherein the active solder wire master alloy is an Ag-based alloy or a Cu-based alloy, the active element is Ti, the active element accounts for 6-12wt%, and the rest is the active solder wire master alloy.

[0011] Further, the active solder wire master alloy is one of Ag-28Cu, Ag-35Cu, Ag-50Cu, Ag-30Cu-10Sn, Ag-24Cu-17Sn, Ag-26Cu-14In, Ag-21Cu-20In, Ag-19Cu-30In, Ag-22Cu-13In-7Sn, Cu-8Sn, Cu-10Sn and Cu-12Sn, but not limited to; the master alloy basically covers the existing active solder system, and also involves the AgCuIn series of medium and low temperature active solders, enriching the active solder wire product system used in gradient packaging. According to the mass percentage of the finished wire composition, the active element accounts for 6 to 12wt%, and the rest is the master alloy.

[0012] A method for preparing alloy-state active solder wire, which adopts the method of "solid-liquid mixing and stirring + rapid casting and solidification" to evenly disperse spherical Ti powder in a master alloy, vertically cast an alloy rod with uniform composition, and obtain an active solder wire with a diameter of 0.3 mm through cold drawing.

[0013] A method for preparing alloy active solder wire, the method comprising the following steps:

[0014] Step I: weigh the master alloy, put it into the first crucible, tighten the furnace cover, evacuate through the first exhaust port, and heat it with a medium frequency induction coil; after the master alloy is completely melted, reduce the heating power and perform refining;

[0015] Step II: After the refining of the master alloy melt in step I is completed, the first gas inlet is opened and inert argon gas is filled in; then the control valve in the flow guide pipe is opened, and the master alloy melt vertically enters the second crucible along the flow guide pipe;

[0016] Step III: before the master alloy melt flows in step II, the spherical titanium powder weighed in proportion is placed in the powder funnel; the interior of the second crucible is evacuated through the second exhaust port; and the resistance heating package is turned on to preheat the temperature of the second crucible to the liquidus temperature of the master alloy and maintain the temperature; after the master alloy melt flows in, the rotating blade is lowered, sunk into the melt, and the rotation is started; at the same time, the stainless steel funnel is opened to control the spherical titanium powder to fall into the second crucible;

[0017] Step IV: After the master alloy melt and the spherical titanium powder in step III are stirred by the rotating blades, inert argon gas is filled in through the second air inlet; the graphite crystallizer is opened, and the alloy rod is pulled downward by the traction guide roller to prepare an active brazing alloy rod with a diameter of φ6 to 10 mm;

[0018] Step V: The active solder alloy rod prepared in step IV is processed to a diameter of less than 3.0 mm by cold rotary forging and intermediate vacuum annealing; and processed to an alloy wire with a diameter of 0.3-1.0 mm by cold drawing and intermediate vacuum annealing.

[0019] In step I, the refining temperature of the master alloy melt is 150° C. above the liquidus temperature of the master alloy, and the refining time is 5 to 10 minutes.

[0020] In step Ⅰ, the alumina crucible was evacuated to 10 -1 Pa or less; the heating power of medium frequency induction coil is 30-50kw; after the master alloy is completely melted, the power is reduced to 15-18kw.

[0021] In step II, the inflation pressure is 5-8 MPa, and the melt flow rate is 50-100 g / s.

[0022] In step III, the spherical titanium powder used has a particle size of 15-25 μm and a tap density of 2.66 g / cm 3 , bulk density is 2.90g / cm 3 .

[0023] In step III, the second crucible and the rotating blades are both made of pure tungsten.

[0024] In step III, the interior of the second crucible is evacuated to 10 -2Pa or less; the preheating temperature of the crucible is consistent with the liquidus temperature of the master alloy; the stirring speed of the rotating blade is 1000-2000n / min, and the powder flow rate is 3-14g / s.

[0025] In step IV, the master alloy melt and the spherical titanium powder are stirred by the rotating blades for 1 to 2 minutes, and the crucible inflation pressure is 2 to 4 MPa.

[0026] In step IV, the pulling speed of the alloy rod is 5-8 mm / s; the diameter of the active solder alloy rod is φ6-10 mm.

[0027] In step V, during the rotary forging and drawing process, the intermediate vacuum annealing temperature is 450°C±3°C, and the deformation rate of each annealing pass is 25%±5%. The alloy wire with a diameter of 0.3-1.0 mm is prepared, with a bright surface and no defects.

[0028] The device used in the method for preparing alloy-state active solder wire of the present invention mainly includes a master alloy smelting pool, a solid-liquid mixing pool, a guide pipe and a vertical casting device, etc. The master alloy smelting pool is connected to the solid-liquid mixing pool through a guide pipe, and the vertical casting device is arranged at the lower end of the solid-liquid mixing pool; the master alloy smelting pool includes a first crucible, a furnace cover, a quartz glass observation hole, a first exhaust port, a first air inlet and a medium frequency induction coil, etc. The furnace cover is arranged at the upper end of the first crucible, and the furnace cover is provided with a quartz glass observation hole, a first exhaust port and a first air inlet, and the medium frequency induction coil is arranged outside the first crucible; the solid-liquid mixing pool includes a second crucible, a furnace cover, a second exhaust port, a second air inlet, a rotating blade, a powder funnel and a resistance heating package, etc. The furnace cover is arranged at the upper end of the second crucible, and the furnace cover is provided with a second exhaust port and a second air inlet, the rotating blade and the stainless steel funnel are arranged on the upper part of the second crucible, and the resistance heating package is arranged outside the second crucible.

[0029] Furthermore, the vertical casting device comprises a graphite crystallizer, a pulling guide roller and an alloy rod, etc. The graphite crystallizer, the pulling guide roller and the alloy rod are sequentially connected to the bottom of the second crucible.

[0030] Furthermore, the first crucible is made of alumina, the second crucible and the rotating blades are made of tungsten, and the powder funnel is a stainless steel funnel.

[0031] Furthermore, the first crucible contains a master alloy melt, and the second crucible contains a solid-liquid alloy melt.

[0032] Furthermore, the guide tube is provided with a control valve, which can control the flow rate of the master alloy melt vertically entering the second crucible along the guide tube.

[0033] Furthermore, a heating and heat preservation device is arranged outside the guide pipe.

[0034] Furthermore, the bottom of the first crucible is connected to the top of the second crucible through a flow guide tube.

[0035] The preparation device of the present invention is a complete set of equipment, which can realize that the master alloy and the active solder alloy are in a vacuum environment in a molten state to avoid air absorption oxidation, etc.; it can also effectively reduce the contact reaction between the active elements and materials such as crucibles and molds, and ensure that the active element Ti is dispersed in the alloy in the form of particles and is metallurgically combined with the master alloy, thereby reducing the active element Ti being dissolved by the alloy and solidifying to form a brittle intermetallic compound.

[0036] Advantages of the present invention:

[0037] 1. The active solder wire of the present invention basically covers the existing active solder system, and also involves the new grade AgCuIn series of medium and low temperature active solders, enriching the active solder wire product system used in gradient packaging, and is suitable for various materials that are not suitable for brazing, such as ceramic-ceramic, ceramic-metal, graphite-metal, refractory metal, etc., and also meets the brazing requirements of complex structure designs such as T-joints, shaft hole connections, and rib wall structures.

[0038] 2. The active solder wire preparation device of the present invention realizes that the master alloy and the active solder alloy are in a vacuum environment in a molten state to avoid air absorption oxidation, etc.; it also effectively reduces the contact reaction between the active elements and materials such as crucibles and molds, and ensures that the active element Ti is dispersed in the alloy in the form of particles and is metallurgically combined with the master alloy, reducing the dissolution of the active element Ti in the alloy and the formation of brittle intermetallic compounds during solidification, thereby providing a strong guarantee for the drawing preparation of ultra-fine active solder wires.

[0039] 3. The active solder wire preparation device of the present invention has a novel design and combines multiple technologies such as vacuum melting, powder addition, solid-liquid stirring and mixing, rapid solidification vertical casting, etc., and can be widely used in the preparation of various doped material wires such as particle reinforcement and fiber reinforcement.

[0040] 4. The active solder wire preparation method of the present invention successfully prepares active solder wire in alloy state; the method adopted is to evenly disperse spherical Ti powder in the master alloy by "solid-liquid mixing and stirring + rapid casting and solidification", and vertically cast an alloy rod with uniform composition. The alloy rod prepared by this method is densely connected because Ti is wrapped in the alloy in the form of particles, and the surface of the Ti particles is metallurgically bonded with the alloy. During the alloy processing process, the spherical titanium powder is easy to slip along the direction of rotary forging and drawing, which can effectively improve the alloy processing plasticity. Therefore, active solder wire with a diameter of 0.3 mm can be processed by cold rotary forging and cold drawing. And it is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a schematic diagram of the general assembly of an active solder wire preparation device;

[0042] Figure 2 It is a schematic diagram of the master alloy melting pool of the active solder wire preparation device;

[0043] Figure 3 It is a schematic diagram of the solid-liquid mixing tank and vertical casting of the active solder wire preparation device;

[0044] Figure 4 It is a cross-sectional view of the general assembly of the active solder wire preparation device;

[0045] Figure 5 The DSC melting curve photograph of Ag-26Cu-6Ti alloy active solder wire obtained in Example 1;

[0046] Figure 6 The metallographic photograph of the cross section of the Ag-26Cu-6Ti alloy active solder wire was obtained for Example 1.

[0047] Description of main reference numerals:

[0048] 1-first crucible, 2-first exhaust port, 3-medium frequency induction coil, 4-first air inlet, 5-quartz glass observation hole, 6-mother alloy melt, 7-flow guide tube, 8-second crucible, 9-resistance heating package, 10-rotating blade, 11-stainless steel funnel, 12-solid-liquid alloy melt, 13-second exhaust port, 14-second air inlet, 15-graphite crystallizer, 16-traction guide roller, 17-alloy rod. DETAILED DESCRIPTION

[0049] The method for preparing the active solder wire of the present invention will be further described below in conjunction with an example of specific ingredient calculation.

[0050] The alloy-state active solder wire of the present invention comprises an Ag-based alloy or a Cu-based alloy, an active element is Ti, the active element accounts for 6-12%, and the rest is a master alloy. The preparation device mainly comprises a master alloy smelting pool, a guide tube, a solid-liquid mixing pool, a stirring blade, a powder funnel, a crystallizer, a guide wheel and a guide rod, etc. The preparation method is to uniformly disperse the spherical Ti powder in the master alloy by the method of "solid-liquid mixing and stirring + rapid casting and solidification", vertically cast an alloy rod with uniform composition, and process an active solder wire with a diameter of 0.3 mm by cold drawing. The present invention mainly solves the problem that active solder alloy-state wire products cannot be formed. The wire prepared by the device and method has uniform composition, excellent performance, high yield rate, and low cost, which is conducive to mass production.

[0051] The alloyed active solder wire of the present invention has a master alloy of Ag-based alloy or Cu-based alloy, an active element of Ti, and the active element Ti accounts for 6-12wt% and the rest is the master alloy. The master alloy of the active solder wire is one of Ag-28Cu, Ag-35Cu, Ag-50Cu, Ag-30Cu-10Sn, Ag-24Cu-17Sn, Ag-26Cu-14In, Ag-21Cu-20In, Ag-19Cu-30In, Ag-22Cu-13In-7Sn, Cu-8Sn, Cu-10Sn, and Cu-12Sn, but is not limited to.

[0052] The active solder wire of the present invention is obtained by the following method, which specifically comprises the following steps:

[0053] Step I: Weigh the master alloy and put it into the first crucible 1 (made of alumina, master alloy smelting pool), tighten the furnace cover, and evacuate the first exhaust port 2 to 10 -1 Pa or less; use medium frequency induction coil 3 for heating, power: 30 ~ 50kw; when the mother alloy is observed from the quartz glass observation hole 5 to be completely melted, the power is reduced to 15 ~ 18kw, the refining temperature is maintained at 50 ° C above the liquidus temperature of the mother alloy, and the refining time is 5 ~ 10min;

[0054] Step II: After the refining of the master alloy melt 6 in step I is completed, the first air inlet 4 is opened, and inert argon gas is charged, and the charging pressure is 5-8 MPa; then the control valve in the guide tube 7 is opened, and the master alloy melt 6 vertically enters the second crucible 8 along the guide tube 7, and the melt flow rate is: 50-100 g / s;

[0055] Step III: Before the master alloy melt flows into step II, the spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10°C through the second exhaust port 13. -2 Pa or less; turn on the resistance heating package 9, preheat the temperature of the second crucible 8 to the liquidus temperature of the master alloy, and maintain the temperature; after the master alloy melt 6 flows in, lower the rotating blade 10 (tungsten material), sink it into the melt, start rotating, and stir at a speed of 1000-2000n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8, the powder flow rate: 3-14g / s. The particle size of the spherical titanium powder is 15-25μm, and the tap density is 2.66g / cm 3 , bulk density is 2.90g / cm 3 ;

[0056] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 1 minute under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 2 to 4 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 5 to 8 mm / s to prepare Active brazing alloy rods;

[0057] Step V: The active solder alloy rod prepared in step IV is processed to a diameter of less than 3.0 mm by cold rotary forging, with an intermediate vacuum annealing temperature of 450°C±3°C and a deformation rate of 25%±5% between each annealing pass; and processed to an alloy wire with a diameter of 0.3-1.0 mm by cold drawing, with an intermediate vacuum annealing temperature of 450°C±3°C and a deformation rate of 25%±5% between each annealing pass.

[0058] like Figure 1-4 As shown, the alloy state active solder wire preparation device of the present invention mainly comprises a first crucible 1, a first exhaust port 2, a medium frequency induction coil 3, a first air inlet 4, a quartz glass observation hole 5, a master alloy melt 6, a guide tube 7, a second crucible 8, a resistance heating package 9, a rotating blade 10, a stainless steel funnel 11, a solid-liquid alloy melt 12, a second exhaust port 13, a second air inlet 14, a graphite crystallizer 15, a traction guide roller 16 and an alloy rod 17. The preparation device is a complete set of equipment, which can realize that the master alloy and the active solder alloy are in a vacuum environment in a molten state to avoid air absorption oxidation, etc.; it also effectively reduces the contact reaction between the active element and the crucible, mold and other materials, and also ensures that the active element Ti is dispersed in the alloy in the form of particles and is metallurgically combined with the master alloy, reducing the active element Ti being dissolved by the alloy and solidifying to form a brittle intermetallic compound.

[0059] like Figure 1-4 As shown, the alloy-state active solder wire preparation device of the present invention mainly includes a mother alloy smelting pool, a solid-liquid mixing pool, a guide pipe 7 and a vertical drawing device, etc. The mother alloy smelting pool and the solid-liquid mixing pool are connected by the guide pipe 7, and the vertical drawing device is arranged at the lower end of the solid-liquid mixing pool.

[0060] like Figure 2 As shown, the master alloy smelting pool includes a first crucible 1, a furnace cover, a quartz glass observation hole 5, a first exhaust port 2, a first air inlet 4 and a medium frequency induction coil 3, etc. The furnace cover is arranged on the upper end of the first crucible 1, a quartz glass observation hole 5 is arranged in the middle of the furnace cover, the first exhaust port 2 and the first air inlet 4 are arranged on both sides of the furnace cover, and the medium frequency induction coil 3 is arranged outside the first crucible 1; the first crucible 4 is an alumina crucible, and the first crucible 1 contains a master alloy melt 6.

[0061] like Figure 3-4As shown, the solid-liquid mixing tank includes a second crucible 8, a furnace cover, a second exhaust port 13, a second air inlet 14, a rotating blade 10, a stainless steel funnel 11 and a resistance heating package 9, etc. The furnace cover is arranged on the upper end of the second crucible 8, and the furnace cover is provided with a second exhaust port 13 and a second air inlet 14, the rotating blade 10 and the stainless steel funnel 11 are arranged on the upper part of the second crucible 8, and the resistance heating package 9 is arranged outside the second crucible 8. The second crucible 8 and the rotating blade 10 are made of tungsten, and the second crucible 8 contains a solid-liquid alloy melt 12.

[0062] like Figure 3 As shown, the vertical drawing device includes a graphite crystallizer 15, a pulling guide roller 16 and an alloy rod 17, etc. The graphite crystallizer 15, the pulling guide roller 16 and the alloy rod 17 are sequentially connected to the lower part of the second crucible 8.

[0063] like Figure 4 As shown, the bottom of the first crucible 1 is connected to the top of the second crucible 8 via a flow guide tube 7, on which a control valve is provided to control the flow rate of the master alloy melt 6 vertically entering the second crucible 8 along the flow guide tube 7. A heating and heat preservation device is provided outside the flow guide tube 7.

[0064] Example 1

[0065] Step I: Select Ag-28Cu alloy, solid-liquid melting point 779°C, weighing 18.8kg; put it into the first crucible 1 (alumina crucible, master alloy smelting pool), tighten the furnace cover, and evacuate from the first exhaust port 2 to 10 -1 Pa; using medium frequency induction coil 3 for induction heating, power: 40kw; when observing from the quartz glass observation hole 5 that the mother alloy is completely melted, the power is reduced to 16kw, the refining temperature is maintained at 829℃, and the refining time is 5min.

[0066] Step II: After the refining of step I is completed, open the first air inlet 4 and fill it with inert argon gas with a filling pressure of 5 MPa; then open the control valve in the flow guide tube 7, and the master alloy melt 6 vertically enters the second crucible 8 (solid-liquid alloy pool) along the flow guide tube 7, and the melt flow rate is: 50 g / s.

[0067] Step III: Before the master alloy melt 6 in step II flows in, 1.2 kg of spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10 -2 Pa or less; and turn on the resistance heating pack 9, preheat the temperature of the second crucible 8 to 779°C, and maintain this temperature; after the mother alloy melt 6 flows in, lower the rotating blade 10 (made of tungsten), sink it into the melt, start the rotation, and the stirring speed is 1000n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8 (solid-liquid alloy pool), and the powder flow rate is 3.2g / s.

[0068] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 1.5 minutes under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 4 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 6 mm / s to prepare Active brazing alloy rods.

[0069] Step V: The active solder alloy rod prepared in step IV is processed to a diameter of 3.0 mm by cold rotary forging and intermediate vacuum annealing; and processed to a diameter of 0.3 mm by cold drawing and intermediate vacuum annealing. The intermediate vacuum annealing temperature is 450°C ± 3°C, and the deformation rate per annealing pass is 25% ± 5%, which is the same as in the following embodiments.

[0070] like Figure 5 As shown, it is a photograph of the DSC melting curve of the Ag-26Cu-6Ti alloy active solder wire obtained in Example 1. It can be seen from the figure that the melting temperature of the Ag-26Cu-6Ti alloy obtained by adopting the alloy proportion and preparation method designed by the present invention is 778.76-789.82°C, the melting range is 11.06°C, the endothermic peak and the exothermic peak curves are smooth and obvious, and there is no high melting point phase precipitation (Ti element melting point 1668°C), which indicates that the Ti element is in a dispersed state and there is no large block enrichment problem; and an endothermic peak appears at 808.07°C, which indicates that an active reaction occurs with the alumina crucible of the DSC test equipment, and the Ti element can achieve a metallurgical effect on the ceramic at a lower brazing temperature, meeting the patent design requirements.

[0071] Figure 6 The cross-sectional metallographic photograph of the Ag-26Cu-6Ti alloy active solder wire was obtained for Example 1. From the metallographic structure photograph, it can be seen that there are mainly three phases in the Ag-26Cu-6Ti alloy active solder wire alloy, the light gray is the Ag-rich phase solid solution, the dark color is the free Ti phase, and the dark surrounding is the white phase Cu-rich phase solid solution. It can be seen that the dark free Ti phase is dispersed in the alloy and is wrapped by the Cu-rich phase solid solution, and it is obvious that the Ti particles are partially dissolved to form a bonding transition.

[0072] Example 2

[0073] Step I: Select Ag-50Cu alloy, solid-liquid melting point 779 ~ 865 ℃, weigh 17.6kg; put it into the first crucible 1 (alumina crucible, master alloy smelting pool), tighten the furnace cover, and evacuate from the first exhaust port 2 to 10 -1 Pa; using medium frequency induction coil 3 for heating, power: 50kw; when observing from the quartz glass observation hole 5 that the mother alloy is completely melted, the power is reduced to 18kw, the refining temperature is maintained at 915℃, and the refining time is 10min.

[0074] Step II: After the refining of step I is completed, open the first air inlet 4 and fill it with inert argon gas with a filling pressure of 8 MPa; then open the control valve in the flow guide tube 7, and the master alloy melt 6 vertically enters the second crucible 8 (solid-liquid alloy pool) along the flow guide tube 7, and the melt flow rate is: 100 g / s.

[0075] Step III: Before the master alloy melt flows into step II, 2.4 kg of spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10 -2 Pa or less; and turn on the resistance heating pack 9, preheat the temperature of the second crucible 8 to 865°C, and maintain this temperature; after the mother alloy melt 6 flows in, lower the rotating blade 10 (made of tungsten), sink it into the melt, start the rotation, and the stirring speed is 2000n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8 (solid-liquid alloy pool), and the powder flow rate is 13.6g / s.

[0076] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 2 minutes under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 2 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 8 mm / s to prepare Active brazing alloy rods.

[0077] Step V: The active solder alloy rod prepared in step IV is processed into a diameter of 2.8 mm by cold rotary forging and intermediate vacuum annealing; and processed into an alloy wire with a diameter of 0.5 mm by cold drawing and intermediate vacuum annealing.

[0078] Example 3

[0079] Step I: Select Ag-21Cu-20In alloy, solid-liquid melting point 558 ~ 593 ℃, weigh 18.4kg; put it into the first crucible 1 (alumina crucible, master alloy smelting pool), tighten the furnace cover, and evacuate from the first exhaust port 2 to 10 -1 Pa; using medium frequency induction coil 3 for heating, power: 30kw; when observing from the quartz glass observation hole 5 that the mother alloy is completely melted, the power is reduced to 15kw, the refining temperature is maintained at 643℃, and the refining time is 6min.

[0080] Step II: After the refining of step I is completed, open the first air inlet 4 and fill it with inert argon gas with a filling pressure of 6 MPa; then open the control valve in the flow guide tube 7, and the master alloy melt 6 vertically enters the second crucible 8 (solid-liquid alloy pool) along the flow guide tube 7, and the melt flow rate is: 80 g / s.

[0081] Step III: Before the master alloy melt flows into step II, 1.6 kg of spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10 -2 Pa or less; and turn on the resistance heating pack 9, preheat the temperature of the second crucible 8 to 593°C, and maintain this temperature; after the mother alloy melt 6 flows in, lower the rotating blade 10 (made of tungsten), sink it into the melt, start the rotation, and the stirring speed is 1500n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8 (solid-liquid alloy pool), and the powder flow rate is 7.0g / s.

[0082] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 1 minute under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 3 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 5 mm / s to prepare Active brazing alloy rods.

[0083] Step V: The active solder alloy rod prepared in step IV is processed into a diameter of 3.0 mm by cold rotary forging and intermediate vacuum annealing; and processed into an alloy wire with a diameter of 1.0 mm by cold drawing and intermediate vacuum annealing.

[0084] Example 4

[0085] Step I: Select Ag-30Cu-10Sn alloy, solid-liquid melting point 600-720°C, weigh 18.0kg; put it into the first crucible 1 (alumina crucible, master alloy smelting pool), tighten the furnace cover, and evacuate from the first exhaust port 2 to 10 -1 Pa; using medium frequency induction coil 3 for heating, power: 30kw; when observing from the quartz glass observation hole 5 that the mother alloy is completely melted, the power is reduced to 15kw, the refining temperature is maintained at 770℃, and the refining time is 8min.

[0086] Step II: After the refining of step I is completed, open the first air inlet 4 and fill it with inert argon gas with a filling pressure of 5 MPa; then open the control valve in the flow guide tube 7, and the master alloy melt 6 vertically enters the second crucible 8 (solid-liquid alloy pool) along the flow guide tube 7, and the melt flow rate is: 100 g / s.

[0087] Step III: Before the master alloy melt flows into step II, 2.0 kg of spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10 -2Pa or less; and turn on the resistance heating pack 9, preheat the temperature of the second crucible 8 to 720°C, and maintain this temperature; after the mother alloy melt 6 flows in, lower the rotating blade 10 (made of tungsten), sink it into the melt, start the rotation, and the stirring speed is 2000n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8 (solid-liquid alloy pool), and the powder flow rate is 10.5g / s.

[0088] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 1.5 minutes under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 4 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 7 mm / s to prepare Active brazing alloy rods.

[0089] Step V: The active solder alloy rod prepared in step IV is processed into a diameter of 2.5 mm by cold rotary forging and intermediate vacuum annealing; and processed into an alloy wire with a diameter of 0.8 mm by cold drawing and intermediate vacuum annealing.

[0090] Example 5

[0091] Step I: Select Cu-10Sn alloy, solid-liquid melting point 825 ~ 1010 ℃, weigh 18.0kg; put it into the first crucible 1 (alumina crucible, master alloy smelting pool), tighten the furnace cover, and evacuate from the first exhaust port 2 to 10 -1 Pa; using medium frequency induction coil 3 for heating, power: 50kw; when observing from the quartz glass observation hole 5 that the mother alloy is completely melted, the power is reduced to 18kw, the refining temperature is maintained at 1060℃, and the refining time is 10min.

[0092] Step II: After the refining in step I is completed, the first air inlet 4 is opened and inert argon gas is charged at a pressure of 8 MPa; then the control valve in the flow guide tube 7 is opened, and the master alloy melt 6 vertically enters the second crucible 8 (solid-liquid alloy pool) along the flow guide tube 7, and the melt flow rate is: 100 g / s. ;

[0093] Step III: Before the master alloy melt 6 in step II flows in, 2.0 kg of spherical titanium powder weighed in proportion is placed in a stainless steel funnel 11; the interior of the second crucible 8 (made of tungsten) is evacuated to 10 -2Pa or less; and turn on the resistance heating pack 9, preheat the temperature of the second crucible 8 to 1010°C, and maintain this temperature; after the master alloy melt 6 flows in, lower the rotating blade 10 (made of tungsten), sink it into the melt, start the rotation, and the stirring speed is 2000n / min; at the same time, open the stainless steel funnel 11 to control the spherical titanium powder to fall into the second crucible 8 (solid-liquid alloy pool), and the powder flow rate is 11.5g / s.

[0094] Step IV: After the master alloy melt 6 and the spherical titanium powder in step III are stirred for 2 minutes under the rotating blade 10 to obtain a solid-liquid alloy melt 12, inert argon gas is filled in through the second air inlet 14 at a pressure of 2 MPa; the graphite crystallizer 15 is opened, and the alloy rod 17 is pulled downward by the pulling guide roller 16 at a pulling speed of 6 mm / s to prepare Active brazing alloy rods.

[0095] Step V: The active solder alloy rod prepared in step IV is processed into a diameter of 3.0 mm by cold rotary forging and intermediate vacuum annealing; and processed into an alloy wire with a diameter of 1.0 mm by cold drawing and intermediate vacuum annealing.

[0096] The alloy active solder wires prepared in Examples 1-5 were subjected to Ti element composition determination, differential thermal determination, alumina ceramic joint shear strength test, etc. The test data obtained are shown in Table 1.

[0097] Table 1 Properties of alloy active solder wires prepared in Examples 1 to 5

[0098]

[0099]

[0100] The invention mainly solves the problem that active solder alloy wire products cannot be formed. The wire prepared by the device and method has uniform composition, excellent performance, high yield rate and low cost, which is conducive to mass production.

[0101] The above embodiments only illustrate some embodiments of the preparation of alloy-state active solder wires of the present invention. In the above technical solutions of the present invention, the selection of the master alloy and the content of the active element Ti can be freely selected within the prescribed range and are not listed here one by one. Therefore, the technical solutions contained in the above description should be regarded as illustrative rather than limiting the scope of protection of the patent application of the present invention.

Claims

1. An alloy active solder wire, characterized in that: It comprises an active solder wire master alloy and an active element, wherein the active solder wire master alloy is an Ag-based alloy or a Cu-based alloy, the active element is Ti, the active element accounts for 6-12wt%, and the rest is the active solder wire master alloy.

2. The alloy active solder wire according to claim 1, characterized in that: The active solder wire master alloy is one of Ag-28Cu, Ag-35Cu, Ag-50Cu, Ag-30Cu-10Sn, Ag-24Cu-17Sn, Ag-26Cu-14In, Ag-21Cu-20In, Ag-19Cu-30In, Ag-22Cu-13In-7Sn, Cu-8Sn, Cu-10Sn and Cu-12Sn.

3. The method for preparing the alloy active solder wire according to claim 1 or 2, characterized in that: The spherical Ti powder is evenly dispersed in the master alloy by solid-liquid mixing and rapid casting solidification, and the alloy rods with uniform composition are vertically cast, and the active solder wire with a diameter of 0.3mm is obtained by cold drawing.

4. The method for preparing the alloy active solder wire according to claim 3, characterized in that: The following steps are involved: Step I: weigh the master alloy, put it into the first crucible, tighten the furnace cover, evacuate through the first exhaust port, and heat it with a medium frequency induction coil; after the master alloy is completely melted, reduce the heating power and perform refining; Step II: After the refining of the master alloy melt in step I is completed, the first gas inlet is opened and inert argon gas is filled in; then the control valve in the flow guide pipe is opened, and the master alloy melt vertically enters the second crucible along the flow guide pipe; Step III: before the master alloy melt flows in step II, the spherical titanium powder weighed in proportion is placed in the powder funnel; the interior of the second crucible is evacuated through the second exhaust port; and the resistance heating package is turned on to preheat the temperature of the second crucible to the liquidus temperature of the master alloy and maintain the temperature; after the master alloy melt flows in, the rotating blade is lowered, sunk into the melt, and the rotation is started; at the same time, the stainless steel funnel is opened to control the spherical titanium powder to fall into the second crucible; Step IV: After the master alloy melt and the spherical titanium powder in step III are stirred by the rotating blades, inert argon gas is filled in through the second air inlet; the graphite crystallizer is opened, and the alloy rod is pulled downward by the traction guide roller to prepare an active brazing alloy rod with a diameter of φ6 to 10 mm; Step V: The active solder alloy rod prepared in step IV is processed to a diameter of less than 3.0 mm by cold rotary forging and intermediate vacuum annealing; and processed to an alloy wire with a diameter of 0.3-1.0 mm by cold drawing and intermediate vacuum annealing.

5. The method for preparing the alloy active solder wire according to claim 4, characterized in that: In step I, the master alloy melt refining temperature is 150°C above the master alloy liquidus temperature, and the refining time is 5 to 10 minutes; the alumina crucible is evacuated to 10 -1 Pa or less; the power of medium frequency induction coil heating is 30-50kw; after the master alloy is completely melted, the power is reduced to 15-18kw; in step II, the inflation pressure is 5-8MPa, and the melt flow rate is 50-100g / s.

6. The method for preparing the alloy active solder wire according to claim 4, characterized in that: In step III, the spherical titanium powder used has a particle size of 15-25 μm and a tap density of 2.66 g / cm 3 , bulk density is 2.90g / cm 3 ; The second crucible is evacuated to 10 -2 Pa or less; the preheating temperature of the crucible is consistent with the liquidus temperature of the master alloy; the stirring speed of the rotating blade is 1000-2000n / min, and the powder flow rate is 3-14g / s.

7. The method for preparing the alloy active solder wire according to claim 4, characterized in that: In step IV, the mother alloy melt and the spherical titanium powder are stirred by rotating blades for 1 to 2 minutes, and the crucible inflation pressure is 2 to 4 MPa; the pulling speed of the alloy rod is 5 to 8 mm / s; the diameter of the active solder alloy rod is φ6 to 10 mm; in step V, during the rotary forging and drawing process, the intermediate vacuum annealing temperature is 450°C ± 3°C, and the deformation rate of each annealing pass is 25% ± 5%.

8. The method for preparing the alloy active solder wire according to any one of claims 3 to 7, characterized in that: The preparation device adopted includes a mother alloy smelting pool, a solid-liquid mixing pool, a guide pipe and a vertical casting device. The mother alloy smelting pool is connected to the solid-liquid mixing pool through a guide pipe, and the vertical casting device is arranged at the lower end of the solid-liquid mixing pool; the mother alloy smelting pool includes a first crucible, a furnace cover, a quartz glass observation hole, a first exhaust port, a first air inlet and a medium frequency induction coil. The furnace cover is arranged at the upper end of the first crucible, and the furnace cover is provided with a quartz glass observation hole, a first exhaust port and a first air inlet, and the medium frequency induction coil is arranged outside the first crucible; the solid-liquid mixing pool includes a second crucible, a furnace cover, a second exhaust port, a second air inlet, a rotating blade, a powder funnel and a resistance heating package. The furnace cover is arranged at the upper end of the second crucible, and the furnace cover is provided with a second exhaust port and a second air inlet. The rotating blade and the powder funnel are arranged on the upper part of the second crucible, and the resistance heating package is arranged outside the second crucible.

9. The method for preparing alloy active solder wire according to claim 8, characterized in that: The vertical drawing device comprises a graphite crystallizer, a pulling guide roller and an alloy rod, and the graphite crystallizer, the pulling guide roller and the alloy rod are sequentially connected to the bottom of the second crucible.

10. The method for preparing alloy active solder wire according to claim 8, characterized in that: The first crucible is made of alumina, and the second crucible and the rotating blades are made of tungsten. A control valve is provided on the guide tube. A heating and heat preservation device is provided outside the guide tube. The bottom of the first crucible is connected to the top of the second crucible through the guide tube.

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