Extrusion device, system, filamentous solder and preparation method thereof

Abstract

The present invention provides an extrusion device, system, filamentary solder and its preparation method. The extrusion device includes: an extrusion die, a pressure head and an extrusion nozzle; one end of the extrusion die is an extrusion part, and the other end is an extrusion part; the pressure head is arranged at the extrusion part, and the extrusion nozzle is arranged at the extrusion part; the extrusion die, the pressure head and the extrusion nozzle together form a cavity for accommodating the material; the extrusion device also includes a flow-guiding structure, which is arranged at the extrusion part; the flow-guiding structure includes a flow-guiding end and a fixed end arranged up and down; the maximum cross-sectional area of ​​the flow-guiding end is greater than the maximum cross-sectional area of ​​the fixed end. The present invention solves the problem that the process of extruding the solder and flux powder after compounding in a fixed ratio is complicated, the process is cumbersome, and continuous production cannot be achieved.

Description

Technical Field

[0001] The present invention relates to the field of brazing technology, and in particular to an extrusion device, a system, a filamentous brazing material and a preparation method thereof. Background Art

[0002] With the development of brazing technology, the current brazing filler metals are more focused on achieving the goals of green energy conservation, quality improvement and loss reduction; thus, a series of fixed-ratio composite brazing materials such as flux-cored brazing filler metals and flux-coated brazing filler metals have been developed to avoid a series of problems during the brazing process, such as excessive brazing filler metal or flux, which leads to waste of raw materials, difficulty in cleaning after welding, unsatisfactory welding quality, and difficulty in long-term storage of brazing filler metals.

[0003] Based on the above reasons, some people have proposed the idea of ​​extruding the brazing material and flux powder after compounding them in a certain ratio. However, most of the processes are complicated and the procedures are tedious, which makes it impossible to achieve continuous production. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides an extrusion device, comprising: an extrusion die, a pressure head and an extrusion nozzle; one end of the extrusion die is an extrusion part, and the other end is an extrusion part; the pressure head is arranged in the extrusion part, and the extrusion nozzle is arranged in the extrusion part; the extrusion die, the pressure head and the extrusion nozzle together form a cavity for accommodating materials; the extrusion device also includes a guide structure, which is arranged in the extrusion part; wherein the guide structure includes a guide end and a fixed end arranged upper and lower; the maximum cross-sectional area of ​​the guide end is greater than the maximum cross-sectional area of ​​the fixed end.

[0005] The advantage of adopting the above solution is that, due to the large cross-sectional area of ​​the guide end, a first space can be formed between the guide end and the extrusion nozzle. Under the pressure of the pressure head, the material to be extruded moves to the upper surface of the guide end and moves along the surface of the guide end to the first space. The specific movement trajectory is shown in FIG. Figure 1 R1 and R2 in the solder paste are used to achieve a large rheological function. In the preparation process of the filamentous solder, it is beneficial to induce shear and tensile deformation of the raw material powder, and promote welding and powder metallurgy synthesis of the raw material powder.

[0006] On the other hand, due to the setting of the flow-guiding structure, a large extrusion deformation index can be achieved; that is, the ratio of the cross-sectional area between the widest and narrowest parts of the extrusion die is large. Specifically, the extrusion die is generally a columnar structure, and its widest cross-sectional area Smax is also its original cross-sectional area S0; due to the setting of the flow-guiding structure, the narrowest cross-sectional area Smin in the extrusion die is S0-the maximum cross-sectional area of ​​the flow-guiding end. Preferably, the value range of Smax / Smin is 2-5. Extrusion dies with a large deformation index have the following advantages: ① During the extrusion process, the powdered solder and flux undergo severe plastic deformation, achieving multiple mechanical alloying in one extrusion, and more complete atomic bonding between the powdered solder and flux, thereby improving the powder metallurgy bonding strength; ② In the subsequently extruded wire, the flux is crushed and the particle size is further reduced, making the distribution more uniform; ③ It is conducive to the discharge of gas between the powders, thereby improving the density of the wire. Under the combined action of these three factors, the strength of the wire is further improved.

[0007] Furthermore, the vertical distance between the upper surface and the lower surface of the extrusion nozzle is the height of the extrusion nozzle; wherein the height of the center position of the extrusion nozzle is less than the height of the periphery of the extrusion nozzle; and / or, the extrusion nozzle includes multiple extrusion ports, and the cross-sectional area S0 of the cavity and the cross-sectional area S2 of the multiple extrusion ports satisfy: S0 / S2>10; wherein, each extrusion port is circumferentially arranged around the axis of the guide structure; and / or, the extrusion die includes an upper section and a lower section; a temperature control part is provided on the outer periphery of the lower section, and the temperature control part includes a heating layer and a heat preservation layer; and / or, the extrusion device further includes: a material storage part, and / or, a material receiving part; wherein, the material storage part is used to store materials and transport the materials to the extrusion die; the material receiving part is close to the extrusion part and is used to collect the extruded material.

[0008] In this technical solution, the extrusion nozzle adopts a design that is low in the middle and high at both ends. Specifically, the vertical distance between the upper and lower surfaces of the extrusion nozzle is its height, and the height at the center of the extrusion nozzle is less than the height at the edge of the extrusion nozzle; more specifically, along the direction extending from the center of the extrusion nozzle to the edge, its height change trend is as follows: remain unchanged and then gradually increase. The above design can prevent the raw material powder from forming a dead zone during deformation; in addition, in the segmented extrusion die, the raw material powder in the upper section is at low temperature and low viscosity, which can reduce the oxidation of the powder, promote the downward transmission of pressure, and on the other hand, protect the flux. The raw material powder in the lower section of the extrusion die is in a violent deformation area, and under the action of heating, it presents a high-temperature softening state, which is beneficial to the plasticity of the raw material powder. The extrusion temperature is positively correlated with the extrusion deformation index, that is, the larger the extrusion deformation index, the higher the extrusion temperature; in addition, in order to make the entire process more coherent and complete, a storage section and a receiving section are further provided. The material storage section is located near the extrusion section, and the two can be connected by a pipeline. Generally speaking, the capacity of the material storage section is much larger than the capacity of the cavity inside the extrusion section, so as to achieve long-term continuous production, avoid the trouble caused by multiple feedings, and achieve a significant increase in production capacity. The material collection section is located near the extrusion section. Specifically, the extrusion nozzle includes multiple extrusion ports. Correspondingly, the material collection section can include multiple automatic winders for winding the filamentous solder from different extrusion ports.

[0009] Furthermore, along the direction away from the fixed end, the guide end includes a transition section, a straight section and a guide section in sequence; wherein, the cross-sectional area S0 of the cavity in the horizontal direction and the cross-sectional area S1 of the straight section in the horizontal direction satisfy: S0 / S1=1.25-2.

[0010] Furthermore, the transition section connects the straight section and the fixed end; the cross-sectional area of ​​the transition section in the horizontal direction gradually increases in the direction away from the fixed end; and / or, the guide section is a curved surface convex in the direction away from the straight section; and / or, the distance between the axis of any extrusion port and the axis of the guide structure is D, the straight section is a cylindrical structure with a radius of R1, and the fixed end is a cylindrical structure with a radius of R2; wherein, R1>D>R2.

[0011] This technical solution also provides an extrusion system, comprising: a sealed cabin and a vacuum pump; the sealed cabin is used to accommodate the extrusion device provided by the above technical solution; and the vacuum pump is connected to the sealed cabin.

[0012] In this technical solution, the extrusion system includes a sealed cabin and a vacuum pump, which are used to provide a relatively vacuum environment. Vacuuming helps eliminate oxygen and other gases between the particles of the raw powder, increase the bulk density of the raw powder, reduce the oxidation of the solder and flux during the extrusion process, and reduce the porosity content in the extruded wire. The vacuum degree can be divided into high vacuum and low vacuum. Low vacuum is suitable for solder containing zinc and mixed powders that are not easily oxidized. It can prevent the volatilization of zinc and save vacuuming time, thereby improving production efficiency. High vacuum is suitable for mixed powders that are easily oxidized and have high usage requirements to improve product quality.

[0013] The present technical solution also provides a method for preparing a filamentous solder, which adopts the extrusion system of the above technical solution; the preparation method comprises the following steps:

[0014] S10: placing the raw material powder in the cavity, evacuating the cavity, and heating the extrusion die to the extrusion temperature;

[0015] S20: controlling the extrusion part to maintain the first pressure for T time; then controlling the extrusion part to extrude the raw material powder into a filamentous solder at a first extrusion speed.

[0016] Furthermore, the vacuum environment can be divided into low vacuum and high vacuum. The vacuum degree of low vacuum is 1-10Pa, and the vacuum degree of high vacuum is 0.1-1Pa.

[0017] Furthermore, the raw material powder includes solder and flux; wherein the particle size of the flux is smaller than that of the solder; the particle size of the flux is 100-325 meshes; and the particle size of the solder is 40-250 meshes.

[0018] Furthermore, the first pressure is 100-150 MPa, and the value range of T is 20-30 min.

[0019] In the above scheme, the purpose of heating is to raise the solder powder above its recrystallization temperature, thereby increasing its deformability and reducing the pressure required for extrusion. Holding the pressure for a period of time helps eliminate interstitial spaces between the powders, significantly reducing the porosity in the compact. This further increases the density of the extruded blank, laying a solid foundation for subsequent high-quality wire drawing. The provision of a storage and receiving section enables continuous wire production under vacuum, significantly increasing production capacity.

[0020] After adopting the technical solution of the present invention, the following technical effects can be achieved:

[0021] The present invention realizes multiple mechanical alloying of the mixed powder of solder and flux by subjecting it to a single hot extrusion with a large rheological and extrusion degeneration index under a vacuum environment. The special extrusion die structure design is conducive to improving the strength and production efficiency of the extruded wire. An automatic feeder and an automatic winder are used to achieve continuous and efficient production, greatly improving production efficiency. In the prepared wire, the solder and flux are evenly distributed, the wire strength is high, and subsequent cold processing is convenient. Since the flux is evenly wrapped in the solder, the problems of powder leakage, difficult storage, and uneven distribution of components of ordinary flux core and flux coating solders are avoided. This method realizes continuous and efficient production, and the quality and cost advantages of the prepared wire are obvious, and it has broad market prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic structural diagram of an extrusion device provided in an embodiment of the present invention.

[0023] Figure 2 A schematic structural diagram of an extrusion system provided in an embodiment of the present invention.

[0024] Figure 3 for Figure 2 Cross-section of the middle diversion structure.

[0025] Figure 4 for Figure 2 Top view of the central diversion structure.

[0026] Figure 5 for Figure 2 Cross-section of the extrusion nozzle.

[0027] Figure 6 for Figure 2 Top view of the extrusion nozzle.

[0028] Description of reference numerals:

[0029] 1-dynamic seal; 2-pressure head; 3-raw material powder; 4-material storage part; 5-extrusion die; 501-upper section; 502-lower section; 6-heating layer; 7-insulation layer; 8-sealing cabin; 9-mandrel; 10-support seat; 11-material receiving part; 12-extrusion nozzle; 13-pad; 14-flow guide structure; 141-flow guide end; 141a-transition section; 141b-straight section; 141c-guide section; 142-fixed end; 15-vacuum pump. DETAILED DESCRIPTION

[0030] To make the above-mentioned objects, features, and advantages of the present invention more clearly understood, the technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment provides an extrusion device, including: an extrusion die 5, a pressure head 2 and an extrusion nozzle 12; one end of the extrusion die 5 is an extrusion part, and the other end is an extrusion part; the pressure head 2 is arranged in the extrusion part, and the extrusion nozzle 12 is arranged in the extrusion part; the extrusion die 5, the pressure head 2 and the extrusion nozzle 12 together form a cavity for accommodating materials; the extrusion device also includes a guide structure 14, which is arranged in the extrusion part; wherein the guide structure 14 includes a guide end 141 and a fixed end 142 arranged upper and lower; the maximum cross-sectional area of ​​the guide end 141 is greater than the maximum cross-sectional area of ​​the fixed end 142.

[0033] See also Figures 1-6 In this embodiment, the extrusion device includes an extrusion die 5, a pressure head 2 and an extrusion nozzle 12. The three together define a cavity for accommodating the material. The material to be extruded is placed in the cavity, and the pressure head 2 applies pressure. Under the pressure of the pressure head 2, the material to be extruded is extruded from the extrusion nozzle 12 to form a strip or wire-shaped material.

[0034] In a specific embodiment of this embodiment, the extrusion device further includes a flow-guiding structure 14; the flow-guiding structure 14 includes a flow-guiding end 141 and a fixed end 142 disposed above and below. Generally, the fixed end 142 is a columnar structure with a constant cross-sectional area, while the flow-guiding end 141 serves as a flow guide, and its cross-sectional area varies with height. Specifically, along the direction extending from the fixed end 142 to the flow-guiding end 141, the cross-sectional area of ​​the flow-guiding end 141 gradually increases, then gradually decreases. Preferably, the cross-sectional area of ​​the flow-guiding end 141 gradually increases, then remains constant, and finally gradually decreases.

[0035] In the related art, the extrusion molding of filamentary solder generally adopts a multi-stage extrusion method, which is to squeeze the raw material into multiple dies with gradually decreasing diameters to finally form the filamentary solder. In this embodiment, preferably, the extrusion device 5 and the cavity therein are cylindrical structures with unchanged diameters. The provision of the flow guide structure 14 achieves the functions of large rheology and large deformation, and the filamentary solder can be produced in a single extrusion; there is no need for multiple stages of continuous extrusion.

[0036] The advantage of adopting the above solution is that, due to the large cross-sectional area of ​​the guide end 141, a first space can be formed between the guide end 141 and the extrusion nozzle 12. The material to be extruded moves to the upper surface of the guide end 141 under the pressure of the pressure head 2, and moves along the upper surface of the guide end 141 to the first space. The specific movement trajectory is shown in FIG. Figure 1 R1 and R2 in the solder are used to achieve a large rheological function, which is beneficial to inducing shear and tensile deformation of the raw material powder 3 during the preparation of the filamentous solder, and promoting welding and powder metallurgy synthesis of the raw material powder 3.

[0037] On the other hand, the provision of the flow-guiding structure 14 enables a high extrusion deformation index; that is, a large ratio of the cross-sectional area between the widest and narrowest points of the extrusion die 5. Specifically, the internal cavity of the extrusion die 5 is generally a cylindrical structure, and the widest cross-sectional area Smax of this cavity is also its original cross-sectional area S0. Due to the provision of the flow-guiding structure 14, the cross-sectional area Smin at the narrowest point in the extrusion die 5 is S0 minus the maximum cross-sectional area at the flow-guiding end. Preferably, the value of Smax / Smin ranges from 2 to 5. That is, S0 / S1 = 1.25 - 2, where S1 is the horizontal cross-sectional area of ​​the straight segment 141b. The extrusion die 5 with a large deformation index offers the following advantages: ① During extrusion, the powdered brazing filler metal and flux undergo intense plastic deformation, achieving multiple mechanical alloying processes in a single extrusion. This results in more complete atomic bonding between the powdered brazing filler metal and the flux, improving the powder metallurgy bond strength. ② In the subsequently extruded wire, the flux is crushed and its particle size is further reduced, resulting in a more uniform distribution. ③ This facilitates the expulsion of gas between the powders, increasing the density of the wire. These three factors contribute to a further increase in wire strength.

[0038] In another embodiment of this embodiment, the fixed end 142 is fixedly connected to the extrusion nozzle 12. In a preferred embodiment, the extrusion nozzle 12 includes an opening for accommodating the fixed end 142, thereby allowing the flow guide structure 14 to be detachably connected to the extrusion nozzle 12 and making the distance between the flow guide end 141 and the extrusion nozzle 12 adjustable. In a specific implementation, the distance between the flow guide end 141 and the extrusion nozzle 12 can be adjusted according to the properties of the raw material to achieve a large rheological function.

[0039] Furthermore, the vertical distance between the upper and lower surfaces of the extrusion nozzle 12 is the height h of the extrusion nozzle 12; the height at the center of the extrusion nozzle 12 is less than the height at the periphery of the extrusion nozzle 12. In this embodiment, the extrusion nozzle 12 adopts a design with a low center and high ends. Specifically, the vertical distance between the upper and lower surfaces of the extrusion nozzle 12 is the height, and the height at the center of the extrusion nozzle 12 is less than the height at the edges of the extrusion nozzle 12. More specifically, along the direction extending from the center of the extrusion nozzle 12 to the edges, the height changes in the following trend: remaining constant and then gradually increasing. This design prevents the formation of dead zones in the raw material powder 3 during deformation.

[0040] Furthermore, the extrusion nozzle 12 includes a plurality of extrusion ports 121 , and the cross-sectional area S0 of the cavity and the cross-sectional area S2 of the plurality of extrusion ports 121 satisfy: S0 / S2>10.

[0041] In this embodiment, the cross-sectional area of ​​the cavity is significantly larger than that of the extrusion ports 121. The large-diameter extrusion die 5 design facilitates increased powder loading and improves production efficiency. Specifically, the cross-sectional area S0 of the cavity and the cross-sectional area S2 of the multiple extrusion ports 121 satisfy the following relationship: S0 / S2>10; preferably, S0 / S2>15; and more preferably, S0 / S2=20. It is worth noting that S2 is the sum of the cross-sectional areas of the multiple extrusion ports 121.

[0042] Furthermore, each extrusion port 121 is circumferentially arranged around the axis of the flow guiding structure 14 .

[0043] In this embodiment, the distance between any two adjacent extrusion ports 121 is equal, and each extrusion port 121 is axially arranged around the axis of the guide structure 14. The advantage of adopting this technical solution is that the force between the raw material powders 3 inside the extrusion die 5 is balanced, and various mechanical alloying processes such as mutual collision, shearing, and stretching are more uniform and dispersed, and the movement trajectory of the raw material powders 3 is more regular, which is conducive to improving the density of the wire.

[0044] Furthermore, a temperature control portion is provided on the outer periphery of the extrusion die 5 , and the temperature control portion is close to the extrusion portion; the temperature control portion includes a heating layer 6 and a heat insulation layer 7 .

[0045] In this embodiment, the extrusion die 5 can be divided into an upper section 501 and a lower section 502. During the specific implementation process, the lower section 502 of the extrusion die 5 needs to be heated. Specifically, the end closest to the extrusion portion is the lower section 502 of the extrusion die 5. The temperature control unit is arranged around the lower section 502 of the extrusion die 5, thereby ensuring more uniform heating of the extrusion die 5. In a specific implementation of this embodiment, the temperature control unit includes a heating layer 6 and an insulation layer 7 disposed outside the heating layer 6. The two-layer design enables precise temperature control.

[0046] In this embodiment, the segmented extrusion die 5 is designed so that the raw material powder 3 in the upper section is at a low temperature and low viscosity. This reduces oxidation of the powder, facilitates downward pressure transfer, and also protects the flux. The raw material powder 3 in the lower section of the extrusion die 5 is in a highly deformed region. Due to the heating, it softens at high temperatures, which promotes the plasticity of the raw material powder 3. The extrusion temperature and the extrusion deformation index are positively correlated; that is, the higher the extrusion deformation index, the higher the extrusion temperature.

[0047] Furthermore, the extrusion device also includes a material storage portion 4 and / or a material receiving portion 11; wherein the material storage portion 4 is used to store materials and transport the materials to the extrusion die 5; the material receiving portion 11 is close to the extrusion portion and is used to collect the extruded materials.

[0048] In this embodiment, in order to make the entire process more coherent and complete, a storage unit 4 and a receiving unit 11 are further provided. The storage unit 4 is provided near the extrusion unit, and the two can be connected by a pipeline. Generally speaking, the capacity of the storage unit 4 is much larger than the capacity of the cavity inside the extrusion unit, so as to achieve long-term continuous production, avoid the trouble caused by multiple feedings, and achieve a significant increase in production capacity. The receiving unit 11 is close to the extrusion unit. Specifically, the extrusion nozzle 12 includes multiple extrusion ports. Correspondingly, the receiving unit 11 can include multiple automatic winders for winding the filamentous solder from different extrusion ports.

[0049] Furthermore, the distance between the axis of any extrusion port 121 and the axis of the guide structure 14 is D, the straight segment 141b is a cylindrical structure with a radius of r1, and the fixed end 142 is a cylindrical structure with a radius of r2; wherein R1>D>R2.

[0050] In this embodiment, since the cross-sectional area of ​​the straight section 141b is large, a first space can be formed between the guide end 141 and the extrusion nozzle 12. Under the pressure of the pressure head 2, the material to be extruded moves to the upper surface of the guide end 141, that is, the guide section 141c, and moves along the surface of the guide end 141 to the first space. The specific movement trajectory is shown in FIG. Figure 1 R1 and R2 in the figure. This achieves a large rheological function, and the flow direction of the raw material powder 3 undergoes a significant change during the extrusion process. Therefore, the location of the extrusion port 121 is also particularly important. Specifically, r1>D>r2 must be satisfied. This facilitates shear and tensile deformation of the raw material powder 3 during the preparation of the filamentous solder, promoting welding and powder metallurgy synthesis of the raw material powder 3.

[0051] This embodiment further provides an extrusion system, including: a sealed cabin 8 and a vacuum pump 15 ; the sealed cabin 8 is used to accommodate the extrusion device provided by the above embodiment; the vacuum pump 15 is connected to the sealed cabin 8 .

[0052] In this embodiment, the extrusion system includes a sealed cabin 8 and a vacuum pump 15, which are used to provide a vacuum environment. Vacuuming helps eliminate oxygen and other gases between particles of the raw material powder 3, increases the bulk density of the raw material powder 3, reduces oxidation of the solder and flux during the extrusion process, and reduces the porosity in the extruded wire. Vacuum can be divided into high vacuum and low vacuum. Low vacuum is suitable for solder containing zinc and mixed powders that are not easily oxidized. It can prevent the volatilization of zinc and save vacuuming time, thereby improving production efficiency. High vacuum is suitable for mixed powders that are easily oxidized and have high usage requirements to improve product quality.

[0053] In a specific embodiment of this embodiment, a pad 13 is located below the extrusion nozzle 12 for supporting the extrusion nozzle 12. A push rod 9 and a support base 10 are located below the pad 13 for supporting the pad 13. The filament solder manufacturing apparatus further includes a vacuum pump 15 connected to the sealed cabin 8 for providing a vacuum environment.

[0054] This embodiment also provides a method for preparing filamentous solder, using the extrusion system of the above embodiment; the preparation method comprises the following steps:

[0055] S10: Under vacuum conditions, the raw material powder 3 is placed in the cavity, and the extrusion die 5 is heated to the extrusion temperature;

[0056] S20: Control the extrusion unit to maintain the first pressure for T time; then control the extrusion unit to extrude the raw material powder 3 into a filamentous solder at a first extrusion speed.

[0057] Furthermore, the vacuum environment can be divided into low vacuum and high vacuum. The vacuum degree of low vacuum is 1-10Pa, and the vacuum degree of high vacuum is 0.1-1Pa.

[0058] Furthermore, the raw material powder 3 includes solder and flux; wherein the particle size of the flux is smaller than that of the solder; the particle size of the flux is 100-325 meshes; and the particle size of the solder is 40-250 meshes.

[0059] Furthermore, the first pressure is 100-150 MPa, and the value range of T is 20-30 min.

[0060] In this embodiment, the solder and the flux are first prepared in a certain proportion, and then a mixer is used to evenly mix the two to obtain a mixed raw material powder 3 of the solder and the flux. The raw material powder 3 is loaded into the storage portion 4. Generally, the storage portion 4 can be an automatic feeder, which can automatically convey the raw material powder 3 to the extrusion die 5. The entire extrusion device is arranged in a sealed cabin 8. The sealed cabin 8 can be evacuated to a specific vacuum degree by opening the valve of the vacuum pump 15. Then the temperature control portion is adjusted to heat the extrusion die 5 to the extrusion temperature. The extrusion temperature varies according to the characteristics of the solder and the flux. For example, when the raw material powder 3 is an aluminum silicon solder, the extrusion temperature is preferably 400-470°C; therefore, the extrusion temperature is not specifically limited in this embodiment, and those skilled in the art can adjust it according to actual needs.

[0061] When the extrusion die 5 reaches the extrusion temperature, the pressure head 2 is controlled to press down, generating a first pressure on the raw material powder 3 and maintaining it for T time. Preferably, the first pressure is 100-150MPa, and the value range of T is 20-30min. In order to facilitate the application of pressure to the pressure head 2, generally speaking, the end of the pressure head 2 extends out of the sealed cabin 8, and a dynamic seal 1 is used between the sealed cabin 8 and the pressure head 2, so as to ensure that the vacuum degree in the sealed cabin 8 remains unchanged as the pressure head 2 is pressed down. Then the pressure head 2 is controlled to extrude the raw material powder 3 in the extrusion die 5 at a first extrusion speed. The raw material powder 3 is filamentous after being formed through the extrusion hole of the extrusion nozzle 12; the extruded filamentous solder is wound up through the receiving part 11. In a specific embodiment of this embodiment, there is a pad 13 under the extrusion nozzle 12 for supporting the extrusion nozzle 12. There are a push rod 9 and a support seat 10 under the pad 13, both of which are used to support the pad 13.

[0062] Furthermore, when the pressure head 2 is pressed down to the set value, it returns and rises back to the initial position. The storage section 4 continues to add the raw material powder 3 to the extrusion die 5, and repeats the above steps until the receiving section 11 is fully loaded and stops working. When the temperature of the extrusion die 5 drops to 60°C-80°C, the vacuum environment of the sealed cabin 8 is released, the wound filamentary solder is taken out and refilled with the storage section 4, and the continuous production of the filamentary solder can be achieved. The wound filamentary solder is drawn at room temperature and atmospheric environment to obtain a finished wire material with a smooth surface and high quality.

[0063] In the above scheme, the purpose of heating is to bring the solder powder above its recrystallization temperature, thereby increasing its deformability and reducing the pressure required for extrusion. Maintaining pressure for a period of time helps eliminate the pores between the powders and significantly reduces the porosity in the compact. This further increases the density of the extruded blank, laying a good foundation for subsequent drawing of high-quality wire. The provision of the storage section 4 and the receiving section 11 allows for continuous production of wire in a vacuum environment, significantly increasing production capacity.

[0064] Example 2

[0065] This embodiment provides a method for preparing a filamentous solder, comprising the following steps:

[0066] 1. 100-mesh aluminum-silicon brazing filler metal (88 wt.% aluminum and 12 wt.% silicon, respectively) and 300-mesh brazing flux (45 wt.% potassium fluoroaluminate, 45 wt.% potassium fluorosilicate, and 10 wt.% cesium fluoroaluminate) were mixed in a mixer at a volume ratio of 8:2 to obtain a raw material powder. The raw material powder was then placed in a hopper, which then conveyed it to the extrusion die.

[0067] 2. Place the extrusion die in a sealed cabin, turn on the vacuum pump to reduce the vacuum degree in the sealed cabin to 0.1 Pa, and then adjust the temperature control device to raise the temperature of the lower section of the extrusion die to 400°C.

[0068] 3. Control the downward pressure of the ram, applying a pressure of 100 MPa to the raw material powder in the extrusion die and maintaining the pressure for 20 minutes. The ram then presses down at a speed of 1 mm / min to extrude the raw material powder in the extrusion die. The extruded filament passes through the receiving section for continuous winding.

[0069] 4. The ram returns to its initial position after being pressed down to the set value. The material storage unit continues to add raw material powder to the extrusion die and repeats the above steps until the material receiving unit is full and stops working.

[0070] When the temperature of the extrusion die drops to 70°C, the vacuum environment is released, the wound filamentous solder is taken out, and the storage part is refilled.

[0071] 5. The wound filamentous solder is drawn to a wire diameter of φ2.0 mm at room temperature to obtain the finished wire.

[0072] Example 3

[0073] This embodiment provides a method for preparing a filamentous solder, comprising the following steps:

[0074] 1. Prepare a 50-mesh aluminum-silicon-zinc brazing filler metal (containing 63 wt.%, 6.7 wt.%, and 30.4 wt.% aluminum, silicon, and zinc, respectively) and a 200-mesh brazing flux (containing 45 wt.% potassium fluoroaluminate, 45 wt.% potassium fluorosilicate, and 10 wt.% cesium fluoroaluminate) in a volume ratio of 8:2. Mix the two in a mixer to obtain a raw powder. This powder is then placed in a hopper, which then conveys it to the extrusion die.

[0075] 2. Place the extrusion die in a sealed cabin, turn on the vacuum pump to reduce the vacuum degree in the sealed cabin to 1 Pa, and then adjust the temperature control device to raise the temperature of the lower section of the extrusion die to 450°C.

[0076] 3. Control the downward pressure of the ram, applying a pressure of 150 MPa to the raw material powder in the extrusion die and maintaining the pressure for 25 minutes. The ram then presses down at a speed of 1 mm / min to extrude the raw material powder in the extrusion die. The extruded filament passes through the receiving section for continuous winding.

[0077] 4. The ram returns to its initial position after being pressed down to the set value. The material storage unit continues to add raw material powder to the extrusion die and repeats the above steps until the material receiving unit is full and stops working.

[0078] When the temperature of the extrusion die drops to 80°C, the vacuum environment is released, the wound filamentous solder is taken out, and the storage part is refilled.

[0079] 5. The wound filamentous solder is drawn to a wire diameter of φ2.0 mm at room temperature to obtain the finished wire.

[0080] Example 4

[0081] This embodiment provides a method for preparing a filamentous solder, comprising the following steps:

[0082] 1. Prepare a 70-mesh aluminum-silicon-copper brazing filler metal (containing 66 wt.%, 6 wt.%, and 28 wt.% aluminum, silicon, and copper, respectively) and a 250-mesh brazing flux (45 wt.% potassium fluoroaluminate, 45 wt.% potassium fluorosilicate, and 10 wt.% cesium fluoroaluminate) in a volume ratio of 8:2. Mix the two in a mixer to obtain a raw powder. This powder is then placed in a hopper, which then conveys it to the extrusion die.

[0083] 2. Place the extrusion die in a sealed cabin, turn on the vacuum pump to reduce the vacuum level in the sealed cabin to 10 Pa, and then adjust the temperature control device to raise the temperature of the lower section of the extrusion die to 470°C.

[0084] 3. Control the downward pressure of the ram, applying a pressure of 150 MPa to the raw material powder in the extrusion die and maintaining the pressure for 25 minutes. The ram then presses down at a speed of 1 mm / min to extrude the raw material powder in the extrusion die. The extruded filament passes through the receiving section for continuous winding.

[0085] 4. The ram returns to its initial position after being pressed down to the set value. The material storage unit continues to add raw material powder to the extrusion die and repeats the above steps until the material receiving unit is full and stops working.

[0086] When the temperature of the extrusion die drops to 60°C, the vacuum environment is released, the wound filamentous solder is taken out, and the storage part is refilled.

[0087] 5. The wound filamentous solder is drawn to a wire diameter of φ2.0 mm at room temperature to obtain the finished wire.

[0088] The following table is a performance comparison table of the examples and the corresponding commercially available composite solders. It can be seen from the table that the samples prepared by the present invention have improvements of about 13% and 20% in wettability and spreadability and wire tensile strength compared with the commercially available composite solders.

[0089]

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. An extrusion device, characterized in that: include: An extrusion die (5), a pressing head (2) and an extrusion nozzle (12); One end of the extrusion die (5) is an extrusion portion, and the other end is an extrusion portion; the pressure head (2) is provided at the extrusion portion, and the extrusion nozzle (12) is provided at the extrusion portion; the extrusion die (5), the pressure head (2), and the extrusion nozzle (12) together form a cavity for accommodating material; The extrusion device further comprises a flow guiding structure (14), wherein the flow guiding structure (14) is provided on the extrusion portion; The guide structure (14) comprises a guide end (141) and a fixed end (142) arranged above and below; the maximum value of the cross-sectional area of ​​the guide end (141) is greater than the maximum value of the cross-sectional area of ​​the fixed end (142); Along a direction away from the fixed end (142), the flow guide end (141) sequentially comprises a transition section (141a), a straight section (141b), and a guide section (141c); The cross-sectional area S0 of the cavity in the horizontal direction and the cross-sectional area S1 of the straight line segment (141b) in the horizontal direction satisfy: S0 / S1=1.25-2; The transition section (141a) connects the straight section (141b) and the fixed end (142); the cross-sectional area of ​​the transition section (141a) in the horizontal direction gradually increases in a direction away from the fixed end (142); The guide section (141c) is a curved surface that convexly extends in a direction away from the straight section (141b); The distance between the axis of the extrusion port (121) of any one of the extrusion nozzles (12) and the axis of the flow guide structure (14) is D, the straight line segment (141b) is a cylindrical structure with a radius of R1, and the fixed end (142) is a cylindrical structure with a radius of R2; R1>D>R2; The extrusion nozzle (12) includes a plurality of extrusion ports (121), and the cross-sectional area S0 of the cavity and the total cross-sectional area S2 of the plurality of extrusion ports (121) satisfy: S0 / S2>10; wherein each of the extrusion ports (121) is circumferentially arranged around the axis of the flow guide structure (14).

2. The extrusion device according to claim 1, characterized in that The vertical distance between the upper surface and the lower surface of the extrusion nozzle (12) is the height of the extrusion nozzle (12); wherein the height of the center position of the extrusion nozzle (12) is less than the height of the periphery of the extrusion nozzle (12); And / or, the extrusion die (5) comprises an upper section (501) and a lower section (502); a temperature control portion is provided on the outer periphery of the lower section (502), and the temperature control portion comprises a heating layer (6) and a heat-insulating layer (7); And / or, the extrusion device further includes: a material storage portion (4), and / or, a material receiving portion (11); wherein the material storage portion (4) is used to store the material and transport the material to the extrusion die (5); the material receiving portion (11) is close to the extrusion portion and is used to collect the material after extrusion.

3. An extrusion system, characterized in that: include: Sealed cabin (8) and vacuum pump (15); The sealed cabin (8) is used to accommodate the extrusion device according to any one of claims 1-2; The vacuum pump (15) is connected to the sealed cabin (8); One end of the pressure head (2) is connected to the extrusion die (5), and the other end extends out of the sealing chamber (8); a dynamic seal (1) is used between the pressure head (2) and the sealing chamber (8).

4. A method for preparing a filamentous solder, characterized in that: Using the extrusion system as claimed in claim 3; The preparation method comprises the following steps: S10: placing raw material powder in the cavity under a vacuum environment, and heating the extrusion die to an extrusion temperature; S20: controlling the pressing head to maintain a first pressure for T time; and then controlling the pressing head to extrude the raw material powder into the filamentous solder at a first extrusion speed.

5. The preparation method according to claim 4, characterized in that The vacuum environment can be divided into low vacuum and high vacuum. The vacuum degree of the low vacuum is 1-10 Pa, and the vacuum degree of the high vacuum is 0.1-1 Pa.

6. The preparation method according to claim 4, characterized in that The raw material powder includes brazing material and brazing flux; Wherein, the particle size of the flux is smaller than the particle size of the solder; The particle size of the flux is 100-325 meshes; the particle size of the solder is 40-250 meshes.

7. The preparation method according to claim 4, characterized in that The first pressure is 100-150 MPa, and the value range of T is 20-30 min.

8. A filamentous solder, characterized in that: The product is prepared by the preparation method according to any one of claims 4 to 7.

Images