A cemented carbide microporous tin nozzle and microporous generation method

Abstract

The invention discloses a cemented carbide microporous tin nozzle and a microporous generation method, comprising the steps of calcining and crushing a raw material ammonium paratungstate multiple times to form tungsten oxide powder, reducing, wherein the reduction carbonization temperature is 900°C-1080°C; mixing the tungsten carbide, cobalt, vanadium carbide, chromium carbide, tantalum carbide, metal rhenium, metal nickel, metal niobium and zirconium oxide in proportion to form a mixed powder; adding an organic monomer, a dispersant, an initiator and an aqueous solution to convert the mixture into an aqueous suspension; injecting the aqueous suspension into a prefabricated microporous mold by a gel injection molding method to obtain a solid microporous tin nozzle blank; performing impurity removal pre-sintering and vacuum pre-sintering, and finally stopping the furnace for cooling to obtain a microporous tin nozzle rough blank; processing the microporous tin nozzle rough blank to form a cemented carbide microporous tin nozzle. In the technical solution of the invention, the powder is formed into an aqueous suspension, which is then injected into a prefabricated microporous mold and sintered to form a microporous product, so that smaller micropores can be achieved while the inner hole precision is high, so as to meet the existing high-end industry needs.

Description

Technical Field

[0001] The invention relates to the technical field of micropore forming of cemented carbide, and in particular to a cemented carbide micropore tin nozzle and a micropore forming method. Background Art

[0002] Cemented carbide is mainly composed of micron-sized powder of carbide (WC, TiC) of high-hardness refractory metal, with cobalt (Co) or nickel (Ni) and molybdenum (Mo) as binders; existing microporous cemented carbide is generally used in the tin nozzle of tinning machine or wire drawing die, etc. The quality of microporous cemented carbide directly affects the effect of tinning machine and wire drawing die, and the existing microporous cemented carbide forming process is generally up and down pressing forming or laser perforation forming; up and down pressing forming refers to the forming of raw material powder by up and down pressing of the mold, and the powder resistance is large, which is easy to hinder the forming, resulting in the mold The core rod is easy to break, and it is difficult to achieve the smallest microhole, resulting in the minimum formed hole diameter of about 0.10mm and the surface roughness of about Ra1.6; laser perforation forming is to form the inner hole on the cemented carbide blind hole blank by laser perforation. The high melting point during laser perforation will destroy the performance structure of the cemented carbide material and affect the service life. The production cost is high and the efficiency is low. The minimum formed hole diameter is about 0.05mm and the surface roughness is about Ra3.2; Therefore, a new process is needed to achieve smaller microholes on cemented carbide products with high inner hole precision to meet the needs of existing high-end industries. Summary of the invention

[0003] The main purpose of the present invention is to provide a method for generating micropores of a cemented carbide micropore tin nozzle, aiming to solve the problem that the existing process cannot achieve smaller micropores on cemented carbide products while having high inner hole precision to meet the needs of existing high-end industries.

[0004] To achieve the above object, the present invention provides a method for generating micropores of a cemented carbide micropore tin nozzle, comprising the following steps:

[0005] The raw material ammonium paratungstate is calcined and crushed multiple times to form tungsten oxide powder, and argon gas is introduced to reduce the tungsten oxide powder after carbonization to form tungsten carbide powder, wherein the reduction and carbonization temperature is 900°C-1080°C;

[0006] The tungsten carbide, metal cobalt, vanadium carbide, chromium carbide, tantalum carbide, metal rhenium, metal nickel, metal niobium and zirconium oxide are added in a weight percentage of 90% to 99%: 0.05% to 10%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.4%: 0.05%-10%: 0.1%-0.5%: 0.1-0.5%, and ethanol and polyethylene glycol are added for wet grinding and mixing to form a mixed powder;

[0007] Adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer and convert the mixed powder into an aqueous suspension;

[0008] After adding the initiator to the aqueous suspension, the initiator is injected into the prefabricated microporous mold, and the initiator is cured according to the corresponding initiation conditions provided by the initiator. After curing, the initiator is demoulded to obtain a solid microporous tin nozzle blank:

[0009] The microporous tin nozzle blank formed by injection molding is placed in a pre-sintering furnace for removing impurities, and then vacuum sintered. Finally, the furnace is stopped for cooling to obtain a microporous tin nozzle rough blank.

[0010] Preferably, after the step of placing the microporous tin nozzle blank formed by injection molding into a pre-sintering furnace for impurity removal, performing pre-sintering for impurity removal, performing vacuum sintering, and finally stopping the furnace for cooling to obtain a rough microporous tin nozzle blank, the following steps are included:

[0011] Perform metallographic inspection and size profile inspection on the cemented carbide microporous tin nozzle by physical and high-definition electron microscope, and judge whether the microporous tin nozzle rough blank is qualified according to the physical performance index parameter data;

[0012] The rough blank of microporous tin nozzle is subjected to precision grinding and polishing to form a fine blank of microporous tin nozzle;

[0013] The contour dimensions and appearance of the microporous tin nozzle blank are inspected by physical and high-definition electron microscopes.

[0014] Preferably, the physical performance index parameters in the step of performing metallographic inspection and size profile inspection on the cemented carbide microporous tin nozzle by physical and high-definition electron microscope and judging whether the microporous tin nozzle rough blank is qualified according to the physical performance index parameter data include: product bending strength of 3000-3400N / mm2; product coercive force of 42-46kA / m; product density of 14.6-15.2g / cm3; product porosity of A02B00C00; product Vickers hardness of 2000-2300HV30; product tungsten carbide grain size of 100-400nm.

[0015] Preferably, the step of placing the injection-molded microporous tin nozzle blank into a pre-sintering furnace for impurity removal, performing vacuum sintering, and finally stopping the furnace for cooling to obtain a microporous tin nozzle rough blank comprises:

[0016] The microporous tin nozzle blank formed by injection molding is placed in a high-temperature resistant boat, and placed in a de-doping pre-sintering furnace for argon pre-sintering, wherein: the argon de-doping temperature is finally controlled at 550°C-650°C, and the argon de-doping insulation time is 110-130 minutes; the vacuum pre-sintering temperature is 750°C-950°C, and the vacuum pre-sintering insulation time is 40-100 minutes; finally, the furnace is stopped for cooling to obtain the semi-finished microporous tin nozzle blank;

[0017] The semi-finished microporous tin nozzle blank is packed in a high temperature resistant boat and placed in a 6-11Mpa pressure sintering furnace for vacuum overpressure high temperature sintering, wherein: the high temperature sintering temperature is controlled at 1400℃-1500℃, and the pressurization time of 10Mpa is 120 minutes; the furnace is stopped for cooling, and finally the microporous tin nozzle blank is obtained by stopping the furnace for cooling.

[0018] Preferably, the organic monomer includes dimethyldichlorosilane or phenylchlorosilane; the dispersant includes sodium tripolyphosphate, sodium hexametaphosphate or sodium pyrophosphate; the initiator includes azobisisobutyronitrile, diacyl peroxide or persulfate; the aqueous solution includes ether or ethanol, wherein; the function of the dispersant is to reduce the time and energy required to complete the dispersion process, the aqueous solution allows the mixed powder to become the aqueous suspension, stabilizes the dispersed powder slurry, and improves the fluidity of the aqueous suspension, the initiator is used to initiate the polymerization of the organic monomer, transforming small molecules into large molecules, and finally forming a polymer three-dimensional network structure, and finally transforming the aqueous suspension into a solid state.

[0019] Preferably, the step of injecting the aqueous suspension into a prefabricated microporous mold by gel injection molding, providing corresponding initiation conditions according to the initiator, thereby obtaining a solid microporous tin nozzle blank, comprises:

[0020] The aqueous suspension is injected into the prefabricated microporous mold by an injection machine;

[0021] The heating temperature is to the initiation temperature, and the initiation condition corresponding to the initiator is that the initiation temperature is 40° C.-100° C., so that the aqueous suspension becomes solid, and after solidification, demoulding is performed to obtain a solid microporous tin nozzle blank.

[0022] Preferably, the step of adding an organic monomer, a dispersant, an initiator and an aqueous solution to the ball-milled mixed powder to mix the organic monomers and convert the mixed powder into an aqueous suspension comprises:

[0023] Adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer;

[0024] The mixed liquid is mixed into a ball mill for ball milling;

[0025] The initiator is added to form an aqueous suspension.

[0026] The present invention also provides a cemented carbide microporous tin nozzle, which is produced by the micropore generation method of any of the above cemented carbide microporous tin nozzles, comprising a straight section and a tapered section, the inner diameter and outer diameter of the end of the tapered section away from the straight section gradually decrease, the outer diameter of the straight section is 1.8-2.4mm, and the length of the straight section is 3-5mm; the inner diameter of the end of the straight section away from the tapered section is 1.4-2.0mm, the inner wall length of the straight section is 2.5-4.0mm, the inner wall angle of the straight section is 0°~5°, the outer wall taper of the tapered section is 20°~40°, the inner wall taper of the tapered section is 10°~30°, and the inner diameter of the end of the tapered section away from the straight section is 0.04mm-1mm.

[0027] Preferably, the smoothness of the inner walls of the straight tube section and the tapered section and the smoothness of the outer diameter are 0.1 μm to 0.4 μm; the smoothness of the end surface of the tapered section away from the straight tube section is 0.05 μm to 0.2 μm.

[0028] In the technical scheme of the present invention, the raw materials are selected to strictly control the coarseness and improve the subsequent ultrafine WC powder. An aqueous suspension is formed by adding organic monomers, dispersants, initiators and aqueous solutions. The aqueous suspension is then injected into a prefabricated microporous mold by a gel injection molding method. After that, a microporous product is formed by pre-sintering and vacuum sintering. Smaller micropores can be achieved on cemented carbide products with high inner hole precision to meet the existing high-end industry needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0030] Figure 1 The present invention is a flowchart of a method for generating micropores of a cemented carbide micropore tin nozzle.

[0031] Figure 2 It is a technical parameter comparison diagram of the micropore forming method of the cemented carbide micropore tin nozzle of the present invention and the forming method of the prior art.

[0032] Figure 3 This is a comparison chart of the physical parameters of the alloy nozzle part of the micropore generation method of the cemented carbide micropore tin nozzle of the present invention and the physical parameters of the alloy nozzle part of the prior art (for tinning).

[0033] Figure 4The figure is a comparison diagram between the alloy metallographic phase of the micropore generation method of the cemented carbide micropore tin nozzle of the present invention and the alloy metallographic phase of the prior art.

[0034] Figure 5 The figure is a comparison chart of the alloy part performance of the micropore generation method of the cemented carbide micropore tin nozzle of the present invention and the alloy part performance of the prior art.

[0035] Figure 6 It is a structural diagram of the cemented carbide micro-hole nozzle of the present invention.

[0036] Figure 7 It is a schematic diagram of the structure of the cemented carbide micro-hole nozzle of the present invention.

[0037] Figure 8 This is a comparison chart of the physical parameters of the alloy nozzle part of the micropore generation method of the cemented carbide micropore tin nozzle of the present invention and the physical parameters of the alloy nozzle part of the prior art (used for drawing steel cord with a micropore wire drawing die).

[0038] Fig. 9 The present invention is a schematic flow diagram of a method for generating micropores of a cemented carbide micropore tin nozzle.

[0039] Description of Figure Numbers:

[0040] 1. Straight section; 2. Conical section.

[0041] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0047] Please refer to Figure 1-Figure 9 The present invention provides a method for generating micropores of a cemented carbide micropore tin nozzle, comprising the following steps:

[0048] S100, calcining and crushing the raw material ammonium paratungstate multiple times to form tungsten oxide powder, introducing argon gas to mix the tungsten oxide powder with carbon and then reducing it to form tungsten carbide powder, wherein the reduction and carbonization temperature is 900° C.-1080° C.;

[0049] S200, adding the tungsten carbide, metal cobalt, vanadium carbide, chromium carbide, tantalum carbide, metal rhenium, metal nickel, metal niobium and zirconium oxide according to the weight percentage of 90% to 99%: 0.05% to 10%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.4%: 0.05%-10%: 0.1%-0.5%: 0.1-0.5%, and wet grinding and mixing to form a mixed powder;

[0050] S300, adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer and convert the mixed powder into an aqueous suspension;

[0051] S400, adding an initiator to the aqueous suspension and then injecting it into a prefabricated microporous mold, providing corresponding initiation conditions according to the initiator for curing, and demoulding after curing to obtain a solid microporous tin nozzle blank:

[0052] S500, placing the microporous tin nozzle blank formed by injection molding into a pre-sintering furnace for impurity removal, performing pre-sintering for impurity removal, and then performing vacuum sintering, and finally stopping the furnace for cooling to obtain a microporous tin nozzle rough blank.

[0053] In the technical scheme of the present invention, the raw materials are selected to strictly control the coarseness and improve the subsequent ultrafine WC powder. An aqueous suspension is formed by adding organic monomers, dispersants, initiators and aqueous solutions. The aqueous suspension is then injected into a prefabricated microporous mold by a gel injection molding method. After that, a microporous product is formed by pre-sintering and vacuum sintering. Smaller micropores can be achieved on cemented carbide products with high inner hole precision to meet the existing high-end industry needs.

[0054] Specifically, the microporous molding method is used to mix the raw materials, organic monomers, dispersants, etc. to convert the powder into an aqueous suspension. The microporous mold core rod has no resistance during the injection molding process, which can make the microporous mold easy to mold and demold, which is beneficial to the mass production of cemented carbide microporous products and achieve smaller micropores.

[0055] Specifically, during the impurity removal pre-firing, the added ethanol, polyethylene glycol and initiator are pre-firing to remove these impurities and prevent these impurities from affecting the sintering quality of tungsten carbide.

[0056] Specifically, adding 0.2% to 0.8% of vanadium carbide improves wear resistance and inhibits the growth of tungsten carbide, adding 0.2% to 0.8% of chromium carbide improves corrosion resistance and oxidation resistance, adding 0.2% to 0.8% of tantalum carbide improves the toughness of the microporous tin nozzle rough blank, adding 0.1% to 0.4% of metal rhenium to resist high temperature and improve the thermal conductivity of the microporous tin nozzle rough blank, which is suitable for high temperature working environment, metal nickel can improve the thermal strength and corrosion resistance of steel, adding metal niobium can achieve the effect of strengthening steel, and high-temperature alloys containing niobium have high-temperature stability, zirconium oxide is added to cemented carbide, and the bending strength of the alloy is improved, and polyethylene glycol is used for cemented carbide powder forming.

[0057] By optimizing the raw materials, strictly controlling the inclusion of coarse particles and increasing the subsequent carbonization temperature of ultrafine WC powder, the inclusion of coarse particles and coarse particles in the alloy metallographic structure can be reduced. At the same time, after multiple calcinations of the APT raw materials and increasing the carburization temperature, the grain distribution of tungsten carbide is uniform, and the alloy is made without grains larger than 3um. The collapse resistance and stability of the alloy are significantly improved, thereby ensuring the size of the formed micropores with higher precision.

[0058] In another embodiment of the present invention, the step of S500 includes:

[0059] S510, performing metallographic inspection and size profile inspection on the cemented carbide microporous tin nozzle by physical and high-definition electron microscopes, and judging whether the microporous tin nozzle rough blank is qualified according to physical performance index parameter data;

[0060] S520, performing precision grinding and polishing on the rough blank of the microporous tin nozzle to form a fine blank of the microporous tin nozzle;

[0061] S530, uses physical and high-definition electron microscopes to inspect the contour dimensions and appearance of microporous tin nozzle blanks.

[0062] In another embodiment of the present invention, the physical performance index parameters in the S510 step include: product bending strength of 3000-3400N / mm2; product coercive force of 42-46kA / m; product density of 14.6-15.2g / cm3; product porosity of A02B00C00; product Vickers hardness of 2000-2300HV30; product tungsten carbide grain size of 100-400nm.

[0063] Specifically, the product's flexural strength, coercive force, product density, porosity, Vickers hardness and tungsten carbide grain size are important bases for judging alloy products, and can also ensure product performance, such as corrosion resistance, wear resistance and crack resistance.

[0064] In another embodiment of the present invention, the step of S500 includes:

[0065] S501, the microporous tin nozzle blank formed by injection molding is placed in a high temperature resistant boat, and placed in a de-doping pre-sintering furnace for argon pre-sintering, wherein: the argon de-doping temperature is finally controlled at 550°C-650°C, and the argon de-doping insulation time is 110-130 minutes; the vacuum pre-sintering temperature is 750°C-950°C, and the vacuum pre-sintering insulation time is 40-100 minutes; finally, the furnace is stopped for cooling to obtain a semi-finished microporous tin nozzle blank;

[0066] S502, pack the semi-finished microporous tin nozzle rough blank into a high temperature resistant boat, and put it into a 6Mpa-11Mpa pressure sintering furnace for vacuum overpressure high temperature sintering, wherein: the high temperature sintering temperature is controlled at 1400℃-1500℃, and the pressurization time of 10Mpa is 120 minutes; stop the furnace for cooling, and finally stop the furnace for cooling to obtain the microporous tin nozzle rough blank.

[0067] Specifically, when the existing WC powder is used to prepare alloy products, after the sintering temperature is increased, more 2-3μm and some 3-5μm inclusions often appear in the metallographic phase; by optimizing the raw materials, strictly controlling the inclusions and increasing the subsequent ultrafine WC powder carbonization temperature, the inclusions and coarse particles in the alloy metallographic phase can be reduced. However, in the current carburization process, when the carburization temperature exceeds 1400°C, the alloy small ball mill test of tungsten carbide powder will show a more serious inclusion phenomenon. Therefore, the tungsten carbide powder formed after multiple calcinations can withstand higher temperatures in the subsequent carburization process, but reduce the inclusion phenomenon, thereby reducing the metallographic particle size and improving the performance of the alloy product.

[0068] In another embodiment of the present invention, the organic monomer includes dimethyldichlorosilane or phenylchlorosilane; the dispersant includes sodium tripolyphosphate, sodium hexametaphosphate or sodium pyrophosphate; the initiator includes azobisisobutyronitrile, diacyl peroxide or persulfate; the aqueous solution includes ether or ethanol, wherein; the function of the dispersant is to reduce the time and energy required to complete the dispersion process, the aqueous solution allows the mixed powder to become the aqueous suspension, stabilizes the dispersed powder slurry, and improves the fluidity of the aqueous suspension, the initiator is used to initiate the polymerization of the organic monomer, transforming small molecules into large molecules, and finally forming a polymer three-dimensional network structure, and finally transforming the aqueous suspension into a solid state.

[0069] Specifically, the organic monomer is a simple compound of a polymer compound formed by a polymerization reaction. The role of the dispersant is to use a wetting dispersant to reduce the time and energy required to complete the dispersion process; the aqueous solution allows the mixed powder to become the aqueous suspension to stabilize the dispersed powder slurry and improve the fluidity of the aqueous suspension. The initiator is used to initiate the polymerization of the organic monomer, transforming small molecules into large molecules, and finally forming a polymer three-dimensional network structure, and finally transforming the aqueous suspension into a solid state.

[0070] In another embodiment of the present invention, the step S400 includes:

[0071] S410, injecting the aqueous suspension into a prefabricated microporous mold through an injection machine;

[0072] S420, heating the temperature to the initiation temperature, the initiation condition corresponding to the initiator is the initiation temperature of 40°C-100°C, so that the aqueous suspension becomes solid, and demolding is performed after solidification to obtain a solid microporous tin nozzle blank.

[0073] Specifically, the initiator includes azobisisobutyronitrile, diacyl peroxide or persulfate. The initiation condition of the initiator is a temperature of 40°C-100°C, which is generally not reachable at room temperature, preventing direct initiation at ambient temperature. At the same time, when the initiation temperature is 40°C-100°C, the required heating temperature is not high, the heating difficulty is low, and the damage to the mold can be reduced, while preventing errors caused by thermal expansion.

[0074] In another embodiment of the present invention, the step of S300 includes:

[0075] S310, adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer;

[0076] S320, mixing the mixed liquid into a ball mill for ball milling;

[0077] S330, adding an initiator to form an aqueous suspension.

[0078] Specifically, after the mixed powder after ball milling is added with organic monomer, dispersant and aqueous solution to mix the organic monomer, the mixed liquid is mixed into a ball mill for ball milling to form a stable and uniform suspension, while preventing accidental initiation, and adding the initiator before injection into the microporous mold.

[0079] Please refer to Figure 7 and Figure 8 The present invention also includes a cemented carbide microporous nozzle, a cemented carbide microporous tin nozzle is produced by the micropore generation method of any of the cemented carbide microporous tin nozzles described above, comprising a straight section 1 and a tapered section 2, the inner diameter and outer diameter of the end of the tapered section 2 away from the straight section 1 are gradually reduced, the outer diameter of the straight section 1 is 1.8mm-2.4mm, and the length of the straight section 1 is 3mm-5mm; the inner diameter of the end of the straight section 1 away from the tapered section 2 is 1.4mm-2.0mm, the inner wall length of the straight section 1 is 2.5mm-4.0mm, the inner wall angle of the straight section 1 is 0°~5°, the outer wall taper of the tapered section 2 is 20°~40°, the inner wall taper of the tapered section 2 is 10°~30°, and the inner diameter of the end of the tapered section 2 away from the straight section 1 is 0.04mm-1mm.

[0080] In another embodiment of the present invention, a cemented carbide microporous tin nozzle, the smoothness of the inner walls of the straight section 1 and the tapered section 2 and the smoothness of the outer diameter are 0.1ym to 0.4ym; the smoothness of the end face of the tapered section 2 away from the straight section 1 is 0.05ym to 0.2ym.

[0081] In another embodiment of the present invention, the degree of smoothness affects the service life and smoothness during use. The cemented carbide micro-hole nozzle of the present application can be used continuously for 600,000 times without tinning, and can produce solder balls for more than 500,000 times.

[0082] In another embodiment of the present invention, the microporous mold is made of a light-transmitting material, and the initiator includes a light-triggered initiator.

[0083] Specifically, errors caused by thermal expansion and contraction can be prevented by light initiation.

[0084] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A method for generating micropores of a cemented carbide micropore tin nozzle, characterized in that: The steps include: The raw material ammonium paratungstate is calcined and crushed multiple times to form tungsten oxide powder, and argon gas is introduced to reduce the tungsten oxide powder after carbonization to form tungsten carbide powder, wherein the reduction and carbonization temperature is 900°C-1080°C; The tungsten carbide, metal cobalt, vanadium carbide, chromium carbide, tantalum carbide, metal rhenium, metal nickel, metal niobium and zirconium oxide are added in a weight percentage of 90% to 99%: 0.05% to 10%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.8%: 0.1% to 0.4%: 0.05%-10%: 0.1%-0.5%: 0.1-0.5%, and wet-grinded and mixed to form a mixed powder; Adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer and convert the mixed powder into an aqueous suspension; After adding the initiator to the aqueous suspension, the initiator is injected into the prefabricated microporous mold, and the initiator is cured according to the corresponding initiation conditions provided by the initiator. After curing, the initiator is demoulded to obtain a solid microporous tin nozzle blank: The microporous tin nozzle blank formed by injection molding is placed in a pre-sintering furnace for removing impurities, and then vacuum sintered. Finally, the furnace is stopped for cooling to obtain a microporous tin nozzle rough blank.

2. The micropore generation method of a cemented carbide micropore tin nozzle according to claim 1, characterized in that: After the step of placing the microporous tin nozzle blank formed by injection molding into a pre-sintering furnace for impurity removal, pre-sintering for impurity removal, vacuum sintering, and finally stopping the furnace for cooling to obtain a rough microporous tin nozzle blank, the method comprises: Perform metallographic inspection and size profile inspection on the cemented carbide microporous tin nozzle by physical and high-definition electron microscope, and judge whether the microporous tin nozzle rough blank is qualified according to the physical performance index parameter data; The rough blank of microporous tin nozzle is subjected to precision grinding and polishing to form a fine blank of microporous tin nozzle; The contour dimensions and appearance of the microporous tin nozzle blank are inspected by physical and high-definition electron microscopes.

3. The method for generating micropores of a cemented carbide micropore tin nozzle according to claim 2, characterized in that: The physical performance index parameters in the step of performing metallographic inspection and size profile inspection on the cemented carbide microporous tin nozzle by physical and high-definition electron microscope and judging whether the microporous tin nozzle rough blank is qualified according to the physical performance index parameter data include: the product bending strength is 3000-3400N / mm 2 ; Product coercive force is 42~46kA / m; Product density is 14.6~15.2g / cm 3 ; The product porosity is A02B00C00; the product Vickers hardness is 2000~2300HV30; the product tungsten carbide grain size is 100~400nm.

4. The method for generating micropores of a cemented carbide micropore tin nozzle according to claim 1, characterized in that: The steps of placing the injection-formed microporous tin nozzle blank into a pre-sintering furnace for impurity removal, performing pre-sintering for impurity removal, performing vacuum sintering, and finally stopping the furnace for cooling to obtain a rough microporous tin nozzle blank include: The microporous tin nozzle blank formed by injection molding is placed in a high-temperature resistant boat, and placed in a de-doping pre-sintering furnace for argon pre-sintering, wherein: the argon de-doping temperature is finally controlled at 550°C-650°C, and the argon de-doping insulation time is 110-130 minutes; the vacuum pre-sintering temperature is 750°C-950°C, and the vacuum pre-sintering insulation time is 40-100 minutes; finally, the furnace is stopped for cooling to obtain the semi-finished microporous tin nozzle blank; The semi-finished microporous tin nozzle blank is packed in a high temperature resistant boat and placed in a 6-11MPa pressure sintering furnace for vacuum overpressure high temperature sintering, wherein: the high temperature sintering temperature is controlled at 1400°C-1500°C, and the pressurization time of 10MPa is 120 minutes; finally, the furnace is stopped for cooling to obtain the microporous tin nozzle blank.

5. The method for generating micropores of a cemented carbide micropore tin nozzle according to claim 1, characterized in that: The organic monomer includes dimethyldichlorosilane or phenylchlorosilane; the dispersant includes sodium tripolyphosphate, sodium hexametaphosphate or sodium pyrophosphate; the initiator includes azobisisobutyronitrile, diacyl peroxide or persulfate; the aqueous solution includes ether or ethanol, wherein; the function of the dispersant is to reduce the time and energy required to complete the dispersion process, the aqueous solution allows the mixed powder to become the aqueous suspension, stabilizes the dispersed powder slurry, and improves the fluidity of the aqueous suspension. The initiator is used to initiate the polymerization of the organic monomer, transforming small molecules into large molecules, and finally forming a polymer three-dimensional network structure, and finally transforming the aqueous suspension into a solid state.

6. The method for generating micropores of a cemented carbide micropore tin nozzle according to claim 5, characterized in that: The steps of adding an initiator to the aqueous suspension and then injecting the initiator into a prefabricated microporous mold, curing the initiator according to corresponding initiation conditions, and demoulding the initiator after curing to obtain a solid microporous tin nozzle blank include: The aqueous suspension is injected into the prefabricated microporous mold by an injection machine; The heating temperature is to the initiation temperature, and the initiation condition corresponding to the initiator is that the initiation temperature is 40° C.-100° C., so that the aqueous suspension becomes solid, and after solidification, demoulding is performed to obtain a solid microporous tin nozzle blank.

7. The method for generating micropores of a cemented carbide micropore tin nozzle according to claim 1, characterized in that: The step of adding an organic monomer, a dispersant, an initiator and an aqueous solution to the ball-milled mixed powder to mix the organic monomers and convert the mixed powder into an aqueous suspension comprises: Adding the ball-milled mixed powder to an organic monomer, a dispersant and an aqueous solution to mix the organic monomer; The mixed liquid is mixed into a ball mill for ball milling; The initiator is added to form an aqueous suspension.

8. A cemented carbide microporous tin nozzle, characterized in that: The micropore generation method of the cemented carbide micropore tin nozzle as described in any one of claims 1 to 7 is used for production, comprising a straight section and a tapered section, the inner diameter and outer diameter of the end of the tapered section away from the straight section gradually decrease, the outer diameter of the straight section is 1.8mm-2.4mm, and the length of the straight section is 3mm-5mm; the inner diameter of the end of the straight section away from the tapered section is 1.4mm-2.0mm, the inner wall length of the straight section is 2.5mm-4.0mm, the inner wall angle of the straight section is 0°~5°, the outer wall taper of the tapered section is 20°~40°, the inner wall taper of the tapered section is 10°~30°, and the inner diameter of the end of the tapered section away from the straight section is 0.04mm-1mm.

9. A cemented carbide microporous tin nozzle as claimed in claim 8, characterized in that: The smoothness of the inner walls of the straight tube section and the tapered section and the outer diameter is 0.1ym to 0.4ym; the smoothness of the end surface of the tapered section away from the straight tube section is 0.05ym to 0.2ym.

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