Tungsten-copper alloy pipe and preparation method thereof
Technical Field
The invention relates to the technical field of tungsten-copper tube preparation, in particular to a tungsten-copper alloy tube and a preparation method thereof.
Background
The tungsten-copper alloy has the high melting point of tungsten and the high electric conductivity and the high thermal conductivity of copper. And the thermal expansion coefficient, the thermal conductivity and the electric conductivity of the material can be adjusted according to the percentage content of tungsten and copper components. The tungsten-copper alloy has good ablation resistance and is widely used in the fields of welding electrodes, high-voltage switches, electric spark machining electrodes and the like. When used as an electric discharge electrode, tungsten copper is often processed into a tungsten copper tube, and cooling water is introduced into the tube to lower the temperature of the electric discharge process.
The traditional method for preparing the tungsten copper pipe is to machine or electrically spark process a tungsten copper rod, but the size range of the tungsten copper pipe is limited by the traditional processing method, and the production efficiency of the tungsten copper pipe is seriously influenced.
In view of this, the invention is particularly proposed.
Disclosure of Invention
The invention aims to provide a preparation method of a tungsten-copper alloy tube, which can effectively reduce the consumption of tungsten and copper in the traditional processing process and improve the production efficiency of the tungsten-copper alloy tube.
Another object of the present invention is to provide a tungsten copper alloy tube, which is prepared by the above method. Therefore, the tungsten-copper alloy pipe has high production efficiency and high yield.
The invention is realized by the following steps:
in a first aspect, an embodiment provides a method for preparing a tungsten-copper alloy tube, including:
mixing 50-90% of tungsten powder and 10-50% of copper powder by mass percent to obtain a mixture;
banburying the mixture and a wax-based binder at a preset temperature, and then sequentially carrying out granulation, plasticizing extrusion, debonding and sintering operations;
wherein the wax-based binder comprises the following raw materials in percentage by mass:
20-35% of polyethylene, 40-60% of paraffin, 8-15% of salicylic acid and 3-10% of ethylene-vinyl acetate copolymer.
In an alternative embodiment, the wax-based binder comprises the following raw materials in percentage by mass:
25-30% of polyethylene, 45-60% of paraffin, 10-15% of salicylic acid and 5-10% of ethylene-vinyl acetate copolymer.
In an alternative embodiment, the tungsten powder is tungsten powder with a Fisher size of 1.0-10.0um, the copper powder is electrolytic copper powder with a mesh size of (-400) — (-100), and the mixture is prepared by mixing the tungsten powder and the electrolytic copper powder for 12-24 h by using a Y-type mixer.
In an alternative embodiment, the preset temperature for the banburying step is from 85 to 150 ℃.
In an alternative embodiment, the step of granulating is performed in a granulator, and the powder after the step of granulating is a step of performing plasticization extrusion in a single-screw extruder to obtain the tungsten-copper powder tube green compact by extrusion, and the extrusion temperature of the single-screw extruder is 80-150 ℃.
In an optional embodiment, the step of de-bonding is to remove the binder from the green tungsten-copper powder tube in a de-bonding furnace to obtain a tungsten-copper tube blank;
the technological parameters of the debonding are as follows: sequentially carrying out debonding at the temperature of 60-80 ℃ for 12 hours, debonding at the temperature of 85-150 ℃ for 12 hours and debonding at the temperature of 150-250 ℃ for 12 hours.
In an alternative embodiment, the sintering operation comprises a pre-sintering step and a sintering step;
the pre-sintering step is to pre-sinter the debonded tungsten copper tube blank in a hydrogen sintering furnace at the pre-sintering temperature of 600-900 ℃ for 2-8 h;
the sintering step is to sinter the presintered tungsten-copper tube blank in a vacuum sintering furnace at the sintering temperature of 1100-1380 ℃ for 1-6 h.
In an optional embodiment, the density of the tungsten-copper tube blank after the step of de-bonding is 40% to 60%, the density of the tungsten-copper tube blank after the step of pre-sintering is 60% to 80%, and the density of the tungsten-copper tube finished product after the step of sintering is 96% to 99%.
In a second aspect, embodiments provide a tungsten-copper alloy tube produced by the method of producing a tungsten-copper alloy tube according to any one of the preceding embodiments.
In an alternative embodiment, the tungsten copper alloy tube has an inner diameter of 0.1mm to 10mm, an outer diameter of 1.0mm to 30mm, and a length of 10mm to 500 mm.
Embodiments of the invention have at least the following advantages or benefits:
the preparation method of the tungsten-copper alloy provided by the embodiment of the invention comprises the steps of mixing 50-90% of tungsten powder and 10-50% of copper powder in percentage by mass to obtain a mixture; banburying the mixture and a wax-based binder at a preset temperature, and then sequentially carrying out granulation, plasticizing extrusion, debonding and sintering operations; wherein the wax-based binder comprises the following raw materials in percentage by mass: 20-35% of polyethylene, 40-60% of paraffin, 8-15% of salicylic acid and 3-10% of ethylene-vinyl acetate copolymer. On one hand, the method can prepare the tungsten-copper alloy pipe by directly mixing, banburying, granulating, extruding, debonding, sintering and other steps, can effectively reduce the consumption of tungsten and copper in the traditional process, saves the material cost, simultaneously improves the production efficiency, and ensures the utilization rate and the yield of raw materials. On the other hand, through the use of the removable binder, the strength and uniformity of the tungsten-copper alloy are effectively improved, and the rheological property in the preparation process is fully ensured, so that the production efficiency and the yield of the tungsten-copper alloy pipe are further ensured.
The embodiment of the invention also provides a tungsten-copper alloy pipe which is prepared by the method. Therefore, the tungsten-copper alloy pipe has high production efficiency and high yield.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The features and properties of the present invention are described in further detail below with reference to examples.
The embodiment of the invention provides a preparation method of a tungsten-copper alloy pipe, which comprises the following steps:
mixing 50-90% of tungsten powder and 10-50% of copper powder by mass percent to obtain a mixture; and banburying the mixture and a wax-based binder at a preset temperature, and then sequentially carrying out granulation, plasticizing extrusion, debonding and sintering operations. The tungsten powder, the copper powder and the binder are directly mixed, and then are sequentially subjected to densification, granulation, plasticizing extrusion, debonding and sintering operation to obtain the tungsten-copper alloy pipe, compared with the prior art, the processing steps of the traditional processes such as machining or electric spark processing and the like are omitted, the consumption of tungsten and copper in the processing process of the traditional processes can be effectively reduced, the material cost is saved by about 5-20%, the production efficiency is improved, and the utilization rate and the yield of raw materials are ensured.
The wax-based binder comprises the following raw materials in percentage by mass: 20-35% of Polyethylene (PE), 40-60% of Paraffin Wax (PW), 8-15% of Salicylic Acid (SA) and 3-10% of ethylene-vinyl acetate copolymer (EVA). Polyethylene (PE) has the molecular formula: (C)2H4)nThe molecular formula of the Paraffin Wax (PW) is: cnH2n+2(and n is not less than 20 and not more than 24), Salicylic Acid (SA): CH of the formula3CH216COOH, ethylene-vinyl acetate copolymer (EVA) has the molecular formula: (C)2H4)x(C4H6O2)y. On one hand, the wax-based binder can ensure the strength and uniformity of the tungsten-copper alloy, and simultaneously ensures that the binder can enable tungsten-copper alloy powder to generate good rheological property. Therefore, the strength and uniformity of the tungsten-copper alloy are effectively improved by using the removable binder, and the rheological property in the preparation process is fully ensured, so that the production efficiency and the yield of the tungsten-copper alloy tube are further ensured. On the other hand, the adhesive does not have any chemical reaction with the tungsten-copper alloy, is easy to be separated from a tungsten-copper alloy product, does not remain and has no pollution, so the adhesive also has the advantages of no toxicity, low cost and the like.
Preferably, in the embodiment of the present invention, the wax-based binder includes the following raw materials by mass: 25-30% of polyethylene, 45-60% of paraffin, 10-15% of salicylic acid and 5-10% of ethylene-vinyl acetate copolymer. By controlling the dosage of each component in the wax-based binder, the wax-based binder has more excellent chemical properties, thereby more ensuring the strength and uniformity of tungsten and copper.
And further preferably, in the embodiment of the present invention, the wax-based binder includes the following raw materials by mass: 30% of polyethylene, 50% of paraffin, 15% of salicylic acid and 5-10% of ethylene-vinyl acetate copolymer. When the wax-based binder components are added at this level, the near strength and uniformity of the tungsten copper is effectively ensured. Of course, in other embodiments of the present invention, the amount of each component of the wax-based binder may be adjusted and selected according to the requirement, and the embodiments of the present invention are not limited thereto.
In the embodiment of the present invention, the selected tungsten powder is tungsten powder with a fisher particle size of 1.0-10.0um, the selected copper powder is electrolytic copper powder with a mesh size of (-400) — (-100), and the mixture is prepared by mixing the tungsten powder and the electrolytic copper powder for 12-24 hours by using a Y-type mixer. The tungsten powder and the copper powder are mixed uniformly in advance, so that the uniformity of the tungsten powder and the copper powder after the tungsten powder and the copper powder are added into the wax-based binder can be effectively guaranteed, the waste of materials is reduced, and the utilization rate and the yield of the materials are guaranteed. Of course, in other embodiments of the present invention, the types of the tungsten powder and the copper powder may be adjusted and selected according to requirements, and the mixing apparatus and the mixing time may also be adjusted according to requirements, which is not limited in the embodiments of the present invention.
It should be further noted that, in the embodiment of the present invention, the temperature control of banburying may also be used to ensure the overall uniformity after mixing. For example, in the embodiment of the present invention, the mixture may be subjected to banburying with a wax-based binder at a temperature of 85 to 150 ℃, and then the operations of granulation, plasticization and extrusion, debonding and sintering are sequentially performed to ensure the effect of the subsequent operations, thereby ensuring the quality of the final product. Of course, in other embodiments of the present invention, the temperature of the stirring and mixing can be adjusted according to the operation environment, and the embodiments of the present invention are not described in detail.
Specifically, in the embodiment of the present invention, the granulating step is performed in a granulator, the model of the granulator can be selected according to the operation requirement, and the embodiment of the present invention is not described in detail. And the powder after the granulating step is subjected to plasticizing extrusion in a single-screw extruder to obtain a tungsten copper powder tube green compact by extrusion, and the extrusion temperature of the single-screw extruder is 80-150 ℃. The extrusion temperature is set to be matched with the preset temperature, so that the extrusion effect of the granulated powder in the extrusion operation is better, the forming rate is higher, and the yield of the final tungsten-copper alloy pipe is ensured. Of course, in other embodiments of the present invention, the extrusion equipment and the extrusion temperature may be changed or adjusted according to the operation requirement and the operation environment, and the embodiments of the present invention are not limited.
Specifically, in the embodiment of the invention, the step of de-bonding is to remove the binder from the green tungsten-copper powder tube in a de-bonding furnace to obtain a tungsten-copper tube blank. The wax-based binder adopted by the embodiment of the invention is easy to be separated from the tungsten-copper alloy product, has no residue and no pollution, so that the formula of the binder also has the advantages of no toxicity, low cost and the like.
Wherein, the technological parameters of the de-bonding are as follows: sequentially carrying out debonding at the temperature of 60-80 ℃ for 12 hours, debonding at the temperature of 85-150 ℃ for 12 hours and debonding at the temperature of 150-250 ℃ for 12 hours. The effect of debonding is fully ensured by gradually increasing the debonding temperature, so that the added wax-based binder can be successfully debonded from the tungsten-copper alloy product. Of course, in other embodiments of the present invention, the parameter characteristics of the debonding may also be adjusted according to the operation environment and the operation requirement, and the embodiments of the present invention are not limited.
Specifically, in the embodiment of the present invention, the sintering operation includes a pre-sintering step and a sintering step, and the pre-sintering step and the sintering step are combined to ensure the sintering effect, so as to ensure the yield of the tungsten-copper alloy tube.
Wherein, the pre-sintering step is to pre-sinter the debonded tungsten copper tube blank in a hydrogen sintering furnace, the pre-sintering temperature is 600-. The hydrogen sintering furnace is mainly used for sintering processes of various metal materials, non-metal materials and the like under the protection of hydrogen, and can effectively ensure the sintering effect and the sintering quality. The sintering step is to sinter the presintered tungsten-copper tube blank in a vacuum sintering furnace at the sintering temperature of 1100-1380 ℃ for 1-6 h. The vacuum sintering furnace is a high-temperature sintering furnace, and can ensure the final molding of a product in a high-temperature environment, thereby ensuring the molding rate of the product by matching with a pre-sintering step and reducing the waste of materials. Of course, in other embodiments of the present invention, the temperature and time of the pre-sintering step and the temperature and time of the sintering step may be adjusted according to requirements, and the embodiments of the present invention are not limited.
In the embodiment of the present invention, in order to further ensure the yield of the product and the quality of the product obtained by final sintering, the operation may be assisted by controlling the densification. For example, in the embodiment of the present invention, the compactness of the tungsten-copper tube blank after the de-bonding step is 40% to 60%, the compactness of the tungsten-copper tube blank after the pre-sintering step is 60% to 80%, and the compactness of the tungsten-copper tube finished product after the sintering step is 96% to 99%.
The embodiment of the invention also provides a tungsten-copper alloy tube which is prepared by the method, and the tungsten-copper alloy tube has the inner diameter of 0.1-10 mm, the outer diameter of 1.0-30 mm and the length of 10-500 mm. The tungsten-copper alloy tube has high yield and utilization rate, and is suitable for batch production.
The process flow is described in detail below with reference to specific examples.
Example 1
The embodiment provides a tungsten-copper alloy tube, which has an inner diameter of 0.8mm, an outer diameter of 10mm and a length of 100mm, and is specifically prepared through the following steps:
s1: taking tungsten powder with Fisher granularity of 1.5 mu m and electrolytic copper powder with a granularity of-400 meshes, adding 85% of tungsten and 15% of copper according to mass percentage, and mixing for 12 hours by adopting a Y-shaped mixer to obtain a mixture;
s2: mixing the mixture and a wax-based binder uniformly at 100 ℃; and the main components of the wax-based binder are as follows: PE: 25 percent; EVA: 5 percent; PW: 50 percent; and SA: 20 percent;
s3: granulating, namely granulating the mixed powder and the binder in a granulator;
s4: plasticizing and extruding, namely extruding the granulated powder into a tungsten copper powder tube green blank in a single-screw extruder, wherein the extrusion temperature is 150 ℃;
s5: and (4) debonding, namely debonding the binder of the extruded tungsten copper tube green body in a debonding furnace. The technological parameters of the de-bonding are as follows: sequentially carrying out debonding at the temperature of 60 ℃ for 12 hours, debonding at the temperature of 150 ℃ for 12 hours and debonding at the temperature of 200 ℃ for 12 hours;
s6: pre-sintering, namely pre-sintering the debonded tungsten copper tube blank in a hydrogen sintering furnace at the pre-sintering temperature of 700 ℃ for 2 hours;
s7: and sintering the presintered tungsten-copper tube blank in a vacuum sintering furnace at the sintering temperature of 1200 ℃ for 3 hours.
Example 2
The embodiment provides a tungsten-copper alloy tube, which has an inner diameter of 1.5mm, an outer diameter of 10mm and a length of 120mm, and is specifically prepared through the following steps:
s1: taking tungsten powder with Fisher granularity of 1.5um and electrolytic copper powder with a granularity of-400 meshes, adding 80% of tungsten and 20% of copper according to mass percentage, and mixing for 12 hours by adopting a Y-shaped mixer to obtain a mixture;
s2: mixing the mixture and a wax-based binder uniformly at 100 ℃; and the main components of the wax-based binder are as follows: PE: 20 percent; EVA: 5 percent; PW: 50 percent; and SA: 25 percent;
s3: granulating, namely granulating the mixed powder and the binder in a granulator;
s4: plasticizing and extruding, namely extruding the granulated powder into a tungsten copper powder tube green blank in a single-screw extruder, wherein the extrusion temperature is 140 ℃;
s5: and (4) debonding, namely debonding the binder of the extruded tungsten copper tube green body in a debonding furnace. The technological parameters of the de-bonding are as follows: sequentially carrying out debonding at the temperature of 60 ℃ for 12 hours, debonding at the temperature of 150 ℃ for 12 hours and debonding at the temperature of 200 ℃ for 12 hours;
s6: pre-sintering, namely pre-sintering the debonded tungsten copper tube blank in a hydrogen sintering furnace at the pre-sintering temperature of 700 ℃ for 2 hours;
s7: and sintering the presintered tungsten-copper tube blank in a vacuum sintering furnace at the sintering temperature of 1200 ℃ for 3 hours.
Example 3
The embodiment provides a tungsten-copper alloy tube, which has an inner diameter of 2.0mm, an outer diameter of 10mm and a length of 150mm, and is specifically prepared through the following steps:
s1: taking tungsten powder with Fisher granularity of 1.5um and electrolytic copper powder with a granularity of-400 meshes, adding 70% of tungsten and 30% of copper according to mass percentage, and mixing for 12 hours by adopting a Y-shaped mixer to obtain a mixture;
s2: mixing the mixture and a wax-based binder uniformly at 100 ℃; and the main components of the wax-based binder are as follows: PE: 20 percent; EVA: 5 percent; PW: 45 percent; and SA: 30 percent;
s3: granulating, namely granulating the mixed powder and the binder in a granulator;
s4: plasticizing and extruding, namely extruding the granulated powder into a tungsten copper powder tube green blank in a single-screw extruder, wherein the extrusion temperature is 130 ℃;
s5: and (4) debonding, namely debonding the binder of the extruded tungsten copper tube green body in a debonding furnace. The technological parameters of the de-bonding are as follows: sequentially carrying out debonding at the temperature of 60 ℃ for 12 hours, debonding at the temperature of 150 ℃ for 12 hours and debonding at the temperature of 200 ℃ for 12 hours;
s6: pre-sintering, namely pre-sintering the debonded tungsten copper tube blank in a hydrogen sintering furnace at the pre-sintering temperature of 700 ℃ for 2 hours;
s7: and sintering the presintered tungsten-copper tube blank in a vacuum sintering furnace at the sintering temperature of 1200 ℃ for 3 hours.
Experimental example 1
The performance parameters of the tungsten-copper alloy tubes prepared in examples 1 to 3 were measured, and the results are shown in the following table:
item
|
Density (g/cm)3)
|
Electrical conductivity (% IACS)
|
Thermal conductivity (W/mk)
|
Example 1
|
16.4
|
25%
|
160
|
Example 2
|
15.5
|
33%
|
180
|
Example 3
|
14.3
|
45%
|
200 |
According to the contents recorded in the table, the tungsten-copper alloy pipe prepared by the preparation method of the tungsten-copper alloy pipe provided by the embodiment of the invention has high performance, and the tungsten-copper alloy pipe can be prepared by directly carrying out the steps of mixing, banburying, granulating, extruding, debonding, sintering and the like on the one hand, so that the consumption of tungsten and copper in the traditional process can be effectively reduced, the material cost is saved, the production efficiency is improved, and the utilization rate and the yield of raw materials are ensured. On the other hand, through the use of the removable binder, the strength and uniformity of the tungsten-copper alloy are effectively improved, and the rheological property in the preparation process is fully ensured, so that the production efficiency and the yield of the tungsten-copper alloy pipe are further ensured.
In summary, the preparation method of the tungsten-copper alloy tube provided by the embodiment of the invention can effectively reduce the consumption of tungsten and copper in the traditional processing process, and simultaneously improve the production efficiency of the tungsten-copper alloy tube. The tungsten-copper alloy pipe provided by the embodiment of the invention is prepared by the method. Therefore, the tungsten-copper alloy pipe has high production efficiency and high yield.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.