阅读说明：本技术 钨铜复合材料及其制备方法 (Tungsten-copper composite material and preparation method thereof ) 是由 程楚 宋克兴 刘海涛 韩超 周延军 李韶林 张凌亮 宋金涛 张彦敏 莫长春 赵培 于 2019-10-30 设计创作，主要内容包括：本发明涉及一种钨铜复合材料及其制备方法,属于钨基复合材料技术领域。本发明提供了一种钨铜复合材料的制备方法,包括以下步骤：将混匀的钨氧化物、铜氧化物、铝粉和造渣剂进行铝热反应,得到反应物料,经金渣分离后得到合金熔体,冷却后除渣得到钨铜复合材料坯料；钨铜复合材料坯料作为自耗电极进行真空自耗感应熔炼,冷却后得到钨铜复合材料。该方法直接以钨氧化物、铜氧化物和铝粉为原料,通过铝热反应和金渣分离得到钨铜复合材料坯料,可使得原位生成的钨、铜熔体在高温下混合均匀,真空自耗感应熔炼可显著脱除氢与易挥发杂质,明显降低夹杂物含量,熔炼后的钨铜成分较均匀,偏析较少,该方法操作工艺简单,生产成本低。(The invention relates to a tungsten-copper composite material and a preparation method thereof, belonging to the technical field of tungsten-based composite materials. The invention provides a preparation method of a tungsten-copper composite material, which comprises the following steps: carrying out aluminothermic reaction on the uniformly mixed tungsten oxide, copper oxide, aluminum powder and slag former to obtain a reaction material, separating gold slag to obtain an alloy melt, cooling and deslagging to obtain a tungsten-copper composite material blank; and taking the tungsten-copper composite material blank as a consumable electrode to carry out vacuum consumable induction melting, and cooling to obtain the tungsten-copper composite material. The method directly uses tungsten oxide, copper oxide and aluminum powder as raw materials, obtains the tungsten-copper composite material blank through thermit reaction and gold slag separation, can ensure that tungsten and copper melts generated in situ are uniformly mixed at high temperature, can obviously remove hydrogen and volatile impurities through vacuum consumable induction smelting, obviously reduces the content of inclusions, has more uniform components and less segregation of the smelted tungsten and copper, and has simple operation process and low production cost.)

1. The preparation method of the tungsten-copper composite material is characterized by comprising the following steps:

(1) carrying out aluminothermic reaction on the uniformly mixed tungsten oxide, copper oxide, aluminum powder and slag former to obtain a reaction material, separating gold slag to obtain an alloy melt, cooling and deslagging to obtain a tungsten-copper composite material blank;

(2) and (2) performing vacuum consumable induction melting by using the tungsten-copper composite material blank obtained in the step (1) as a consumable electrode, and cooling to obtain the tungsten-copper composite material.

2. The method for preparing the tungsten-copper composite material according to claim 1, wherein in the step (1), the weight ratio of the tungsten element in the tungsten oxide to the copper element in the copper oxide is 100: 6.25-100.

3. The preparation method of the tungsten-copper composite material according to claim 1, wherein in the step (1), the molar ratio of oxygen in the tungsten oxide and the copper oxide to aluminum in the aluminum powder is 100: 27.5-62.5.

4. The preparation method of the tungsten-copper composite material according to claim 1, wherein in the step (1), the weight ratio of the total weight of the tungsten oxide, the copper oxide and the aluminum powder to the slag former is 100: 3.9-9.

5. The method for producing a tungsten-copper composite material according to any one of claims 1 to 4, wherein in the step (1), the tungsten oxide is tungsten trioxide or tungsten dioxide.

6. The method for producing a tungsten-copper composite material according to any one of claims 1 to 4, wherein in the step (1), the copper oxide is copper oxide and/or cuprous oxide.

7. The method for preparing a tungsten-copper composite material according to any one of claims 1 to 4, wherein in the step (1), the slagging agent is calcium oxide.

8. The method for preparing the tungsten-copper composite material according to any one of claims 1 to 4, wherein in the step (2), the number of times of the vacuum consumable induction melting is 2 to 5.

9. The method for preparing the tungsten-copper composite material according to any one of claims 1 to 4, wherein in the step (2), the current for the vacuum consumable induction melting is 1000A to 2500A.

10. A tungsten-copper composite material produced by the production method according to claim 1.

Technical Field

The invention relates to a tungsten-copper composite material and a preparation method thereof, belonging to the technical field of tungsten-based composite materials.

Background

The tungsten-copper composite material is a two-phase structure pseudo alloy which mainly comprises tungsten and copper elements, the copper content is 7-50%, and the tungsten-copper composite material is a metal-based composite material. Because the two metals of tungsten and copper are not mutually soluble, the tungsten-copper composite material has the low expansibility, the wear resistance and the corrosion resistance of tungsten and the high electric conductivity and the heat conductivity of copper, is suitable for various machining, can be widely used as an electric contact material, an electronic package, a heat sink material, a military high-temperature-resistant material, an electric alloy for a high-voltage switch, an electric machining electrode and a microelectronic material, and can be widely applied to the industries of aerospace, aviation, electronics, electric power, metallurgy, machinery, sports equipment and the like as parts and components.

The difference between the physical properties of the metal copper and tungsten is large, so that the tungsten has high melting point (the melting point of tungsten is 3410 ℃ and the melting point of copper is 1080 ℃) and high density (the density of tungsten is 19.34 g/cm)³Of copperThe density is 8.89g/cm³) Therefore, the alloy can not be produced by a fusion casting method, and is generally produced by a powder alloy technology. Common methods include high temperature liquid phase sintering, activated liquid phase sintering and infiltration. The high-temperature liquid phase sintering method has the advantages of higher sintering temperature, long sintering time and low sintering density, and the obtained W-Cu composite material has poor performance. The liquid phase sintering method is activated, and the addition of the activating agent obviously reduces the electric conduction and heat conduction performance of the material. The W-Cu material prepared by the infiltration method needs to be machined to remove redundant metal copper after infiltration, needs subsequent machining, reduces the yield, and is not suitable for preparing parts with very complex shapes. And the copper powder and the tungsten powder which are expensive are adopted as raw materials, so that the production cost is high.

Disclosure of Invention

The first purpose of the invention is to provide a preparation method of a tungsten-copper composite material, which is beneficial to obtaining the tungsten-copper composite material with higher density.

The second purpose of the invention is to provide a tungsten-copper composite material.

The technical scheme of the invention is as follows:

a preparation method of a tungsten-copper composite material comprises the following steps:

(1) carrying out aluminothermic reaction on the uniformly mixed tungsten oxide, copper oxide, aluminum powder and slag former to obtain a reaction material, separating gold slag to obtain an alloy melt, cooling and deslagging to obtain a tungsten-copper composite material blank;

(2) and (2) performing vacuum consumable induction melting by using the tungsten-copper composite material blank obtained in the step (1) as a consumable electrode, and cooling to obtain the tungsten-copper composite material.

The tungsten oxide, copper oxide and slag former are generally dry, preferably under the following drying conditions: the drying temperature is 150-300 ℃, and the drying time is 12-30 h.

The tungsten oxide, the copper oxide, the aluminum powder and the slagging agent are uniformly mixed by adopting a conventional uniform mixing mode in the field, and can be uniformly mixed by stirring or ball milling, and the preferable ball milling conditions are as follows: and ball-milling for 1-4 h on a ball mill.

The aluminothermic reaction is spontaneously carried out after ignition, and the ignition mode can be a conventional ignition mode in the field, can be laser ignition and can also be metal magnesium powder open fire ignition. The thermite reaction is carried out in a graphite reactor.

The container for separating gold slag may be a graphite crucible.

The gold slag separation can be carried out under the action of electromagnetic stirring, and the preferred electromagnetic field frequency is more than 1000 Hz. Further preferably 1000 to 2500 Hz.

The particle size of the tungsten oxide is preferably 100 to 200 mesh.

The particle size of the copper oxide is preferably 100 to 200 mesh.

The granularity of the aluminum powder is preferably less than or equal to 100 meshes.

The granularity of the slag former is preferably less than or equal to 100 meshes.

In the aluminothermic reaction process, sufficient heat can be generated when the aluminum powder reacts with the metal oxide to melt and separate the reduced metal and the formed slag to obtain metal or alloy; but because the reaction system is heated and cooled rapidly, a small amount of impurities exist in the prepared alloy.

The content of the inclusion can be obviously reduced by the floating action of the vacuum consumable induction melting, and because the melting and condensing speed is higher, the alloy after melting has more uniform components and less segregation.

The invention relates to a method for preparing tungsten-copper composite material, which directly uses tungsten oxide, copper oxide and aluminum powder as raw materials, and obtains tungsten-copper composite material blank through aluminothermic reaction and gold slag separation, the instantaneous high temperature (up to more than 3000 ℃) generated in the aluminothermic reaction process can lead the tungsten and copper melt generated in situ to be evenly mixed at high temperature, the slag former adsorbs alumina to form reducing slag, meanwhile, the generated instantaneous high temperature is beneficial to effectively separating the tungsten-copper alloy melt from the reducing slag, the tungsten-copper composite material blank is used as a consumable electrode to carry out vacuum consumable induction melting, and the tungsten-copper composite material is obtained after cooling, the content of inclusions such as alumina and the like can be obviously reduced through the floating effect of the vacuum consumable induction melting, and because the melting and condensing speed is higher, the tungsten-copper composition after melting is more even, the segregation is less, the method combines the aluminothermic reaction and the vacuum consumable induction melting, and can prepare the tungsten-copper composite material with even composition, The tungsten-copper composite material with high density has simple operation process, and compared with copper powder and tungsten powder, the tungsten oxide and copper oxide have low price and low production cost.

The weight ratio of the tungsten element in the tungsten oxide to the copper element in the copper oxide is adjusted according to the weight ratio of the tungsten element to the copper element in the tungsten-copper composite material prepared as required, and in order to enable the mass percentage content of the copper element in the tungsten-copper composite material to be in the range of 7.0% -50.0%, preferably, in the step (1), the weight ratio of the tungsten element in the tungsten oxide to the copper element in the copper oxide is 100: 6.25-100.

In order to further control the cost and reduce the residual of aluminum, in step (1), the molar ratio of oxygen in the tungsten oxide and the copper oxide to aluminum in the aluminum powder is preferably 100: 27.5-62.5.

In order to adsorb alumina which is a product of thermite reaction, the cost is controlled, and preferably, in the step (1), the weight ratio of the total weight of the tungsten oxide, the copper oxide and the aluminum powder to the slag former is 100: 3.9-9.

Preferably, in the step (1), the tungsten oxide is tungsten trioxide or tungsten dioxide.

Preferably, in the step (1), the copper oxide is cupric oxide and/or cuprous oxide.

Preferably, in the step (1), the slagging agent is calcium oxide. The melting point of the reducing slag formed by combining the calcium oxide and the alumina generated by the thermite reaction is far lower than that of the alumina, so that the method is not only favorable for adsorbing the alumina, but also favorable for separating the slag.

Preferably, in the step (2), the number of times of the vacuum consumable induction melting is 2-5. The method is favorable for floating of impurities in the tungsten-copper composite metal through 2-5 times of vacuum consumable induction melting, reduces the defects of impurities in the material, removes hydrogen and volatile impurities, and improves the density of the tungsten-copper composite through repeated melting. The number of times of vacuum consumable induction melting is further increased, so that the performance of the tungsten-copper composite material is not deteriorated, the cost is not favorably controlled, and the efficiency is low.

In order to ensure that the metal ingot can be melted, the current of the vacuum consumable induction melting in the step (2) is preferably 1000-2500A.

In order to further ensure that the metal ingot can be melted, the voltage of the vacuum consumable induction melting is preferably 20V-35V.

Preferably, in the step (2), the vacuum degree of the vacuum consumable induction melting is 2 x 10^-3Pa-5×10^-2Pa. The vacuum consumable induction melting under the vacuum condition is favorable for reducing the content of gas and volatile impurities in the tungsten-copper composite material, and is favorable for improving the purity and the density of the tungsten-copper composite material.

A tungsten-copper composite material is prepared by adopting a preparation method of the tungsten-copper composite material.

The tungsten-copper composite material prepared by the preparation method of the tungsten-copper composite material has the advantages that the mass percentage content of copper element is 7.0-50.0%, the tungsten-copper composite material is uniform in components, high in compactness and less in impurities, the content of Al is below 0.45%, the performance of the tungsten-copper composite material cannot be influenced by the aluminum, the sum of other impurities is below 0.05%, and the tungsten-copper composite material has good comprehensive performance.

Drawings

FIG. 1 is a metallographic structure of a tungsten-copper composite electrode obtained by separating gold slag in step (2) in example 1;

FIG. 2 is a metallographic structure of a tungsten-copper composite material obtained by melting in step (3) of example 1;

FIG. 3 is a metallographic structure of a tungsten-copper composite electrode obtained by separating gold slag in step (2) in example 4;

FIG. 4 shows the metallographic structure of the tungsten-copper composite material obtained by melting in step (3) of example 4.

Detailed Description

The present invention will be further described with reference to the following embodiments.

The purity of the copper oxide powder adopted in the embodiment of the invention is more than or equal to 99.5%, and the granularity is 100-200 meshes.

The purity of the tungsten trioxide powder adopted in the embodiment of the invention is more than or equal to 99.5%, and the granularity is 100-200 meshes.

The purity of the calcium oxide serving as the slagging agent adopted in the embodiment of the invention is more than or equal to 99.5 percent, and the granularity is less than or equal to 100 meshes.

The purity of the Al powder adopted in the embodiment of the invention is more than or equal to 99.5 percent, and the granularity is less than or equal to 100 meshes.

The electromagnetic field for separating the gold slag in the embodiment of the invention is an induced electromagnetic field formed by an induction coil of an intermediate frequency induction furnace during heating, and the frequency of the electromagnetic field during action is 1000-2500 Hz.

The specific embodiment of the preparation method of the tungsten-copper composite material is as follows: