阅读说明：本技术 铝白铜合金的制备方法 (Preparation method of aluminum cupronickel alloy ) 是由 程楚 宋克兴 张彦敏 周延军 韩超 陈拂晓 李继文 刘伟 莫长春 赵培峰 刘亚民 于 2019-09-26 设计创作，主要内容包括：本发明涉及一种铝白铜合金的制备方法,属于铜合金技术领域。本发明提供了一种铝白铜合金的制备方法,包括以下步骤：混匀的铜氧化物、镍氧化物、铝粉和造渣剂经过铝热自蔓延反应,得到高温熔体；对高温熔体进行金渣熔炼分离,分离后下层为铜镍铝合金熔体层,上层为残渣层,除去全部或部分残渣后,加入预熔渣进行精炼,将精炼后的熔体进行浇铸,得到铝白铜合金。该方法以成本较低的铜氧化物、镍氧化物和铝粉为原料,成本低,缓解了现有铝白铜合金生产成本高的问题,且铝热自蔓延反应充分利用自身释放的化学能使体系快速升温,得到高温熔体,反应迅速、升温快,降低了生产能耗,提高了生产效率。(The invention relates to a preparation method of an aluminum cupronickel alloy, belonging to the technical field of copper alloys. The invention provides a preparation method of an aluminum cupronickel alloy, which comprises the following steps: carrying out aluminothermic self-propagating reaction on the uniformly mixed copper oxide, nickel oxide, aluminum powder and slag former to obtain a high-temperature melt; and carrying out gold slag smelting separation on the high-temperature melt, wherein the lower layer is a copper-nickel-aluminum alloy melt layer and the upper layer is a residue layer after separation, adding premelting slag for refining after all or part of residues are removed, and casting the refined melt to obtain the aluminum-copper alloy. The method takes copper oxide, nickel oxide and aluminum powder with lower cost as raw materials, has low cost, relieves the problem of high production cost of the existing aluminum white copper alloy, fully utilizes the chemical energy released by the self-propagating reaction to quickly heat the system to obtain high-temperature melt, has quick reaction and heating, reduces the production energy consumption, and improves the production efficiency.)

1. The preparation method of the aluminum cupronickel alloy is characterized by comprising the following steps of:

(1) Carrying out aluminothermic self-propagating reaction on the uniformly mixed copper oxide, nickel oxide, aluminum powder and slag former to obtain a high-temperature melt consisting of a copper-nickel-aluminum alloy melt and residues;

(2) And (2) carrying out gold slag smelting separation on the high-temperature melt obtained in the step (1), wherein the lower layer is a copper-nickel-aluminum alloy melt layer and the upper layer is a residue layer after separation, adding premelting slag for refining after all or part of residues are removed, and casting the refined melt to obtain the aluminum-copper alloy.

2. The method for preparing the aluminum cupronickel alloy according to claim 1, wherein in the step (1), the weight ratio of the total weight of the copper oxide, the nickel oxide and the aluminum powder to the slag former is 4.5-9: 1;

In the step (1), the weight ratio of the copper element in the copper oxide to the nickel element in the nickel oxide is 100: 6.5-20;

In the step (1), the molar ratio of the aluminum element in the aluminum powder to the oxygen element in the copper oxide and the nickel oxide is 1: 1.43-1.65.

3. The method for preparing the aluminum cupronickel alloy according to claim 2, wherein the molar ratio of the aluminum element in the aluminum powder to the oxygen element in the copper oxide and the nickel oxide is 1: 1.55-1.65; the weight ratio of the copper element in the copper oxide to the nickel element in the nickel oxide is 100: 6.5-12;

or the molar ratio of the aluminum element in the aluminum powder to the oxygen element in the copper oxide and the nickel oxide is 1: 1.43-1.47; the weight ratio of the copper element in the copper oxide to the nickel element in the nickel oxide is 100: 17.5-20.

4. The method for producing an aluminum cupronickel alloy according to any one of claims 1 to 3, characterized in that, in the step (1), the copper oxide is CuO or Cu 2O; the nickel oxide is NiO; the slagging agent is CaO.

5. The method according to any one of claims 1 to 3, wherein in the step (1), the partial residue is 80 to 95 percent of the volume of the residue layer.

6. The method for preparing the aluminum cupronickel alloy according to any one of claims 1 to 3, wherein in the step (2), the gold slag smelting separation is carried out under the action of electromagnetic stirring, the frequency of the electromagnetic stirring is 1000-2500 Hz, the temperature of the gold slag smelting separation is 1500-1900 ℃, and the time of the gold slag smelting separation is 1-5 min.

7. The method for preparing the aluminum cupronickel alloy according to any one of claims 1 to 3, wherein in the step (2), the pre-melted slag is a combination of CaF2 and one of NaF and Na3AlF6, and the content of CaF2 is 45-65% by mass;

The volume of the pre-melted slag is 10-30% of the volume of the copper-nickel-aluminum alloy melt.

8. The method for producing an aluminum cupronickel alloy according to any one of claims 1 to 3, characterized in that in the step (2), the refining includes the steps of: introducing carrier gas carrying deoxidant to the bottom of the melt, and refining under the action of electromagnetic field.

9. The method for preparing the aluminum cupronickel alloy according to claim 8, wherein the deoxidizer is CaB6 powder and/or B powder; the weight of the deoxidizer is 0.1-0.6% of the weight of the copper-nickel-aluminum alloy melt; the carrier gas is an inert gas.

10. The method for preparing the aluminum cupronickel alloy according to claim 8, wherein the frequency of the electromagnetic field is 1000 to 2500 Hz; the refining temperature is 1300-1500 ℃, and the refining time is 5-30 min.

Technical Field

The invention relates to a preparation method of an aluminum cupronickel alloy, belonging to the technical field of copper alloys.

Background

The corrosion-resistant copper alloy has excellent corrosion resistance in complex environments such as seawater, acid and alkali, and the like, and is widely applied to the fields of shipbuilding industry, seawater desalination, petrochemical industry, medical appliances, and the like. Currently, there are several major types of corrosion resistant copper alloys used in industry: (1) aluminum brass and tin brass known as "navy brass" are used as the elements, such as HSn70-1 and HSn 60-1; (2) tin bronzes, such as QSn4-4-4, QSn-5-5, QSn6-6-3, and the like; (3) Cu-Ni based cupronickel alloys such as Cu-6Ni-1.5Al, Cu-13Ni-3Al, Cu-10Ni-1Fe-1Mn, Cu-30Ni-1 Fe-lMn. Wherein, the aluminum-containing Cu-Ni series cupronickel alloy (Cu-6Ni-1.5Al, Cu-13Ni-3Al), namely the aluminum cupronickel alloy not only has excellent marine organism adhesion resistance and seawater corrosion resistance, but also has higher strength and heat exchange coefficient, and is commonly used for various high-strength corrosion-resistant parts in industrial departments such as shipbuilding, electric power, chemical engineering and the like.

The aluminum white copper alloy is formed by adding aluminum on the basis of a copper-nickel alloy, wherein the mass fraction of Ni in the aluminum white copper alloy is 5.5-15.0%, and the mass fraction of Al in the aluminum white copper alloy is 1.2-3.0%. The aluminum white copper alloy comprises Cu-6Ni-1.5Al and Cu-13Ni-3Al, wherein the Cu-13Ni-3Al comprises the following components in percentage by weight: 12.0-15.0% of Ni, 2.3-3.0% of Al, less than or equal to 1.0% of Fe, less than or equal to 0.50% of Mn, less than or equal to 0.003% of Pb, less than or equal to 0.01% of P, and the balance of copper and inevitable impurities; the Cu-6Ni-1.5Al comprises the following components in percentage by weight: 5.5 to 6.5 percent of Ni, 1.2 to 1.8 percent of Al, less than or equal to 0.5 percent of Fe, less than or equal to 0.20 percent of Mn, less than or equal to 0.003 percent of Pb, and the balance of copper and inevitable impurities. At present, the preparation of the aluminum cupronickel alloy (Cu-6Ni-1.5Al and Cu-13Ni-3Al) mainly comprises the steps of directly smelting metal copper, metal nickel and metal aluminum at a certain temperature, and casting after components are uniform to obtain an alloy ingot.

Therefore, the development of a low-cost preparation method has important significance for industrial application of the aluminum cupronickel alloy in the fields of shipbuilding, electric power, chemical engineering and the like.

disclosure of Invention

The invention aims to provide a preparation method of an aluminum cupronickel alloy, which takes copper oxide and nickel oxide as raw materials and reduces the cost.

The technical scheme of the invention is as follows:

A preparation method of an aluminum cupronickel alloy comprises the following steps:

(1) Carrying out aluminothermic self-propagating reaction on the uniformly mixed copper oxide, nickel oxide, aluminum powder and slag former to obtain a high-temperature melt consisting of a copper-nickel-aluminum alloy melt and residues;

(2) and (2) carrying out gold slag smelting separation on the high-temperature melt obtained in the step (1), wherein the lower layer is a copper-nickel-aluminum alloy melt layer and the upper layer is a residue layer after separation, adding premelting slag for refining after all or part of residues are removed, and casting the refined melt to obtain the aluminum-copper alloy.

The residue includes alumina produced by thermite self-propagating reactions, and also includes unreacted copper oxide and nickel oxide.

in the copper-nickel-aluminum alloy melt in the high-temperature melt obtained by the aluminothermic self-propagating reaction of the uniformly mixed copper oxide, nickel oxide, aluminum powder and slag former, the content of nickel, copper and aluminum is the same as the proportion of nickel element, copper element and aluminum element in the aluminum cupronickel in the prior art, and the dosage of the copper oxide, the nickel oxide and the aluminum powder can be reasonably adjusted according to the grade of the aluminum cupronickel prepared according to the requirement, so that the target product is obtained.

If the atmosphere is inert, all residues can be removed. If the gas environment is air, 80 vol% -95 vol% of the residue layer can be removed, and at the moment, a residue layer is also arranged on the surface of the copper-nickel-aluminum alloy melt and can be isolated from the air.

The copper oxide, nickel oxide and slag former are generally dry, preferably under the following drying conditions: the drying temperature is 150-250 ℃, and the drying time is 18-36 h.

the copper oxide, the nickel 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 1-3 h on a ball mill.

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

The alumina generated by the aluminothermic self-propagating reaction has higher melting point, and the slag former is combined with the alumina to obtain the residue with lower melting point, wherein the residue is in a molten state.

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.

In order to smoothly carry out the thermite self-propagating reaction and avoid the situation that the thermite self-propagating reaction is insufficient due to overlarge granularity of copper oxide and the thermite self-propagating reaction is too fast due to undersize granularity of copper oxide, the granularity of the copper oxide is preferably 60-300 meshes.

In order to smoothly carry out the thermite self-propagating reaction and avoid the situation that the thermite self-propagating reaction is insufficient due to overlarge nickel oxide granularity and the thermite self-propagating reaction is too fast due to undersize nickel oxide granularity, the granularity of the nickel oxide is preferably 60-300 meshes.

In order to smoothly carry out the thermite self-propagating reaction and avoid the situation that the thermite self-propagating reaction is insufficient due to overlarge granularity of the aluminum powder and the thermite self-propagating reaction is too fast due to undersize granularity of the aluminum powder, the granularity of the aluminum powder is preferably 0.05-0.3 mm.

The particle size of the slag former is preferably 100 mesh or less.

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

The preparation method of the aluminum cupronickel alloy uses copper oxide, nickel oxide and aluminum powder as raw materials, and mainly obtains the aluminum cupronickel alloy through thermite self-propagating reaction, gold slag smelting separation, refining, casting and deslagging.

in order to reduce the amount of generated residues and ensure the slag-metal separation effect, the weight ratio of the total weight of the copper oxide, the nickel oxide and the aluminum powder to the slagging constituent in the step (1) is preferably 4.5-9: 1. In order to further control the proportion of copper and nickel in the aluminum white copper alloy, in the step (1), the weight ratio of copper element in the copper oxide to nickel element in the nickel oxide is preferably 100: 6.5-20. In order to further control the content of aluminum in the aluminum cupronickel alloy, the molar ratio of aluminum element in the aluminum powder to oxygen element in the copper oxide and the nickel oxide in the step (1) is preferably 1: 1.43-1.65.

In order to prepare the aluminum white copper Cu-6Ni-1.5Al, the molar ratio of aluminum element in the aluminum powder to oxygen element in the copper oxide and the nickel oxide is preferably 1: 1.55-1.65; the weight ratio of the copper element in the copper oxide to the nickel element in the nickel oxide is 100: 6.5-12.

In order to prepare the aluminum white copper Cu-13Ni-3Al, the molar ratio of aluminum element in the aluminum powder to oxygen element in copper oxide and nickel oxide is preferably 1: 1.43-1.47; the weight ratio of the copper element in the copper oxide to the nickel element in the nickel oxide is 100: 17.5-20.

Preferably, in the step (1), the copper oxide is CuO or Cu 2O; the nickel oxide is NiO; the slagging agent is CaO.

The melting point of residue formed by combining CaO and alumina generated by aluminothermic self-propagating reaction is far lower than that of the alumina, which is beneficial to separating gold slag.

in order to further improve the efficiency of the gold slag smelting separation, preferably, in the step (2), the gold slag smelting separation is performed under the action of electromagnetic stirring, the frequency of the electromagnetic stirring is 1000-2500 Hz, the temperature of the gold slag smelting separation is 1500-1900 ℃, and the time of the gold slag smelting separation is 1-5 min.

Preferably, in the step (2), the pre-melted slag is a combination of CaF2 and one of NaF and Na3AlF6, and the mass percentage of CaF2 is 45% -65%. The premelting slag formed by combining CaF2 with one of NaF and Na3AlF6 can reduce the melting point and viscosity of the slag, improve the fluidity and alkalinity of the slag, facilitate the removal of impurities such as alumina and the like, and improve the removal efficiency of the impurities through the action of an electromagnetic field.

In order to further improve the refining efficiency and control the cost, in the step (2), the volume of the pre-melted slag is preferably 10-30% of the volume of the copper-nickel-aluminum alloy melt.

Preferably, in step (2), the refining comprises the steps of: introducing carrier gas carrying deoxidant to the bottom of the melt, and refining under the action of electromagnetic field. And the carrier gas carrying the deoxidizer is introduced to the bottom of the melt for deep deoxidation, so that not only is the oxygen in the alloy effectively removed, but also the aggregation and floating of oxide inclusions in the alloy are facilitated, and the refining effect is enhanced.

Preferably, the deoxidizer is CaB6 powder and/or B powder; the weight of the deoxidizer is 0.1-0.6% of the weight of the copper-nickel-aluminum alloy melt; the carrier gas is an inert gas. The deep deoxidation is carried out by introducing inert gas carrying CaB6 powder and/or B powder to the bottom of the melt, so that not only is the oxygen in the alloy effectively removed, but also the obtained boron oxide and calcium oxide have low density and are easy to float upwards, and are adsorbed by premelting slag, and the aggregation and floating upwards of oxide inclusions in the alloy are facilitated, and the refining effect is enhanced.

In order to improve the refining efficiency and control the refining cost, preferably, the frequency of the electromagnetic field is 1000-2500 Hz; the refining temperature is 1300-1500 ℃, and the refining time is 5-30 min.

The aluminum white copper alloy Cu-6Ni-1.5Al with good high-strength corrosion resistance can be prepared by adopting the preparation method of the aluminum white copper alloy. The mass percentage of nickel in the aluminum cupronickel alloy Cu-6Ni-1.5Al is 5.5-6.5%, and the mass percentage of aluminum in the aluminum cupronickel alloy Cu-6Ni-1.5Al is 1.2-1.8%.

The aluminum white copper alloy Cu-13Ni-3Al with good high-strength corrosion resistance can be prepared by adopting the preparation method of the aluminum white copper alloy. The mass percentage of nickel in the aluminum cupronickel alloy Cu-13Ni-3Al is 12.0-15.0%, and the mass percentage of aluminum in the aluminum cupronickel alloy Cu-13Ni-3Al is 2.3-3.0%.

Drawings

FIG. 1 is a gold phase diagram of an aluminum white copper alloy formed by a copper-nickel-aluminum alloy melt obtained after separation of gold slag in step (3) of example 4;

FIG. 2 is a gold phase diagram of the white aluminum copper alloy Cu-13Ni-3Al obtained by the electromagnetic refining in the step (4) of example 4.

Detailed Description

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

The purity of the CuO powder adopted in the embodiment of the invention is more than or equal to 99.5%. The particle size is 100-200 meshes.

The purity of NiO powder adopted in the embodiment of the invention is more than or equal to 99.5 percent. The particle size is 100-200 meshes.

The purity of the CaO of the slagging agent adopted in the embodiment of the invention is more than or equal to 98.5%. The granularity is less than or equal to 100 meshes.

The purity of the premelting slag NaF adopted in the embodiment of the invention is more than or equal to 99.8%. The particle size is 100-200 meshes.

The purity of the premelting slag Na3AlF6 adopted in the embodiment of the invention is more than or equal to 99.8%. The particle size is 100-200 meshes.

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

The inert gas adopted in the embodiment of the invention is high-purity argon with the purity of more than 99.99 percent.

The electromagnetic field in the embodiment of the invention is an induced electromagnetic field formed by heating an induction coil of the medium-frequency induction furnace, and the frequency of the electromagnetic field is 1000-2500 Hz.

The reactor used in the examples of the present invention was a graphite reactor.

The specific embodiment of the preparation method of the aluminum cupronickel alloy of the invention is as follows: