WO2022000864A1

WO2022000864A1 - Copper-titanium 50 intermediate alloy and method for preparing same by using magnetic suspension smelting process

Info

Publication number: WO2022000864A1
Application number: PCT/CN2020/121572
Authority: WO
Inventors: 王沛; 王群; 郭创立
Original assignee: 西安斯瑞先进铜合金科技有限公司
Priority date: 2020-06-29
Filing date: 2020-10-16
Publication date: 2022-01-06
Also published as: CN111763847A; CN111763847B

Abstract

Disclosed is a method for preparing a copper-titanium 50 intermediate alloy by using a magnetic suspension smelting process, the method comprising the following steps: firstly, matching copper alloy elements according to the weight percentage content whereby Ti accounts for 31%-55% and the balance is Cu; charging metal raw materials into a cold crucible of a vacuum magnetic suspension furnace, energizing same, vacuumizing same and introducing argon therein for protection, increasing the power by gradient so as to raise the temperature within the furnace body, such that metal ingots fully melt and are in a half-suspended state by means of joule heat released in the furnace body, and under the action of a continuous Lorentz Force, the melt is completely suspended and electromagnetic stirring is carried out; the formed alloy being continuously kept in the molten state for a period of time, so that the alloy components are homogenized; and finally, a CuTi50 intermediate alloy bar being obtained by means of casting, cooling and cylindrical turning. The CuTi50 intermediate alloy prepared from the method has advantages such as good homogeneity, having no inclusions and oxidation defects and having a low gas content, and can be used for copper-titanium alloy (the titanium content being 1%-5%) smelting.

Description

A kind of copper-titanium 50 master alloy and its preparation method using magnetic levitation smelting process

This application claims the priority of Chinese patent application 202010610331.2 with the filing date of 2020/6/29. This application cites the full text of the above Chinese patent application.

technical field

The invention belongs to the technical field of copper alloy preparation, and in particular relates to a copper-titanium 50 intermediate alloy and a method for preparing it using a magnetic suspension smelting process.

Background technique

Copper-titanium alloy (Ti content of 1% to 5%) was developed by the former Soviet Union in the late 1950s. After proper treatment, it has high ductility, elasticity, heat resistance, fatigue resistance, good processability and minimum bending. radius ratio, as well as pulse-free spark performance and good high temperature stress relaxation resistance. Since the last century, my country has started the smelting production process of titanium-copper alloys. According to the production research of Jiangxi Nonferrous Metal Smelter, it uses first-grade sponge titanium and electrolytic copper plate, and uses non-vacuum melting low-titanium copper alloy. During the production process, depending on the degree of stirring, there will be different degrees of uneven composition, mainly due to titanium The specific gravity is light, and there will be a floating phenomenon, which leads to the phenomenon that the titanium content of the upper part of the ingot is higher than that of the lower part. In addition, titanium is very active at high temperature and can react with many elements and compounds. It is easy to burn out and generate impurities using conventional vacuum or non-vacuum induction melting. At present, the mature copper-titanium alloy smelting process in the world mainly uses copper and intermediate alloys for vacuum smelting. The production enterprises are mainly concentrated in Japan. The research on this alloy in my country is still in its infancy, and no domestic enterprises have put it into mass production. The use of this material is completely dependent on imports, and the overall supply is in short supply, so localization is urgently needed.

The master alloy is hereditary, and its properties will be completely transferred to the smelted alloy. Therefore, the master alloy plays a vital role in the localization of copper-titanium alloys (with Ti content of 1% to 5%) in China. .

Based on the actual production, the overall production cost of CuTi (20-55) master alloy is not very different. Therefore, considering the production cost of the enterprise and meeting the use requirements and characteristics of the master alloy, the higher the titanium content of the master alloy, our The production cost of CuTi (1% to 5%) is lower. Therefore, a CuTi (31-55) master alloy prepared by the magnetic levitation melting method is proposed.

Water-cooled copper crucible magnetic levitation smelting is an effective method for preparing high-melting, high-purity, active or radioactive materials. By inputting high-frequency alternating current to the induction coil surrounding the outer surface of the crucible, a high-frequency alternating magnetic field is generated around the coil; under vacuum conditions Next, the smelting material is placed in a high-frequency magnetic field, and the metal crucible cooled by water is used as a "concentrator" of the magnetic field, so that the energy of the energy magnetic field is concentrated in the volume space of the crucible, and then a strong eddy current is formed near the surface of the charge. At this time, a large amount of Joule heat is released from the furnace to melt the charge, and a Lorentz force field is formed to suspend the melt and electromagnetic stirring; the melt is separated from the crucible, which avoids the contamination of the crucible during the melting process of the melt. Keep the melt composition uniform. In this process, large induced eddy currents and levitation forces are generated in the melt, so that the melt does not contact the crucible wall, thus also allowing the melt to obtain a high temperature and prevent contamination. However, the electromagnetic stirring force used in electromagnetic suspension stirring is limited, and the problem of mixing difficulty is more likely to occur when preparing master alloys with large titanium content. It is often necessary to prolong the melting time to achieve the purpose of uniform mixing, but excessive melting time is easy to lead to metal elements. The volatilization loss results in a large deviation of the Ti content in the final alloy.

SUMMARY OF THE INVENTION

In view of the above existing technical problems, the present invention provides a method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process.

The technical scheme of the present invention is: a method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process, comprising the following steps:

(1) batching: according to the weight percentage content of Ti is 31%-55%, and Cu is the balance, the copper alloy elements are proportioned, and the corresponding raw materials are selected and weighed;

(2) Magnetic levitation smelting: the deposition block is loaded into the cold crucible of the vacuum magnetic levitation furnace, electrified, evacuated and filled with argon protection, and the power is increased to make the furnace body heat up until the deposition block is fully melted and semi-suspended. Under the continuous Loren magnetic force, the melt is completely suspended, and electromagnetic stirring is performed, and the formed alloy is kept in the molten state for a period of time, so that the alloy composition is uniform;

(3) Pouring: turn off the power supply and gradually turn off the power button at a certain rate, the device is completely turned off, and the alloy solution is poured into the mold cavity;

(4) Cooling: first open the lock on the cover of the vacuum melting furnace, open the gas valve, when the air pressure in the vacuum melting furnace drops to atmospheric pressure, close the gas valve, open the furnace for cooling, and release the furnace after it is completely cooled into an ingot;

(5) Turning the outer circle: The ingot is clamped on a lathe for turning the outer circle to obtain a CuTi50 master alloy bar.

Further, in the step (1), Ti adopts grade 0 sponge titanium with a purity of ≥99.7%, and Cu adopts an electrolytic copper plate with a purity of ≥99.99%.

Further, the cold crucible described in step (2) is a copper crucible. Using a copper crucible can avoid introducing impurities into the copper-titanium alloy.

Further, in the magnetic levitation smelting process in step (2), vacuumize for about 20min-25min, until the vacuum degree reaches ^10-3 Pa, and then rush into argon for protection, so that the pressure in the furnace reaches 0.02MPa-0.03MPa.

Further, in the magnetic levitation smelting process of step (2), first increase the power at 10-15KW/min to 100KW-120KW to make the temperature in the furnace reach 1750°C-1850°C, and heat for 5min-8min until the metal ingot is completely melted.

Further, in the magnetic levitation smelting process in step (2), the alloy is kept in a molten state for 1min-5min to make the alloy composition uniform. The two metals of copper and titanium are deposited by cold spray powder and then smelted by magnetic suspension, which can speed up the convection rate of the melt, facilitate the homogenization of components and the discharge of impurities and gases, shorten the total smelting time, and reduce the volatilization loss of metal elements.

Further, after smelting, the power was cut off to stop heating, and argon gas was introduced to the furnace to balance the pressure with the external atmospheric pressure. The temperature was 0-4°C, and the NaCl aqueous solution with a volume concentration of 10% was used as the cooling circulating water of the cold crucible. The alloy melt was cooled to room temperature at a rate of -200°C/s. By adding low-temperature cooling circulating water to rapidly cool down the alloy melt, the microstructure density of the alloy can be improved.

Further, the alloy smelting pretreatment is also included before the magnetic levitation smelting: the Ti raw materials and the Cu raw materials are respectively powdered by the EIGA method to obtain Ti powder and Cu powder with a particle size of 100 μm-200 μm, and the Ti powder and Cu powder are obtained. After mixing, use an inert gas-protected jet mill for grinding, so that the Ti powder and Cu powder collide with each other under the action of air flow to fully activate to obtain a copper-titanium mixture. Bombard the spray gun and perform cold spraying layer by layer to obtain a deposit block;

Further, the specific method of using jet mill for the Ti powder and Cu powder is as follows: the Ti powder and the Cu powder are mixed uniformly and put into the pulverizing chamber of the jet mill, and the inert gas is filled to make the Ti powder and the Cu powder completely isolated from the air, Increasing the flow rate of the inert gas is used to pressurize the Ti powder and Cu powder from two opposite nozzles. The nozzle pressure is controlled at 0.7-1.0Mpa, so that the Ti powder and Cu powder are repeatedly impacted and collided to achieve the effect of grinding activation and time control. Within 40-60min, the copper-titanium mixture powder obtained after grinding enters the impeller classification area, and the copper-titanium mixture powder in the appropriate particle size range is sieved under the action of the centrifugal force of the classification wheel at 3500-4000 rpm and the fan. The use of inert gas for grinding can effectively control the oxidation rate of Ti powder and Cu powder, and also reduce grinding loss and avoid raw material powder pollution caused by grinding media. Larger nozzle pressure can make the impact particle size of Ti powder and Cu powder larger, shorten the jet milling time, and avoid powder grinding too fine and difficult for cold spraying.

Further, the suitable particle size range of the copper-titanium mixture powder is 20 μm-40 μm. The use of copper-titanium solid solution powder less than 20μm is prone to fly powder and is not easy to deposit during the cold spraying process, while the use of copper-titanium mixture powder larger than 40μm will cause the internal density of the deposit block to decrease relatively due to the large particle size.

Further, the cold spraying process is specifically as follows: the copper-titanium mixture powder is loaded into the supersonic particle bombardment spray gun, the electrolytic copper plate is used as the cushion layer, and the copper-titanium mixture powder sprayed from the gun mouth during the cold spraying process is 1200m/s. The speed spraying is carried out layer-by-layer deposition on the electrolytic copper plate. The gas pressure of the cold spraying process is 1.0-2.0MPa, the gas heating temperature is 150℃, the powder feeding rate is controlled at 30g/min, the distance from the spray gun outlet to the deposition surface is controlled at 10mm, and the spray gun moves The speed is 50mm/min, the deposition thickness is 50mm-80mm, and after the cold spraying is completed, the deposition layer and the cushion layer are cut and separated to obtain a deposition block. After cold spray deposition, the copper-titanium mixture powder can be closely combined without high-temperature sintering, which can reduce the element loss during magnetic levitation smelting, and further improve the uniformity of the melt mixing of copper and titanium during the smelting process. Shorten the homogenization time of alloy components, which is beneficial to the discharge of impurities in the melt.

The invention provides a preparation method of a copper-titanium 50 master alloy, which comprises the following steps: smelting alloy raw materials through vacuum magnetic levitation to obtain a molten liquid, and pouring and cooling the molten liquid; wherein:

In terms of weight percentage, Ti in the alloy raw material is 31-55%, and the balance is Cu.

In the present invention, the Ti can be sponge titanium, such as grade 0 sponge titanium with a purity of ≥99.7%.

In the present invention, the Cu can be electrolytic copper, such as electrolytic copper plate with a purity of ≥99.99%. The electrolytic copper plate can be cut into small pieces with a side length of less than 3 cm and mixed with the Ti.

In the present invention, the content of Ti is preferably 31%, 50.5% or 55%.

In the present invention, the magnetic levitation smelting process can be a conventional magnetic levitation smelting process in the field. For example, in a vacuum magnetic levitation furnace, the temperature is increased by electrification, and the temperature is kept warm, so that the alloy raw material is melted to form a molten liquid, and under the continuous action of Loren magnetic force , suspend the molten liquid and conduct electromagnetic stirring.

Wherein, the alloy raw material is generally placed in the crucible of the vacuum magnetic levitation furnace. The crucible may be a copper crucible.

Wherein, after the power is turned on, it should generally be evacuated and filled with argon for protection. The evacuation time may be about 20-25 min (eg, 22 min). The vacuuming can be performed until the degree of vacuum reaches 10 ^-3 Pa, and then filled with argon for protection, so that the pressure in the furnace reaches 0.02MPa-0.03MPa.

Wherein, the power-on temperature increase may be 10-15KW/min (eg, 12KW/min) to increase the power to 100-120KW (eg, 110KW).

Wherein, the temperature of the heat preservation may be 1750-1850°C, for example, 1800°C.

Wherein, the holding time may be 5-8min, for example, 7min.

Wherein, the molten state can be maintained for 0.5-5 min, for example, 0.5 min, 1.5 min or 5 min.

In the present invention, the pouring process may be a conventional pouring process in the field, for example, pouring the molten liquid into a mold cavity.

Wherein, before the pouring, the magnetic suspension furnace in the magnetic suspension melting can be gradually closed at a rate of 5KW/3min.

In the present invention, the cooling process can be a conventional cooling process in the field. For example, the vacuum magnetic levitation melting furnace is opened, and the gas valve is opened. When the pressure in the vacuum melting furnace is reduced to atmospheric pressure, the gas valve is closed, and the furnace is opened for cooling. After it is completely cooled into an ingot, it can be released from the furnace.

Wherein, in the process of opening the furnace for cooling, circulating water may be introduced for cooling.

The temperature of the circulating water may be 0-4°C, such as 4°C.

The circulating water can be an aqueous NaCl solution with a volume concentration of 10%.

The cooling rate of the circulating water for cooling may be 150-200°C/s.

In the present invention, after the cooling, it can also be processed by turning the outer circle according to the conventional operation in the field. For example, the ingot formed after cooling is processed by turning the outer circle to obtain a bar of the copper-titanium 50 master alloy.

In the present invention, the Ti and the Cu can be separately pulverized to obtain Ti powder and Cu powder, and then mixed to obtain a copper-titanium mixture powder, and the copper-titanium mixture powder is formed into a deposition layer before vacuum magnetic suspension smelting.

Wherein, the milling method may be the EIGA method.

Wherein, the particle size of the Ti powder may be 100-200 μm, for example, 150 μm.

Wherein, the particle size of the Cu powder may be 100-200 μm, for example, 150 μm.

Wherein, the Ti powder and the Cu powder can be ground under the condition of jet mill to obtain the copper-titanium mixture powder. Preferably, the Ti powder and the Cu powder are sprayed from two opposite nozzles and then subjected to jet milling to obtain the copper-titanium mixed powder.

The pressure of the gas in the nozzle may be 0.7-1.0 Mpa, for example, 0.8 Mpa.

The grinding time may be 40-60 min, eg 50 min.

After the grinding, the copper-titanium mixture powder with a particle size of 20-40 μm (eg, 30 μm) can be sieved. The sieving can be performed by the centrifugal force of the classification wheel and the fan. The rotational speed of the classification wheel may be 3500-4000 rpm, eg 3800 rpm.

Wherein, the copper-titanium mixture powder can form a deposition layer on the electrolytic copper plate by a cold spraying process.

The cold spraying can be carried out by means of a supersonic particle bombardment spray gun. The distance from the outlet of the supersonic particle bombardment lance to the deposition surface may be 8-12 mm, eg, 10 mm. The moving speed of the supersonic particle bombardment lance may be 45-50 mm/min, such as 50 mm/min.

The gas pressure of the cold spraying process may be 1.0-2.0 Mpa, for example, 1.5 Mpa.

The gas temperature of the cold spray process may be 140-160°C, eg 150°C.

In the cold spraying process, the powder feeding amount may be 25-35 g/min, for example, 30 g/min.

The thickness of the deposited layer may be 60-80 mm, eg 70 mm.

In the present invention, the Ti and the Cu can be pulverized to obtain Ti powder and Cu powder, respectively, and then molded, and then sintered in sections, and the sintered copper-titanium alloy is smelted by vacuum magnetic suspension.

Wherein, the segmented sintering process is preferably firstly treated at 1350-1400°C (eg 1380°C) for 0.5-1.5h (eg 1h), then heated to 1650-1700°C (eg 1680°C) for 0.5-1.5h (eg 1680°C) 1h).

In the present invention, the Ti and the Cu can be separately pulverized to obtain Ti powder and Cu powder, mixed and then ball-milled, and then deposited to obtain a deposition block, and the deposition block is smelted by vacuum magnetic levitation.

Wherein, the time of the ball milling may be 1-3h, for example, 2h.

Wherein, the ratio of balls to material can be 1:(8-12), such as 1:10.

Wherein, the deposition method may be cold spray deposition.

In the present invention, the Ti and the Cu can be separately pulverized to obtain Ti powder and Cu powder, and after mixing, deposition is performed to obtain a deposition block, and the deposition block is smelted by vacuum magnetic suspension.

Wherein, the deposition method may be cold spray deposition.

The present invention also provides a copper-titanium 50 intermediate alloy prepared by the above method.

The present invention also provides a copper-titanium 50 master alloy, in terms of weight percentage, in the copper-titanium 50 master alloy:

Ti is 31-55%; relative to the content of the added Ti raw material, the deviation of the Ti content in each part of the copper-titanium 50 master alloy is within ±2.5;

O content≤0.0040%;

N content≤0.0015%;

C content≤0.0144%;

S content≤0.006%.

Wherein, preferably, relative to the content of the added Ti raw material, the deviation of the Ti content of each part in the copper-titanium 50 master alloy is within ±1, for example, within ±0.5.

Wherein, preferably, the O content is less than 0.0020%.

Wherein, preferably, the N content is less than 0.0010%.

Wherein, preferably, the C content is less than 0.0050%.

Wherein, preferably, the S content is less than 0.0010%.

Wherein, preferably, the metallographic diagram of the copper-titanium 50 master alloy is shown in FIG. 1 or FIG. 2 .

The beneficial effects of the present invention are as follows: the present invention uses electrolytic copper plate and grade 0 sponge titanium as raw materials, and the smelting process adopts water-cooled copper crucible magnetic levitation smelting, so that the CuTi (31-55) alloy is suspended in the furnace during smelting without contacting the crucible wall, Continuous stirring under the action of magnetic force ensures that the material is not contaminated and has high uniformity, and also avoids the occurrence of oxidation and inclusion of the material. In a word, the CuTi50 master alloy prepared by the present invention can realize the detection of Ti content within a tolerance of ±0.5, and the content of O, N, C, S and other gases can be controlled below 50ppm. The CuTi (31-55) master alloy prepared by the method has the advantages of good uniformity, no inclusions, oxidation defects and low gas content, and can be used for smelting copper-titanium gold (1%-5% titanium content).

Description of drawings

1 is a ×50 metallographic diagram of the CuTi50 master alloy prepared in Example 1 of the present invention;

FIG. 2 is a ×500 metallographic diagram of the CuTi50 master alloy prepared in Example 1 of the present invention.

detailed description

Example 1

A method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process, comprising the following steps:

(1) Ingredients: Proportion the copper alloy elements according to the weight percentage of Ti as 50.5% and Cu as the balance, select and weigh the corresponding raw materials; Ti uses grade 0 sponge titanium with a purity of ≧ 99.7%, and Cu uses Electrolytic copper plate with purity ≥99.99%;

(2) Pretreatment of alloy smelting: The Ti raw materials and Cu raw materials are respectively powdered by an electrode induction melting gas atomization system (EIGA method) to obtain Ti powder and Cu powder with a particle size of 150 μm. After mixing evenly, put it into the crushing chamber of the jet mill, fill it with inert gas to completely isolate the Ti powder and Cu powder from the air, and increase the flow rate of the inert gas to pressurize the Ti powder and Cu powder from two opposite nozzles. The pressure is controlled at 0.8Mpa, and the Ti powder and Cu powder are repeatedly impacted and collided to achieve the effect of grinding activation. The time is controlled within 50min. After grinding, the obtained copper-titanium mixture powder enters the impeller classification area. The centrifugal force of the classification wheel at 3800rpm The copper-titanium mixture powder with a particle size of 30 μm is sieved under the action of the fan; then the copper-titanium mixture powder is loaded into the supersonic particle bombardment spray gun. The powder is sprayed on the electrolytic copper plate at a speed of 1200m/s for layer-by-layer deposition. The gas pressure of the cold spraying process is 1.5MPa, the gas heating temperature is 150℃, the powder feeding rate is controlled at 30g/min, and the distance from the spray gun outlet to the deposition surface is controlled at 10mm , the moving speed of the spray gun is 50mm/min, and the deposition thickness is 70mm. After the cold spraying is completed, the deposition layer and the cushion layer are cut and separated to obtain a deposition block.

(3) Magnetic levitation smelting: the deposition block is loaded into the cold crucible of the vacuum magnetic levitation furnace, energized, evacuated for about 22min, to the degree of vacuum reaching 10 ^-3 Pa, and then rushing into argon protection to make the pressure in the furnace reach 0.03 MPa. First increase the power at 12KW/min to 110KW to make the temperature in the furnace reach 1800 ℃, keep heating for 7 minutes until the metal ingot is completely melted and semi-suspended. Under the continuous action of Loren magnetic force, the melt is completely suspended and electromagnetic stirring is carried out. , the formed alloy is kept in the molten state for 1.5min to homogenize the alloy composition.

(4) Pouring: turn off the power supply and gradually turn off the power button at a rate of 5KW/3min, the device is completely turned off, and the alloy solution is poured into the mold cavity;

(5) Cooling and forming: Cooling: first open the lock on the cover of the vacuum melting furnace, open the gas valve, when the pressure in the vacuum melting furnace drops to atmospheric pressure, close the gas valve, open the furnace for cooling, and completely cool it into an ingot before releasing it; During cooling, a NaCl aqueous solution with a temperature of 4°C and a volume concentration of 10% was used as the cooling circulating water of the cold crucible, and the alloy melt was cooled to room temperature at a speed of 180°C/s to obtain melting balls.

(6) lathe outer circle: the ingot is clamped on a lathe to carry out lathe outer circle processing to obtain a CuTi50 master alloy bar.

Example 2

(2) Magnetic levitation smelting: the sedimentary block obtained by step (2) in Example 1 is loaded into the cold crucible of the vacuum magnetic levitation furnace, energized, and evacuated for about 22min, to the degree of vacuum reaching 10 ^-3 Pa, and then rush into Argon protection, so that the furnace pressure reached 0.03MPa. First increase the power at 12KW/min to 110KW to make the temperature in the furnace reach 1800°C, keep heating for 7 minutes until the metal ingot is completely melted and semi-suspended. Under the continuous action of Loren magnetic force, the melt is completely suspended and electromagnetic stirring is performed. , the formed alloy was kept in molten state for 5 min to homogenize the alloy composition.

Example 3

This example is basically the same as Example 1, except that in step (2) of this example, the Ti raw materials and Cu raw materials are respectively powdered by the EIGA method to obtain Ti powder and Cu powder with a particle size of 150 μm. The two metal powders are filled into the product mold for molding, and then the molded compact is sintered in stages. The staged sintering process is to first treat at 1380 ° C for 1 hour, then heat up to 1680 ° C for 1 hour, and obtain sintered copper after cooling. Titanium alloy. The copper-titanium alloy is then smelted by magnetic suspension in step (3), and the conditions of the remaining steps are the same as those in Example 1.

Example 4

This example is basically the same as Example 1, except that in step (2) of this example, a ball mill is used to grind and activate Ti powder and Cu powder for 2 hours, and the ratio of ball to material is 1:10. Then, cold spray deposition is performed to obtain a deposition block. The rest of the step conditions are the same as in Example 1.

Example 5

This example is basically the same as Example 1, the difference is that in step (2) of this example, the Ti powder and Cu powder are not ground and activated, but are directly mixed evenly and then deposited by cold spray to obtain a deposit block. The rest of the step conditions are the same as in Example 1.

Example 6

This embodiment is basically the same as Embodiment 1, the difference is that in step (2) of this embodiment, after the electrolytic copper plate is cut into small pieces less than about 3 cm, it is directly mixed with Ti raw material to perform magnetic levitation smelting. The rest of the step conditions are the same as in Example 1.

The uniformity of the CuTi50 master alloy prepared in Example 6 is comparable to that of the CuTi50 master alloy prepared in Example 5.

Experimental example 1

For the CuTi50 master alloys prepared by different methods in Examples 1-5 (the original addition of Ti is 50wt%, and the balance is Cu), more than five different parts are randomly selected. After ICP detection, the mass fraction of Ti is shown in Table 1.

Table 1 ICP composition detection of CuTi25 master alloy

As can be seen from Table 1, the Ti content detection of the master alloy (CuTi50) prepared in Example 1 is within the tolerance of ±0.5, indicating that the composition difference of different parts is not large, while the detection tolerance of Ti content of other embodiments is all outside ±1 , indicating that the composition of different parts is quite different.

Experimental example 2

Four alloys of CuTi25, CuTi31, CuTi55, and CuTi60 were prepared by the preparation method of Example 1. The initial addition amounts of Ti of the four alloys of CuTi25, CuTi31, CuTi55, and CuTi60 were 25wt%, 31wt%, 55wt%, and 60wt%, respectively. All are the remainder, and more than 5 different parts of each alloy are randomly selected. After ICP detection, the mass fraction of Ti is shown in Table 2.

Table 2 ICP composition detection of CuTi(25-60) master alloy

It can be seen from Table 2 that the detection tolerances of Ti content of CuTi31 and CuTi55 and CuTi50 in Table 1 are within ±0.5, indicating that the composition difference of different parts is not large, while the detection tolerances of Ti content of CuTi25 and CuTi60 are both outside ±1. This may be due to the fact that the ratio of Ti powder and Cu powder must be controlled within an appropriate ratio range during jet milling in the alloy pretreatment method of Example 1 of the present invention, otherwise Ti powder and Cu powder are evenly collided and combined to form a copper-titanium mixture. If the quantity is small, the homogenization of the copper-titanium melt will be affected to a certain extent during magnetic levitation smelting, resulting in a large deviation of the alloy composition.

Experimental example 3

For the CuTi50 master alloy prepared by different methods in Examples 1-5 (the original addition amount of Ti is 50wt%, and the balance is Cu), five or more different parts are randomly selected, and the gas content is detected by an oxygen-nitrogen analyzer and a carbon-sulfur analyzer. , the test results are shown in Table 3 below.

Table 3 Detection of gas content in CuTi50 master alloy

It can be seen from Table 3 that the content of O, N, C, S and other gases in the CuTi50 master alloy prepared in Examples 1 and 2 can be controlled to be less than 30 ppm, and Example 1 is better. And from the metallographic photos of the two CuTi50 master alloys in Figure 1 and Figure 2, the CuTi50 master alloy prepared in Example 1 has a uniform phase distribution of copper-titanium compounds with different atomic ratios, no obvious segregation is found, and no obvious oxide inclusions and pores are found in the structure. And loose and other defects, can be used for copper-titanium alloy (titanium content 1%-5%) smelting.

Example 2-5 adopts the same magnetic levitation smelting parameters as in Example 1 because the alloy pretreatment method is different from that in Example 1, especially the time that the alloy is kept in the molten state to make the alloy composition uniform. The copper and titanium are mixed evenly in advance, so the impurities can be expelled in a short smelting time, thereby obtaining an alloy with a purer composition. However, under this smelting time, Examples 2-5 could not remove the impurities in time, which eventually led to ineffectiveness. good.

Experimental example 4

Taking the preparation method of Example 1 as an example, the effects of different smelting and homogenization times on the composition and gas impurities in the CuTi50 master alloy (the original addition of Ti is 50.5wt% and the balance is Cu) are studied. The smelting and homogenization times of experimental groups 1-3 were set to be 0.5min, 1.5min, and 5min respectively, and the rest of the magnetic levitation smelting conditions were the same. The test results are shown in Tables 4 and 5.

Table 4 ICP composition detection of CuTi50 master alloy under different melting and homogenization time in experimental groups 1-3

Table 5 Detection of gas content of CuTi50 master alloy under different melting and homogenization time in experimental groups 1-3

It can be seen from Table 5 that the impurity gas contents of experimental groups 2 and 3 are similar, and both are significantly better than those of experimental group 1, indicating that the longer the smelting homogenization time is, the more conducive to the homogenization of components and the discharge of impurity gases, but the combination of the table 4 It can be seen that the Ti content of experimental group 2 is detected within the tolerance ±0.5, while the Ti content of experimental groups 1 and 3 is detected outside the tolerance ±1, indicating that although the long melting time is conducive to the homogenization of the alloy composition, the melting time is prolonged. It will cause copper to evaporate, resulting in a relatively high proportion of titanium. Therefore, on the whole, the smelting homogenization time of 1.5min in experimental group 2 has the best overall effect.

In the present invention, the Ti raw material and the Cu raw material are respectively prepared by EIGA method, and ground by an inert gas-protected airflow mill, so that the Ti powder and the Cu powder are collided with each other under the action of the airflow to be fully activated to obtain a copper-titanium mixture, which improves the chemical properties of the two metals. The degree of bonding, and then layer-by-layer deposition of cold spray to obtain a high-density Ti-Cu deposit block, which can greatly improve the degree of homogenization of copper and titanium elements during magnetic levitation smelting, and solve the problem of insufficient mixing due to density difference. And it only needs to be smelted once, which also avoids the element burnout and composition deviation caused by multiple smelting. In a word, the Ti content of the CuTi50 master alloy prepared by the present invention is detected within the tolerance ±0.5, and the gas content of O, N, C, S and the like can be controlled below 30ppm. The CuTi (31-55) master alloy prepared by the method has the advantages of good uniformity, no inclusions, oxidation defects, and low gas content, and can be used for smelting copper-titanium alloys (with titanium content of 1%-5%).

Comparative Example 1

Take the CuTi25 master alloy smelted in vacuum, and the raw materials are grade 0 or 1 sponge titanium and electrolytic copper plate.

Table 6 shows the composition detection results of the CuTi25 master alloy using vacuum melting. Table 7 shows the gas composition detection of the CuTi25 master alloy using vacuum melting.

Table 6 ICP composition detection of vacuum melting CuTi25 master alloy

Table 7 Detection of ICP gas composition of CuTi25 master alloy in vacuum melting

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and various changes may be made to these embodiments without departing from the principle and essence of the present invention. Revise. Accordingly, the scope of protection of the present invention is defined by the appended claims.

Claims

A preparation method of a copper-titanium 50 master alloy, characterized in that it comprises the following steps: smelting alloy raw materials through vacuum magnetic levitation to obtain a molten liquid, pouring and cooling the molten liquid, and getting final product; wherein:

In terms of weight percentage, Ti in the alloy raw material is 31-55%, and the balance is Cu.
The method for preparing a copper-titanium 50 master alloy according to claim 1, wherein the Ti is sponge titanium, such as grade 0 sponge titanium with a purity of ≥99.7%;

And/or, the Cu is electrolytic copper, such as electrolytic copper plate with a purity of ≥99.99%;

And/or, the content of Ti is 31%, 50.5% or 55%;

And/or, the process of the magnetic levitation smelting is: in a vacuum magnetic levitation furnace, electrified to heat up and keep warm, so that the alloy raw material is melted to form a molten liquid, and under the continuous Loren magnetic force, the molten liquid is suspended and carried out. Electromagnetic stirring is enough; wherein, the power-on heating can be increased to 100-120KW at 10-15KW/min; the temperature of the heat preservation can be 1750-1850°C, for example, 1800°C; the time of the heat preservation can be 5-8min, such as 7min; the molten state can be maintained for 0.5-5min, such as 0.5min, 1.5min or 5min;

And/or, the pouring process is as follows: pouring the molten liquid into a mold cavity, that is;

And/or, the cooling process is: opening the vacuum magnetic levitation smelting furnace, opening the gas valve, when the pressure in the vacuum smelting furnace drops to atmospheric pressure, closing the gas valve, opening the furnace for cooling, and completely cooling it into an ingot and releasing it, that is, Yes; wherein, in the process of opening the furnace for cooling, circulating water can be introduced for cooling; the temperature of the circulating water can be 0-4°C, such as 4°C; the circulating water can be a volume concentration of 10%. NaCl aqueous solution; the cooling rate of the circulating water for cooling can be 150-200°C/s;

And/or, after the cooling, the ingot formed after cooling is processed by turning the outer circle to obtain a rod of the copper-titanium 50 master alloy.
The method for preparing a copper-titanium 50 master alloy according to claim 1 or 2, wherein the Ti and the Cu are respectively powdered to obtain Ti powder and Cu powder, and then mixed to obtain a copper-titanium mixture powder, and the After the copper-titanium mixture powder forms a deposition layer, vacuum magnetic levitation smelting is carried out;

The milling method can be the EIGA method;

The particle size of the Ti powder may be 100-200 μm, such as 150 μm;

The particle size of the Cu powder may be 100-200 μm, such as 150 μm;

The Ti powder and the Cu powder can be ground under the condition of jet milling to obtain the copper-titanium mixture powder; preferably, the Ti powder and the Cu powder are sprayed from two opposite nozzles and then subjected to jet milling to obtain the powder. Copper-titanium mixture powder; the pressure of the gas in the nozzle can be 0.7-1.0Mpa, such as 0.8Mpa; the grinding time can be 40-60min, such as 50min; after the grinding, the particle size that can be sieved is 20 -40μm copper-titanium mixture powder;

The copper-titanium mixture powder can form a deposition layer on the electrolytic copper plate by a cold spraying process; the cold spraying can be performed by a supersonic particle bombardment spray gun; the distance from the outlet of the supersonic particle bombardment spray gun to the deposition surface can be 8-12mm, For example, 10mm; the moving speed of the supersonic particle bombardment spray gun can be 45-50mm/min, such as 50mm/min; the gas pressure of the cold spraying process can be 1.0-2.0Mpa, such as 1.5Mpa; the cold spraying process The gas temperature can be 140-160 ℃, such as 150 ℃; in the cold spraying process, the powder feeding rate can be 25-35g/min, such as 30g/min; the thickness of the deposition layer can be 60-80mm, such as 70mm.
The method for preparing a copper-titanium 50 master alloy according to claim 1 or 2, wherein the Ti and the Cu are powdered to obtain Ti powder and Cu powder, respectively, and then molded, and then sintered in sections, and the sintered Vacuum magnetic levitation smelting of copper-titanium alloys;

The segmented sintering process is preferably firstly treated at 1350-1400°C for 0.5-1.5h, and then heated to 1650-1700°C for 0.5-1.5h.
The method for preparing a copper-titanium 50 master alloy according to claim 1 or 2, wherein the Ti and the Cu are respectively powdered to obtain Ti powder and Cu powder, mixed and then ball-milled, and then deposited to obtain a deposit block , carry out vacuum magnetic levitation smelting to the sedimentary block;

The time of the ball milling can be 1-3h, such as 2h;

The ball to charge ratio can be 1:(8-12), eg 1:10.
The method for preparing a copper-titanium 50 master alloy according to claim 1 or 2, wherein the Ti and the Cu are respectively powdered to obtain Ti powder and Cu powder, and after mixing, deposition is performed to obtain a deposited block, and the The deposition block is smelted by vacuum magnetic suspension; the deposition method can be cold spray deposition.
A method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process, characterized in that it comprises the following steps:

(1) batching: according to the weight percentage content of Ti is 31%-55%, and Cu is the balance, the copper alloy elements are proportioned, and the corresponding raw materials are selected and weighed;

(2) Magnetic levitation smelting: the above-mentioned metal raw materials are loaded into the cold crucible of the vacuum magnetic levitation furnace, energized, evacuated and filled with argon protection, and the power is increased to make the furnace body heat up until the sediment blocks are fully melted and semi-suspended. Under the action of the Loren magnetic force, the melt is completely suspended, and electromagnetic stirring is performed, and the formed alloy is kept in the molten state for a period of time to make the alloy composition uniform;

(3) Pouring: turn off the power supply and gradually turn off the power button at a certain rate, the device is completely turned off, and the alloy solution is poured into the mold cavity;

(4) Cooling: first open the lock on the vacuum melting furnace cover, open the gas valve, when the air pressure in the vacuum melting furnace drops to atmospheric pressure, close the gas valve, open the furnace for cooling, and completely cool it into an ingot and release it;

(5) Turning the outer circle: The ingot is clamped on a lathe for turning the outer circle to obtain a CuTi50 master alloy bar.
A method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process as claimed in claim 7, wherein in the step (1), Ti adopts grade 0 sponge titanium with a purity of ≧99.7%, and Cu adopts a purity of ≧99.99 % of electrolytic copper plate.
A method for preparing CuTi50 master alloy using a magnetic levitation smelting process as claimed in claim 7 or 8, wherein the cold crucible in step (2) is a copper crucible.
A method for preparing copper-titanium 50 master alloy using magnetic levitation smelting process according to at least one of claims 7-9, it is characterized in that, in the magnetic levitation smelting process in step (2), vacuum is drawn for about 20min-25min, to The vacuum degree reaches 10 -3 Pa, and then rush into argon protection, so that the pressure in the furnace reaches 0.02MPa-0.03MPa.
A method for preparing copper-titanium 50 master alloy using magnetic levitation smelting process according to at least one of claims 7-10, it is characterized in that, in the process of smelting metal ingots by magnetic levitation in step (2), firstly 10-15KW/ min. Increase the power to 100KW-120KW to make the temperature in the furnace reach 1750℃-1850℃, and keep heating for 5min-8min until the metal ingot is completely melted.
A method for preparing a copper-titanium 50 master alloy using a magnetic levitation smelting process according to at least one of claims 7 to 11, characterized in that, during the magnetic levitation smelting of the metal ingot in step (2), the alloy continues to be in a molten state. Hold for 1min-5min to homogenize the alloy composition.
A method for preparing CuTi50 master alloy using magnetic levitation smelting process according to at least one of claims 7-12, characterized in that, in step (3), the speed of gradually closing the power button at a certain rate is 5KW/3min.
A copper-titanium 50 master alloy prepared by the preparation method according to at least one of claims 1-13.
A copper-titanium 50 master alloy, characterized in that, by weight percentage, in the copper-titanium 50 master alloy:

Ti is 31-55%; relative to the content of the added Ti raw material, the deviation of the Ti content in each part of the copper-titanium 50 master alloy is within ±2.5;

O content≤0.0040%;

N content≤0.0015%;

C content≤0.0144%;

S content≤0.006%;

Preferably, relative to the content of the added Ti raw material, the deviation of the Ti content of each part in the copper-titanium 50 master alloy is within ±1, for example, within ±0.5;

Preferably, the O content is less than 0.0020%;

Preferably, the N content is less than 0.0010%;

Preferably, the C content is less than 0.0050%;

Preferably, the S content is less than 0.0010%;

Preferably, the metallographic diagram of the copper-titanium 50 master alloy is shown in FIG. 1 or FIG. 2 .