High-strength high-conductivity tib2 / cu composite material and in-situ liquid forming method thereof

Abstract

The application discloses a high-strength and high-conductivity TiB2 / Cu composite material and an in-situ liquid forming method thereof, and the TiB2 content in the TiB2 / Cu composite material is 1-3 wt.%, and the Cu-Ti intermediate alloy, the Cu-B intermediate alloy and pure copper are weighed according to the content, the weighed components are put into a double-cavity crucible, the Cu-Ti intermediate alloy and the Cu-B intermediate alloy are respectively put into two cavities, the pure copper is also put into the two cavities, then the double-cavity crucible is placed in a vacuum induction melting furnace for melting to obtain a metal liquid, meanwhile, the plugs of the two liquid outlets of the double-cavity crucible are pulled out, the metal liquid in the two cavities is poured into a gradient water-cooled copper mold through a current combiner, and a cast TiB2 / Cu composite material is obtained, and finally, rolling is carried out, and a high-strength and high-conductivity TiB2 / Cu composite material is obtained; the application blocks the generation of TiB2 particles in the melting process, and solves the component segregation problem in the existing TiB2 / Cu composite material.

Description

Technical Field

[0001] This invention belongs to the field of liquid forming technology of metal matrix composites, and relates to high-strength and high-conductivity TiB2 / Cu composite materials and their in-situ liquid forming method. Background Technology

[0002] Compared to commonly used high-conductivity dispersion copper alloys, dispersion-reinforced copper matrix composites have become the preferred choice for electrical materials in many high-temperature, high-load, and high-wear environments due to their excellent resistance to high-temperature softening, arc erosion, and wear. At high temperatures, dispersion-reinforced copper matrix composites can maintain high strength and hardness while still retaining high electrical and thermal conductivity, making them widely applicable in fields such as power transmission, electrical contact, and resistance welding.

[0003] The preparation of composite materials using conventional liquid-phase solidification methods is prone to problems such as porosity inclusions, component segregation, severe agglomeration of the second phase, and incomplete in-situ reaction. Traditional mixed casting uses mechanical stirring to ensure that the second phase particles are evenly distributed throughout the ingot. However, TiB2 particles react and form rapidly in liquid copper, are prone to agglomeration, and have a large density difference with the copper matrix. Traditional casting methods cannot meet the requirements, which limits the preparation of TiB2-reinforced copper matrix composites. Therefore, it is urgent to develop a simple, low-cost preparation technology suitable for industrial production to achieve the preparation of TiB2 / Cu composites with dispersed distribution of reinforcing particles. Summary of the Invention

[0004] One objective of this invention is to provide an in-situ liquid forming method for high-strength and high-conductivity TiB2 / Cu composite materials, which solves the problem of large differences between TiB2 and copper grains in TiB2 / Cu composite materials prepared by existing casting methods, leading to compositional segregation.

[0005] Another object of the present invention is to provide a high-strength, high-conductivity TiB2 / Cu composite material.

[0006] The first technical solution adopted in this invention is an in-situ liquid forming method for high-strength and high-conductivity TiB2 / Cu composite materials, comprising the following steps:

[0007] Step 1: Prepare a Cu-Ti master alloy, consisting of 75-92 wt.% Cu and 8-25 wt.% Ti, with the sum of the mass percentages of the above components being 100%;

[0008] Step 2: Prepare a Cu-B master alloy, consisting of 75-94 wt.% Cu and 6-25 wt% B, with the sum of the mass percentages of the above components being 100%.

[0009] Step 3: Weigh out Cu-Ti master alloy, Cu-B master alloy, and pure copper according to the TiB2 content of 1-3 wt.% in the TiB2 / Cu composite material. Place the weighed components into a double-cavity crucible. The bottom of the double-cavity crucible is equipped with a manifold, and the bottom of the two cavities of the double-cavity crucible is equipped with liquid outlets. Plugs are installed in the liquid outlets. Place the Cu-Ti master alloy and Cu-B master alloy into the two cavities respectively, and also place the pure copper into the two cavities to make the total weight of the materials in the two cavities the same. Then place it in a vacuum induction melting furnace for melting at 1300-1500℃ to obtain molten metal.

[0010] Step 4: Simultaneously unplug the plugs of the two outlets of the double-chamber crucible and pour the molten metal from the two chambers into the gradient water-cooled copper mold through the manifold to obtain the as-cast TiB2 / Cu composite material.

[0011] Step 5: The as-cast TiB2 / Cu composite material is first hot-rolled until the hot rolling deformation reaches 10-50%, and then cold-rolled until the cold rolling deformation reaches 70-90%, thus obtaining the high-strength and high-conductivity TiB2 / Cu composite material.

[0012] In step 1, the Cu-Ti master alloy is prepared by weighing 75-92 wt.% pure Cu and 8-25 wt.% pure Ti, with the sum of the mass percentages of pure Cu and pure Ti being 100%. The weighed pure Cu and pure Ti are placed in a graphite crucible and melted in a vacuum induction melting furnace at 1300-1500℃. After cooling, the Cu-Ti master alloy is obtained.

[0013] Pure Cu and pure Ti are either powdered or block materials. If they are powdered materials, the pure Cu and pure Ti powders are first mixed evenly, then pressed into blocks, and then placed in a graphite crucible for melting. If they are block materials, they are placed directly in a graphite crucible for melting.

[0014] In step 2, the Cu-B master alloy is prepared by weighing 75-94 wt.% pure Cu and 6-25 wt.% pure B, with the sum of the mass percentages of pure Cu and pure B being 100%. The weighed pure Cu and pure B are placed in a graphite crucible and melted in a vacuum induction melting furnace at 1300-1500℃. After cooling, the Cu-B master alloy is obtained.

[0015] Pure Cu and pure B are either powdered or block materials. If they are powdered, the pure Cu and pure B powders are first mixed evenly, then pressed into blocks, and then placed in a graphite crucible for melting. If they are block materials, they are placed directly in a graphite crucible for melting.

[0016] The double-chamber crucible is a cylindrical graphite crucible with a vertical partition installed in the center of the interior. The partition divides the crucible's interior into two separate chambers. Graphite paper is wrapped around the outside of the partition, and graphite paper is also laid on the inner sides of the two chambers. The liquid outlets at the bottom of the two chambers of the double-chamber crucible are the same size and symmetrically positioned.

[0017] The gradient water-cooled copper mold has an annular water-cooling ramp inside its sidewall, with the number of annular water-cooling ramps gradually decreasing from top to bottom.

[0018] In step 3, the molten metal from the two cavities is poured into the gradient water-cooled copper mold through the manifold at a casting temperature of 1300–1500°C.

[0019] The second technical solution adopted in this invention is a high-strength, high-conductivity TiB2 / Cu composite material prepared by the above-mentioned in-situ liquid forming method.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) TiB2 / Cu composite material was prepared by Cu-Ti master alloy, Cu-B master alloy and pure copper. The Cu-Ti master alloy and Cu-B master alloy were placed in the two cavities of the double-cavity crucible, respectively, which blocked the generation of TiB2 particles during the melting process and effectively avoided the generation of segregation and agglomeration.

[0022] (2) In the casting stage, the bimetallic liquid bottom casting method is adopted. The bimetallic liquid is fully mixed and reacted through the manifold. The TiB2 ceramic reinforcing phase is generated in situ by the turbulence effect of the double-beam melt during the collision process. Under the action of the manifold, it smoothly enters the gradient water-cooled copper mold cavity, which is conducive to the discharge of gas in the cavity, greatly reduces the generation of casting defects, and achieves macroscopic uniformity of ingot composition.

[0023] (3) Graphite paper is wrapped around the outside of the partition and graphite paper is laid on the inner sides of the two cavities to avoid the molten metal contaminating the crucible and the partition.

[0024] (4) A gradient water-cooled copper mold is adopted. The inside of the side wall of the copper mold is provided with an annular water-cooling ramp. The number of annular water-cooling ramps gradually decreases from top to bottom. This controls the regular difference in cooling speed of each part of the gradient water-cooled copper mold. The cooling speed gradually decreases from top to bottom. Rapid solidification is conducive to ensuring the uniformity of the composite material structure.

[0025] (5) Cu-Ti master alloy and Cu-B master alloy are placed in two cavities respectively, and pure copper is also placed in two cavities respectively, so that the total weight of the materials in the two cavities is the same, the liquid outlets at the bottom of the two cavities are the same size and symmetrical in position, ensuring that the casting speed of the molten metal on both sides is the same, so as to obtain a TiB2 / Cu composite material with macroscopically uniform composition.

[0026] (6) The casting temperature is controlled at 1300-1500℃ to prevent the molten metal from sticking and clogging the manifold. Attached Figure Description

[0027] Figure 1 This is a metallographic image of the high-strength, high-conductivity TiB2 / Cu composite material prepared in Example 1 of this invention;

[0028] Figure 2 This is a SEM microstructure image of the high-strength, high-conductivity TiB2 / Cu composite material prepared in Example 1 of this invention. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] Example 1

[0031] An in-situ liquid forming method for a high-strength, high-conductivity TiB2 / Cu composite material includes the following steps:

[0032] Step 1: Prepare a Cu-Ti master alloy by weighing 92 wt.% pure Cu blocks and 8 wt% pure Ti blocks, with the sum of the mass percentages of pure Cu and pure Ti being 100%. Place the weighed pure Cu and pure Ti blocks in a graphite crucible and melt them in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1300℃, hold at this temperature for 1 min, turn off the power, cool and take out the sample to obtain Cu-Ti master alloy.

[0033] Step 2: Prepare the Cu-B master alloy, including weighing 94 wt.% pure Cu powder and 6 wt.% pure B powder, with the sum of the mass percentages of pure Cu and pure B being 100%. Place the weighed pure Cu and pure B powders into a container, add stainless steel balls at a ball-to-powder ratio of 2:1, and place the container in a mixer. Mix the powders at a speed of 100 r / min for 8 hours. After pre-pressing at a pressure of 40 MPa for 30 seconds to form a block blank, place it in a graphite crucible and melt it in a vacuum induction melting furnace, ensuring the vacuum degree is less than 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1300℃, hold at this temperature for 1 min, turn off the power, cool and remove the sample to obtain Cu-B master alloy.

[0034] Step 3: Weigh out Cu-Ti master alloy, Cu-B master alloy, and pure copper according to the TiB2 content of 1 wt.% in the TiB2 / Cu composite material. Place each component into a double-chamber crucible. The double-chamber crucible is equipped with a manifold at the bottom, and each of the two chambers has a liquid outlet at the bottom, with a plug installed in the outlet. Place the Cu-Ti master alloy and Cu-B master alloy into the two chambers respectively, and also place the pure copper into the two chambers, ensuring that the total weight of the materials in both chambers is the same. Then place it in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, and hold at 1500℃ for 1 min to obtain molten metal;

[0035] The double-chamber crucible is a cylindrical graphite crucible with a vertical partition installed in the center of the interior. The partition is covered with graphite paper, which divides the crucible's interior into two separate chambers. Graphite paper is laid on the inner sides of the two chambers. The liquid outlets at the bottom of the two chambers are the same size and symmetrically positioned.

[0036] Step 4: Simultaneously remove the plugs from the two outlets of the double-cavity crucible and pour the molten metal from the two cavities into the gradient water-cooled copper mold through a funnel-shaped manifold. The casting temperature is 1500℃. The fluids are fully mixed into a stream of molten metal by gravity through the manifold, and an in-situ reaction occurs to form TiB2 reinforcement. Finally, it is injected into the gradient water-cooled copper mold to undergo gradient solidification. The gradient water-cooled copper mold has annular water-cooling ramps inside its sidewalls. The number of annular water-cooling ramps gradually decreases from top to bottom to control the regular difference in cooling rate of different parts of the gradient water-cooled copper mold. Finally, it is cooled to room temperature to obtain the as-cast TiB2 / Cu composite material.

[0037] Step 5: Roll the as-cast TiB2 / Cu composite material, including hot rolling until the hot rolling deformation reaches 10%, and then cold rolling until the cold rolling deformation reaches 90%, thus obtaining the high-strength and high-conductivity TiB2 / Cu composite material.

[0038] The high-strength and high-conductivity TiB2 / Cu composite material prepared in Example 1 was tested for performance. Its conductivity reached 90.1% IACS and its tensile strength reached 465 MPa.

[0039] The microstructure of the high-strength, high-conductivity TiB2 / Cu composite material prepared in Example 1 was observed, and its metallographic structure is shown in the figure below. Figure 1 As shown, the SEM microstructure is as follows Figure 2 As shown, from Figure 1 As can be seen, the high-strength, high-conductivity TiB2 / Cu composite material prepared by the method of this invention has a uniform overall macroscopic structure. Figure 2As can be seen, the TiB2 ceramic particles are small and uniformly dispersed in the copper matrix, which can ensure the high conductivity of the material while playing a good strengthening role.

[0040] Example 2

[0041] An in-situ liquid forming method for a high-strength, high-conductivity TiB2 / Cu composite material includes the following steps:

[0042] Step 1: Preparation of Cu-Ti master alloy, including weighing 85 wt.% pure Cu powder and 15 wt.% pure Ti powder, with the sum of the mass percentages of pure Cu and pure Ti being 100%. The weighed pure Cu and pure Ti powders are loaded into a hopper, and stainless steel balls are added at a ball-to-powder ratio of 2:1. The hopper is placed in a mixer, and the powders are mixed at a speed of 150 r / min for 8 hours. After pre-pressing at a pressure of 40 MPa for 30 seconds to form a block blank, it is then placed in a graphite crucible and melted in a vacuum induction melting furnace, ensuring a vacuum degree of less than 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1400℃, hold at this temperature for 3 min, and then turn off the power to obtain Cu-Ti master alloy.

[0043] Step 2: Prepare the Cu-B master alloy by weighing 85 wt.% pure Cu blocks and 15 wt.% pure B blocks, with the sum of the mass percentages of pure Cu and pure B being 100%. Place the weighed pure Cu and pure B blocks in a graphite crucible and melt them in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1400℃, hold at this temperature for 3 min, turn off the power, cool and remove the sample to obtain Cu-B master alloy.

[0044] Step 3: Weigh out Cu-Ti master alloy, Cu-B master alloy, and pure copper according to the TiB2 content of 2 wt.% in the TiB2 / Cu composite material. Place the weighed components into a double-cavity crucible. The double-cavity crucible is equipped with a manifold at the bottom, and each of the two cavities has a liquid outlet at the bottom, with a plug installed in the outlet. Place the Cu-Ti master alloy and Cu-B master alloy into the two cavities respectively, and also place the pure copper into the two cavities, ensuring that the total weight of the materials in the two cavities is the same. Then place it in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, and hold at 1400℃ for 2 min to obtain molten metal;

[0045] The double-chamber crucible is a cylindrical graphite crucible with a vertical partition installed in the center of the interior. The partition is covered with graphite paper, which divides the crucible's interior into two separate chambers. Graphite paper is laid on the inner sides of the two chambers. The liquid outlets at the bottom of the two chambers are the same size and symmetrically positioned.

[0046] Step 4: Simultaneously remove the plugs from the two outlets of the double-cavity crucible and pour the molten metal from the two cavities into the gradient water-cooled copper mold through a funnel-shaped manifold. The casting temperature is 1400℃. The fluids are fully mixed into a stream of molten metal by gravity through the manifold, and an in-situ reaction occurs to form TiB2 reinforcement. Finally, it is injected into the gradient water-cooled copper mold to undergo gradient solidification. The gradient water-cooled copper mold has annular water-cooling ramps inside its sidewalls. The number of annular water-cooling ramps gradually decreases from top to bottom to control the regular difference in cooling rate of each part of the gradient water-cooled copper mold. Finally, it is cooled to room temperature to obtain the as-cast TiB2 / Cu composite material.

[0047] Step 5: Roll the as-cast TiB2 / Cu composite material, including hot rolling until the hot rolling deformation reaches 30%, and then cold rolling until the cold rolling deformation reaches 80%, thus obtaining the high-strength and high-conductivity TiB2 / Cu composite material.

[0048] The high-strength and high-conductivity TiB2 / Cu composite material prepared in Example 2 was tested for performance. Its conductivity reached 85.4% IACS and its tensile strength reached 513 MPa.

[0049] Example 3

[0050] An in-situ liquid forming method for a high-strength, high-conductivity TiB2 / Cu composite material includes the following steps:

[0051] Step 1: Prepare a Cu-Ti master alloy by weighing 75 wt.% pure Cu blocks and 25 wt.% pure Ti blocks, with the sum of the mass percentages of pure Cu and pure Ti being 100%. Place the weighed pure Cu and pure Ti blocks in a graphite crucible and melt them in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1500℃, hold at this temperature for 2 min, turn off the power, cool and take out the sample to obtain Cu-Ti master alloy.

[0052] Step 2: Prepare the Cu-B master alloy, including weighing 75 wt.% pure Cu powder and 25 wt.% pure B powder, with the sum of the mass percentages of pure Cu and pure B being 100%. Place the weighed pure Cu and pure B powders into a container, add stainless steel balls at a ball-to-powder ratio of 2:1, and place the container in a mixer. Mix the powders at a speed of 100 r / min for 8 hours. After pre-pressing at a pressure of 40 MPa for 30 seconds to form a block blank, place it in a graphite crucible and melt it in a vacuum induction melting furnace, ensuring the vacuum degree is less than 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1500℃, hold at this temperature for 2 min, turn off the power, cool and remove the sample to obtain Cu-B master alloy.

[0053] Step 3: Weigh out Cu-Ti master alloy, Cu-B master alloy, and pure copper according to the TiB2 content of 3 wt.% in the TiB2 / Cu composite material. Place the weighed components into a double-cavity crucible. The double-cavity crucible is equipped with a manifold at the bottom, and each of the two cavities has a liquid outlet at the bottom, with a plug installed in the outlet. Place the Cu-Ti master alloy and Cu-B master alloy into the two cavities respectively, and also place the pure copper into the two cavities, ensuring that the total weight of the materials in the two cavities is the same. Then place it in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, and keep at 1300℃ for 5 min to obtain molten metal;

[0054] The double-chamber crucible is a cylindrical graphite crucible with a vertical partition installed in the center of the interior. The partition is covered with graphite paper, which divides the crucible's interior into two separate chambers. Graphite paper is laid on the inner sides of the two chambers. The liquid outlets at the bottom of the two chambers are the same size and symmetrically positioned.

[0055] Step 4: Simultaneously remove the plugs from the two outlets of the double-cavity crucible and pour the molten metal from the two cavities into the gradient water-cooled copper mold through a funnel-shaped manifold. The casting temperature is 1500℃. The fluids are fully mixed into a stream of molten metal by gravity through the manifold, and an in-situ reaction occurs to form TiB2 reinforcement. Finally, it is injected into the gradient water-cooled copper mold to undergo gradient solidification. The gradient water-cooled copper mold has annular water-cooling ramps inside its sidewalls. The number of annular water-cooling ramps gradually decreases from top to bottom to control the regular difference in cooling rate of different parts of the gradient water-cooled copper mold. Finally, it is cooled to room temperature to obtain the as-cast TiB2 / Cu composite material.

[0056] Step 5: Roll the as-cast TiB2 / Cu composite material, including hot rolling until the hot rolling deformation reaches 50%, and then cold rolling until the cold rolling deformation reaches 70%, thus obtaining the high-strength and high-conductivity TiB2 / Cu composite material.

[0057] The high-strength and high-conductivity TiB2 / Cu composite material prepared in Example 3 was tested for performance. Its conductivity reached 75.2% IACS and its tensile strength reached 605 MPa.

Claims

1. An in-situ liquid forming method for high-strength, high-conductivity TiB2 / Cu composite materials, characterized in that, Includes the following steps: Step 1: Prepare a Cu-Ti master alloy by weighing 75 wt.% pure Cu blocks and 25 wt.% pure Ti blocks, with the sum of the mass percentages of pure Cu and pure Ti being 100%. Place the weighed pure Cu and pure Ti blocks in a graphite crucible and melt them in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1500℃, hold at this temperature for 2 min, turn off the power, cool and take out the sample to obtain Cu-Ti master alloy; Step 2: Prepare the Cu-B master alloy, including weighing 75 wt.% pure Cu powder and 25 wt.% pure B powder, with the sum of the mass percentages of pure Cu and pure B being 100%. Place the weighed pure Cu and pure B powders into a container, add stainless steel balls at a ball-to-powder ratio of 2:1, and place the container in a mixer. Mix the powders at a speed of 100 r / min for 8 hours. After pre-pressing at a pressure of 40 MPa for 30 seconds to form a block blank, place it in a graphite crucible and melt it in a vacuum induction melting furnace, ensuring the vacuum degree is less than 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, heat to 1500℃, hold at this temperature for 2 min, turn off the power, cool and take out the sample to obtain Cu-B master alloy; Step 3: Weigh out Cu-Ti master alloy, Cu-B master alloy, and pure copper according to the TiB2 content of 3 wt.% in the TiB2 / Cu composite material. Place each component into a double-chamber crucible. The double-chamber crucible is equipped with a manifold at the bottom, and each of the two chambers has a liquid outlet at the bottom, with a plug installed in the outlet. Place the Cu-Ti master alloy and Cu-B master alloy into the two chambers respectively, and also place the pure copper into the two chambers, ensuring that the total weight of the materials in both chambers is the same. Then place it in a vacuum induction melting furnace, ensuring a vacuum degree of 5.5 × 10⁻⁶. -3 Pa, fill with protective argon gas to 0.05 MPa, and keep at 1300℃ for 5 min to obtain molten metal; The double-chamber crucible is a cylindrical graphite crucible with a vertical partition installed in the center of the interior. The partition is covered with graphite paper, which divides the crucible's interior into two separate chambers. Graphite paper is laid on the inner sides of the two chambers. The liquid outlets at the bottom of the two chambers of the double-chamber crucible are the same size and symmetrically positioned. Step 4: Simultaneously remove the plugs from the two outlets of the double-cavity crucible and pour the molten metal from the two cavities into the gradient water-cooled copper mold through a funnel-shaped manifold. The casting temperature is 1500℃. The fluids are fully mixed into a stream of molten metal by gravity through the manifold, and an in-situ reaction occurs to form TiB2 reinforcement. Finally, it is injected into the gradient water-cooled copper mold to undergo gradient solidification. The gradient water-cooled copper mold has annular water-cooling ramps inside its sidewalls. The number of annular water-cooling ramps gradually decreases from top to bottom to control the regular difference in cooling rate of different parts of the gradient water-cooled copper mold. Finally, it is cooled to room temperature to obtain the as-cast TiB2 / Cu composite material. Step 5: Roll the as-cast TiB2 / Cu composite material, including hot rolling until the hot rolling deformation reaches 50%, and then cold rolling until the cold rolling deformation reaches 70%, thus obtaining the high-strength and high-conductivity TiB2 / Cu composite material.

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