A method for preparing a titanium-copper bimetallic composite

Abstract

The application discloses a preparation method of titanium-copper bimetallic composite material, and belongs to the field of preparation of bimetallic composite material. The bimetallic material is pure titanium and pure copper, and the preparation method comprises the following steps: titanium pipe pretreatment, preheating, smelting, solid-liquid composite, rolling, drawing, heat treatment and finishing. The composite material produced by the application has the cross-section hardness of 125-550HV, the interface bonding strength of 13-20N / mm, the bending strength of 180-250MPa, the elongation A of greater than or equal to 28%, the composite interface shear strength of 240-260MPa and the conductivity of 40%IACS-50%IACS. The application has the advantages that the solid-liquid composite casting method is used to realize the relatively uniform metallurgical bonding of the titanium-copper bimetallic interface, and then the rolling and drawing processes are used to promote the breaking of the intermediate compound and the outflow of the fresh metal, so that the finally obtained composite material has excellent comprehensive performance, especially the good electric conductivity and corrosion resistance can significantly improve the service life of the material, and the composite material is expected to be widely applied in many fields.

Description

TECHNICAL FIELD

[0001] The application discloses a preparation method of titanium-copper bimetallic composite material and belongs to the field of preparation of bimetallic composite material. BACKGROUND

[0002] Titanium has excellent corrosion resistance in acid and alkali, and copper has excellent electrical conductivity, so the superposition of the performances of the two will be very useful; at present, titanium-copper composite materials have been widely used in electronic, electroplating, chlor-alkali, electrolysis, hydrometallurgy, electric power, military industry and other industries by taking advantages of the two. However, the titanium-copper composite process mostly adopts solid-solid composite modes such as explosive compounding, explosive compounding + rolling compounding and extrusion.

[0003] The patent application 201920482363.1 discloses a titanium-copper explosive composite plate structure applied in the technical field of composite plates, and the technical scheme is as follows: a copper plate is horizontally placed on a workbench, a titanium plate is suspended above the copper plate, a first explosive layer is arranged on the side of the titanium plate away from the copper plate, the first explosive layer is circular, a plurality of first explosive layers are uniformly arranged on the same plane on the side of the titanium plate away from the copper plate, the outer circumferences of the first explosive layers of two adjacent circles are tangent to each other, and an electric detonator is buried in the center of the first explosive layer. Although this titanium-copper compounding mode has good effects, the compounding mode has certain danger in operation, needs special sites and also pollutes the environment to a certain extent.

[0004] The patent application 201710942660.5 discloses a preparation method of high-precision titanium-copper composite rods, which is prepared through the following steps of material selection, pipe penetration, coating, heating treatment, drawing, finishing and polishing, the materials are selected according to strict standards, the temperature and time of heating treatment are controlled, and the polishing equipment is adopted to perform rough polishing and fine polishing, so that the comprehensive performance of the titanium-copper composite rods is ensured. The titanium-copper compounding mode has many steps and is very troublesome in operation.

[0005] The above titanium-copper composite material manufacturing methods have achieved some results, but in actual production and application, there are still production technical problems such as high cost, low production efficiency, unsuitability for mass production, low bonding strength and the like. Therefore, the titanium-copper composite is prepared by adopting the casting solid-liquid compounding mode, the requirement for experimental equipment is low, the process is simple and easy to operate, the interface bonding strength is large, the material yield is high, and the metallurgical bonding of the copper-titanium solid-liquid interface can be realized. SUMMARY

[0006] The application aims to provide a preparation method of titanium-copper bimetallic composite material, so that the titanium layer and the copper layer are closely attached and have excellent comprehensive performance, thereby being expected to be widely applied in many fields, and the method comprises the following steps:

[0007] (1) Titanium tube pretreatment: the inner surface of the pure titanium tube with plugs at both ends is turned and polished to have a certain surface roughness, then the inner and outer surfaces are chemically cleaned to remove the surface oxides and oil stains, and finally the inner and outer surfaces are coated with an antioxidant and dried.

[0008] (2) Preheating: the mold, the upper end plug, the lower end plug and the pretreated pure titanium tube are respectively preheated; the lower end plug is tightly connected with the lower end of the pretreated pure titanium tube, the pure titanium tube with the installed lower end plug is placed in the mold, and the gap between the mold and the pure titanium tube directly constitutes a liquid nitrogen circulating channel.

[0009] (3) Melting: the pure copper is put into a resistance furnace and inert gas is introduced for melting to obtain a pure copper liquid.

[0010] (4) The pure copper liquid is cast into the preheated titanium tube, the mold cavity is filled with inert gas before the casting starts, liquid nitrogen is injected into the liquid nitrogen circulating channel, then the melted copper liquid is cast into the preheated titanium tube, and the upper end plug 1 is installed at the upper end of the pure titanium tube 4, and the titanium-copper composite tube blank is obtained after the interface solidification and cooling in air.

[0011] (5) Rolling: the titanium-copper composite tube blank is hot-rolled.

[0012] (6) Drawing: the titanium-copper composite material after rolling is heated in an electric furnace, then a suitable mold is matched to draw the titanium-copper composite wire to the required size, the cooling method is air cooling, and then heat treatment is carried out.

[0013] (7) Finishing: the outer surface of the heat-treated titanium-copper composite material is polished until the surface roughness is less than 8 μm, and finally the titanium-copper composite wire is made.

[0014] Preferably, in step (1) of the present application, the material of the plug is pure titanium TA1; the titanium tube is polished on the inner surface with 400#, 600#, 800#, 1000#, 1500# and 2000# sandpaper in sequence to make the surface roughness of the titanium tube 20-100 μm.

[0015] Preferably, in step (2) of the present application, the preheating conditions are that the mold is preheated in a resistance furnace, the preheating temperature is 200-300 ℃, and the holding time is 20-30 min; the pretreated pure titanium tube is preheated in a resistance furnace, the preheating temperature is 200-300 ℃, and the holding time is 2-3 min.

[0016] Preferably, in step (3) of the present application, the melting conditions are 1200-1250 ℃, stirring for 3-4 min after melting, and slagging 4-6 times.

[0017] Preferably, the casting temperature in step (4) of the present application is 1100-1200 DEG C, and the casting rate is 6-13 kg / s.

[0018] Preferably, the rolling condition in step (5) of the present application is as follows: the rolling temperature is 750-800 DEG C, the holding time is 40 min, the cooling mode is air cooling, the rolling rate is 1-1.4 m / s, the rolling passes are 3-5, the pass deformation is 15%-17%, and the cumulative deformation is 40%-60%.

[0019] Preferably, the drawing condition in step (6) of the present application is as follows: the heating temperature is 350-450 DEG C, the holding time is 0.8-1 h, the drawing passes are 4-7, the pass diameter reduction is 0.8-1.2 mm, the drawing speed is 1.5-2.5 m / min, and the diameter after drawing is 0.5-1.8 mm.

[0020] Preferably, the heat treatment in step (6) of the present application is as follows: the annealing temperature is 450-650 DEG C, the holding time is 2-3 h, the furnace cooling is to 150-200 DEG C, and the air cooling after furnace discharge is to room temperature.

[0021] The titanium-copper composite material prepared by the method has a cross-section hardness of 125-550 HV, an interface bonding strength of 13-20 N / mm, a bending strength of 180-250 MPa, an elongation A of no less than 28%, a composite interface shear strength of 240-260 MPa, and an electrical conductivity of 40%IACS-50%IACS.

[0022] Preferably, the material of the mold device in step (2) of the present application is H13 mold steel, and the inert gas in step (3) is argon.

[0023] Preferably, any process in steps (4)-(6) of the present application can be protected by argon or vacuum.

[0024] Preferably, the titanium pipe material of the present application is pure titanium TA1, and the pure copper material is T2.

[0025] The method of the present application realizes the manufacturing of titanium-copper composite wires in a liquid-solid composite manner.

[0026] The present application has the following advantages:

[0027] (1) The present application uses argon protection atmosphere in many places. On the one hand, argon is inert and difficult to react with other substances. On the other hand, it prevents the metal from being oxidized or nitrided by air, otherwise the generated intermediate oxide will affect the quality of the composite material.

[0028] (2) The titanium-copper composite wire is prepared by solid-liquid composite method, compared with explosion composite, the composite method has less operation danger, does not need to find special site, and has less environmental pollution.

[0029] (3) The mold is provided with a quenching channel filled with liquid nitrogen, and the liquid nitrogen is circulated, and the cooling speed of the liquid nitrogen is extremely fast; the copper liquid is poured into the titanium pipe while the liquid nitrogen is introduced into the quenching channel for quenching, and the titanium-copper bonding surface is made more compact by using the principle of thermal expansion and cold contraction.

[0030] (4) The mold is provided with a quenching channel filled with liquid nitrogen, and the quenching of the liquid nitrogen can form more surface quenching fine crystal regions in the solidification process of the copper liquid, and the amount of fine crystals is increased.

[0031] (5) The mold is composed of two identical structures, and the middle part can be separated, so that the mold can be separated after the copper liquid is solidified, and the demolding process can be completed by separating the two sides of the mold, so that the demolding is easy and convenient.

[0032] (6) The mold has reasonable structure, simple and convenient operation, can realize mechanization and automatic control, reduces labor cost, can realize continuous batch production, saves cost, and improves efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a device structure schematic view of the titanium-copper solid-liquid bimetallic composite material.

[0034] Figure 1 Center: 1 - upper end plug; 2 - mold; 3 - liquid nitrogen circulation channel; 4 - pure titanium pipe; 5 - mold cavity; 6 - lower end plug.

[0035] Figure 2 is the microstructure of the titanium-copper composite material in embodiment 1.

[0036] Figure 3 is the element diffusion condition of the transition zone of the titanium-copper composite material in embodiment 1: (a), (b) BSE diagram and line scanning of copper side composite interface; (c), (d) BSE diagram and line scanning of titanium side composite interface.

[0037] Figure 4 is the element diffusion condition of the transition zone of the titanium-copper composite material: (a), (b), (c) are BSE diagram and surface scanning of copper side composite interface; (d), (e), (f) are BSE diagram and surface scanning of titanium side composite interface. DETAILED DESCRIPTION

[0038] The application will be further described in connection with specific embodiments, but the scope of the application is not limited to the described content.

[0039] Please refer to Figure 1 , Figure 1 is a schematic diagram of the device structure when titanium copper is subjected to liquid-solid compounding according to the application; in the device, the mold cavity 5 is finally filled with pure copper liquid; the lower end plug 6 is tightly connected to the lower end of the pure titanium pipe 4 before the pouring process is performed; the upper end plug 1 is installed at the upper end of the pure titanium pipe 4 after the pouring is completed; the inner wall of the liquid nitrogen circulating channel 3 is arranged on the outer surface of the pure titanium pipe 4; the inner wall of the mold 7 is arranged on the outer surface of the liquid nitrogen circulating channel 3.

[0040] The working principle of the titanium copper solid-liquid bimetallic composite material device according to the application is as follows: first, the surface of the TA1 pure titanium pipe 4 is turned and polished and chemically cleaned; then, the pretreated pure titanium pipe 4, the upper and lower end plugs and the mold device 2 are preheated, and pure copper is melted; then, in an argon atmosphere, the mold device is removed and liquid nitrogen is circulated and flowed in the liquid nitrogen circulating channel 3, then the TA1 pure titanium pipe and the lower end plug 4 are matched and quickly moved to the mold 2, and at the same time, the melted T2 pure copper liquid is quickly poured into the pretreated TA1 pure titanium pipe and stirred and degassed; after pouring, the upper end plug 1 is installed at the upper end of the pure titanium pipe. Embodiment

[0041] The method for preparing a bimetallic composite material by titanium copper liquid-solid compounding and rolling and drawing according to the embodiment comprises titanium pipe pretreatment, preheating, melting, solid-liquid compounding, rolling, drawing, heat treatment and finishing, and the specific steps are as follows:

[0042] (1) Titanium pipe pretreatment: first, the surface of the titanium pipe TA2 with the upper end plug 1 and the lower end plug 6 (the same material as the titanium pipe) at both ends is turned and polished and chemically cleaned; the turning and polishing is to polish the inner surface of the titanium pipe with 400#, 600#, 800#, 1000#, 1500# and 2000# sandpaper in sequence to make the surface roughness reach 50 μm; the chemical cleaning is to clean the surface of the titanium rod with 5% NaOH solution, deionized water, 5% hydrochloric acid solution, deionized water and anhydrous ethanol in sequence to remove surface oil stains and oxides; finally, the titanium pipe 4 is dried after the inner and outer surfaces are coated with an antioxidant.

[0043] (2) Preheating: Put the mold 2 into the pit-type resistance furnace for preheating, the preheating temperature is 300℃, and the heat preservation time is 30 min; Put the pretreated titanium tube 4, the upper end plug 1 and the lower end plug 6 into the resistance furnace for preheating treatment, the preheating temperature is 300℃, and the heat preservation time is 3 min; connect the lower end plug with the pretreated pure titanium tube closely, put the pure titanium tube with the installed lower end plug into the mold, and the gap between the mold and the pure titanium tube directly forms a liquid nitrogen circulating channel.

[0044] (3) Melting: Put the pure copper T1 into the resistance furnace, and melt under the protection of argon atmosphere, the melting temperature is 1250℃, and after melting, stir for 3 min and remove slag for 5 times to obtain the pure copper liquid.

[0045] (4) Pour the pure copper liquid into the preheated titanium tube, fill the mold cavity with inert gas before pouring, inject liquid nitrogen into the liquid nitrogen circulating channel, then pour the melted copper liquid into the preheated titanium tube, and then install the upper end plug 1 at the upper end of the pure titanium tube 4, the pouring temperature is 1150℃, and the pouring rate is 6 kg / s, after the interface solidifies, place it in the air to cool to obtain the titanium-copper composite pipe blank.

[0046] (5) Rolling: hot roll the titanium-copper composite pipe blank, the rolling temperature is 780℃, the heat preservation time is 40 min, and the cooling mode is air cooling; the rolling speed is 1 m / s, the rolling is 5 passes, the pass deformation is 15%, and the cumulative deformation is 55%.

[0047] (6) Drawing: heat the titanium-copper composite material after rolling in the electric furnace, the heating temperature is 350℃, and the heat preservation time is 1 h, then match the appropriate mold to draw the titanium-copper composite wire with the required size, and the cooling mode is air cooling; the drawing is 6 passes, the pass diameter reduction is 0.8 mm, the drawing speed is 1.5 m / min, and the diameter after drawing is 1.5 mm; the titanium-copper composite material after drawing is coiled into a roll.

[0048] (7) Heat treatment: the annealing temperature is 450℃, the heat preservation time is 2 h, the furnace cooling is to 150℃, and the air cooling is to room temperature after taking out of the furnace.

[0049] (8) Finishing: polish the outer surface of the heat-treated titanium-copper composite material until the surface roughness is 7μm, and finally obtain the titanium-copper composite wire.

[0050] Any process in steps (4) to (6) is protected by argon or vacuum.

[0051] The titanium-copper composite material prepared in this embodiment has good comprehensive performance, the cross-section hardness is 150-550 HV, the interface bonding strength is 15 N / mm, the bending strength is 200 MPa, the elongation is 29%, the composite interface shear strength is 245 MPa, and the electrical conductivity is 42% IACS.

[0052] Figure 2 The SEM image of the titanium-copper composite material prepared in this example can be seen that the interface between copper and titanium basically reaches metallurgical bonding, there is no obvious defect and gap, the bonding is tight, and different regions of the bonding interface have obvious boundary lines; Figure 3 The BSE image and line scanning of the copper side composite interface and the titanium side composite interface in the SEM image can be seen that in the interface transition zone and the connection between the two matrices, the contents of titanium and copper elements both have a relatively obvious gradual change process, and the contents of titanium and copper elements in the interface transition zone are obviously different from those in the matrices, which shows that the two elements have diffused to a certain extent at the two interfaces; the content of copper element in the copper side transition zone is higher than that in the corresponding titanium side transition zone, which shows that the diffusion degree of copper element to the middle transition zone decreases with the increase of diffusion distance; the distribution of titanium element on the interface also has this phenomenon. Figure 4 The element diffusion situation of the titanium-copper composite material transition zone can be seen that the face scanning image of the titanium-copper composite material transition zone confirms the Figure 3 phenomenon appeared in the line scanning. Embodiment

[0053] The preparation method and device of the titanium-copper solid-liquid bimetallic composite material described in this embodiment, the preparation method comprises titanium tube pretreatment, preheating, smelting, solid-liquid composite, rolling, drawing, heat treatment and finishing, and the specific steps are as follows:

[0054] (1) Titanium tube pretreatment: first, the surface of the titanium tube TA2 with the upper end plug 1 and the lower end plug 6 (the same material as the titanium tube) at both ends is turned and polished, and chemically cleaned; the turning and polishing is to polish the inner surface of the titanium tube with 400#, 600#, 800#, 1000#, 1500# and 2000# sandpaper in sequence to make the surface roughness reach 80 μm; the chemical cleaning is to clean the surface of the titanium rod with 5% NaOH solution, deionized water, 5% hydrochloric acid solution, deionized water and anhydrous ethanol in sequence to remove surface oil stains and oxides; finally, the titanium tube 4 is dried after being coated with an antioxidant on the inner and outer surfaces.

[0055] (2) Preheating: the mold 2 is placed in the pit-type resistance furnace for preheating, and the preheating temperature is 250°C, and the holding time is 20 min; the pretreated titanium tube 4, the upper end plug 1 and the lower end plug 6 are placed in the resistance furnace for preheating treatment, and the preheating temperature is 250°C, and the holding time is 3 min; the lower end plug is tightly connected with the lower end of the pretreated pure titanium tube, the pure titanium tube with the installed lower end plug is placed in the mold, and the gap between the mold and the pure titanium tube constitutes a liquid nitrogen circulation channel.

[0056] (3) Melting: pure copper T2 is put into a resistance furnace and argon protective atmosphere is introduced for melting, the melting temperature is 1225℃, after melting, stirring is carried out for 4 min and slagging is carried out for 6 times, and pure copper liquid is obtained.

[0057] (4) The pure copper liquid is cast into the preheated titanium tube, the mold cavity is filled with inert gas before casting starts, liquid nitrogen is injected into the liquid nitrogen circulation channel, then the melted copper liquid is cast into the preheated titanium tube, then the upper end plug 1 is installed at the upper end of the pure titanium tube 4, the casting temperature is 1200℃, the casting rate is 8 kg / s, and after the interface solidifies, it is cooled in air to obtain a titanium-copper composite pipe blank.

[0058] (5) Rolling: the titanium-copper composite pipe blank is hot-rolled, the rolling temperature is 800℃, the holding time is 40 min, and the cooling mode is air cooling. The rolling speed is 1.4 m / s, the rolling is carried out for 5 passes, the pass deformation is 17%, and the cumulative deformation is 60%.

[0059] (6) Drawing: the titanium-copper composite material after rolling is heated in an electric furnace, the heating temperature is 450℃, the holding time is 0.8 h, then a suitable die is matched to draw the titanium-copper composite wire to the required size, and the cooling mode is air cooling; the drawing is carried out for 5 passes, the pass reduction is 1.2 mm, the drawing speed is 2.5 m / min, and the diameter after drawing is 0.5 mm; the titanium-copper composite material after drawing is coiled and placed.

[0060] (7) Heat treatment: the annealing temperature is 650℃, the holding time is 3 h, the furnace is cooled to 200℃, and the furnace is taken out and air cooled to room temperature.

[0061] (8) Finishing: the outer surface of the titanium-copper composite material after heat treatment is polished until the surface roughness is 7 μm, and finally the titanium-copper composite wire is prepared.

[0062] Any process in steps (4) to (6) can be protected by argon or vacuum.

[0063] The titanium-copper composite material prepared in this embodiment has good comprehensive performance, the cross-sectional hardness is 135-530 HV, the interface bonding strength is 14 N / mm, the bending strength is 230 MPa, the elongation is 35%, the composite interface shear strength is 245 MPa, and the electrical conductivity is 42% IACS. Embodiment

[0064] The preparation method and device of the titanium-copper solid-liquid bimetallic composite material described in this embodiment, the preparation method comprises titanium tube pretreatment, preheating, melting, solid-liquid composite, rolling, drawing, heat treatment and finishing, and the specific steps are as follows:

[0065] (1) Titanium tube pretreatment: firstly, the surface of titanium tube TA3 with upper end plug 1 and lower end plug 6 (material same as titanium tube) at both ends is turned and polished, and chemically cleaned; the turning and polishing is to polish the inner surface of the titanium tube with 400#, 600#, 800#, 1000#, 1500# and 2000# sandpaper in sequence to make the surface roughness reach 100 μm; the chemical cleaning is to clean the surface of the titanium rod with 5% NaOH solution, deionized water, 5% hydrochloric acid solution, deionized water and anhydrous ethanol in sequence to remove surface oil and oxides; finally, the inner and outer surfaces of the titanium tube 4 are coated with an antioxidant and dried.

[0066] (2) Preheating: the mold 2 is put into the pit-type resistance furnace for preheating, the preheating temperature is 200 ℃, and the holding time is 25 min; the pretreated titanium tube 4, upper end plug 1 and lower end plug 6 are put into the resistance furnace for preheating, the preheating temperature is 200 ℃, and the holding time is 3 min; the lower end plug is tightly connected with the lower end of the pretreated pure titanium tube; the pure titanium tube with the installed lower end plug is placed in the mold, and the gap between the mold and the pure titanium tube constitutes a liquid nitrogen circulating channel.

[0067] (3) Melting: the pure copper T3 is put into the resistance furnace and an argon protective atmosphere is introduced for melting, the melting temperature is 1200 ℃, and after melting, the stirring time is 4 min and the slagging time is 4 times to obtain pure copper liquid.

[0068] (4) The pure copper liquid is cast into the preheated titanium tube, the mold cavity is filled with inert gas before casting starts, liquid nitrogen is injected into the liquid nitrogen circulating channel, then the melted copper liquid is cast into the preheated titanium tube, the upper end plug 1 is installed at the upper end of the pure titanium tube 4, the casting temperature is 1100 ℃, the casting rate is 13 kg / s, and after the interface solidifies, it is cooled in air to obtain a titanium-copper composite tube blank.

[0069] (5) Rolling: the titanium-copper composite tube blank is hot rolled, the rolling temperature is 750 ℃, the holding time is 40 min, and the cooling method is air cooling; the rolling speed is 1 m / s, the rolling is 4 passes, the pass deformation is 16%, and the cumulative deformation is 50%.

[0070] (6) Drawing: the titanium-copper composite material after rolling is heated in an electric furnace, the heating temperature is 400 ℃, the holding time is 0.9 h, then a suitable mold is matched to draw the titanium-copper composite wire to the required size, and the cooling method is air cooling. The drawing is 7 passes, the pass reduction is 1 mm, the drawing speed is 2 m / min, and the diameter after drawing is 1.2 mm. The titanium-copper composite material after drawing is coiled into a roll.

[0071] (7) Heat treatment: the annealing temperature is 550 ℃, the holding time is 2.5 h, the furnace cooling is to 175 ℃, and the air cooling is to room temperature after taking out of the furnace.

[0072] (8) Finishing: polishing the outer surface of the titanium-copper composite material after heat treatment until the surface roughness is 7 μm, to finally produce a titanium-copper composite wire.

[0073] Any of the processes in the steps (4) to (6) can be protected by argon or vacuum.

[0074] The titanium-copper composite material prepared in this example has good comprehensive performance, with cross-section hardness of 130-480 HV, interface bonding strength of 16 N / mm, bending strength of 220 MPa, elongation of 33%, composite interface shear strength of 255 MPa, and electrical conductivity of 50% IACS.

[0075] Comparative Example 1

[0076] Compared with Example 1, the comparative example does not pass liquid nitrogen in the step (4); this will result in the following consequences: on the one hand, the cooling speed of the cast composite titanium-copper composite material is slow, so that the residence time in the high temperature section is longer, leading to grain growth, which adversely affects the interface bonding strength and shear strength and bending strength of the material; on the other hand, the slow cooling speed will allow titanium and copper to have a longer active reaction time, resulting in brittle intermetallic compounds at the interface of the titanium-copper composite material, thus also causing the interface bonding strength and shear strength and bending strength to decrease.

[0077] Comparative Example 2

[0078] Compared with Example 2, the comparative example adopts a rolling temperature of 900°C in the step (5) and a holding time of 2 h with a deformation amount of 5% per pass; the high rolling temperature and long holding time will lead to the formation of hard and brittle titanium-copper intermetallic compounds, thus reducing the interface bonding strength and shear strength and other properties, which will greatly affect the application of the titanium-copper composite material; too small deformation amount per pass will result in insufficient fragmentation of the dendrites in the as-cast structure, reducing the newly formed bonding interface at the composite and increasing the inclusions at the bonding site, thus also having an important impact on the interface bonding strength and shear strength and other properties.

[0079] Comparative Example 3

[0080] Compared with Example 3, the comparative example does not have the step (7); since there will be certain internal stress and residual stress during the rolling and drawing process, which will reduce the atomic diffusion efficiency of titanium and copper, thus possibly leading to a decrease in the comprehensive performance of the titanium-copper composite material and failure to achieve full metallurgical bonding.

Claims

1. A method for producing a titanium-copper bimetallic composite material, characterized by, Specifically comprising the following steps: (1) pure titanium tube pretreatment: the inner surface of the pure titanium tube with plugs at both ends is turned and polished to have a certain surface roughness, then the inner and outer surfaces are chemically cleaned to remove the surface oxides and oil stains, and finally the inner and outer surfaces are coated with an antioxidant and dried; (2) preheating: the mold, the upper end plug, the lower end plug and the pretreated pure titanium tube are respectively preheated; the lower end plug is tightly connected with the lower end of the pretreated pure titanium tube, the pure titanium tube with the installed lower end plug is placed in the mold, and the gap between the mold and the pure titanium tube forms a liquid nitrogen circulating channel; (3) smelting: the pure copper is put into a resistance furnace and inert gas is introduced for smelting to obtain pure copper liquid; (4) pouring the pure copper liquid into the preheated pure titanium tube: before pouring, the mold cavity is filled with inert gas, liquid nitrogen is injected into the liquid nitrogen circulating channel, then the smelted pure copper liquid is poured into the preheated pure titanium tube, then the upper end plug is installed at the upper end of the pure titanium tube, and after the interface solidifies, it is cooled in air to obtain a titanium-copper composite pipe blank; (5) rolling: the titanium-copper composite pipe blank is hot rolled; (6) drawing: the titanium-copper composite pipe blank after rolling is heated in an electric furnace, then a suitable mold is matched to draw a titanium-copper composite wire of the required size, the cooling method is air cooling, and then heat treatment is carried out; (7) finishing: the outer surface of the heat treated titanium-copper composite wire is polished until the surface roughness is less than 8μm, and finally a titanium-copper composite wire is made; The rolling conditions in step (5) are: rolling temperature is 750-800℃, holding time is 40min, cooling method is air cooling; the rolling speed is 1-1.4m / s, the rolling passes are 3-5, the pass deformation is 15%-17%, and the cumulative deformation is 40%-60%; The drawing conditions in step (6) are: heating temperature is 350-450℃, holding time is 0.8-1h, drawing passes are 4-7, pass diameter reduction is 0.8-1.2mm, drawing speed is 1.5-2.5m / min, and the diameter after drawing is 0.5-1.8mm.

2. The method for preparing the titanium-copper bimetallic composite material according to claim 1, characterized in that: In step (1), the material of the plug is pure titanium TA1; the inner surface of the pure titanium tube is polished with 400#, 600#, 800#, 1000#, 1500# and 2000# sandpaper in sequence to make the surface roughness of the pure titanium tube 20-100μm.

3. The method for preparing the titanium-copper bimetallic composite material according to claim 1, characterized in that: In step (2), the preheating conditions are: the mold is preheated in a resistance furnace, the preheating temperature is 200-300℃, and the holding time is 20-30min; the pretreated pure titanium tube is preheated in a resistance furnace, the preheating temperature is 200-300℃, and the holding time is 2-3min.

4. The method for preparing the titanium-copper bimetallic composite material according to claim 1, characterized in that: In step (3), the smelting conditions are: 1200-1250℃, stirring for 3-4min after melting, and slagging for 4-6 times.

5. The method for preparing the titanium-copper bimetallic composite material according to claim 1, characterized in that: In step (4), the pouring temperature is 1100-1200℃, and the pouring rate is 6-13kg / s.

6. The method of claim 1, wherein the titanium-copper bimetallic composite is prepared by the steps of: In step (6), the heat treatment is: annealing temperature is 450-650℃, holding time is 2-3h, furnace cooling to 150-200℃, and air cooling to room temperature after taking out of the furnace. ​

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