A method of making a second phase strengthened copper alloy

Abstract

The present application belongs to the field of metal materials, and particularly relates to a preparation method of a second-phase reinforced copper alloy. Main steps are as follows: a molten copper alloy is poured into two sizing nozzles through an intermediate pouring, and a spray ring is designed at the outlet of the nozzles. The spray ring uniformly disperses the liquid alloy after spraying high-speed gas and solid-phase powder, the solid phase acts as a coolant and nucleating agent, and the dispersed solid-liquid mixture is solidified into an ingot blank on a rotating deposition disc. The solidification process is carried out in a negative pressure environment below 3000 Pa, so as to eliminate solidification porosity and shrinkage. Uniform second-phase particles exist in the final ingot blank, so as to greatly improve the strength and wear resistance of the matrix.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metal materials, and particularly relates to a preparation method of a second-phase reinforced copper alloy. BACKGROUND

[0002] With the development of China's manufacturing industry towards high-end and the rapid development in the fields of national defense, ocean, aerospace, etc., the use of copper alloys is upgraded from single performance requirement to composite performance requirement. In device design, it is hoped that the copper alloy can meet the requirements of special structure-function, and also has higher strength, higher toughness, higher wear resistance and even higher thermal / electrical conductivity. Powder metallurgy can realize the uniform compounding of copper matrix and second phase through mechanical alloying, but there are problems such as low efficiency, large batch performance fluctuation and low material yield, and a high-efficiency and low-cost copper-based composite material preparation process is urgently needed. However, due to the limitations of traditional preparation methods of copper alloys, the composition system design, strengthening and toughening method and electromagnetic performance control are greatly limited, and the performance needs to be improved and the function needs to be expanded through the innovation and upgrading of forming process. The development trend is high-alloy materials and composite materials.

[0003] Under the condition of the existing process flow, the melting process cannot add a large amount of second phase, and the segregation flow formed in the solidification process directly restricts the development of various metal composite copper alloy materials. The development of new generation of composite functional special copper alloy materials needs to be carried out through rapid solidification technology and experimental equipment. The application is an application process for rapid solidification and metallurgical combination by gas-solid two-phase flow jet dispersion of copper alloy liquid, which has great application value in the development of high-alloy copper, ceramic strong reinforcement wear-resistant copper alloy and oxide dispersion strengthened copper alloy, etc. SUMMARY

[0004] In view of the problems in the prior art, the application provides a preparation method of a second-phase reinforced copper alloy, which solves the common problems of jet deposition porosity defects, difficulty in adding second-phase particles, excessive amount of jet gas and high cost of metal composite material preparation.

[0005] The technical scheme of the application is as follows:

[0006] A preparation method of a second-phase reinforced copper alloy, comprising the following steps:

[0007] Step (1), a double-vacuum cabin closed structure device is used to realize negative pressure environment jetting: the double-vacuum cabin structure device is divided into a melting cabin, an intermediate ladle cabin and a jet deposition cabin, the intermediate ladle cabin is connected with the melting cabin and the jet deposition cabin, and the connection and isolation are realized through pouring plug valve; the melting cabin is provided with a melting ladle, and the intermediate ladle outside the cabin is preheated to a temperature and then put into the intermediate ladle cabin; the melting cabin is connected with a high vacuum pump set, the vacuum degree of the melting cabin is ≤5x10 -2Pa; the spray deposition cabin is provided with a high-speed vacuum pump group to maintain the environmental pressure at ≤3000 Pa under the input condition of the spray gas;

[0008] Step (2), the copper alloy is vacuum melted and the composition is controlled through the melting cabin, the base alloy is a high proportion copper alloy, including but not limited to pure copper, manganese copper white, nickel tin copper, titanium copper;

[0009] Step (3), the copper alloy solution after melting in step (2) is controlled to have a superheat of +40~100℃, the sealing door of the tundish cabin is closed, the argon bottom blowing degassing treatment is performed by the melting ladle, the control valve a is opened, the pouring plug valve is closed, the tundish cabin is filled with the tundish preheated to above 1000℃, the tundish cabin is connected with the pouring port position, the furnace cover is closed, the high-speed vacuum pump group starts to vacuumize to below 3000 Pa, at this time, the melting cabin is filled with the protective gas to 0.02 Mpa and then the gas filling is stopped, then the control valve b and the control valve c of the spray deposition cabin 12 are maintained by the high-speed vacuum pump group to have an environmental pressure of ≤3000 Pa, the melting ladle is poured, the inclusions are fully adsorbed after the copper alloy solution passes through the tundish slag retaining mechanism, and the liquid level is kept stable after reaching the set height;

[0010] Step (4), second phase particle surface modification: the second phase particles include one of silicon carbide, boron nitride, aluminum oxide, diamond sand, graphene, carbon nanotube and graphite particle; wherein, the ceramic particles silicon carbide, boron nitride and aluminum oxide are ball milled with Cu material powder in liquid nitrogen, the mass fraction of the ceramic particles is above 60%, the grinding ball material is super S280 stainless steel, the particle size of the ceramic particles is below 2 μm, the particle size of the Cu material powder is 20~30 μm, the ball milling time is above 24 hours, the second phase particle surface is promoted to adhere to the metal powder, and the second phase particle and the copper alloy solution are promoted to be fully wetted; the graphene, carbon nanotube, diamond and graphite particle need to be treated by metal evaporation to improve the wettability;

[0011] Step (5), the second phase particles after the surface modification in step (4) are mixed with inert gas Ar in the gas-solid two-phase flow mixing and preheating device, are preheated to form a gas-solid two-phase flow, and are divided into two paths to enter the spray mechanism through two-phase flow pipelines, the copper alloy solution is sprayed out through the spray mechanism, the inert gas Ar blows the second phase particles into the alloy solution in the spray through the two-phase flow pipelines, and the two are converged and deposited on the deposition blank;

[0012] Step (6), the gas-solid two-phase flow disperses the copper alloy solution flowing out of the two pouring spouts of the spray mechanism into uniform droplets in the spray deposition cabin, and completes the spray of the deposition blank on the deposition disc;

[0013] After the spraying in step (7) is completed, the top temperature is controlled at ≤ (Ts-50℃) and the bottom temperature is controlled at ≤ (Ts-200℃), the ingot is taken out and sent to a 1180℃ forging holding furnace for 1-3h, then forged into a square or round billet for subsequent processing and heat treatment into a piece, and the final rolling thickness is 3.0-12mm; or the ingot is directly perforated for pipe rolling.

[0014] Further, in the preparation method of the second phase strengthened copper alloy, the number of pores on the solidification end face in the spray deposition cabin is ≤5 / 10mm 2 , and the pore size is ≤1μm, and all the pores are completely closed after forging in step (7).

[0015] Further, in the preparation method of the second phase strengthened copper alloy, after hot rolling in step (7), the mass fraction of the second phase particles in the forging billet is 1-8%, the particle size is controlled at 20-50nm or 800-1200nm, the second phase particles are uniformly distributed on the matrix without grain boundary segregation, the wear life is increased by more than 30% due to the strengthening of the particles, the macro hardness is increased by more than 30%, and the yield strength, tensile strength and impact energy are decreased by ≤2% compared with the non-second phase strengthened matrix.

[0016] Further, in the preparation method of the second phase strengthened copper alloy, the preheating temperature of the second phase particles after surface modification in step (5) is ≥400℃, and the powder feeding amount of the 10-3000nm particle size second phase particles is 100-1250g / min.

[0017] Further, in the preparation method of the second phase strengthened copper alloy, in step (1), two water outlets are arranged horizontally at the lower end of the tundish, the water outlet diameter is φ4-10mm, two tundish nozzles are arranged, the tundish nozzle is located in the middle of the spray deposition ring of the spraying mechanism, the center lines are aligned, the nozzle lower plane is parallel to the spray deposition ring lower plane, the single nozzle flow rate is 10-80kg / min, the nozzle outlet flow rate is 1.0-2.0m / min, the water outlet position is opposite to different positions of the deposition billet radius, the flow rate of different nozzles is controlled by the size of the sizing water outlet, and the aperture area ratio is controlled at 1:0.7-0.8.

[0018] Further, in the preparation method of the second phase strengthened copper alloy, in step (5), the number of openings of the spray deposition ring of the spraying mechanism is 12-18, the aperture is 4-8mm; the spray deposition ring is designed as an inclined slit structure, the slit width is controlled at 2-4mm; the gas hole or slit inclination angle is controlled at 25-45° with the shaft center line, the focal length plane is controlled at 40-100mm; the whole spray deposition ring can be rotated by -40° to +40°, the scanning frequency is 0-5Hz; the gas spraying pressure is 0.2-0.7MPa, the single spray deposition ring gas injection amount is 5-40m 3 / min, and the particle loading amount is 0-2500g / min.

[0019] Further, the preparation method of the second phase reinforced copper alloy, in the step (6) of the spray deposition process, the distance between the deposition disc and the lower end of the spray deposition ring is controlled to be 200-450 mm, the deposition blank diameter is 200-850 mm, the rotation speed of the deposition disc is 40-200 r / min, the falling speed is 50-200 mm / min, and the surface molten pool depth is controlled to be 2-5 mm.

[0020] Further, the preparation method of the second phase reinforced copper alloy, the graphite or alumina material working layer, the adsorption layer and the pouring nozzle area of the smelting ladle are designed, the adsorption layer can be replaced each time, the smelting ladle is designed to have a tilt angle of -30° to +90°, after smelting is completed, the smelting ladle is tilted positively and negatively to make large inclusions be captured by the adsorption layer, sampling and composition fine adjustment are completed, and pouring is prepared.

[0021] Further, the preparation method of the second phase reinforced copper alloy, the gas-solid two-phase flow is used to drive the liquid phase, and the gas phase and the solid phase can both be used as cooling media, and the proportion of gas-solid consumption to solidification latent heat is 1:2-3.

[0022] The advantages and beneficial effects of the present application are as follows:

[0023] 1. The present application combines the advanced metal matrix composite material preparation method of gas-solid two-phase flow and vacuum spray deposition technology. The process can realize the spray deposition forming of copper alloy and its composite materials in a vacuum environment by driving the gas-solid two-phase flow. This rapid solidification process can realize copper-based ceramic phase reinforcement, uniform solid solution of high alloy, fine grain strengthening and reduction of solidification defects, thereby significantly improving the mechanical properties, corrosion resistance and high temperature resistance of the material. This has important significance for the demand for high-performance materials in the fields of marine engineering, shipbuilding, aerospace, automobile manufacturing, energy and the like.

[0024] 2. The present application can adjust the gas pressure, the type and content of the second phase particles, the deposition temperature and other parameters as needed, so as to prepare copper alloy and its composite materials with different properties and uses. This flexibility provides more possibilities for the design and preparation of various copper alloys. At the same time, the deposition process in a vacuum environment reduces the oxidation and pollution of the material and reduces the subsequent processing cost. The process introduces solid phase medium particles on the basis of gas atomization to form a gas-solid two-phase mixed flow. This new atomization mechanism significantly improves the atomization efficiency, refines the particle size of the atomized powder, and improves the uniformity of the reinforcing phase in the matrix alloy. This innovative forming process provides a new idea and method for the preparation of high-performance composite materials.

[0025] 3、The second phase particle loading method and the composite method of the application can realize the spray forming of various copper alloy composite materials. The second phase particle is not only the kinetic energy carrier of the dispersed liquid phase, but also the cooling medium of the alloy liquid phase, and is the strengthening or functional structure of the metal matrix composite material. Currently, there is no patent and literature report on introducing the second phase functional particle into the copper alloy by the gas-solid two-phase flow driving. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The process schematic diagram for preparing the second phase strengthened copper alloy of the application is shown in the figure.

[0027] In the figure: 1-high vacuum pump group; 2-control valve a; 3-melting cabin; 4-melting ladle; 5-tundish; 6-pouring plug valve; 7-tundish cabin sealing door; 8-tundish cabin; 9-gas-solid two-phase flow mixing and preheating device; 10-two-phase flow pipeline; 11-spraying mechanism; 12-spraying and depositing cabin; 13-deposited billet; 14-depositing disc; 15-control valve b; 16-solid phase particle cyclone separator; 17-control valve c; 18-high-speed vacuum pump group. DETAILED DESCRIPTION

[0028] The process schematic diagram for preparing the second phase strengthened copper alloy of the application is shown in the figure. Figure 1 The specific embodiments of the application are described in further detail below in combination with the description of the drawings and the examples. The following examples are used to illustrate the application, but cannot be used to limit the scope of the application.

[0029] In the following examples, the double vacuum cabin closed structure device is used to realize the negative pressure environment spraying. The double vacuum cabin structure device is divided into the melting cabin 3, the tundish cabin 8 and the spraying and depositing cabin 12. The tundish cabin 8 is connected with the melting cabin 3 and the spraying and depositing cabin 12, and the communication and isolation are realized through the pouring plug valve 6. The melting ladle 4 is arranged in the melting cabin 3, and the tundish 5 which can be lifted is preheated outside the cabin to a certain temperature and then put into the tundish cabin 8. The melting cabin 3 is connected with the high vacuum pump group 1, and the spraying and depositing cabin 12 is separately provided with the high-speed vacuum pump group 18. Example 1

[0030] In this embodiment, a preparation method of a second phase strengthened copper alloy is provided. The alloy to be melted is nickel-tin-copper, and the composition is as follows: Ni: 15%; Sn: 8%; Mn: 0.5%; Zn: 0.2%; Fe: 0.1%; and Cu is the balance. The second phase particle is SiC, and the addition amount is 2%, and the particle size is 200 nm. The preparation method specifically includes the following steps.

[0031] Step (1) open control valve a2, close pouring plug valve 6, adjust the vacuum degree in the melting cabin 3 to be less than or equal to 5*10 -2 Pa;

[0032] Step (2) nickel tin copper alloy liquid control overheat + 100℃, by smelting ladle 4 is bottom blowing argon deslagging degassing treatment, close control valve a2 and intermediate package cabin sealing door 7, then open control valve b15 and control valve c17, then open smelting cabin 3 and injection deposition cabin 12 pouring plug valve 6, start high speed vacuum pump set 18 to maintain the ambient pressure ≤3000Pa, smelting ladle 4 pour over. Liquid level reaches the set height 250mm. The lower edge of the tundish 5 is arranged with two water holes with diameters of φ8mm and φ6.5mm. According to the diameter of the injection deposition disc 14, 400mm, two nozzles are configured, with a single nozzle flow of 55kg / min and 38kg / min, and the nozzle outlet flow rate is controlled at 1.1m / min. The water hole position is opposite to the different positions of the deposited billet radius, and the flow rate of different nozzles is controlled by the size of the sizing water hole. The hole area ratio is controlled at 1:0.7. The tundish cabin 8 is opened, the tundish 5 is loaded into the tundish cabin 8 after being preheated to 1100℃, and is connected with the pouring port position, then the furnace cover is closed, the high speed vacuum pump set 18 starts to vacuum to 1000Pa, at this time the smelting cabin 3 is filled with protective gas to 0.01MPa and then stops filling; After smelting, the large inclusions near the positive and negative tilting of the smelting ladle 4 are captured by the adsorption layer, the sampling and composition fine adjustment are completed, and the pouring is prepared;

[0033] Step (3) the nozzle of the tundish 5 is located in the middle of the injection deposition ring of the injection mechanism 11, the center line is aligned, the nozzle lower plane is parallel to the injection deposition ring lower plane, the injection deposition ring has 16 openings with a diameter of 5mm. The gas hole or slit inclination is controlled at 25° to the center line of the shaft, and the focal length plane is controlled at 80mm; the injection deposition ring as a whole can rotate-20~+30°, the scanning frequency is 3Hz; the gas injection pressure is 0.4MPa, the single injection deposition ring gas injection amount is 25m 3 / min, and the single ring particle loading amount is 470g / min.

[0034] Step (4) before the second phase particle SiC is added into the gas-solid two-phase flow mixing and preheating device 9, surface modification is needed, which is to mix 95% SiC by mass fraction with 5% nickel tin copper particle by mass fraction in liquid nitrogen for 30h, the SiC particle size is below 2μm, and the metal powder particle size is 20μm.

[0035] Step (5) after the surface modified second phase particle SiC is mixed and preheated with inert gas Ar in the gas-solid two-phase flow mixing and preheating device 9, a gas-solid two-phase flow is formed, and the two-phase flow is divided into two paths by the two-phase flow pipeline 10. The copper alloy solution is sprayed out through the injection mechanism 11, and the inert gas Ar blows the second phase particle SiC into the nickel tin copper alloy solution in the injection through the two-phase flow pipeline 10, and the two are converged and deposited on the deposited billet 13; wherein the preheating temperature is 700℃, and the 1000nm particle size second phase particle SiC powder feeding amount is 500g / min.

[0036] Step (6) The gas-solid two-phase flow fully disperses the nickel-tin-copper alloy solution flowing out of the two gating ingots of the spraying mechanism 11 into uniform droplets in the spray deposition chamber 12. The distance between the deposition plate 14 and the lower end of the spray deposition ring is controlled at 380 mm. The diameter of the deposition billet 13 is 400 mm. The rotation speed of the deposition plate 14 is 80 r / min, the descent speed is 72 mm / min, the surface molten pool depth is controlled at 2 mm, and the high-speed vacuum pump group 18 controls the negative pressure of the solidification environment to be ≤3000 Pa.

[0037] After the spraying in step (7), the top temperature is controlled at 1050℃ and the bottom temperature is 950℃. After the billet is taken out, it is sent to the forging holding furnace for uniform temperature for 1 hour. Then it is forged into a 400mm wide and 100mm thick square billet for rolling, with a final rolling thickness of 10mm.

[0038] The number of pores on the solidification end face inside the jet deposition chamber is 5 per 10 mm. 2 Furthermore, the pore size is 1μm, and all the pores are pressed together after forging.

[0039] In this embodiment, the mass fraction of second-phase particles in the forged billet is 2%, with a particle size of 200~1000nm, uniformly distributed on the matrix without grain boundary segregation. The reinforcing particles increase wear resistance by more than 30%, improve macroscopic hardness by more than 20%, and reduce yield strength, tensile strength, and impact energy by 1% compared to the non-second-phase reinforced matrix, while maintaining the same conductivity. Example 2

[0040] In this embodiment, a method for preparing a second-phase strengthened copper alloy is described. The smelted alloy is a Cu-Ag-Ce alloy with the following composition: Ag: 2%; Ce: 0.2%; Cu as the balance. The second-phase particles are Al2O3, added at 0.5% with a particle size of 2 nm. The preparation method specifically includes the following steps:

[0041] Step (1) Open control valve a2, close casting gate valve 6, and adjust the vacuum degree in melting chamber 3 to ≤5×10 -2 Pa;

[0042] Step (2) Cu-Ag-Ce alloy liquid control superheat +80℃, by smelting ladle 4 for bottom blowing argon deslagging degassing treatment, close control valve a2 and tundish cabin sealing door 7, then open control valve b15 and control valve c17, then open smelting cabin 3 and injection deposition cabin 12 pouring plug valve 6, start high speed vacuum pump set 18 to maintain the environment pressure ≤3000Pa, smelting ladle 4 pour over. Liquid level reaches the set height 240mm. The lower edge of the tundish 5 is horizontally arranged with two water holes, the water hole diameter is φ8mm and φ6.5mm, according to the diameter of the injection deposition disc 14 400mm, two nozzles are configured, the single nozzle flow is 55kg / min and 38kg / min, the nozzle outlet flow rate is controlled at 1.1m / min. The water hole position is opposite to the different positions of the deposited billet radius, the different nozzle flow rates are controlled by the sizing water hole size, the aperture area control is 1:0.8. The tundish cabin 8 is opened, the tundish 5 preheated to 1080℃ is loaded into the tundish cabin 8 and connected with the pouring port position, then the furnace cover is closed, the high speed vacuum pump set 18 starts to vacuum to 1000Pa, at this time the smelting cabin 3 is filled with protective gas to 0.01MPa and then stops filling; After smelting, the near large inclusions of the smelting ladle 4 are captured by the adsorption layer, sampling and composition fine tuning are completed, and pouring is prepared;

[0043] Step (3) The nozzle of the tundish 5 is located in the injection deposition ring of the injection mechanism 11, the center line is aligned, the nozzle lower plane is parallel to the injection deposition ring lower plane, the injection deposition ring has 12 openings with a hole diameter of 6mm. The gas hole or slit inclination is controlled at 30° to the shaft center line, the focal length plane control is 90mm; The injection deposition ring as a whole can rotate-20~+30°, the scanning frequency is 3Hz; The gas injection pressure is 0.4MPa, the single injection deposition ring gas injection amount is 20m 3 / min, the single ring particle loading amount is 280g / min.

[0044] Step (4) The second phase particle Al2O3 needs surface modification before being added into the gas-solid two-phase flow mixing and preheating device 9, which is to ball mill 75% Al2O3 by mass fraction and 25% Cu-2Ag-0.2Ce particle liquid nitrogen for 30h; The ceramic particle size is 1.5μm, and the Cu material powder particle size is 30μm;

[0045] Step (5) the second phase particle Al2O3 after surface modification is mixed with inert gas Ar uniformly in the gas-solid two-phase flow mixing and preheating device 9, and is preheated to form a gas-solid two-phase flow, and is divided into two paths by the two-phase flow pipeline 10 to enter the injection mechanism 11, the Cu-Ag-Ce alloy solution is sprayed out by the injection mechanism 11, the inert gas Ar blows the second phase particle Al2O3 into the Cu-Ag-Ce alloy solution in the injection through the two-phase flow pipeline 10, and the two are converged and deposited on the deposition blank 13; wherein the preheating temperature is 400℃, and the powder amount of the 600nm particle size second phase particle SiC is 100g / min.

[0046] Step (6) the gas-solid two-phase flow disperses the Cu-Ag-Ce alloy solution flowing out of the two sprue gates of the injection mechanism 11 into uniform droplets in the spray deposition cabin 12, the deposition disc 14 is controlled at a distance of 380mm from the lower end of the spray deposition ring, the deposition blank 13 has a diameter of 400mm, the rotation speed of the deposition disc 14 is 80r / min, the falling speed is 65mm / min, the surface molten pool depth is controlled at 2mm, and the high-speed vacuum pump group 18 controls the solidification environment negative pressure to be less than or equal to 3000Pa.

[0047] Step (7) after the spraying is completed, the top temperature is 1050℃ and the bottom temperature is 950℃, the blank is taken out and sent into a forging holding furnace to be uniformly heated for 3h, and then forged into a 400mm wide and 100mm thick square blank for rolling, and the final rolling thickness is 10mm. After face milling and polishing, the blank is continuously hot-rolled to 2.5mm, and pickled and cold-rolled to 0.1mm.

[0048] The number of pores on the solidification end face in the spray deposition cabin is 5 / 10mm 2 , and the pore diameter is 1μm, and all the pores are pressed together after forging.

[0049] In the embodiment, the second phase particles in the forging blank are cerium oxide and aluminum oxide, the mass fraction is 0.6%, the particle size is 5-50nm, and the particle density is 5×1024 / m 3 , and the particles are uniformly distributed on the matrix without grain boundary segregation. Compared with the non-second phase strengthened matrix, the yield strength, tensile strength and impact energy are increased by 15%, the high temperature strength is increased by 20%, the creep resistance is increased by 30%, and the relative electrical conductivity IACS is 95%. Embodiment 3

[0050] In the embodiment, a preparation method of a second phase strengthened copper alloy, the alloy is a Cu-Fe-Ce alloy, the composition is Fe: 20%, Ce: 0.05%, and the balance is Cu. The second phase particle is SiC, the addition amount is 1%, and the particle size is 500nm. The preparation method specifically includes the following steps:

[0051] Step (1) open control valve 2, close pouring plug valve 6, adjust the vacuum degree in the smelting cabin 3 to be less than or equal to 5*10 -2 Pa;

[0052] Step (2) the Cu-Fe-Ce alloy liquid is controlled to have a superheat of +100℃ (the Ce element is added at the end), argon bottom blowing is performed on the smelting ladle 4 to remove slag and gas, the control valve a2 and the tundish cabin sealing door 7 are closed, then the control valve b15 and the control valve c17 are opened, then the smelting cabin 3 and the pouring plug valve 6 of the spray deposition cabin 12 are opened, and the high-speed vacuum pump group 18 is started to maintain an environment pressure of less than or equal to 3000 Pa, and the smelting ladle 4 is poured by tilting to a liquid level reaching a set height of 240 mm. Two water outlets are horizontally arranged at the lower edge of the tundish 5, the water outlet diameters are φ8 mm and φ6.5 mm, two nozzles are configured according to the diameter of the spray deposition disc 14 being 400 mm, the single nozzle flow rate is 35 kg / min and 29 kg / min, and the nozzle outlet flow rate is controlled to be 1.0 m / min. The water outlet position is opposite to different positions of the deposited blank radius, the flow rate of different nozzles is controlled by the size of the sizing water outlet, and the aperture area control is 1:0.7. The tundish cabin 8 is opened, the tundish 5 preheated to 1050℃ is loaded into the tundish cabin 8, and is connected with the pouring port position to complete the pouring, then the furnace cover is closed, the high-speed vacuum pump group 18 starts to be pumped to 1000 Pa, at this time, the smelting cabin 3 is filled with protective gas to 0.01 MPa and then stopped; after the smelting is completed, the large inclusions near the positive and negative tilting of the smelting ladle 4 are captured by the adsorption layer, sampling and composition fine adjustment are completed, and pouring is prepared;

[0053] Step (3) the nozzle of the tundish 5 is located in the middle of the spray deposition ring of the spray mechanism 11, the center line is aligned, the nozzle lower plane is parallel to the lower plane of the spray deposition ring, the number of openings of the spray deposition ring is 18, and the aperture is 5 mm. The gas hole or slit inclination is controlled to be 20° inclined to the shaft center line, the focal length plane control is 100 mm; the whole spray deposition ring can be rotated by -20~+30°, the scanning frequency is 3 Hz; the gas injection pressure is 0.4 MPa, the single spray deposition ring gas injection amount is 25 m 3 / min, and the single ring particle loading amount is 500 g / min.

[0054] Step (4) before the second phase particle SiC is added into the gas-solid two-phase flow mixing and preheating device 9, surface modification is needed, that is, 80% SiC by mass fraction and 20% Cu-Fe-0.05Ce particle by mass fraction are liquid nitrogen ball milled for 30 h; the ceramic particle size is 1 μm, and the Cu material powder particle size is 20 μm.

[0055] Step (5) the second phase particles SiC after surface modification is mixed with inert gas Ar uniformly in the gas-solid two-phase flow mixing and preheating device 9, and forms a gas-solid two-phase flow after preheating, and is divided into two paths by the two-phase flow pipeline 10 to enter the injection mechanism 11, the Cu-Fe-Ce alloy solution is sprayed out by the injection mechanism 11, the inert gas Ar blows the second phase particles SiC into the Cu-Fe-Ce alloy solution in the injection through the two-phase flow pipeline 10, and the two are converged and deposited on the deposition blank 13; wherein the preheating temperature is 600℃, and the powder feeding amount of the 3000nm particle size second phase particles SiC is 1250g / min.

[0056] Step (6) the gas-solid two-phase flow disperses the Cu-Fe-Ce alloy solution flowing out of the two sprue gates of the injection mechanism 11 into uniform droplets in the spray deposition cabin 12, the deposition disc 14 is controlled at a distance of 420mm from the lower end of the spray deposition ring, the deposition blank 13 has a diameter of 400mm, the rotation speed of the deposition disc 14 is 80r / min, the lowering speed is 58mm / min, the surface molten pool depth is controlled to be 2mm, and the high-speed vacuum pump group 18 controls the solidification environment negative pressure to be ≤3000Pa.

[0057] Step (7) after the spraying is completed, the top temperature is controlled to be 1050℃ and the bottom temperature is controlled to be 950℃, the blank is taken out and sent to a forging holding furnace to be uniformly heated for 2h, and then forged into a 400mm wide and 100mm thick square blank for rolling, and the final rolling thickness is 10mm. After face milling and polishing, the blank is continuously hot-rolled to 2.5mm, and pickled and cold-rolled to 0.1mm.

[0058] The number of pores on the solidification end face in the spray deposition cabin is 5 / 10mm 2 , and the pore diameter is 1μm, and all the pores are pressed together after forging.

[0059] In the embodiment, the second phase particles in the forged blank are SiC and Fe particles. The SiC has a mass fraction of 1%, a particle size of 100-800nm, and is uniformly distributed on the matrix without grain boundary segregation. The Fe particles have a particle size of 5-20nm and 1-4μm, and a mass fraction of 19.8%. Compared with the non-second phase strengthened matrix, the yield strength, tensile strength and impact energy are increased by 15%, the high temperature strength is increased by 20%, the creep resistance is increased by 30%, and the matrix saturation magnetic induction Ms is ≥35emu / g.

Claims

1. A method of making a second phase strengthened copper alloy, characterized by, Comprise the following steps: Step (1), a double vacuum chamber closed structure device is used to realize negative pressure environment injection: the double vacuum chamber closed structure device is divided into a smelting chamber, a tundish chamber and a spray deposition chamber, the tundish chamber is connected with the smelting chamber and the spray deposition chamber, and the tundish chamber is communicated and isolated through a pouring plug valve; the smelting chamber is provided with a smelting ladle, and a liftable tundish is preheated outside the chamber to a certain temperature and then placed in the tundish chamber; the smelting chamber is communicated with a high vacuum pump set, and the vacuum degree of the smelting chamber is ≤5×10 -2 Pa; the spray deposition chamber is separately provided with a high-speed vacuum pump set, and the environmental pressure under the input condition of the spray gas is maintained to be ≤3000 Pa; Step (2), the vacuum melting and composition control of copper alloy are realized by the melting cabin, the base alloy is high proportion copper alloy, including one of manganese copper white, nickel tin copper or titanium copper; Step (3), the copper alloy solution after melting in step (2) is controlled to have a superheat of +40~100℃, the intermediate cabin sealing door is closed, the bottom blowing argon degassing treatment is carried out by the melting ladle, the control valve a is opened, the pouring plug valve is closed, the intermediate cabin is filled after being preheated to 1000℃ or above, the intermediate cabin is connected with the pouring port position, the furnace cover is closed, the high speed vacuum pump group starts to vacuum to 3000Pa or below, at this time the melting cabin is filled with protective gas to 0.02MPa and then stops filling, then the control valve b and the control valve c of the spray deposition cabin are opened, the environment pressure is maintained to be less than or equal to 3000Pa by the high speed vacuum pump group, the melting ladle is poured, the inclusions are fully adsorbed after the copper alloy solution passes through the intermediate cabin slag retaining mechanism, the liquid level is kept stable after reaching the set height; Step (4), second phase particle surface modification: the second phase particles include one of silicon carbide, boron nitride, aluminum oxide, diamond sand, graphene, carbon nanotube and graphite particle; wherein, the ceramic particles silicon carbide, boron nitride and aluminum oxide are ball milled with Cu material powder in liquid nitrogen, the mass fraction of the ceramic particles is more than 60%, the grinding ball material is super S280 stainless steel; the particle size of the ceramic particles is 2μm or below, the particle size of the Cu material powder is 20~30μm, the ball milling time is more than 24 hours, which promotes the second phase particle surface to adhere to the metal powder and promotes the second phase particle and the copper alloy solution to be fully wetted; the graphene, carbon nanotube, diamond sand and graphite particle need to be treated by metal evaporation to improve the wettability; Step (5), the second phase particles after surface modification in step (4) are mixed with inert gas Ar in the gas-solid two-phase flow mixing and preheating device, preheated to form gas-solid two-phase flow, and then enter the spray mechanism through two-phase flow pipelines in two ways, the copper alloy solution is sprayed out through the spray mechanism, the inert gas Ar blows the second phase particles into the alloy solution in the spray through the two-phase flow pipeline, and the two are gathered and deposited on the deposition billet; Step (6), the gas-solid two-phase flow disperses the copper alloy solution flowing out of the two pouring spouts of the spray mechanism into uniform droplets in the spray deposition cabin, and completes the spray of the deposition billet on the deposition disc; Step (7), after the spray is completed, the top temperature is controlled to be less than or equal to (Ts-50℃), the bottom temperature is controlled to be less than or equal to (Ts-200℃), the ingot billet is taken out and sent to a 1180℃ forging holding furnace for 1~3h, and then forged into a square billet or a round billet for subsequent processing and heat treatment into a piece, the final rolling thickness is 3.0~12mm; or the ingot billet is directly perforated for pipe rolling.

2. The method of claim 1, wherein the second phase strengthened copper alloy is prepared by the steps of: The number of statistical pores on the solidification end face in the spray deposition cabin is ≤5 / 10 mm 2 , and the pore diameter is ≤1 μm, and all the pores are compressed after forging in step (7).

3. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, After hot rolling in step (7), the mass fraction of the second phase particles in the forged billet is 1~8%, the particle size is controlled to be 20~50nm or 800~1200nm, the particles are uniformly distributed on the base body without grain boundary segregation, the strengthening particles enhance the wear life by more than 30%, the macro hardness is improved by more than 30%, and the yield strength, tensile strength and impact energy are decreased by less than or equal to 2% compared with the non-second phase strengthened base body.

4. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, The preheating temperature of the second phase particles after surface modification in step (5) is ≥400℃, and the feeding amount of the 10-3000 nm particle size second phase particles is 100-1250 g / min.

5. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, In step (1), two water outlets are horizontally arranged at the lower edge of the tundish, the water outlet diameter is φ4-10 mm, two tundish nozzles are arranged, the tundish nozzles are located in the middle of the jet deposition ring of the jetting mechanism, the center lines are aligned, the nozzle lower plane is parallel to the jet deposition ring lower plane, the single nozzle flow rate is 10-80 kg / min, the nozzle outlet flow rate is 1.0-2.0 m / min, the water outlet position is opposite to different positions of the deposited blank radius, the flow rate of different nozzles is controlled by the size of the sizing water outlet, and the aperture area control is 1:0.7-0.

8.

6. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, The number of the spray deposition ring opening holes of the spray mechanism in step (5) is 12-18, and the hole diameter is 4-8 mm; the spray deposition ring is designed as an inclined slit structure, the slit width is controlled to be 2-4 mm; the gas hole or slit inclination is controlled to be 25-45° with the shaft center line, the focal length plane is controlled to be 40-100 mm; the whole spray deposition ring can rotate by -40° to +40°, the scanning frequency is 0-5 Hz; the gas spray pressure is 0.2-0.7 MPa, the single spray deposition ring gas injection amount is 5-40 m 3 / min, and the particle loading amount is 0-2500 g / min.

7. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, In step (6), during the jet deposition process, the distance between the deposition disc and the lower end of the jet deposition ring is controlled to be 200-450 mm, the diameter of the deposited blank is 200-850 mm, the rotation speed of the deposition disc is 40-200 r / min, the descending speed is 50-200 mm / min, and the surface molten pool depth is controlled to be 2-5 mm.

8. The method for preparing a second-phase strengthened copper alloy according to claim 1, characterized in that, The graphite or alumina material working layer, the adsorption layer and the pouring nozzle area of the smelting ladle are designed, the adsorption layer can be replaced each time, the smelting ladle is designed to have an inclination angle of -30° to +90°, after smelting is completed, the smelting ladle is positively and negatively tilted to make large inclusions be captured by the adsorption layer, sampling and composition fine adjustment are completed, and pouring is prepared.

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