An efficient and short process superplastic forming method for TC4 titanium alloy fan blisk forgings

Abstract

An ultrafine forming method for an integral blisk forging of a high-efficiency short-process TC4 titanium alloy fan, which comprises the following steps: 1) obtaining a TC4 titanium alloy ingot with a diameter of Φ820~1020mm by vacuum consumable melting; 2) forging the TC4 titanium alloy ingot for at least 3 heats, and water-cooling after completion to obtain a forging blank; 3) forging the forging blank for at least 3 heats; air-cooling after completion; 4) performing upsetting and drawing on the forging blank for 3~5 heats, and air-cooling to room temperature after completion to obtain a TC4 titanium alloy bar; 5) spraying glass lubricant on the TC4 titanium alloy bar and the forming die, and heating to T β -(20~60)°C; loading the TC4 titanium alloy bar into the forming die, and forming in one heat with a super-large deformation amount of more than 95% to obtain an integral blisk forging of a TC4 titanium alloy fan, and water-cooling to room temperature; 6) annealing the integral blisk forging of the TC4 titanium alloy fan at 650~750°C, and air-cooling to room temperature after the treatment is completed.

Description

Technical Field

[0001] The invention belongs to the technical field of titanium alloy processing, and in particular relates to a high-efficiency short-process superplastic forming method for a TC4 titanium alloy fan integral blade disk forging. Background Art

[0002] The development of science and technology is driving the rapid iteration of aircraft. As the "heart" of the aircraft, the performance requirements of the engine are increasing day by day. As a key component in aircraft engines, the integral blade disk significantly reduces the mass of the rotor and improves the working efficiency by integrating the blades and the disk. This design not only directly reduces the weight of the engine, but also helps to reduce airflow losses, thereby improving the working efficiency and thrust of the engine; this is crucial to improving the flight performance and speed of the aircraft. Therefore, the integral blade disk is widely used in modern high-performance aircraft engines.

[0003] TC4 titanium alloy is a lightweight and high-strength metal material that has become an ideal choice for lightweight design in the aerospace field. However, the conventional forming process of TC4 titanium alloy has difficulties such as poor plasticity and narrow forging temperature range, which makes it easy to produce defects during its forming process. These problems not only limit the comprehensive performance of the material, but also affect production efficiency. Therefore, it is necessary to explore new forming methods to optimize its processing process. However, despite its poor processing performance, it has good plasticity and fluidity in the superplastic state, which is suitable for processing into complex shapes. This feature can be used to achieve superplastic forming of TC4 titanium alloy.

[0004] Chinese patent publication number CN113510207A discloses a method for manufacturing a large-size variable-section integral blade disk forging of TC17 titanium alloy, including designing a forging blank and rough blank according to the shape and size of the part, preparing a final forging and pre-forging die, processing a bar stock to form a bar blank, then moving the bar blank to a pre-forging die to form a pre-forging blank, and finally transferring the pre-forging blank to a final forging die to form a forging.

[0005] Chinese patent publication number CN110773685A discloses a method for preparing a thick and variable-section Ti-6242 alloy integral blade disk forging, comprising forging the bar to obtain an intermediate blank according to ultrasonic detection of the actual noise level of the bar, die forging the intermediate blank to obtain a forging blank, and obtaining the integral blade disk forging after qualified heat treatment.

[0006] Due to the limitation of cooling in the conventional forging process, the bars generally need to be returned to the furnace for reheating after each upsetting and drawing process. Therefore, the deformation amount in a single upsetting and drawing process of the bars and the forming process of the forgings is very limited. Summary of the invention

[0007] The purpose of the present invention is to provide a high-efficiency short-process TC4 titanium alloy fan integral blade disk forging superplastic forming method, which fully utilizes the superplasticity of titanium alloy materials in a high-temperature deformation environment to achieve single-fire ultra-large deformation, greatly improves production efficiency, and reduces manufacturing costs and cycles, with significant economic and social benefits; the room temperature tensile strength of the forging at any position is ≥960MPa, the yield strength is ≥880MPa, the elongation is ≥12.0%, and the cross-sectional shrinkage is ≥25%; the high-temperature tensile performance tensile strength at 400°C is ≥650MPa; the elongation is ≥15%, and the cross-sectional shrinkage is ≥50%; the room temperature impact energy is ≥28J; the fracture toughness is ≥60MPa·m 1 / 2 .

[0008] To achieve the above object, the technical solution of the present invention is:

[0009] A high-efficiency short-process TC4 titanium alloy fan integral blade disk forging superplastic forming method comprises the following steps:

[0010] 1) Vacuum consumable smelting to obtain TC4 titanium alloy ingots with a diameter of Φ820mm~Φ1020mm;

[0011] 2) The TC4 titanium alloy ingot is subjected to at least 3 fire forgings; first, the ingot is heated to 1100°C-1200°C and kept warm for 10h-15h, and then taken out for the first upsetting and drawing; then the ingot is returned to the furnace for insulation at a temperature of 1100°C-1200°C for 4h-10h, and then taken out for the second upsetting and drawing; then the ingot is returned to the furnace for insulation at a temperature of 940°C-980°C for 2h-6h, and then taken out for the third upsetting and drawing; the strain rate for each fire is 0.5s -1 ~0.1s -1 ; After all the forging processes are completed, water cooling is performed to obtain the forging blank;

[0012] 3) The forging blank is subjected to at least 3 fire forgings; first, the forging blank is heated to 1050°C-1100°C and kept warm for 10h-15h, and then taken out for the first upsetting and drawing; then, it is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 940°C-980°C, the keeping warm time is 2h-6h, and then it is taken out for the second upsetting and drawing; then, it is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 1050°C-1100°C, the keeping warm time is 4h-10h, and then it is taken out for the third upsetting and drawing; the strain rate for each fire is 0.05s -1 ~0.005s -1 ; Air cooling after all forging is completed;

[0013] 4) The forging blank is subjected to 3 to 5 fires of upsetting and drawing; first, the forging blank is heated to 940°C to 980°C and kept at this temperature for 10h to 15h, and then taken out for the first upsetting and drawing; each subsequent fire is returned to the furnace for keeping at this temperature, and the keeping temperature is 940°C to 980°C, and the keeping time is 2h to 6h, and then taken out for upsetting and drawing; the strain rate for each fire is 0.05s -1 ~0.005s -1 After all the forging steps are completed, the TC4 titanium alloy rod is air-cooled to room temperature;

[0014] 5) Spray glass lubricant on the surface of the TC4 titanium alloy rod and heat it to T β - (20~60) ℃, heating time T = D × (0.7~1.0), T heating time, unit, min; D is the diameter of TC4 titanium alloy rod, unit, mm; spray glass lubricant on the mold surface of the integral blade disk and heat to T β - (20 ~ 60) ℃ and then keep warm; put the TC4 titanium alloy bar into the forming die, with a forging pressure of 30 ~ 100MN, 0.005 s -1 ~0.001s -1 The TC4 titanium alloy fan integral blade disk forging is obtained by a single fire forming process with a strain rate of more than 95% and an ultra-large deformation amount; after forging, the TC4 titanium alloy fan integral blade disk forging is water-cooled to room temperature;

[0015] 6) The TC4 titanium alloy fan integral blade disk forging is annealed at 650~750℃ and air-cooled to room temperature after the treatment.

[0016] Preferably, in step 2) to step 4), the deformation amount after heating and insulation at 1050°C to 1200°C and / or returning to the furnace for insulation is 60% to 75%, and the deformation amount after heating and insulation at 940°C to 980°C and / or returning to the furnace for insulation is 50% to 60%.

[0017] Preferably, in step 5), the TC4 titanium alloy fan integral blade disk forging is water-cooled within 30 seconds after the forming forging is completed, and the cooling rate is ≥5°C / min.

[0018] The microstructure of the TC4 titanium alloy aero-engine integral blade disk obtained by the present invention is a (α+β) two-phase region structure, the primary α phase content is 40%-60%, and the size is ≤20μm; the room temperature tensile tensile strength of the TC4 titanium alloy fan integral blade disk forging at any position is ≥960MPa, the yield strength is ≥880MPa, the elongation is ≥12.0%, and the cross-sectional shrinkage is ≥25%; the tensile strength of the 400°C high temperature tensile performance is ≥650MPa; the elongation is ≥15%, and the cross-sectional shrinkage is ≥50%; the room temperature impact energy is ≥28J; and the fracture toughness is ≥60MPa·m 1 / 2 .

[0019] In the superplastic forming method of the present invention:

[0020] In the conventional forging process, T is usually completed once. β After deformation due to temperature, it is mostly at T β Continuous upsetting and drawing at high temperature for multiple times will generally result in a small amount of deformation (30%~40%), and have little effect on the crushing and refinement of grains.

[0021] In the method described in the present invention, step 2) forging the TC4 titanium alloy ingot for at least 3 times to fully crush the TC4 titanium alloy ingot structure; step 3) forging the forging blank for at least 3 times is to further refine the grains and transform the morphology of the structure after forging and crushing the ingot, creating conditions for subsequent structure crushing; step 4) upsetting the forging blank for 3 to 5 times is to further refine the grains and obtain the bar structure required for the forging.

[0022] The TC4 titanium alloy forging blank is designed to be forged by three times of upsetting and drawing. β The first upsetting and forging process is carried out at T β The large deformation upsetting and stretching at temperature are used to break the coarse cast grains in the original ingot; after the subsequent T β The reserve distortion can increase the nucleation point for the subsequent β grain nucleation by upsetting and drawing at the same temperature; the T β The large deformation upsetting and stretching at temperature are based on the principle of phase transformation and recrystallization to form β grains. β Deformation at low temperature further refines the grains and makes the structure smaller (for example, less than 20 μm), which provides a good foundation for subsequent single-fire forming. Because the final single-fire forming has limited adjustment on the structure morphology, it is necessary to adjust the structure morphology before single-fire forming. The existing conventional process will not exceed 2 times of upsetting in the single-phase region, while the upsetting combined with isothermal forging process in step 3) and step 4) of the method described in the present invention can control the structure morphology with a small number of fires.

[0023] The present invention also utilizes the superplasticity of TC4 titanium alloy material to achieve a deformation amount close to 100%. Therefore, compared with the common die forging process with multiple fires and small deformation, the one-fire forming of the present invention can save the time of die assembly and heating in the forming forging process, and only one set of dies is needed to complete the work tasks of multiple sets of dies in the common die forging, which greatly improves the efficiency and economic cost.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] Conventional forging at room temperature has a certain limit on the deformation of each upsetting and forging process due to the obvious temperature drop, and the temperature of the core and surface of the forging blank is uneven, so multiple forming processes are required, and the final control of the primary α phase content also needs to be guaranteed by solution treatment. The present invention makes full use of the feasibility of achieving ultra-large deformation under isothermal conditions, and further breaks the original structure by strictly controlling the strain rate and forging temperature in the bar upsetting and forging forming process, so that the primary α phase content is 40%~60% and the size is ≤20μm, which is beneficial to the comprehensive performance of the forging.

[0026] The overall economy of the whole process of the method described in the present invention is better. The forging blank only undergoes 9 to 10 fires. Combined with the large deformation in each fire, the degree of microstructure refinement is basically equivalent to that of more than 20 fires in conventional forging. The forging forming part uses superplasticity to complete one-fire forming, and water cooling is performed under the condition that there is no temperature drop on the surface of the forging after deformation. The forming process is combined with solid solution, which greatly shortens the manufacturing cycle and reduces the manufacturing cost while ensuring equivalent product quality.

[0027] The existing conventional forging does not use isothermal forging, and the surface and core temperatures of the forged billet exposed to the air are uneven. For example, after forging at 960°C, the core is still 920°C, and the surface is only 860°C. The TC4 titanium alloy material ultimately needs to control the primary α phase content of the organization, which needs to be retained by water cooling at the corresponding temperature. For example, Tβ=1000°C, water cooling starting at 960°C can retain 40% of the primary α phase, and water cooling at 920°C can retain 70% of the primary α phase. Conventional solid solution is to heat it to the required temperature to keep the organization warm and then cool it down quickly. This process is also called deformation heat treatment.

[0028] The forging forming of the present invention utilizes superplasticity to complete one-stage forming, and water-cools after deformation, combining the forming process with solid solution, thereby greatly shortening the manufacturing cycle and reducing the manufacturing cost while ensuring comparable product quality.

[0029] The microstructure of the TC4 titanium alloy aero-engine integral blade disk obtained by the present invention is a (α+β) two-phase region structure, the primary α phase content is 40%-60%, and the size is ≤20μm; the room temperature tensile tensile strength of the TC4 titanium alloy fan integral blade disk forging at any position is ≥960MPa, the yield strength is ≥880MPa, the elongation is ≥12.0%, and the area shrinkage is ≥25%; the 400°C high temperature tensile tensile strength is ≥650MPa; the elongation is ≥15%, and the area shrinkage is ≥50%; the room temperature impact energy is ≥28J; and the fracture toughness is ≥60MPa·m 1 / 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a microstructure photograph of the TC4 titanium alloy fan blisk forging in Example 1 of the present invention;

[0031] Figure 2 This is a microstructure photograph of the TC4 titanium alloy fan integral blade disk forging in the comparative example of the present invention. DETAILED DESCRIPTION

[0032] The present invention will be further described below in conjunction with the embodiments and drawings.

[0033] The process parameters of the embodiments of the present invention are shown in Table 1 and Table 2, and the comprehensive performance test results of the embodiments of the present invention and the comparative examples are shown in Table 3.

[0034] Example 1

[0035] TC4 titanium alloy fan blade forging weight 580kg, T β =1000℃, the superplastic forming method includes the following steps:

[0036] 1) A TC4 titanium alloy ingot with a diameter of Φ920 mm is obtained by vacuum consumable melting;

[0037] 2) The TC4 titanium alloy ingot is subjected to three fire forgings; first, the ingot is heated to 1150°C and kept warm for 13 hours, and then taken out for the first upsetting and drawing, with a deformation of 70%; then the ingot is returned to the furnace for insulation at a temperature of 1150°C for 7 hours, and then taken out for the second upsetting and drawing, with a deformation of 70%; then the ingot is returned to the furnace for insulation at a temperature of 960°C for 4 hours, and then taken out for the third upsetting and drawing, with a deformation of 55%; the strain rate for each fire is 0.3s -1 ; After all the forging processes are completed, water cooling is performed to obtain the forging blank;

[0038] 3) The forging billet is subjected to three fire forgings; first, the forging billet is heated to 1080°C and kept warm for 12 hours, and then taken out for the first upsetting and drawing, with a deformation of 72%; then the billet is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 960°C, the keeping warm time is 4 hours, and then the billet is taken out for the second upsetting and drawing, with a deformation of 55%; then the billet is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 1080°C, the keeping warm time is 7 hours, and then the billet is taken out for the third upsetting and drawing, with a deformation of 70%; the strain rate for each fire is 0.02s -1 ; Air cooling after all forging is completed;

[0039] 4) The forging blank is subjected to 4 fire upsetting and drawing; first, the forging blank is heated to 960°C and kept at this temperature for 12 hours, and then taken out for the first upsetting and drawing, with a deformation of 55%; each subsequent fire is returned to the furnace for insulation, and the insulation temperature is 960°C, the insulation time is 4 hours, and then taken out for upsetting and drawing, with a deformation of 55%; the strain rate for each fire is 0.02s -1 After all the forging steps are completed, the TC4 titanium alloy rod is air-cooled to room temperature;

[0040] 5) Spraying glass lubricant on the surface of the TC4 titanium alloy rod and heating it to 960°C for 320 min; Spraying glass lubricant on the surface of the integral blade disk forming mold and heating it to 960°C and then keeping it warm; Loading the TC4 titanium alloy rod into the forming mold and forging it at a forging pressure of 80 MN and a speed of 0.002 s -1 The TC4 titanium alloy fan integral blade disk forging is obtained by a 96% strain rate and a super large deformation amount. After forging, the TC4 titanium alloy fan integral blade disk forging is water-cooled to room temperature at a cooling rate of 6°C / min.

[0041] 6) The TC4 titanium alloy fan integral blade disk forging was annealed at 700°C and then air-cooled to room temperature.

[0042] Example 2

[0043] TC4 titanium alloy fan blade forging weight 800kg, T β =1006℃, the superplastic forming method includes the following steps:

[0044] 1) A TC4 titanium alloy ingot with a diameter of Φ1020 mm is obtained by vacuum consumable melting;

[0045] 2) The TC4 titanium alloy ingot is subjected to three fire forgings; first, the ingot is heated to 1200°C and kept warm for 15 hours, and then taken out for the first upsetting and drawing, with a deformation of 75%; then the ingot is returned to the furnace for insulation at a temperature of 1200°C for 10 hours, and then taken out for the second upsetting and drawing, with a deformation of 75%; then the ingot is returned to the furnace for insulation at a temperature of 980°C for 6 hours, and then taken out for the third upsetting and drawing, with a deformation of 60%; the strain rate for each fire is 0.5s -1 ; After all the forging processes are completed, water cooling is performed to obtain the forging blank;

[0046] 3) The forging blank is subjected to three fire forgings; first, the forging blank is heated to 1100°C and kept warm for 15 hours, and then taken out for the first upsetting and drawing, with a deformation of 75%; then the forging blank is returned to the furnace for heating and keeping warm at 980°C for 6 hours, and then taken out for the second upsetting and drawing, with a deformation of 60%; then the forging blank is returned to the furnace for heating and keeping warm at 1100°C for 10 hours, and then taken out for the third upsetting and drawing, with a deformation of 75%; the strain rate for each fire is 0.05s -1 ; Air cooling after all forging is completed;

[0047] 4) The forging blank is subjected to 5 fire upsetting and drawing; first, the forging blank is heated to 980°C and kept at this temperature for 15 hours, and then taken out for the first upsetting and drawing, with a deformation of 60%; each subsequent fire is returned to the furnace for insulation, and the insulation temperature is 980°C, the insulation time is 6 hours, and then taken out for upsetting and drawing, with a deformation of 60%; the strain rate for each fire is 0.05s -1 After all the forging steps are completed, the TC4 titanium alloy rod is air-cooled to room temperature;

[0048] 5) Spraying glass lubricant on the surface of the TC4 titanium alloy rod and heating it to 986°C for 480 min; Spraying glass lubricant on the surface of the integral blade disk forming mold and heating it to 986°C and then keeping it warm; Loading the TC4 titanium alloy rod into the forming mold, forging it with a forging pressure of 100 MN and a forging speed of 0.005 s -1 The TC4 titanium alloy fan integral blade disk forging is obtained by a 95% strain rate and a super large deformation amount. After forging, the TC4 titanium alloy fan integral blade disk forging is water-cooled to room temperature at a cooling rate of 7°C / min.

[0049] 6) The TC4 titanium alloy fan integral blade disk forging was annealed at 750°C and then air-cooled to room temperature.

[0050] Example 3

[0051] TC4 titanium alloy fan blade forging weight 400kg, T β =995℃, the superplastic forming method includes the following steps:

[0052] 1) A TC4 titanium alloy ingot with a diameter of Φ820 is obtained by vacuum consumable melting;

[0053] 2) The TC4 titanium alloy ingot is subjected to three fire forgings; first, the ingot is heated to 1100°C and kept warm for 10 hours, and then taken out for the first upsetting and drawing, with a deformation of 60%; then the ingot is returned to the furnace for insulation at a temperature of 1100°C for 4 hours, and then taken out for the second upsetting and drawing, with a deformation of 60%; then the ingot is returned to the furnace for insulation at a temperature of 940°C for 2 hours, and then taken out for the third upsetting and drawing, with a deformation of 50%; the strain rate for each fire is 0.1s -1 ; After all the forging processes are completed, water cooling is performed to obtain the forging blank;

[0054] 3) The forging billet is subjected to three fire forgings; first, the forging billet is heated to 1050°C and kept warm for 10 hours, and then taken out for the first upsetting and drawing, with a deformation of 60%; then the billet is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 940°C, the keeping warm time is 2 hours, and then the billet is taken out for the second upsetting and drawing, with a deformation of 50%; then the billet is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 1050°C, the keeping warm time is 4 hours, and then the billet is taken out for the third upsetting and drawing, with a deformation of 60%; the strain rate for each fire is 0.005s -1 ; Air cooling after all forging is completed;

[0055] 4) The forging blank is subjected to 3 fire upsetting and drawing; first, the forging blank is heated to 940°C and kept at this temperature for 10 hours, and then taken out for the first upsetting and drawing, with a deformation of 50%; each subsequent fire is returned to the furnace for insulation, and the insulation temperature is 940°C, the insulation time is 2 hours, and then taken out for upsetting and drawing, with a deformation of 50%; the strain rate for each fire is 0.005s -1 After all the forging steps are completed, the TC4 titanium alloy rod is air-cooled to room temperature;

[0056] 5) Spraying glass lubricant on the surface of the TC4 titanium alloy rod and heating it to 935°C for 280 min; Spraying glass lubricant on the surface of the integral blade disk forming mold and heating it to 935°C and then keeping it warm; Loading the TC4 titanium alloy rod into the forming mold and forging it at a forging pressure of 30 MN and a speed of 0.001 s -1 The TC4 titanium alloy fan integral blade disk forging is obtained by a 97% strain rate and a super large deformation amount. After forging, the TC4 titanium alloy fan integral blade disk forging is water-cooled to room temperature at a cooling rate of 5°C / min.

[0057] 6) The TC4 titanium alloy fan integral blade disk forging was annealed at 650°C and then air-cooled to room temperature.

[0058] Comparative Example

[0059] TC4 titanium alloy fan blade forging weight 580kg, T β =1000℃, and the forming method includes the following steps:

[0060] 1) A TC4 titanium alloy ingot with a diameter of Φ920 mm is obtained by vacuum consumable melting;

[0061] 2) The TC4 titanium alloy ingot is subjected to 5 fire forgings; first, the ingot is heated to 1150°C and kept warm for 15 hours, and then taken out for the first upsetting and drawing, with a deformation of 40% per fire; then the ingot is returned to the furnace for insulation at a temperature of 1150°C for 4 hours, and then taken out for the second upsetting and drawing, with a deformation of 40% per fire; then the ingot is returned to the furnace for insulation at a temperature of 960°C for 2 hours, and then taken out for the third to fifth upsetting and drawing, with a deformation of 30% per upsetting and a strain rate of 0.5s -1 ; After 5 fires, water cooling is performed to obtain the forging blank;

[0062] 3) The forging blank is subjected to 15 fire forgings. The forging blank is heated to 960°C and kept at this temperature for 15 hours, and then taken out for the first upsetting and stretching, with a deformation of 40% for each fire; then the forging blank is returned to the furnace for heating and insulation, with a heating and insulation temperature of 960°C and a insulation time of 2 hours, and then taken out for deformation upsetting and stretching, with a deformation of 40% for each fire, and a strain rate of 0.05s -1 ; After the upsetting is completed, the TC4 titanium alloy rod is air-cooled to room temperature;

[0063] 4) Spraying glass lubricant on the surface of the TC4 titanium alloy rod, performing at least 3 rounds of die forging; heating to 960° C. for 380 min in each round, and heating at 0.05 s -1 The strain rate is 40% and the deformation amount is 40%, and finally the TC4 titanium alloy fan integral blade disk forging is obtained; after the forging is completed, the TC4 titanium alloy fan integral blade disk forging is air-cooled to room temperature;

[0064] 5) The fan integral blade disk obtained in 4) is heated to 960°C, kept at this temperature for 2 hours for solution treatment, and then water-cooled to room temperature at a cooling rate of 6°C / min;

[0065] 6) The TC4 titanium alloy fan integral blade disk forging was annealed at 700°C and then air-cooled to room temperature.

[0066] From the above embodiments and comparative examples combined with Tables 1 to 3, it can be seen that the weight, size and T of the integral blade disk of the comparative example are β The upsetting and drawing times are exactly the same as those in Example 1, but the first T β After forging at temperature above T β The deformation is performed by upsetting and drawing below the temperature, and the final integral blade disk forming process adopts ordinary die forging multiple times.

[0067] In comparison, in Example 1, the forging blank is produced through 10 firings, and the forging is formed by die forging through 1 firing; in the comparative example, the forging blank is produced through 20 firings, and the forging is formed by die forging through no less than 3 firings; compared with the comparative example, the total production firing times of Example 1 of the present invention is reduced by about 50%, while the mechanical properties of forgings produced by the two processes are basically equivalent.

[0068] See also Figure 1 , which shows the microstructure photo of the TC4 titanium alloy fan integral blade disk forging of Example 1 of the present invention, Figure 2 The microstructure of the TC4 titanium alloy fan blade disk forging of the comparative example is shown in the figure. As shown in the figure, the microstructure of the blade disk forging of Example 1 and the comparative example is basically the same, but the total production number of Example 1 of the present invention is reduced by about 50% compared with the comparative example.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

[0070]

[0071]

[0072]

Claims

1. An efficient and short-process superplastic forming method for TC4 titanium alloy fan integral blade disk forgings, characterized in that: The following steps are involved: 1) Vacuum consumable smelting to obtain TC4 titanium alloy ingots with a diameter of Φ820mm~Φ1020mm; 2) The TC4 titanium alloy ingot is subjected to three-time forging; first, the ingot is heated to 1100°C-1200°C and kept warm for 10h-15h, and then taken out for the first upsetting and drawing; then the ingot is returned to the furnace for insulation at a temperature of 1100°C-1200°C for 4h-10h, and then taken out for the second upsetting and drawing; then the ingot is returned to the furnace for insulation at a temperature of 940°C-980°C for 2h-6h, and then taken out for the third upsetting and drawing; the strain rate for each fire is 0.5s -1 ~0.1s -1 ; After all the forging processes are completed, water cooling is performed to obtain the forging blank; 3) The forging blank is subjected to three fire forgings; first, the forging blank is heated to 1050°C~1100°C and kept warm for 10h~15h, and then taken out for the first upsetting and drawing; then the forging blank is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 940°C~980°C, the keeping warm time is 2h~6h, and then taken out for the second upsetting and drawing; then the forging blank is returned to the furnace for heating and keeping warm, the heating and keeping warm temperature is 1050°C~1100°C, the keeping warm time is 4h~10h, and then taken out for the third upsetting and drawing; the strain rate for each fire is 0.05s -1 ~0.005s -1 ; Air cooling after all forging is completed; 4) The forging blank is subjected to 3 to 5 fires of upsetting and drawing; first, the forging blank is heated to 940°C to 980°C and kept at this temperature for 10h to 15h, and then taken out for the first upsetting and drawing; each subsequent fire is returned to the furnace for keeping at this temperature, and the keeping temperature is 940°C to 980°C, and the keeping time is 2h to 6h, and then taken out for upsetting and drawing; the strain rate for each fire is 0.05s -1 ~0.005s -1 After all the forging steps are completed, the TC4 titanium alloy rod is air-cooled to room temperature; In the above steps 2) to 4), the deformation amount after heating and insulation at 1050°C to 1200°C and / or returning to the furnace for insulation is 60% to 75%, and the deformation amount after heating and insulation at 940°C to 980°C and / or returning to the furnace for insulation is 50% to 60%; 5) Spray glass lubricant on the surface of the TC4 titanium alloy rod and heat it to T β - (20~60) ℃, heating time T = D × (0.7~1.0), T is heating time, unit, min; D is the diameter of TC4 titanium alloy rod, unit, mm; Spray glass lubricant on the mold surface of the integral blade disk and heat it to T β - Keep warm after (20~60)℃; The TC4 titanium alloy bar is loaded into the forming die and forged at a forging pressure of 30-100 MN and a speed of 0.005 s -1 ~0.001s -1 The TC4 titanium alloy fan integral blade disk forging is obtained by a single fire forming process with a strain rate of more than 95% and an ultra-large deformation amount; after forging, the TC4 titanium alloy fan integral blade disk forging is water-cooled to room temperature; 6) The TC4 titanium alloy fan integral blade disk forging is annealed at 650~750℃ and air-cooled to room temperature after the treatment.

2. The method according to claim 1, characterized in that: Step 5) After the forming forging is completed, the TC4 titanium alloy fan integral blade disk forging is water-cooled within 30 seconds, and the cooling rate is ≥5°C / min.

3. The method according to claim 1, characterized in that: The microstructure of the obtained TC4 titanium alloy integral blade disk is a (α+β) two-phase region structure, the primary α phase content is 40%~60%, and the size is ≤20μm; the room temperature tensile tensile strength of the TC4 titanium alloy fan integral blade disk forging at any position is ≥960MPa, the yield strength is ≥880MPa, the elongation is ≥12.0%, and the cross-sectional shrinkage is ≥25%; the tensile strength of the 400℃ high temperature tensile performance is ≥650MPa; the elongation is ≥15%, and the cross-sectional shrinkage is ≥50%; the room temperature impact energy is ≥28J; the fracture toughness is ≥60MPa·m 1 / 2 .

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