Titanium alloy isothermal forging intelligent temperature control device and isothermal forging process

Abstract

The invention discloses a titanium alloy isothermal forging intelligent temperature control device and an isothermal forging process in the technical field of metal forging. The temperature control device comprises a multi-section resistor intelligent induction heating module, a circulating water cooling module, a high-frequency induction heating module, a resistor heating module and a temperature controller matched with the multi-section resistor intelligent induction heating module, the circulating water cooling module, the high-frequency induction heating module and the resistor heating module. The forging technology comprises the steps that a high-frequency induction heating module and a resistance heating module are used for heating a blank and a forging machine anvil die to the same temperature before forging, and in the forging process, a multi-section resistance intelligent induction heating module is used for keeping the temperature of all positions of the blank to be the same as that of the forging machine anvil die; and after forging is completed, the circulating water cooling module is controlled to cool the forge piece according to the forge piece temperature. According to the method, gradient temperature control and in-situ cooling-quenching are integrated, the temperature uniformity in the forging process can be improved, the effect of refining grains is achieved, meanwhile, residual stress is avoided, the subsequent heat treatment procedure is omitted, and the comprehensive cost of the whole procedure is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of metal forging, and in particular to an intelligent temperature control device for isothermal forging of a titanium alloy and an isothermal forging process. Background Art

[0002] Titanium alloys have excellent comprehensive properties such as high strength, low density, strong corrosion resistance, and excellent processing performance. Therefore, titanium alloys are widely used in aerospace, shipbuilding, medical biology, and petrochemical industries. Appropriate forging technology can improve the microstructure of titanium alloys, thereby improving their comprehensive performance. At present, the traditional forging process of titanium alloys has problems such as uneven temperature distribution of the billet during forging, large temperature difference between the billet and the die, and uneven thermal stress distribution of the billet, which makes the microstructure of the forgings different; forging is generally carried out under high temperature conditions, and the surface of titanium alloy forgings is easily oxidized and hydrogen embrittled, resulting in relatively poor surface quality; the residual stress of the billet after conventional forging is high, and further heat treatment is required.

[0003] Isothermal forging is an ideal process for precision forming of titanium alloys by maintaining a constant temperature between the billet and the die to reduce the deformation resistance during the forging process. However, existing isothermal forging technologies still have problems such as low temperature control accuracy, delayed dynamic response, and insufficient intelligence. Existing temperature control devices mostly adopt a discrete design, which has systemic defects, such as low hardware integration and weak algorithm adaptability. With the surge in demand for precision and lightweight complex thin-walled titanium alloy components (such as engine blades and cabin frames) in the aerospace field, existing technologies are difficult to meet. Therefore, there is a need for a new type of titanium alloy isothermal forging process and its intelligent temperature control device. Summary of the Invention

[0004] In order to overcome the above-mentioned deficiencies of the existing titanium alloy forging process, the technical problem to be solved by the present invention is to provide a titanium alloy isothermal forging intelligent temperature control device and isothermal forging process that can better control the temperature of the billet and the forging machine anvil die.

[0005] The technical solution adopted by the present invention to solve its technical problem is: An intelligent temperature control device for isothermal forging of titanium alloys comprises a sealed forging chamber and a forging machine anvil die located in the forging chamber, wherein the inner wall of the forging chamber is provided with a multi-segment resistance intelligent induction heating module, a circulating water cooling module and a high-frequency induction heating module in sequence from the outside to the inside, wherein the forging machine anvil die is provided with a resistance heating module, and a temperature controller is provided outside the forging chamber, wherein the temperature controller is configured to control the operation of each module according to the temperature feedback from a plurality of temperature sensors evenly distributed in the forging chamber, wherein before forging, the titanium alloy billet and the forging machine anvil die are respectively heated to the same temperature by using the high-frequency induction heating module and the resistance heating module, wherein during the forging process, the corresponding sections of the multi-segment resistance intelligent induction heating module are controlled to operate according to the temperature conditions at various locations on the surface of the titanium alloy billet, so as to keep the temperature of various locations of the titanium alloy billet the same as that of the forging machine anvil die, and after forging is completed, the circulating water cooling module is controlled to operate according to the temperature of the forging.

[0006] Furthermore, an inert gas charging module and a vacuum pumping module are provided on the side wall of the forging chamber, and the temperature controller is further configured to start the inert gas charging module and the vacuum pumping module according to the temperature of the billet to air-cool the billet.

[0007] Furthermore, a dynamic pressure feedback module electrically connected to the forging machine anvil die is provided outside the forging chamber, and a liquid metal cooling spray system electrically connected to the temperature controller is provided inside the forging chamber.

[0008] Furthermore, it also includes a data transmission module, which is used for data transmission between the control center and the temperature controller and the dynamic pressure feedback module.

[0009] The titanium alloy isothermal forging process, including the above-mentioned titanium alloy isothermal forging intelligent temperature control device, further includes the following steps: Step 1: Pretreatment of blank: Select TC11 titanium alloy blank, first β The phase region was homogenized to remove residual stress. The annealing temperature was set at 1000-1050℃ and the annealing holding time was set at 1-2 h. Subsequently, an anti-oxidation coating was sprayed on the surface of the titanium alloy billet. Step 2: Preheating the billet and die: Heat the titanium alloy billet and the forging machine anvil die to the forging temperature. The forging temperature is set at 920-950°C and PID closed-loop temperature control is used. Step 3: Isothermal forging: After placing the titanium alloy billet in a closed-loop space, fill it with argon inert protective gas, control the oxygen content to below 20-50 ppm, and then forge it. The strain rate is set to 0.001-1.0 s -1The forging machine's loading pressure is dynamically calculated in real time based on the billet size. During the forging process, a high-frequency induction heating module is activated to compensate for heat loss on the billet surface. A multi-segment resistance intelligent induction heating module precisely controls the temperature distribution between the billet and the forging machine anvil die to maintain consistency. The forging machine applies pressure in a multi-stage loading mode, including pre-pressing, holding pressure, and final pressure, with precise control of pressure fluctuations in the three stages to ≤ 1%. Step 4: Cooling after forging: After forging is completed, turn on the circulating water cooling module and cool it down to 400°C at a cooling rate of 20-100°C / min. Then turn off the circulating water cooling module and cool the titanium alloy forging to room temperature through forced convection of inert gas.

[0010] Furthermore, the anti-oxidation coating is a nano-yttrium oxide coating, and the coating thickness is set to 5-10 μm.

[0011] Furthermore, during the isothermal forging process, the temperature difference between the forging machine anvil die and the titanium alloy billet is controlled within 10°C.

[0012] Furthermore, in the pre-pressing stage of step three, the forging machine loading speed is set to 0.1-0.5 mm / s, and the deformation is set to 35-45%. During this period, the temperature controller automatically compensates the temperature of the titanium alloy billet and the forging machine anvil die according to the strain rate.

[0013] Furthermore, in the holding stage of step three, the loading speed is increased to 1~2 mm / s, and the deformation is 65~75%. During this period, a liquid metal cooling spray system is used to spray cool the high strain area in a targeted manner to suppress the adiabatic temperature rise.

[0014] Furthermore, in the final pressing stage of step three, the final forging pressure is maintained for 6 to 10 minutes before the post-forging cooling of step four is performed.

[0015] The beneficial effects of the present invention are as follows: the titanium alloy isothermal forging process and the supporting intelligent temperature control device of the present invention integrate gradient temperature control, superplastic strain rate control and in-situ cooling-quenching, wherein the gradient temperature control strategy is specifically designed for titanium alloys. α + β Two-phase zone characteristics, staged temperature control, composite heating + multi-sensor feedback to improve temperature uniformity and achieve the effect of grain refinement; superplastic strain rate control combined with strain rate control can trigger superplastic behavior of titanium alloy, and superplastic deformation greatly improves the one-time forming qualification rate of complex parts; in-situ cooling-quenching integration: after forging, gradient cooling is achieved through the circulating water cooling module to avoid residual stress, eliminating subsequent heat treatment steps, and significantly reducing the overall cost of the entire process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a structural schematic diagram of the intelligent temperature control device for isothermal forging of titanium alloy of the present invention; Figure 2 It is a flow chart of the titanium alloy isothermal forging process of the present invention; Figure 3 The metallographic microstructure of Example 1 of TC11 titanium alloy prepared by isothermal forging is shown; Figure 4 This is the metallographic microstructure of Example 2 of TC11 titanium alloy prepared by isothermal forging.

[0017] Marked in the figure are: 1- multi-segment resistance intelligent induction heating module, 2- circulating water cooling module, 3- high-frequency induction heating module, 4- forging machine anvil die, 5- dynamic pressure feedback module, 6- titanium alloy billet, 7- temperature controller, 8- data transmission module, 9- vacuum pumping module, 10- inert gas filling module, 11- forging chamber. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] It should be noted that if directional terms are used in this disclosure, such as "up," "down," "left," "right," "forward," and "backward," these are intended to facilitate the description of the relative positions of components and are not intended to specify the absolute positions of the components or the positional relationships between them. They are used only to explain the relative positions and movement of components in a specific posture. If the posture changes, the directional terms will change accordingly. If terms referring to quantity are used in this disclosure, such as "plurality," "multiple," and "several," these specifically refer to two or more.

[0020] like Figure 1As shown, the present invention provides an intelligent temperature control device for isothermal forging of titanium alloys, comprising a sealed forging chamber 11 and a forging machine anvil die 4 located in the forging chamber 11, wherein the inner wall of the forging chamber 11 is provided with a multi-segment resistance intelligent induction heating module 1, a circulating water cooling module 2 and a high-frequency induction heating module 3 in sequence from the outside to the inside, the forging machine anvil die 4 is provided with a resistance heating module, and a temperature controller 7 is provided outside the forging chamber 11, wherein the temperature controller 7 is configured to control the operation of each module according to the temperature feedback from multiple temperature sensors evenly distributed in the forging chamber 11, wherein before forging, the high-frequency induction heating module 3 and the resistance heating module are respectively used to heat the titanium alloy billet 6 and the forging machine anvil die 4 to the same temperature, during the forging process, the corresponding sections of the multi-segment resistance intelligent induction heating module 1 are controlled to operate according to the temperature conditions at various locations on the surface of the titanium alloy billet 6, so as to keep the temperature of the titanium alloy billet 6 at the same temperature as the forging machine anvil die 4, and after forging is completed, the circulating water cooling module 2 is controlled to operate according to the temperature of the forging. Among them, the multi-segment resistance intelligent induction heating module 1 refers to a plurality of heating sections continuously arranged around the inner wall of the forging chamber 11, and each section can be heated separately. The circulating water cooling module 2 is a sandwich structure, and the internal cooling medium is a mixed fluid of liquid nitrogen and deionized water, which can improve the cooling effect. During the heating and forging process, the circulating water cooling module 2 does not pass the cooling medium. The forging machine anvil die 4 refers to the combined structure of the anvil and the die. The temperature sensor can preferably be an infrared sensor, and is arranged according to the shape and size of the forging machine anvil die 4 and the titanium alloy billet 6, so as to achieve all-round temperature detection on the surfaces of the two as much as possible.

[0021] This invention primarily integrates the temperature control structures required for preheating the billet and die before forging, isothermal control during forging, and in-situ cooling and quenching after forging. This ensures a stable forging environment during the forging process. Temperature control is achieved in stages, with composite heating and multi-sensor feedback improving temperature uniformity and achieving grain refinement. After forging, a circulating water cooling module achieves gradient cooling, avoiding residual stresses and eliminating subsequent heat treatment steps, significantly reducing the overall cost of the entire process.

[0022] In order to prevent oxidation of the titanium alloy blank 6 during the forging process, an inert gas charging module 10 and a vacuum pumping module 9 are further provided on the side walls of the forging chamber 11. By dividing the pumping and charging processes into two independent modules and electrically connecting them to the temperature controller 7, air cooling of the titanium alloy blank 6 can also be achieved. During the cooling stage after forging, the temperature controller 7 can start the inert gas charging module 10 to fill the forging chamber 11 with inert gas according to the temperature of the titanium alloy blank 6, while the vacuum pumping module 9 extracts gas outward, thereby air cooling the titanium alloy blank 6 through airflow.

[0023] To achieve pressure control during the forging process, a dynamic pressure feedback module 5 electrically connected to the forging machine anvil die 4 is also provided outside the forging chamber 11. This module can adjust the forging machine loading rate in real time based on the deformation resistance of the titanium alloy billet 6 to match the rheological properties of the titanium alloy billet 6. In addition, to prevent localized high temperatures in the titanium alloy billet 6 during the forging process, a liquid metal cooling spray system electrically connected to the temperature controller 7 is also provided within the forging chamber 11. When the temperature controller 7 detects an adiabatic temperature rise in a certain part of the titanium alloy billet 6, it can control the liquid metal cooling spray system to perform targeted cooling on that part.

[0024] Furthermore, in order to realize remote control, a data transmission module 8 is also included, and the data transmission module 8 is used for data transmission between the control center and the temperature controller 7 and the dynamic pressure feedback module 5.

[0025] The present invention also provides a titanium alloy isothermal forging process, which uses the above-mentioned titanium alloy isothermal forging intelligent temperature control device and specifically includes the following steps: Step 1: Pretreatment of the blank: TC11 titanium alloy blank was selected. First, residual stress was removed in the β phase region by homogenization annealing. The annealing temperature was set at 1000-1050°C and the annealing holding time was set at 1-2 h. Subsequently, an anti-oxidation coating was sprayed on the surface of the titanium alloy blank 6. Step 2: Preheating the blank and die: Heat the titanium alloy blank 6 and the forging machine anvil die 4 to the forging temperature, which is set at 920-950°C and controlled by PID closed loop. Step 3: Isothermal forging: After placing the titanium alloy billet 6 in a closed-loop space, first fill it with argon inert protective gas, control the oxygen content to below 20-50 ppm, and then perform forging. The strain rate is set to 0.001-1.0 s -1 The forging machine's loading pressure is dynamically calculated in real time based on the billet size. During the forging process, the high-frequency induction heating module 3 is activated to compensate for heat loss on the surface of the titanium alloy billet 6. The multi-segment resistance intelligent induction heating module 1 precisely controls the temperature distribution of the titanium alloy billet 6 and the forging machine anvil die 4 to maintain consistency. The forging machine applies pressure in a multi-stage loading mode, including pre-pressing, holding pressure, and final pressure, and precisely controls the pressure fluctuations in these three stages to ≤ 1%. Step 4: Cooling after forging: After forging is completed, the circulating water cooling module 2 is turned on and the temperature is lowered to 400°C at a cooling rate of 20-100°C / min. The circulating water cooling module 2 is then turned off and the titanium alloy forging is cooled to room temperature by forced convection of inert gas.

[0026] Among them, the anti-oxidation coating is preferably a nano-yttrium oxide coating, and the coating thickness is set to 5~10 μm. During the isothermal forging process, the temperature difference between the forging machine anvil die 4 and the titanium alloy billet 6 is controlled within 10 ℃. In the pre-pressing stage of step three, the forging machine loading speed is set to 0.1~0.5 mm / s, and the deformation is set to 35~45%. During this period, the temperature controller 7 automatically compensates the temperature of the titanium alloy billet 6 and the forging machine anvil die 4 according to the strain rate; in the holding pressure stage, the loading speed is increased to 1~2 mm / s, and the deformation is 65~75%. During this period, the liquid metal cooling spray system is used to spray and cool the high strain area in a directional manner to suppress the adiabatic temperature rise; in the final pressing stage, the final forging pressure is maintained for 6~10 minutes before the post-forging cooling of step four is carried out.

[0027] The present invention is further described below by way of examples.

[0028] Example 1: Pre-treatment of titanium alloy blanks: TC11 titanium alloy blanks were selected and β Phase homogenization annealing to remove residual stress, the annealing temperature is set to 1050 o C, the annealing holding time is set to 2 h; a nano-yttrium oxide (Y2O3) coating is sprayed on the surface of the titanium alloy billet, and the coating thickness is set to 10 μm to prevent the titanium alloy billet from oxidizing under high temperature conditions.

[0029] Preheat the forging blank and die and optimize the parameters: Heat the forging blank and die to the forging temperature, and set the forging temperature to 950 o C, and adopt PID closed-loop temperature control; set the strain rate to 0.01 s -1 , the loading pressure of the forging machine is dynamically calculated in real time according to the billet size.

[0030] The titanium alloy billet is subjected to isothermal forging. The specific forging process includes: placing the titanium alloy billet in a closed-loop space, filling it with argon inert protective gas, and controlling the oxygen content to below 20 ppm; starting high-frequency induction heating to compensate for heat loss on the billet surface, and precisely controlling the temperature distribution of the billet and the mold through intelligent induction heating in the mold to keep it consistent; the forging machine applies pressure in a multi-stage loading mode, including three stages of pre-pressing, holding pressure and final pressure, and precisely controlling the pressure fluctuation in the three stages to ≤ 1%.

[0031] Among them, in the pre-pressing stage, the forging machine loading speed is set to 0.5 mm / s, and the deformation is set to 40%; the temperature control device automatically compensates the mold temperature according to the strain rate; in the holding stage, the loading speed is increased to 2 mm / s, and the deformation is 70%; the liquid metal cooling system sprays the high-strain area in a targeted manner to suppress the adiabatic temperature rise; in the final pressing stage, the gradient cooling program is started after holding the pressure for 8 minutes.

[0032] After forging is completed, the mold is cooled in situ in a closed-loop space. The specific process parameters include: after forging is completed, the circulating water cooling system in the mold is turned on at 50 o Cooling rate down to 400 C / min o C. The circulating water cooling system was then turned off, and the titanium alloy forging was cooled to room temperature by forced convection of inert gas. After the forging was taken out, the surface roughness of the titanium alloy forging was kept at Ra ≤ 0.8 μm.

[0033] The mechanical properties of the TC11 titanium alloy prepared by the above process are shown in Table 1. Figure 3 shown.

[0034] Example 2: Pre-treatment of titanium alloy blanks: TC11 titanium alloy blanks were selected and β Phase homogenization annealing to remove residual stress, the annealing temperature is set to 1050 o C, and the annealing holding time was set to 2 h.

[0035] Preheat the forging blank and die and optimize the parameters: Heat the forging blank and die to the forging temperature, and set the forging temperature to 920 o C, and adopt PID closed-loop temperature control; set the strain rate to 0.01 s -1 , the loading pressure of the forging machine is dynamically calculated in real time according to the billet size.

[0036] The titanium alloy billet is subjected to isothermal forging. The specific forging process includes: placing the titanium alloy billet in a closed-loop space, filling it with argon inert protective gas, and controlling the oxygen content to below 20 ppm; starting high-frequency induction heating to compensate for heat loss on the billet surface, and accurately controlling the temperature distribution of the billet and the mold through intelligent induction heating in the mold to keep it consistent; the forging machine applies pressure in a multi-stage loading mode, including three stages of pre-pressing, holding pressure and final pressure, and accurately controlling the pressure fluctuation in the three stages to ≤1%.

[0037] During the pre-pressing phase, the forging machine's loading speed was set to 0.5 mm / s, and the deformation was set to 40%. The temperature control device automatically compensated for the die temperature based on the strain rate. During the holding phase, the loading speed was increased to 2 mm / s, and the deformation was 70%. The liquid metal cooling system used a targeted spray cooling system to target high-strain areas, suppressing adiabatic temperature rise. During the final pressing phase, a gradient cooling process was initiated after holding for 8 minutes.

[0038] After forging is completed, the mold is cooled in situ in a closed-loop space. The specific process parameters include: after forging is completed, the circulating water cooling system in the mold is turned on at 50 o Cooling rate down to 400 C / min oC. The circulating water cooling system was then turned off, and the titanium alloy forging was cooled to room temperature by forced convection of inert gas. After the forging was taken out, the surface roughness of the titanium alloy forging was kept at Ra ≤ 0.8 μm.

[0039] The mechanical properties of the TC11 titanium alloy prepared by the above process are shown in Table 1. Figure 4 shown.

[0040] Comparative Example 1: Pre-treatment of titanium alloy blanks: TC11 titanium alloy blanks were selected and β Phase homogenization annealing to remove residual stress, the annealing temperature is set to 1050 o C, and the annealing holding time was set to 2 h.

[0041] Heat the forging blank and die to the forging temperature, and set the forging temperature to 950 o C. After being taken out of the heating furnace, a composite heating device is installed to forge the blank in air. The strain rate is set to 0.01 s -1 , the forging machine is loaded at a constant rate.

[0042] After forging, the titanium alloy forging was cooled to room temperature by air cooling to prepare TC11 titanium alloy forging, the mechanical properties of which are shown in Table 1.

[0043] Table 1. Comparison of mechanical properties of examples and comparative examples It can be seen from the above table that the titanium alloy forgings prepared by using the titanium alloy isothermal forging intelligent temperature control device and isothermal forging process provided by the present invention have stronger tensile strength and yield strength.

Claims

1. An intelligent temperature control device for isothermal forging of titanium alloy, comprising a sealed forging chamber (11) and a forging machine anvil die (4) located in the forging chamber (11), characterized in that: The inner wall of the forging chamber (11) is provided with a multi-segment resistance intelligent induction heating module (1), a circulating water cooling module (2) and a high-frequency induction heating module (3) in sequence from the outside to the inside, the forging machine anvil die (4) is provided with a resistance heating module, and a temperature controller (7) is provided outside the forging chamber (11), and the temperature controller (7) is configured to control the operation of each module according to the temperature feedback from multiple temperature sensors uniformly distributed in the forging chamber (11), wherein before forging, the high-frequency induction heating module (3) and the resistance heating module are used to heat the titanium alloy billet (6) and the forging machine anvil die (4) to the same temperature respectively. During the forging process, the multi-segment resistance intelligent induction heating module (1) is controlled to operate in corresponding sections according to the temperature conditions at various locations on the surface of the titanium alloy billet (6), so as to keep the temperature at various locations of the titanium alloy billet (6) and the forging machine anvil die (4) the same. After forging is completed, the circulating water cooling module (2) is controlled to operate according to the temperature of the forging.

2. The intelligent temperature control device for isothermal forging of titanium alloy according to claim 1, characterized in that: An inert gas charging module (10) and a vacuum pumping module (9) are also provided on the side wall of the forging chamber (11), and the temperature controller (7) is further configured to start the inert gas charging module (10) and the vacuum pumping module (9) according to the temperature of the titanium alloy billet (6) to air-cool the titanium alloy billet (6).

3. The intelligent temperature control device for isothermal forging of titanium alloy according to claim 2, characterized in that: A dynamic pressure feedback module (5) electrically connected to the forging machine anvil die (4) is further provided outside the forging chamber (11), and a liquid metal cooling spray system electrically connected to the temperature controller (7) is further provided inside the forging chamber (11).

4. The intelligent temperature control device for isothermal forging of titanium alloy according to claim 3, characterized in that: It also includes a data transmission module (8), which is used for data transmission between the control center and the temperature controller (7) and the dynamic pressure feedback module (5).

5. Titanium alloy isothermal forging process, characterized in that, The intelligent temperature control device for isothermal forging of titanium alloy according to claim 4 further comprises the following steps: Step 1: Pretreatment of the blank: TC11 titanium alloy blank was selected. First, the residual stress was removed in the β phase region by homogenization annealing. The annealing temperature was set to 1000~1050℃ and the annealing holding time was set to 1~2 h. Then, an anti-oxidation coating was sprayed on the surface of the titanium alloy blank (6); Step 2: Preheating the blank and the die: Heat the titanium alloy blank (6) and the forging machine anvil die (4) to the forging temperature, set the forging temperature to 920-950°C, and use PID closed-loop temperature control; Step 3: Isothermal forging: After placing the titanium alloy billet (6) in a closed-loop space, first fill it with argon inert protective gas to control the oxygen content to below 20-50 ppm, and then forge it. The strain rate is set to 0.001-1.0 s -1 The loading pressure of the forging machine is dynamically calculated in real time according to the size of the billet; during the forging process, the high-frequency induction heating module (3) is activated to compensate for the heat loss on the surface of the titanium alloy billet (6), and the temperature distribution of the titanium alloy billet (6) and the forging machine anvil die (4) is precisely controlled by the multi-segment resistance intelligent induction heating module (1) to be consistent; the forging machine applies pressure in a multi-stage loading mode, including three stages of pre-pressing, holding pressure and final pressure, and the pressure fluctuation of the three stages is precisely controlled to be ≤ 1%; Step 4: Cooling after forging: After forging is completed, the circulating water cooling module (2) is turned on and the temperature is lowered to 400°C at a cooling rate of 20-100°C / min. The circulating water cooling module (2) is then turned off and the titanium alloy forging is cooled to room temperature by forced convection of inert gas.

6. The titanium alloy isothermal forging process according to claim 5, wherein: The anti-oxidation coating is a nano-yttrium oxide coating, and the coating thickness is set to 5-10 μm.

7. The titanium alloy isothermal forging process according to claim 5, wherein: During the isothermal forging process, the temperature difference between the forging machine anvil die (4) and the titanium alloy billet (6) is controlled within 10°C.

8. The titanium alloy isothermal forging process according to claim 5, wherein: In the pre-pressing stage of step three, the forging machine loading speed is set to 0.1~0.5 mm / s, and the deformation is set to 35~45%. During this period, the temperature controller (7) automatically compensates the temperature of the titanium alloy billet (6) and the forging machine anvil die (4) according to the strain rate.

9. The titanium alloy isothermal forging process according to claim 5, wherein: During the pressure holding stage of step three, the loading speed is increased to 1~2 mm / s, and the deformation is 65~75%. During this period, the liquid metal cooling spray system is used to spray cool the high strain area in a targeted manner to suppress the adiabatic temperature rise.

10. The titanium alloy isothermal forging process according to claim 5, wherein: In the final pressure stage of step three, maintain the final forging pressure for 6 to 10 minutes before performing post-forging cooling in step four.

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