Large-size titanium alloy additive manufacturing device and method

Abstract

The present invention belongs to the technical field of preparing large-sized titanium alloy components, and specifically relates to a large-sized titanium alloy additive manufacturing device and method. The device includes a space environment preparation system, an argon arc welding robot system, a temperature-controlled jig positioner, and a confined working space speckle temperature control module, wherein the space environment preparation system is used to provide a process environment for additive manufacturing; the temperature-controlled jig positioner is used to carry titanium alloy space thin-walled parts, and the temperature-controlled jig positioner can drive the titanium alloy space thin-walled parts to rotate and perform temperature control; the argon arc welding robot system is used to perform continuous surfacing additive in the confined space of titanium alloy space thin-walled parts containing rare earth elements to form a confined rotating thin-walled shell; the confined working space speckle temperature control module is arranged on the welding gun to control the solidification speed of the surfacing molten pool. The present invention realizes additive manufacturing of large-sized titanium alloy parts through continuous surfacing, and improves the overall plasticity of the components in real time to prevent thermal stress cracking of large-sized titanium alloy parts.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparing large-size titanium alloy components, and specifically relates to a large-size titanium alloy additive manufacturing device and method. Background Art

[0002] At present, large-sized titanium alloy parts are generally prepared by casting and 3D printing, and the diameter of large-sized titanium alloy parts is more than 2000mm. The material composition of TC4 titanium alloy is Ti-6Al-4V, which belongs to the (α+β) type titanium alloy. Large-sized titanium alloy parts are prepared by casting and 3D printing. Since the thin-walled spatial special-shaped structure is within the casting structure, the thin-walled spatial special-shaped structure must be 3D printed due to the limitation of the casting process. However, there are still many problems in realizing 3D printing of thin-walled spatial special-shaped structures in confined spaces, and the heat dissipation is too fast, and Ti-6Al-4V is easy to solidify quickly, resulting in the α′ martensite phase of the component due to the supersaturated solid solution of the solute elements, which makes its lattice distortion serious, resulting in hardness and brittleness. How to reduce the content of α martensite phase, increase the content of α phase and β phase with good plasticity and toughness, improve the overall plasticity of the component in real time, and prevent thermal stress cracking of large-sized titanium alloy parts is the key technical bottleneck to break through the large-sized titanium alloy additive manufacturing parts. Therefore, it is very necessary to design a large-sized titanium alloy additive manufacturing device and method. Summary of the invention

[0003] In view of the above problems, the object of the present invention is to provide a large-size titanium alloy additive manufacturing device and method to improve the overall plasticity of large-size titanium alloy parts in real time and prevent thermal stress cracking of large-size titanium alloy parts.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In one aspect, the present invention provides a large-size titanium alloy additive manufacturing device, comprising:

[0006] Space environment preparation system, used to provide a process environment for additive manufacturing;

[0007] The temperature-controlled jig positioner is used to carry titanium alloy space thin-walled parts containing rare earth elements, and the temperature-controlled jig positioner can drive the titanium alloy space thin-walled parts containing rare earth elements to rotate and perform temperature control; the titanium alloy space thin-walled parts containing rare earth elements have a confined space;

[0008] An argon arc welding robot system, comprising a robot and a welding gun arranged at the end of the robot, wherein the robot is fixed in an upside-down manner, and the welding gun is used to continuously build up welding and additive in a confined space of a titanium alloy thin-walled space part containing rare earth elements to form a restricted rotation thin-walled shell;

[0009] The confined working space speckle temperature control module is arranged on the welding gun, and the confined working space speckle temperature control module is used to control the solidification speed of the surfacing welding molten pool.

[0010] In one possible implementation, the temperature-controlled mold positioner includes a positioner and a temperature control platform arranged on the positioner, wherein a titanium alloy spatial thin-walled part containing rare earth elements is arranged on the temperature control platform, and the temperature control platform is used for temperature control; the positioner is used to drive the temperature control platform and the titanium alloy spatial thin-walled part containing rare earth elements to rotate.

[0011] In one possible implementation, the welding gun performs overlay welding in the confined space of the titanium alloy spatial thin-walled part containing rare earth elements through a high-temperature master alloy welding wire containing rare earth elements to form a high-temperature alloy molten pool containing rare earth elements, the positioner drives the titanium alloy spatial thin-walled part containing rare earth elements to rotate, so that the high-temperature alloy molten pool containing rare earth elements continuously grows, the temperature control station provides cooling temperature for the high-temperature alloy molten pool containing rare earth elements, and the high-temperature alloy molten pool containing rare earth elements solidifies to form a cladding layer.

[0012] In one possible implementation, the confined working space speckle temperature control module includes an optical fiber, a bracket and an optical lens, wherein the bracket is installed on the outside of the welding gun, the optical lens is installed on the bracket, and the optical lens is tilted on the laser path, and the optical lens is used to diffuse the laser into a heating speckle light strip and irradiate it onto the cladding layer, and the heating speckle light strip has a gradient temperature field.

[0013] In a possible implementation, the temperature of the gradient temperature field of the heating speckle light strip gradually decreases in a direction away from the high-temperature alloy molten pool containing rare earth elements.

[0014] In a possible implementation, the welding gun is in an arc shape.

[0015] In one possible implementation, the space environment preparation system includes a vacuum chamber and a control unit, a vacuum unit, an argon unit, a hydrogen unit, and a water cooling and temperature control unit arranged on the vacuum chamber.

[0016] Another aspect of the present invention provides an additive manufacturing method using the large-size titanium alloy additive manufacturing device as described above, the method comprising the following steps:

[0017] Step S1: establishing a process environment for additive manufacturing through a space environment preparation system;

[0018] Step S2: the argon arc welding robot system performs surfacing welding in the confined space of the titanium alloy thin-walled space part containing rare earth elements by using the high-temperature master alloy welding wire containing rare earth elements to form a high-temperature alloy molten pool containing rare earth elements;

[0019] Step S3: the positioner drives the titanium alloy spatial thin-walled part containing rare earth elements to rotate, so that the high-temperature alloy molten pool containing rare earth elements continuously grows in the circumferential direction; the temperature control station provides cooling temperature for the high-temperature alloy molten pool containing rare earth elements, so that the high-temperature alloy molten pool containing rare earth elements solidifies into a cladding layer;

[0020] Step S4: the optical fiber outputs laser light to the cladding layer, and the optical lens diffuses the laser light into a heating speckle light strip, and the gradient temperature field of the heating speckle light strip is used to control the gradient solidification of the cladding layer;

[0021] Step S5: repeating steps S2 to S4 to perform continuous cladding, so that the cladding layer grows in the height direction until a restricted rotation thin-walled shell is completed;

[0022] Step S6: Continue to complete N restricted rotation thin-walled shells, where the N restricted rotation thin-walled shells are spaced apart and concentric.

[0023] In a possible implementation, the process environment of the additive manufacturing is an atmosphere with a stable content of argon and hydrogen.

[0024] The advantages and beneficial effects of the present invention are: a large-size titanium alloy additive manufacturing device provided by the present invention realizes 3D printing in a confined space through a robot's specific spatial motion trajectory and a welding end effector verified by offline programming simulation; the confined working space speckle temperature control module reduces the α martensite phase content, increases the α phase and β phase content with better plasticity and toughness, and improves the overall plasticity of large-size titanium alloy parts in real time to prevent thermal stress cracking of large-size titanium alloy parts; the confined working space speckle temperature control module effectively solves the problem of excessive heat dissipation in the molten pool, and Ti-6Al-4V is easy to solidify quickly, which leads to the α′ martensite phase of the component due to the supersaturated solid solution of solute elements, which makes its lattice seriously distorted, and then leads to the problem of hardness and brittleness.

[0025] The present invention adopts the idea of ​​slowly releasing stress by controlling the phase change process to accurately control the temperature gradient of the solidification process; adopts the temperature field model of finite element simulation software to realize the laser speckle heating strategy, and then realizes the temperature control system for large-size titanium alloy additive manufacturing.

[0026] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0027] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0029] Figure 1 It is an axonometric view of a large-size titanium alloy additive manufacturing device of the present invention;

[0030] Figure 2 for Figure 1 A partial enlarged view of the middle part;

[0031] Figure 3 A top view of a large-size titanium alloy additive manufacturing device according to the present invention;

[0032] Figure 4 It is a vertical cross-sectional view of a large-size titanium alloy additive manufacturing device of the present invention;

[0033] Figure 5 for Figure 4 A partial enlarged view of point B in the middle;

[0034] Figure 6 It is a structural schematic diagram of the speckle temperature control module of the confined working space in the present invention;

[0035] Figure 7 This is a partial schematic diagram of a large-size titanium alloy additive manufacturing device completing an additive manufacturing process of the present invention.

[0036] In the figure: 1-space environment preparation system, 101-vacuum chamber, 102-control unit, 103-vacuum unit, 104-argon unit, 105-hydrogen unit, 106-water cooling and temperature control unit, 2-argon arc welding robot system, 201-welding gun, 3-limited operation space speckle temperature control module, 4-bracket, 5-temperature control jig positioner, 501-positioner, 502-temperature control table, 503-temperature control jig, 6-titanium alloy containing rare earth elements Gold space thin-walled parts, 601-casting rotating chassis, 602-casting rotating outer side wall, 603-casting rotating inner side wall, 604-first restricted rotating thin-walled shell, 605-second restricted rotating thin-walled shell, 606-third restricted rotating thin-walled shell, 7-high-temperature master alloy welding wire containing rare earth elements, 9-high-temperature alloy molten pool containing rare earth elements, 10-cladding layer, 11-optical fiber, 12-optical lens, 13-optical axis, 14-heating speckle light strip. DETAILED DESCRIPTION

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0039] An embodiment of the present invention provides a large-sized titanium alloy additive manufacturing device to improve the overall plasticity of the component in real time and prevent thermal stress cracking of large-sized titanium alloy parts. Figures 1 to 7 As shown, the large-size titanium alloy additive manufacturing device includes a space environment preparation system 1, an argon arc welding robot system 2, a temperature-controlled jig positioner 5 and a confined working space speckle temperature control module 3, wherein the space environment preparation system 1 is used to provide a process environment for additive manufacturing; the temperature-controlled jig positioner 5 is used to carry a titanium alloy space thin-walled part 6 containing rare earth elements, and the temperature-controlled jig positioner 5 can drive the titanium alloy space thin-walled part 6 containing rare earth elements to rotate and perform temperature control; the titanium alloy space thin-walled part 6 containing rare earth elements has a confined space; the argon arc welding robot system 2 includes a robot and a welding gun 201 arranged at the end of the robot, wherein the robot is fixed in an upside-down manner, and the welding gun 201 is used to perform continuous surfacing welding additives in the confined space of the titanium alloy space thin-walled part 6 containing rare earth elements to form a confined rotating thin-walled shell; the confined working space speckle temperature control module 3 is used to control the solidification rate of the surfacing molten pool.

[0040] See also Figure 3As shown, in the embodiment of the present invention, the space environment preparation system 1 includes a vacuum chamber 101 and a control unit 102, a vacuum unit 103, an argon unit 104, a hydrogen unit 105 and a water cooling and temperature control unit 106 arranged on the vacuum chamber 101. The five units can effectively control the components and gas atmosphere in the vacuum chamber 101 through relevant equipment and instruments. Specifically, the control unit 102 is used to control the argon arc welding robot system 2, the temperature control mold positioner 5 and the laser speckle heating device in each unit and the vacuum chamber 101; the vacuum unit 103 is used to evacuate the vacuum chamber 101; the argon unit 104 and the hydrogen unit 105 are used to fill the vacuum chamber 101 with argon and hydrogen respectively. Hydrogen is the process gas of the argon arc and also the process gas of the molten pool deoxidation, which is consumable. The internal additive operation space of the vacuum chamber 101 is a positive pressure oxygen-free argon environment. Because there will be leakage during pressure maintenance, it is necessary to compensate for the leakage of argon in the positive pressure space in the vacuum chamber 101.

[0041] See also Figure 4 As shown, in the embodiment of the present invention, the temperature-controlled mold positioner 5 is arranged in the vacuum chamber 101. The temperature-controlled mold positioner 5 includes a positioner 501 and a temperature control table 502 arranged on the positioner 501, wherein the titanium alloy space thin-walled part 6 containing rare earth elements is arranged on the temperature control table 502, and the temperature control table 502 is used for temperature control; the positioner 501 is used to drive the temperature control table 502 and the titanium alloy space thin-walled part 6 containing rare earth elements to rotate.

[0042] Specifically, the positioner 501 is a single-degree-of-freedom positioner, but is not limited to a single-degree-of-freedom positioner. The positioner 501 can drive the temperature control table 502 to rotate. The temperature control table 502 includes structures such as water cooling, heat preservation, sensors, and thermocouples. The temperature control table 502 and the ground can be connected to cooling water, electricity, signals, etc. through a rotary joint. There is a temperature control jig 503 on the temperature control table 502, and the titanium alloy space thin-walled part 6 containing rare earth elements is fixed by the temperature control jig 503.

[0043] See also Figure 5 As shown, in this embodiment, the rare earth element-containing titanium alloy space thin-walled part 6 includes a cast rotating chassis 601, a cast rotating outer side wall 602 and a cast rotating inner side wall 603, wherein an annular confined space is formed between the cast rotating outer side wall 602 and the cast rotating inner side wall 603. Specifically, a casting cold shut titanium alloy casting process is adopted to realize the integral casting of the casting rotating chassis 601, the casting rotating outer side wall 602 and the casting rotating inner side wall 603. Since there is an annular confined space between the casting rotating outer side wall 602 and the casting rotating inner side wall 603, it is impossible to use the casting cold shut titanium alloy casting process to complete the casting of multiple confined rotating thin-walled shells. In response to this problem, the present invention adopts an additive manufacturing method to realize the casting of multiple confined rotating thin-walled shells.

[0044] See also Figure 4and Figure 6 As shown, in the embodiment of the present invention, during additive manufacturing, the welding gun 201 performs surfacing welding in the confined space of the titanium alloy space thin-walled part 6 containing rare earth elements through the high-temperature master alloy welding wire 7 containing rare earth elements to form a high-temperature alloy molten pool 9 containing rare earth elements. The positioner 501 drives the titanium alloy space thin-walled part 6 containing rare earth elements to rotate, so that the high-temperature alloy molten pool 9 containing rare earth elements continuously grows, and the temperature control station 502 provides cooling temperature for the high-temperature alloy molten pool 9 containing rare earth elements, and the high-temperature alloy molten pool 9 containing rare earth elements solidifies to form a cladding layer 10. The cladding layer 10 is the amount of additive material for continuous additive forming of a confined rotary thin-walled shell with a gradient change in rare earth content.

[0045] See also Figure 1 , Figure 2 and Figure 6 As shown, in the embodiment of the present invention, the confined working space speckle temperature control module 3 includes an optical fiber 11, a bracket 4 and an optical lens 12, wherein the optical fiber 11 is arranged in the welding gun 201, and the optical fiber 11 is used to output laser to the cladding layer 10. The bracket 4 is installed on the outside of the welding gun 201, and the optical lens 12 is installed on the bracket 4 at an angle. The optical lens 12 is arranged on the path of the laser, and the laser forms a heating speckle light strip 14 after passing through the optical lens 12. The heating speckle light strip 14 is irradiated onto the cladding layer 10 close to the high-temperature alloy molten pool 9 containing rare earth elements, and the optical axis 13 of the heating speckle light strip 14 has an inclination angle with the vertical plane, that is, the optical axis 13 is non-orthogonal to the cladding layer 10, so that the heating speckle light strip 14 has a temperature gradient field.

[0046] Furthermore, an optical axis 13 of the heating speckle light strip 14 forms an acute angle with the cladding layer 10 , and the temperature of the gradient temperature field of the heating speckle light strip 14 gradually decreases in a direction away from the high-temperature alloy molten pool 9 containing rare earth elements.

[0047] The confined working space speckle temperature control module 3 has two characteristics: characteristic one, online follow-up heat supplement. During the entire additive manufacturing process, the speckle heating area of ​​the heating speckle light strip 14 formed by the confined working space speckle temperature control module 3 follows the molten pool, which makes the molten pool dissipate heat slowly, avoiding the supersaturated solid solution of the α′ martensite phase solute elements of the component due to the rapid solidification of Ti-6Al-4V, thereby avoiding serious lattice distortion and leading to hard and brittle problems. Characteristic two, it has the function of sending energy into the confined working space through the flexible optical fiber 11, and forming the heating speckle light strip 14 for heating through the optical lens 12. Characteristic three, the optical axis deflection angle of the heating speckle light strip 14 is used to realize the gradient temperature field, so that Ti-6Al-4V is slowly solidified in a gradient.

[0048] In this embodiment, the argon arc welding robot system 2 is a prior art, including a welding gun 201, an industrial robot, a servo wire feeder, a wire feeder, etc. The welding gun 201 is installed at the execution end of the industrial robot, and the industrial robot is installed upside down above the vacuum chamber 101.

[0049] Furthermore, the shape of the welding gun 201 is an arc-shaped structure, which is customized according to the robot offline programming simulation, and is suitable for the confined space arc additive manufacturing of a single confined rotating thin-walled shell from bottom to top, and is completed by gradual rotation.

[0050] See also Figure 5 , Figure 7 As shown, in this embodiment, the diameter of the titanium alloy space thin-walled part 6 containing rare earth elements reaches Φ2341mm. The welding gun 201 is close to the casting rotating inner wall 603 in the annular confined space of the titanium alloy space thin-walled part 6 containing rare earth elements, first completes the first confined rotating thin-walled shell 604, then close to the casting rotating outer wall 602 to complete the second confined rotating thin-walled shell 605, and then completes the third confined rotating thin-walled shell 606 between the first confined rotating thin-walled shell 604 and the second confined rotating thin-walled shell 605.

[0051] The present invention provides a large-size titanium alloy additive manufacturing device, which realizes 3D printing in a confined space through a robot's specific spatial motion trajectory and a welding end effector verified by offline programming simulation; the confined working space speckle temperature control module reduces the α martensite phase content, increases the α phase and β phase content with better plasticity and toughness, and prevents thermal stress cracking of large-size titanium alloy parts by improving the overall plasticity of large-size titanium alloy parts in real time; the confined working space speckle temperature control module effectively solves the problem of too fast heat dissipation in the molten pool, and Ti-6Al-4V is easy to solidify quickly, which leads to the problem of severe lattice distortion of the component α′ martensite phase due to the supersaturated solid solution of solute elements, which in turn leads to hardness and brittleness.

[0052] Another embodiment of the present invention provides an additive manufacturing method using the large-size titanium alloy additive manufacturing device in the above embodiment, the method comprising the following steps:

[0053] Step S1: establishing a process environment for additive manufacturing through a space environment preparation system 1;

[0054] Step S2: the argon arc welding robot system 2 performs surfacing welding on the casting rotary chassis 601 in the confined space of the titanium alloy space thin-walled part 6 containing rare earth elements through the high-temperature master alloy welding wire 7 containing rare earth elements, so as to form a high-temperature alloy molten pool 9 containing rare earth elements;

[0055] Step S3: the positioner 501 drives the titanium alloy spatial thin-walled part 6 containing rare earth elements to rotate, so that the high-temperature alloy molten pool 9 containing rare earth elements continuously grows in the circumferential direction; the temperature control station 502 provides cooling temperature for the high-temperature alloy molten pool 9 containing rare earth elements, so that the high-temperature alloy molten pool 9 containing rare earth elements solidifies into a cladding layer 10;

[0056] Step S4: the optical fiber 11 outputs laser light to the cladding layer 10, and the limited working space speckle temperature control module 3 diffuses the laser light into a heating speckle light strip 14, and controls the cladding layer 10 to solidify in a gradient manner through the heating speckle light strip 14;

[0057] Step S5: repeating steps S2 to S4 to perform continuous cladding, so that the cladding layer 10 grows in the height direction until a restricted rotation thin-walled shell is completed;

[0058] Step S6: Continue to complete N restricted rotation thin-walled shells, where the N restricted rotation thin-walled shells are spaced apart and concentric.

[0059] Furthermore, the process environment of additive manufacturing is an atmosphere with a stable content of argon and hydrogen. Specifically, the vacuum chamber 101 is evacuated by the vacuum unit 103, and then the argon unit 104 and the hydrogen unit 105 release argon and hydrogen, so that the vacuum chamber 101 is filled with and maintains a stable content of argon and hydrogen. Hydrogen is the process gas of the argon arc and also the process gas for deoxidation of the molten pool, and is consumed. Argon will leak due to pressure maintenance.

[0060] In this embodiment, the cooling of the cladding layer 10 is controlled by the spot heat flux gradient of the heated speckle light strip 14. The control target is to reduce the content of the α martensite phase and increase the content of the α phase and β phase with better plasticity and toughness, thereby preventing thermal stress cracking of large-sized titanium alloy parts by improving the overall plasticity of the component in real time.

[0061] The present invention provides a large-size titanium alloy additive manufacturing method, which realizes 3D printing in a confined space through a robot's specific spatial motion trajectory and a welding end effector verified by offline programming simulation; the confined working space speckle temperature control module reduces the α martensite phase content, increases the α phase and β phase content with better plasticity and toughness, and prevents thermal stress cracking of large-size titanium alloy parts by improving the overall plasticity of large-size titanium alloy parts in real time; the confined working space speckle temperature control module effectively solves the problem of too fast heat dissipation in the molten pool, and Ti-6Al-4V is easy to solidify quickly, which leads to the problem of severe lattice distortion of the component α′ martensite phase due to the supersaturated solid solution of solute elements, which in turn leads to hard and brittle problems.

[0062] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A large-size titanium alloy additive manufacturing device, characterized in that: include: A space environment preparation system (1), used to provide a process environment for additive manufacturing; The temperature-controlled jig positioner (5) is used to carry a titanium alloy spatial thin-walled part (6) containing a rare earth element, and the temperature-controlled jig positioner (5) can drive the titanium alloy spatial thin-walled part (6) containing a rare earth element to rotate and perform temperature control; the titanium alloy spatial thin-walled part (6) containing a rare earth element has a confined space; An argon arc welding robot system (2) comprises a robot and a welding gun (201) arranged at the end of the robot, wherein the robot is fixed in an upside-down manner, and the welding gun (201) is used to perform continuous cladding welding in a confined space of a titanium alloy thin-walled component (6) containing rare earth elements, so as to form a restricted rotation thin-walled shell; A confined working space speckle temperature control module (3) is arranged on the welding gun (201), and the confined working space speckle temperature control module (3) is used to control the solidification speed of the cladding molten pool; The temperature-controlled mold positioner (5) comprises a positioner (501) and a temperature control platform (502) arranged on the positioner (501), wherein a titanium alloy spatial thin-walled part (6) containing a rare earth element is arranged on the temperature control platform (502), and the temperature control platform (502) is used for temperature control; the positioner (501) is used to drive the temperature control platform (502) and the titanium alloy spatial thin-walled part (6) containing a rare earth element to rotate; The welding gun (201) forms a high-temperature alloy molten pool (9) containing rare earth elements in a confined space of the titanium alloy spatial thin-walled part (6) containing rare earth elements through a high-temperature master alloy welding wire (7) containing rare earth elements, the positioner (501) drives the titanium alloy spatial thin-walled part (6) containing rare earth elements to rotate, so that the high-temperature alloy molten pool (9) containing rare earth elements continuously grows, the temperature control station (502) provides a cooling temperature for the high-temperature alloy molten pool (9) containing rare earth elements, and the high-temperature alloy molten pool (9) containing rare earth elements solidifies to form a cladding layer (10); The confined working space speckle temperature control module (3) comprises an optical fiber (11), a bracket (4) and an optical lens (12), wherein the optical fiber (11) is arranged on the welding gun (201), the optical fiber (11) is used to output laser light, the bracket (4) is installed on the outside of the welding gun (201), the optical lens (12) is installed on the bracket (4), and the optical lens (12) is arranged obliquely on the laser path, the optical lens (12) is used to diffuse the laser light into a heating speckle light strip (14), and irradiate the laser light onto the cladding layer (10), and the heating speckle light strip (14) has a gradient temperature field; The temperature of the gradient temperature field of the heating speckle light strip (14) gradually decreases in a direction away from the high-temperature alloy molten pool (9) containing rare earth elements; The welding gun (201) is in the shape of an arc structure.

2. The large-size titanium alloy additive manufacturing device according to claim 1 is characterized in that: The space environment preparation system (1) comprises a vacuum chamber (101), and a control unit (102), a vacuum unit (103), an argon unit (104), a hydrogen unit (105), and a water cooling and temperature control unit (106) arranged on the vacuum chamber (101).

3. An additive manufacturing method using the large-size titanium alloy additive manufacturing device according to claim 1, characterized in that: The method comprises the following steps: Step S1: Establishing a process environment for additive manufacturing through a space environment preparation system (1); Step S2: the argon arc welding robot system (2) performs overlay welding in a confined space of a titanium alloy thin-walled component (6) containing rare earth elements using a high-temperature master alloy welding wire (7) containing rare earth elements, thereby forming a high-temperature alloy molten pool (9) containing rare earth elements; Step S3: the positioner (501) drives the rare earth element-containing titanium alloy spatial thin-walled part (6) to rotate, so that the rare earth element-containing high-temperature alloy molten pool (9) continuously grows in the circumferential direction; the temperature control station (502) provides cooling temperature for the rare earth element-containing high-temperature alloy molten pool (9), so that the rare earth element-containing high-temperature alloy molten pool (9) solidifies into a cladding layer (10); Step S4: the optical fiber (11) outputs laser light to the cladding layer (10), and the optical lens (12) diffuses the laser light into a heating speckle light strip (14), and controls the cladding layer (10) to solidify in a gradient through the gradient temperature field of the heating speckle light strip (14); Step S5: repeating steps S2 to S4 to perform continuous cladding, so that the cladding layer (10) grows in the height direction until a restricted rotation thin-walled shell is completed; Step S6: Continue to complete N restricted rotation thin-walled shells, where the N restricted rotation thin-walled shells are spaced apart and concentric.

4. The additive manufacturing method according to claim 3, characterized in that: The process environment of the additive manufacturing is an atmosphere with a stable content of argon and hydrogen.

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