Multifunctional titanium alloy welding and additive manufacturing process protection device and method

Abstract

The invention discloses a multifunctional titanium alloy welding and additive manufacturing process protection device and method. The device is mainly composed of a high-temperature-resistant flexible film, a transparent box body, a supporting beam, a water curtain groove, a waterproof ultrasonic impact device, an oxygen meter, a clamp pressing plate, a limiting column, a workpiece supporting plate, an auxiliary device supporting plate, a water inlet flow meter, a water outlet flow meter, a shielding gas inlet channel, a sealing top cover frame, an elastic tightening ring, a welding fume dust removal pipeline and the like. The application method comprises five steps. Air can be effectively isolated, and performance degradation caused by oxidation of a titanium alloy high-temperature area is prevented; meanwhile, a water curtain on the side wall of the transparent box body can be cooled and collect process splashing, and quantitative research and analysis of defect generation are realized in cooperation with high-speed camera shooting. In addition, by adjusting the water level in the transparent box body and combining a built-in ultrasonic peening device, forced cooling in the forming and manufacturing process can be achieved, the manufacturing efficiency is improved, and the structure performance of components is optimized.

Description

Technical Field

[0001] This invention belongs to the field of titanium alloy welding technology, and specifically relates to a multifunctional titanium alloy welding and additive manufacturing process protection device and method. Background Technology

[0002] In the welding and additive manufacturing of titanium alloys, the high temperatures of the molten pool and heat-affected zone make them highly susceptible to chemical reactions with elements such as hydrogen, oxygen, and nitrogen in the air. This accelerates the breakdown of the passivation film on the surface, forming hard and brittle phases such as titanium hydrides, titanium dioxide, and titanium nitride, leading to a deterioration in mechanical properties. Therefore, a vacuum environment or inert gas protection is often required in the welding and additive manufacturing of titanium alloys. Since vacuum welding equipment is expensive, the most common method is to use inert gas for local protection, i.e., adding a protective gas shroud to the tail of the welding torch. This method is simple in structure and low in cost, but it also has some drawbacks. For example, it is difficult to adapt to complex welding and additive forming paths; in multi-layer, multi-pass welding and additive manufacturing processes, the protection effect on previous weld passes is weakened due to the raising of the welding torch; and the shielding of the shroud makes it difficult to capture high-speed imaging of droplet transfer and molten pool dynamics, limiting the research and understanding of the formation mechanisms of defects such as incomplete fusion and spatter. Therefore, there is a need to develop a new type of inert gas protection device for titanium alloy welding and additive manufacturing processes to overcome the shortcomings of using protective shrouds. Summary of the Invention

[0003] To achieve reliable protection during the welding and additive manufacturing processes of titanium alloys to prevent oxidation, facilitate the study of defects such as spatter and lack of fusion, and effectively control the microstructure and mechanical properties, this invention proposes a multifunctional protective device and method for the welding and additive manufacturing processes of titanium alloys.

[0004] A multifunctional protective device for titanium alloy welding and additive manufacturing processes includes a transparent housing, an inlet water flow meter, an outlet water flow meter, a protective gas inlet channel, an exhaust port plug, an oxygen meter, a support beam, an auxiliary device support plate, a workpiece support plate, and a fixture pressure plate. The upper side of the transparent box has an air inlet and a water inlet. The air inlet is connected to a protective gas inlet channel, and the other end of the protective gas inlet channel is connected to an external inert gas cylinder. The water inlet is connected to a water flow meter, and the other end of the water flow meter is connected to an external water pipe. The transparent box has an exhaust hole and a water outlet on the lower side. The exhaust hole is connected to an exhaust plug, and the water outlet is connected to a water flow meter. The other end of the water flow meter is connected to a water collection container. The bottom surface of the transparent box has the same number and diameter of through holes as the support beam, so that the threaded support beam passes through the bottom of the box and is connected to the external flexible workbench by bolts. To ensure the sealing effect of the box protection device, sealing gaskets are installed at the bolt connections. The interior of the transparent box consists of, from bottom to top, an auxiliary device support plate, a workpiece support plate, a welded or additively manufactured workpiece, and a fixture pressure plate. The auxiliary device support plate and the workpiece support plate have the same number and diameter of through holes as the support beam. The support beam passes through these through holes and is fixed and constrained by limit nuts. An oxygen analyzer is installed on the bottom of the inner wall of the transparent box, and the top of the transparent box is covered with a high-temperature resistant flexible film.

[0005] A water curtain trough is also installed around the inner wall of the transparent box, slightly below the water inlet.

[0006] The water curtain trough has an L-shaped structure. The side without sidewalls at the bottom has a protruding bonding section and a long and narrow U-shaped groove. A water leakage hole is provided at one end of the bottom of the trough for supplying water to the water curtain trough on the adjacent side. The water curtain trough is bonded to the transparent box through the adhesive section and fixed horizontally. There is a height difference between the water curtain troughs on two adjacent sides of the transparent box, which facilitates the flow of water from the water inlet in the water curtain troughs on different sides of the transparent box. The water then flows down the inner wall of the box through the long and narrow U-shaped groove to form a water curtain. The water curtain can not only prevent the splashes generated during welding and additive manufacturing from contaminating the inner wall of the transparent box, but also count the number of splashes formed.

[0007] A waterproof ultrasonic impact device is also provided between the auxiliary device support plate and the workpiece support plate. The waterproof ultrasonic impact device is fixed to the middle of the auxiliary device support plate by bolts. The distance between the auxiliary device support plate and the workpiece support plate is controlled by a limiting post to meet the height of the ultrasonic impact device.

[0008] The welded or additively manufactured workpiece is placed on the workpiece support plate. The fixture pressure plate is connected to the workpiece support plate by bolts and nuts to constrain the welded or additively manufactured workpiece. The fixture pressure plate has several constraint holes to accommodate different workpiece sizes.

[0009] The transparent enclosure serves as the outer shell of the entire protective device, and its material is tempered glass, acrylic, polyvinyl chloride, polycarbonate, polyethylene terephthalate, or polypropylene.

[0010] The high-temperature resistant flexible membrane is made of polyethylene, polyimide, or polytetrafluoroethylene. The high-temperature resistant flexible membrane has an opening in the middle and is bonded to an elastic tightening ring. The four sides are bonded to the sealing top cover frame. The sealing top cover frame is a narrow-sided "U"-shaped frame with an inner step. The size of the inner step is the same as the wall thickness of the transparent box. It is tightly fitted onto the upper edge of the transparent box.

[0011] The device of the present invention is also provided with a welding fume removal pipe, which is installed close to the welding torch and connected to an external fume purifier; an elastic tightening ring is fitted on the welding torch and the welding fume removal pipe, and its specific position can be adjusted according to the range of motion of the welding torch.

[0012] The oxygen analyzer is installed by adhesive or bolt connection and is waterproof.

[0013] Applicable welding and additive manufacturing processes include, but are not limited to, arc welding, laser welding, and laser-arc hybrid welding.

[0014] The method of using the multifunctional titanium alloy welding and additive manufacturing process protection device of the present invention includes the following steps: Step 1: Place the welded workpiece or additively manufactured workpiece on the workpiece support plate and fix it with a clamping plate. Step 2: Move the welding torch to the starting point of the welding or additive manufacturing path, and put the elastic tightening ring on the upper part of the welding torch so that it tightly grips the welding torch and the welding fume dust removal pipe to prevent outside air from entering. Then, clip the sealing top cover frame onto the upper edge of the transparent box. Step 3: Open the valve of the external inert gas cylinder to allow it to enter the transparent box through the protective gas inlet channel. At the same time, turn on the oxygen analyzer. When the oxygen content inside the box meets the target requirements, insert the exhaust port plug. Step 4: Turn on the external circulating water and adjust the inlet flow rate through the inlet flow meter to make the water flow steadily to all side walls of the tank and form a water curtain. At the same time, adjust the outlet flow rate through the outlet flow meter to control the water level in the tank to meet different needs such as splash collection, welding or additive manufacturing forced cooling. Step 5: Turn on the welding machine power and the external welding fume purifier. Depending on the specific needs, choose whether to turn on the ultrasonic impact device, and then start welding.

[0015] The beneficial effects of this invention are as follows: (1) It can effectively protect the high-temperature metal areas of titanium alloy welding and additive manufacturing, and prevent them from undergoing oxidation reactions and resulting in mechanical property degradation; (2) The water curtain formed by the side wall of the transparent box can not only avoid the adhesion and pollution of welding fumes on the inner wall of the transparent box, but also cool and collect the spatter generated during the welding and additive manufacturing process for quantitative research on the generation of spatter defects. (3) By controlling the water level inside the tank, forced cooling of thick plate titanium alloy multi-layer multi-pass welding or titanium alloy additive manufacturing structure can be achieved, reducing the interlayer cooling waiting time and improving manufacturing efficiency. (4) The transparent enclosure facilitates the observation of arc morphology, droplet transfer and molten pool flow behavior during the welding process using high-speed cameras, which helps to study and understand the formation mechanism of defects such as incomplete fusion and spatter. (5) The built-in ultrasonic impact device can be used to control the microstructure and properties of titanium alloy welded and additive manufacturing structural parts. Attached Figure Description

[0016] Figure 1 Schematic diagram of the multifunctional titanium alloy welding and additive manufacturing process protection device of the present invention; Figure 2 This is a schematic diagram of the structural features of a water curtain trough; Figure 3 A schematic diagram of the installation cross-section of the water curtain trough and the transparent enclosure; Figure 4 for Figure 1 Enlarged view of a portion of the area near the inlet flow meter; Explanation of reference numerals in the attached drawings: 1. High-temperature resistant flexible membrane; 2. Inlet flow meter; 3. Transparent box; 4. Support beam; 5. Clamping plate; 6. Limiting post; 7. Sealing gasket; 8. Workpiece support plate; 9. Auxiliary device support plate; 10. Bolt; 11. Waterproof ultrasonic impact device; 12. Welded workpiece or additive manufacturing workpiece; 13. Oxygen analyzer; 14. Exhaust vent plug; 15. Outlet flow meter; 16. Protective gas inlet channel; 17. Water curtain trough; 18. Sealed top cover frame; 19. Elastic tightening ring; 20. Welding torch; 21. Welding fume dust removal pipe; 22. Detailed Implementation

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] The following section will introduce a multifunctional titanium alloy welding and additive manufacturing process protection device and method proposed in this invention, in conjunction with titanium alloy welding.

[0019] Example 1

[0020] A schematic diagram of a multifunctional titanium alloy welding process protection device is shown below. Figure 1As shown, it includes a high-temperature resistant flexible membrane 1, an inlet water flow meter 2, a transparent box 3, a support beam 4, a clamping plate 5, a limiting post 6, a sealing gasket 7, a workpiece support plate 8, an auxiliary device support plate 9, bolts 10, nuts 11, a waterproof ultrasonic impact device 12, a welded workpiece or an additively manufactured workpiece 13, an oxygen analyzer 14, an exhaust port plug 15, an outlet water flow meter 16, a protective gas inlet channel 17, a water curtain trough 18, a sealing top cover frame 19, an elastic tightening ring 20, a welding torch 21, and a welding fume dust removal pipe 22.

[0021] Among them, the transparent box 3 is the outer shell of the entire protective device, and its material is acrylic sheet; The transparent box 3 has one air inlet on each of the front and rear sides of the upper part. The air inlet is connected to the protective gas inlet channel 17, and the other end of the protective gas inlet channel 17 is connected to an external inert gas protective gas cylinder. The transparent box 3 has one water inlet on the upper right side. The water inlet is connected to the water inlet flow meter 2, and the other end of the water inlet flow meter 2 is connected to an external water pipe. A vent is opened on the lower front side of the transparent box 3, and the vent is connected to the vent plug 15. A water outlet is opened on the lower left side of the transparent box 3, and the water outlet is connected to the water flow meter 16. The other end of the water flow meter 16 is connected to the water collection container. The bottom surface of the transparent box 3 has four through holes with the same diameter as the support beam 4. The threaded support beam 4 passes through the bottom of the transparent box 3 and is connected to the external flexible workbench by bolts. To ensure the sealing effect of the box protection device, sealing gaskets are installed at the bolt connections.

[0022] Inside the transparent housing 3, from bottom to top, are: an auxiliary device support plate 9, a waterproof ultrasonic impact device 12, a workpiece support plate 8, a welded workpiece or additive manufacturing workpiece 13, and a clamping plate 5. The auxiliary device support plate 9 and the workpiece support plate 8 have four through holes of the same diameter as the support beam 4 at their four corners. The support beam 4 passes through these through holes and is fixed to the auxiliary device support plate 9 and the workpiece support plate 8 with nuts. The waterproof ultrasonic impact device 12 is fixed to the middle of the auxiliary device support plate 9 by bolts and nuts. The distance between the auxiliary device support plate 9 and the workpiece support plate 8 is controlled by limiting posts 6 to meet the height requirements of the ultrasonic impact device. Sealing washers 7 are installed between the limiting posts 6 and both the auxiliary device support plate 9 and the workpiece support plate 8. The welded workpiece or additive manufacturing workpiece 13 is placed on the workpiece support plate 8. The clamping plate 5 is connected to the workpiece support plate 8 by bolts 10 and nuts 11 to constrain the welded workpiece or additive manufacturing workpiece 13. The clamping plate 5 has several constraint holes to accommodate different workpiece sizes.

[0023] A waterproof oxygen meter 14 is attached to the bottom of the inner wall of the transparent housing 3; The water curtain trough 18 has an overall L-shaped geometric feature, such as... Figure 2 and Figure 3 As shown, there is a water leakage hole at one end of its bottom, and the side of the bottom without sidewalls has a protruding adhesive section and a long and narrow U-shaped groove; the adhesive section of the water curtain trough 18 is horizontally fixed to the uppermost part of the inner wall of the transparent box, slightly lower than the water inlet hole, and surrounds the inner wall of the transparent box 3. At the same time, there is a certain height difference between two adjacent sides of the water curtain trough 18 of the transparent box 3, such as... Figure 4 As shown, this allows water from the inlet flow meter 2 to flow in the water curtain troughs 18 on different sides of the transparent housing 3, and to flow down the inner wall of the housing through a long and narrow U-shaped trough to form a water curtain.

[0024] The high-temperature resistant flexible membrane 1 is made of polyethylene and is connected to the sealing top cover frame 19 and the elastic tightening ring 20 by adhesive bonding; the sealing top cover frame 19 is a narrow-sided "U"-shaped frame with an inner step, such as... Figure 4 As shown, the inner step size is consistent with the wall thickness of the transparent box 3, and it is tightly fitted on the upper edge of the transparent box 3; the welding fume extraction pipe 22 is installed close to the welding torch 21 and connected to the external fume purifier; the elastic tightening ring 20 is fitted on the welding torch 21 and the welding fume extraction pipe 22, and its specific position can be appropriately adjusted according to the range of motion of the welding torch during the welding process.

[0025] The method of using a multifunctional titanium alloy welding process protection device includes the following 5 steps: Step 1: Place the welded workpiece or additive manufacturing workpiece 13 on the workpiece support plate 8 and fix it with the clamping plate 5. Step 2: Move the welding torch 21 to the starting point of the welding path and put the elastic tightening ring 20 on the upper part of the welding torch 21 so that it tightly tightens the welding torch 21 and the welding fume dust removal pipe 22 to prevent external air from entering. Then, put the sealing top cover frame 19 on the upper edge of the transparent box 3. Step 3: Open the valve of the external inert gas cylinder to allow it to enter the transparent box 3 through the protective gas inlet channel 17. At the same time, turn on the oxygen meter 14. When the oxygen content inside the transparent box 3 is lower than 0.01%, insert the exhaust plug 15. Step 4: Turn on the external circulating water and adjust the inlet flow rate through the inlet flow meter 2 to make the water flow stably to all the side wall water curtain troughs 18 of the transparent box 3 and form a water curtain. At the same time, adjust the outlet flow rate through the outlet flow meter 16 to control the water level inside the transparent box 3 to meet different needs such as splash collection and forced cooling of welding. Step 5: Turn on the external welding machine power supply and welding fume purifier, turn on the waterproof ultrasonic impact device 12, and then start welding.

[0026] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A multifunctional protective device for titanium alloy welding and additive manufacturing processes, characterized in that, It includes a transparent box (3), an inlet flow meter (2), an outlet flow meter (16), a protective gas inlet channel (17), an exhaust plug (15), an oxygen meter (14), a support beam (4), an auxiliary device support plate (9), a workpiece support plate (8), and a clamping plate (5). The transparent box (3) has an air inlet and a water inlet on the upper side. The air inlet is connected to a protective gas inlet channel (17), and the other end of the protective gas inlet channel (17) is connected to an external inert protective gas cylinder. The water inlet is connected to a water flow meter (2), and the other end of the water flow meter (2) is connected to an external water pipe. The transparent box (3) has an exhaust hole and a water outlet on the lower side. The exhaust hole is connected to the exhaust hole plug (15), and the water outlet is connected to the water flow meter (16). The other end of the water flow meter (16) is connected to the water collection container. The bottom surface of the transparent box (3) has the same number and diameter of through holes as the support beam (4), so that the threaded support beam (4) passes through the bottom of the box and is connected to the external flexible workbench by bolts. Sealing gaskets are installed at all bolt connections. The transparent box (3) contains, from bottom to top, an auxiliary device support plate (9), a workpiece support plate (8), a welded workpiece or additive manufacturing workpiece (13), and a clamping plate (5); the auxiliary device support plate (9) and the workpiece support plate (8) have the same number and diameter of through holes as the support beam (4), and the support beam (4) passes through these through holes and is fixed and constrained by a limiting nut; An oxygen meter (14) is installed on the bottom of the inner wall of the transparent box (3), and a high-temperature resistant flexible film (1) is covered on the top of the transparent box (3). At the top of the inner wall of the transparent box (3), slightly below the water inlet, a water curtain trough (18) is also provided around the inner wall of the transparent box (3).

2. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, The water curtain trough (18) has an L-shaped structure. The bottom side without sidewalls has a protruding bonding section and a long and narrow U-shaped groove. A water leakage hole is provided at one end of the bottom of the trough for supplying water to the water curtain trough on the adjacent side. The water curtain trough (18) is bonded to the transparent box (3) through the adhesive section and fixed horizontally; there is a height difference between the water curtain troughs on two adjacent sides of the transparent box (3).

3. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, A waterproof ultrasonic impact device (12) is also provided between the auxiliary device support plate (9) and the workpiece support plate (8). The waterproof ultrasonic impact device (12) is fixed in the middle of the auxiliary device support plate (9) by bolt connection. The distance between the auxiliary device support plate (9) and the workpiece support plate (8) is controlled by the limiting column (6) so that it meets the height of the ultrasonic impact device.

4. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, The welded workpiece or additive manufacturing workpiece (13) is placed on the workpiece support plate (8). The clamping plate (5) is connected to the workpiece support plate (8) by bolts and nuts to constrain the welded workpiece or additive manufacturing workpiece. Several constraint holes are distributed on the clamping plate (5) to accommodate different workpiece sizes.

5. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, The transparent enclosure (3) is the outer shell of the entire protective device, and its material is tempered glass, acrylic, polyvinyl chloride, polycarbonate, polyethylene terephthalate or polypropylene.

6. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, The high-temperature resistant flexible membrane (1) is made of polyethylene, polyimide or polytetrafluoroethylene. The high-temperature resistant flexible membrane has an opening in the middle and is bonded to an elastic tightening ring (20). It is bonded to the sealing top cover frame (19) around the perimeter. The sealing top cover frame (19) is a narrow-sided "U"-shaped frame with an inner step. The size of the inner step is consistent with the wall thickness of the transparent box (3). It is tightly fitted on the upper edge of the transparent box (3).

7. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1 or 6, characterized in that, It is also equipped with a welding fume extraction duct (22), which is installed close to the welding torch and connected to an external fume purifier; the elastic tightening ring (20) is fitted on the welding torch and the welding fume extraction duct (22).

8. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, The oxygen analyzer (14) is installed by adhesive or bolt connection and is waterproof.

9. The multifunctional titanium alloy welding and additive manufacturing process protection device as described in claim 1, characterized in that, Applicable welding and additive manufacturing processes include, but are not limited to, electric arc welding, laser welding, and laser-arc hybrid welding.

10. The method of using the multifunctional titanium alloy welding and additive manufacturing process protection device according to claim 1, characterized in that, Includes the following steps: Step 1: Place the welded workpiece or additive manufacturing workpiece (13) on the workpiece support plate (8) and fix it with a clamping plate (5); Step 2: Move the welding torch to the starting point of the welding or additive manufacturing path and put the elastic tightening ring (20) on the upper part of the welding torch so that it tightly wraps around the welding torch and the welding fume dust removal pipe (22) to prevent external air from entering. Then, put the sealing top cover frame (19) on the upper edge of the transparent box (3). Step 3: Open the valve of the external inert gas cylinder to allow it to enter the transparent box (3) through the protective gas inlet channel (17), and at the same time turn on the oxygen meter (14). When the oxygen content inside the box meets the target requirements, insert the exhaust plug (15). Step 4: Turn on the external circulating water and adjust the inlet flow rate through the inlet flow meter (2) to make the water flow stably to all side walls of the tank and form a water curtain. At the same time, adjust the outlet flow rate through the outlet flow meter (16) to control the water level in the tank to meet different needs such as splash collection, welding or additive manufacturing forced cooling heat dissipation. Step 5: Turn on the welding machine power and the external welding fume purifier. Depending on the specific needs, choose whether to turn on the waterproof ultrasonic impact device (12) and then start welding.

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