Electro-arc additive and ultrasonic roller compaction combined manufacturing apparatus

Abstract

The application discloses an electric arc additive and ultrasonic rolling combined manufacturing equipment, which comprises an electric arc additive manufacturing welding gun, wherein the electric arc additive manufacturing welding gun is installed on a holding frame arranged horizontally and has a welding head at one end downwardly, and the holding frame is further provided with a roller rolling device; the roller rolling device comprises a pressing device, wherein a telescopic arm of the pressing device is arranged vertically downwardly, a steel ultrasonic vibration rolling roller is installed at a lower end of the telescopic arm, a side surface of the ultrasonic vibration rolling roller is arranged towards the electric arc additive manufacturing welding gun and is an inner concave arc shape suitable for a cross section shape of an electric arc additive manufacturing layer, and the roller rolling device further comprises an ultrasonic vibrator for the roller, wherein the ultrasonic vibrator for the roller is fixedly connected with the pressing device and provides ultrasonic vibration for the pressing device. The application has the advantages of being capable of improving the organization and mechanical properties of electric arc additive manufacturing materials or parts.

Description

[0001] This application is a divisional application of the patent application No. 202110521112.1, filed on May 13, 2021, entitled "Arc additive manufacturing method with post-welding ultrasonic vibration and rolling characteristics". TECHNICAL FIELD

[0002] The present application relates to the field of additive manufacturing, in particular to an arc additive manufacturing method with ultrasonic vibration and rolling characteristics. BACKGROUND

[0003] In recent years, under the background of resource conservation and efficient manufacturing, additive manufacturing technology based on "additive" processing mode shows broad application prospects in the manufacturing of complex shape thin-walled parts. With the increasingly stringent requirements of aerospace, national defense and military industry, rail transportation and other key technology fields on the performance, precision, manufacturing cost and cycle of dense metal parts, it is urgent to carry out related research to break through and master the direct forming technology of metal parts. Arc additive manufacturing mainly uses arc as heat source, such as metal inert gas welding (MIG), tungsten inert gas welding (TIG) and plasma arc welding (PA), and adds wire material. Under the program control, metal parts are gradually formed from line-surface-body according to three-dimensional digital model. The main characteristics are high deposition efficiency and wire utilization rate, short overall manufacturing cycle (deposition rate can reach 1 kg / h), low cost, and also have the ability of in-situ composite manufacturing and forming large size parts (can manufacture up to lm 3 workpiece). However, with the increase of stacking layers, heat accumulation of stacking layers is serious, and heat dissipation condition is poor, which is easy to cause problems such as overheating of molten pool, coarse grain of deposited layer solidification structure and common welding defects (such as porosity, inclusion and hot crack), and it is difficult to obtain high-performance additive manufacturing materials or parts.

[0004] In view of the above problems, two patents with publication numbers CN106363173A and CN111215843A respectively disclose an ultrasonic wave assisted laser welding additive manufacturing device and method and an arc additive manufacturing hot rolling device and method, which can reduce porosity defects and improve weld quality to a certain extent. However, there are still some problems: the structure of laser welding equipment is relatively complex, the process flow and operation steps are complicated, and the cost is high; the hot rolling equipment adopts post-welding multiple rolling, which does not consider rolling when the weld is in a hot plastic state, and cannot solve the cooling problem of additive stacking layers. SUMMARY

[0005] In view of the above problems of the prior art, the technical problem to be solved by the present application is how to provide an electric arc additive manufacturing method with ultrasonic vibration and rolling features, which can better introduce ultrasonic assistance in the electric arc additive manufacturing process, improve the ultrasonic effect, effectively improve the organization and performance of the electric arc additive manufacturing accumulation layer, and cool the electric arc additive manufacturing accumulation layer to a certain extent, and an electric arc additive and ultrasonic rolling combined manufacturing equipment.

[0006] In order to solve the above technical problems, the present application adopts the following technical solution:

[0007] An electric arc additive manufacturing method with ultrasonic vibration and rolling features, characterized in that an ultrasonic vibration and rolling roller which can move synchronously and in the same direction with the electric arc additive manufacturing welding torch is arranged behind the electric arc additive manufacturing welding torch, in the electric arc additive manufacturing process, the electric arc additive manufacturing welding torch is first ignited and translated, the electric arc additive manufacturing is realized through the melting and solidification of the welding material, the ultrasonic vibration and rolling roller moves synchronously and in the same direction with the electric arc additive manufacturing welding torch, the ultrasonic vibration and rolling roller is used to perform ultrasonic vibration and rolling on the electric arc additive manufacturing layer in the hot plastic stage, so that the electric arc additive manufacturing layer is plastically deformed and cooled, and the ultrasonic vibration is transmitted to the electric arc molten pool through the electric arc additive manufacturing layer and the base parent material by the plane vibration combined with the front and rear, so that the solidification process of the molten pool is affected by the ultrasonic vibration at a close distance, and the organization and performance of the electric arc additive layer are improved by the combined action of the two.

[0008] In this way, the technical solution provided by the present application organically combines the ultrasonic vibration and rolling on the steel roller which can move synchronously and in the same direction with the welding torch, the roller performs ultrasonic vibration and rolling when the electric arc additive accumulation layer just solidifies and is still in the hot plastic state, so that the electric arc additive accumulation layer is plastically deformed. The beneficial effects are as follows: 1. the ultrasonic vibration and rolling coupling effect can greatly improve the plasticity of the material, so that the material obtains greater plastic deformation modification, and the organization and performance are improved better; 2. the ultrasonic vibration and rolling are performed when the electric arc additive accumulation layer is still in the hot plastic state, which utilizes the residual heat, is more energy-saving and simple and easy to implement compared with the method of heating and rolling again, and the roller performs forced cooling on the electric arc additive accumulation layer, which is beneficial to reducing the waiting time between layers of the electric arc additive manufacturing and improving the efficiency.

[0009] Further, the ultrasonic vibration and rolling roller is a steel ultrasonic vibration and rolling roller, and the side surface thereof is an inner concave arc shape which is adapted to the cross-sectional shape of the electric arc additive manufacturing layer.

[0010] In this way, the inner arc-shaped pressing surface of the steel roller increases the contact area with the additive layer, so that more ultrasonic wave energy is transmitted to the molten pool, and the cooling effect of the roller on the electric arc additive manufacturing layer is increased. In implementation, the diameter of the roller can be 20-50 mm.

[0011] Further, the average down pressure of the ultrasonic vibration roller on the electric arc additive manufacturing layer is 0.5-2.5KN, and the ultrasonic vibration power is 50-250W.

[0012] The parameter range can better guarantee the ultrasonic rolling effect. In implementation, the roller and the welding gun and the adjacent 5-15mm are arranged.

[0013] Further, the method is implemented by the following electric arc additive manufacturing and ultrasonic rolling combined manufacturing equipment. The electric arc additive manufacturing and ultrasonic rolling combined manufacturing equipment comprises an electric arc additive manufacturing welding gun, the electric arc additive manufacturing welding gun is installed on a holding frame arranged horizontally as a whole and the welding head is downward at one end, and a roller rolling device is further installed on the holding frame, the roller rolling device comprises a pressing device, the telescopic arm of the pressing device is arranged vertically downward, and a steel ultrasonic vibration roller is installed at the lower end of the telescopic arm, the side surface of the ultrasonic vibration roller is arranged towards the direction of the electric arc additive manufacturing welding gun and is an inner concave arc shape adapted to the cross-sectional shape of the electric arc additive manufacturing layer, and the roller rolling device further comprises an ultrasonic vibrator for roller, the ultrasonic vibrator for roller is fixedly connected with the pressing device and provides ultrasonic vibration for the pressing device.

[0014] In this way, the roller rolling device can rely on the pressing device to keep the roller applying pressure on the electric arc additive manufacturing layer, and can rely on the ultrasonic vibrator for roller to apply ultrasonic vibration, so as to realize the ultrasonic rolling effect. The roller rolling device and the electric arc additive manufacturing welding gun are installed on the same holding frame, which can better guarantee synchronous following.

[0015] Further, the electric arc additive manufacturing welding gun is installed on a welding gun mounting sleeve, and the welding gun mounting sleeve is vertically rotatably installed on the holding frame through a welding gun mounting sleeve rotation adjusting handle.

[0016] In this way, loosening the welding gun mounting sleeve rotation adjusting handle can rotate and adjust the inclination angle of the welding gun mounting sleeve in the vertical direction, so as to realize the adjustment of the welding gun angle as needed, and tightening the welding gun mounting sleeve rotation adjusting handle can realize fixation after adjustment. The structure related to the adjustment handle for realizing adjustment and fixation belongs to mature prior art, and a bolt can be arranged on the adjustment handle, passes through the welding gun mounting sleeve and cooperates with the corresponding screw hole on the holding frame, so as to realize the adjustment and fixation, and the specific structure is not described here.

[0017] Further, the electric arc additive manufacturing welding gun is axially slidably installed on the welding gun mounting sleeve, and a welding gun fastening bolt is further rotatably arranged on the welding gun mounting sleeve to realize the fixation of the electric arc additive manufacturing welding gun.

[0018] In this way, the height position of the welding gun can be adjusted after the inclination adjustment, so that the welding gun can maintain sufficient molten pool depth and the relative position matched with the stirring needle can be adjusted.

[0019] Further, the holder is in the shape of a long strip with consistent width, the roller pressing device comprises a sliding sleeve horizontally sleeved on the holder, a bolt is threaded through the sliding sleeve to fix the sliding sleeve, the pressing device is fixedly installed at the lower end of the sliding sleeve, and the ultrasonic vibrator is fixedly installed at the upper end of the sliding sleeve.

[0020] In this way, the relative distance between the roller and the welding gun can be better adjusted as required.

[0021] Further, the arc additive manufacturing is performed while the stirring needle with the reciprocating ultrasonic vibration feature is inserted into the additive manufacturing molten pool and synchronously moved with the molten pool, the ultrasonic vibration and stirring are directly performed on the solidification process of the molten pool metal, and the solidification structure and mechanical properties of the molten pool metal are improved.

[0022] In this way, in the method, the stirring needle in the vibration state is inserted into the molten pool during the arc additive manufacturing, the ultrasonic vibration is introduced into the molten pool through the stirring needle, the cavitation effect and vibration effect of the ultrasonic vibration can be better utilized, the welding pores are reduced, the grains are refined, the bonding strength of the molten pool edge of the welding area and the non-welding area during the crystallization process is improved, and the solidification structure and mechanical properties of the molten pool metal are improved. Compared with other ultrasonic vibration modes, such as loading on the base parent material or through the arc, the ultrasonic vibration loading mode of the present application is more direct for the molten pool, and has good mechanical stirring effect, and the improvement effect on the solidification structure and mechanical properties of the molten pool metal is better.

[0023] As an optimization, the stirring needle is made of tungsten or tungsten alloy.

[0024] In this way, it can be better ensured that the stirring needle does not react with the molten pool metal.

[0025] As an optimization, the vibration direction of the stirring needle is along the axial direction of the stirring needle.

[0026] In this way, the stirring needle only drives the liquid metal in the molten pool to do high-frequency reciprocating vibration in a certain range, and the stirring needle relies on the vibration to produce a stirring effect on the molten pool (which is not actually conventional stirring), so as to reduce the welding pores, improve the molecular-level bonding density of the welding material, and then improve the mechanical properties of the welding area and the welding effect.

[0027] As an optimization, the vibration frequency of the stirring needle is 20-100 KHZ, and the amplitude is 0.2-1 mm. The vibration in this range can better ensure that the vibration has a good effect on the metal crystallization, avoid affecting the crystallization due to excessive vibration, and reduce the welding quality.

[0028] As an alternative, the arc additive manufacturing welding torch is arranged with the upper end inclined forward along the direction of travel of the arc additive manufacturing welding torch, and the stirring needle is arranged behind the arc additive manufacturing welding torch and inserted vertically downward into the middle of the additive manufacturing molten pool to achieve ultrasonic vibration.

[0029] This is because the welding torch is arranged in the direction perpendicular to the product plane during conventional arc additive manufacturing, so this method directly adds the stirring needle to introduce ultrasonic vibration on the basis of the conventional arc additive manufacturing process control, without the need to adjust the control program of the arc additive manufacturing welding torch, facilitating implementation and application.

[0030] As another alternative, the arc additive manufacturing welding torch is arranged with the upper end inclined forward along the direction of travel of the arc additive manufacturing welding torch, and the stirring needle is arranged behind the arc additive manufacturing welding torch and inserted vertically downward into the middle of the additive manufacturing molten pool to achieve ultrasonic vibration.

[0031] In this way, the upper end of the arc additive manufacturing welding torch is inclined along the direction of travel, which can better preheat the to-be-processed area in front of the molten pool, and at the same time can provide space for the stirring needle to be arranged vertically at the middle position of the molten pool. After the stirring needle is arranged vertically at the middle position of the molten pool, the ultrasonic vibration of the stirring needle can be transmitted to the entire molten pool very uniformly, avoiding uneven transmission of ultrasonic vibration in the molten pool, which affects the crystallization and fusion effect of the metal, and greatly improves the product forming quality.

[0032] After the step of directly stirring the molten pool with the stirring needle in the method, the following equipment can be used, that is, a vibration stirring device is further installed on the holder based on the above-mentioned arc additive manufacturing and ultrasonic rolling combined manufacturing equipment, the vibration stirring device includes a stirring needle ultrasonic vibrator, the stirring needle ultrasonic vibrator is provided with a stirring needle at the lower end, and the stirring needle ultrasonic vibrator can provide axial vibration for the stirring needle.

[0033] In this way, the welding torch and the vibration stirring device are installed on the same holder, which can better ensure that the stirring needle vibrates and stirs synchronously with the welding torch.

[0034] Further, the stirring needle ultrasonic vibrator is vertically installed on a vibrator mounting sleeve, the vibrator mounting sleeve is vertically rotatably installed on a sliding sleeve through a vibrator mounting sleeve vibration adjusting handle, and the sliding sleeve is horizontally slidably installed on the holder.

[0035] In this way, the inclination angle of the stirring needle can be conveniently adjusted as needed to be arranged vertically or inclined with respect to the molten pool, and the front and rear distance of the stirring needle with respect to the welding torch can also be conveniently adjusted so that the lower end can be better located at the middle position of the molten pool. The adjustment structure of the vibrator mounting sleeve vibration adjusting handle can be consistent with the welding torch mounting sleeve rotation adjusting handle, which will not be described here.

[0036] Further, the holder is in the shape of a long strip with consistent width from top to bottom, and the sliding sleeve is horizontally slidably sleeved and installed on the holder, and a sliding sleeve fastening bolt is further rotatably arranged through the sliding sleeve to realize the fixation of the sliding sleeve.

[0037] In this way, the front and back positions of the stirring needle can be adjusted and fixed more conveniently.

[0038] Further, the stirring needle ultrasonic vibrator is installed on the vibrator mounting sleeve through the vibration absorbing spring.

[0039] In this way, the vibration absorbing spring acts between the stirring needle ultrasonic vibrator and the vibrator mounting sleeve, so that the ultrasonic vibration can be avoided from being transmitted to the holder through the vibrator mounting sleeve, thereby causing the vibration of the welding gun. The working stability of the welding gun can be better maintained.

[0040] Further, the stirring needle ultrasonic vibrator is a pneumatic stirring needle ultrasonic vibrator.

[0041] In this way, the effect is stable, the control is convenient, the implementation is facilitated, and the effect of the reaction of the ultrasonic vibration on the holder is small. Moreover, the pneumatic ultrasonic vibration source has much higher tolerance to heat and high temperature, and is more suitable for the high-temperature working condition of the electric arc additive manufacturing.

[0042] Further, the holder is fixedly installed on the mechanical arm of the electric arc additive manufacturing special robot.

[0043] In this way, the automatic electric arc additive manufacturing of the product can be realized through the computer control of the robot.

[0044] Further, the lower end of the stirring needle has a horizontal outward protruding protrusion.

[0045] In this way, when the stirring needle vibrates up and down along the axial direction, the protrusion can greatly amplify the vibration of the molten pool, thereby improving the ultrasonic vibration effect. In the specific implementation, the outward protruding distance of the protrusion should not be too large, and can be controlled within three times the diameter of the stirring needle. The specific size can be obtained according to the test verification.

[0046] Further, the protrusion is a plurality of circumferentially uniformly arranged protrusions, and the upper surface and the lower surface of each protrusion are respectively arranged as reverse-symmetric inclined surfaces or spiral blade surfaces.

[0047] Thus, with the reciprocating vibration of the stirring needle along the axial direction, the upper and lower surfaces of the protrusions will form an effect of reciprocating rotation outwardly pushing the molten metal in the circumferential direction during the reciprocating movement, thereby generating an axial vibration and a circumferential reciprocating vibration of the molten metal, wherein the axial vibration can better act on the bottom of the molten pool, and the circumferential vibration can better act on the circumferential wall of the molten pool, the double vibrations form a composite high-frequency vibration effect on the molten metal pool, greatly improve the combination of the molten pool on the circumferential metal, better refine the metal crystal organization, improve the influence of the vibration on the metal crystal fusion effect, and improve the forming quality of the product.

[0048] Therefore, the scheme of the present application further introduces ultrasonic vibration stirring in the electric arc additive manufacturing, which can break the growing columnar crystals, refine and homogenize the grains, and promote the overflow of gas in the molten pool to reduce the porosity, and the comprehensive effect of the two greatly improves the mechanical properties of the electric arc additive manufacturing material or part.

[0049] In summary, the present application has the advantages of being able to roll the electric arc additive accumulation layer by the roller during the electric arc additive manufacturing process, while introducing ultrasonic assistance to improve the ultrasonic effect, so as to improve the organization and mechanical properties of the electric arc additive manufacturing material or part. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 Figure 1 is a structural schematic diagram of an electric arc additive and ultrasonic rolling combined manufacturing equipment adopted in the first embodiment of the present application.

[0051] Figure 2 Figure 2 is a structural schematic diagram of a single ultrasonic vibration rolling roller in the first embodiment of the present application. Figure 1

[0052] Figure 3 Figure 3 is a structural schematic diagram of an electric arc additive and ultrasonic rolling combined manufacturing equipment adopted in the second embodiment of the present application.

[0053] Figure 4 Figure 4 is a structural schematic diagram of a single stirring needle lower end protrusion in the second embodiment of the present application. Figure 3 DETAILED DESCRIPTION

[0054] The present application will be further described in detail below in combination with specific embodiments.

[0055] ​​Specific implementation one: an electric arc additive manufacturing method with welding ultrasonic vibration and rolling characteristics, the gist of which is that an ultrasonic vibration and rolling roller that can move synchronously and in the same direction with an electric arc additive manufacturing welding torch is arranged behind the electric arc additive manufacturing welding torch, during the electric arc additive manufacturing process, the electric arc additive manufacturing welding torch is first ignited and translated, electric arc additive manufacturing is realized through welding material melting and solidification, the ultrasonic vibration and rolling roller moves synchronously and in the same direction with the electric arc additive manufacturing welding torch, ultrasonic vibration and rolling are performed on the electric arc additive manufacturing layer in the hot plastic stage, so that plastic deformation occurs and cooling is promoted, at the same time, ultrasonic vibration is transmitted to the electric arc molten pool through the combination of up-down and front-back plane vibration, so that the solidification process of the molten pool is subjected to close-range ultrasonic vibration, and the structure and performance of the electric arc additive layer are improved through the combined action of the two.

[0056] In this way, the present scheme organically combines ultrasonic vibration and rolling on a steel roller that can move synchronously and in the same direction with the welding torch, the roller performs ultrasonic vibration and rolling when the electric arc additive accumulation layer just solidifies and is still in the hot plastic state, so that plastic deformation of the electric arc additive accumulation layer occurs. The beneficial effects are twofold: first, the coupling effect of ultrasonic vibration and rolling can greatly improve the plasticity of the material, so that greater plastic deformation modification is obtained, and the structure and performance are improved better; second, ultrasonic vibration and rolling are performed when the electric arc additive accumulation layer is still in the hot plastic state, which takes advantage of the residual heat, is more energy-saving and simple and easy to implement compared with the method of subsequent reheating and rolling, and also takes advantage of the forced cooling of the roller on the electric arc additive accumulation layer, which is beneficial to reducing the interlayer waiting time of electric arc additive manufacturing and improving the efficiency.

[0057] Among them, referring to Figure 2 , the ultrasonic vibration and rolling roller is a steel ultrasonic vibration and rolling roller and its side surface is a concave arc shape that adapts to the cross-sectional shape of the electric arc additive manufacturing layer.

[0058] In this way, the arc-shaped pressing surface of the steel roller increases the contact area with the additive layer, so that more ultrasonic wave energy is transmitted to the molten pool, and the cooling effect of the roller on the electric arc additive manufacturing layer is also increased. When implemented, the roller can have a diameter of 20-50 mm.

[0059] Among them, the average downward pressure of the ultrasonic vibration and rolling roller on the electric arc additive manufacturing layer is 0.5-2.5 KN, and the ultrasonic vibration power is 50-250 W.

[0060] This parameter range can better ensure the ultrasonic rolling effect. When implemented, the roller and the welding torch and the adjacent 5-15 mm are arranged.

[0061] In this embodiment, the ultrasonic vibration and rolling roller is arranged behind the electric arc additive manufacturing welding torch. Figures 1-2The electric arc additive manufacturing and ultrasonic rolling combined manufacturing device shown in the embodiment comprises an electric arc additive manufacturing welding torch 1, the electric arc additive manufacturing welding torch 1 is installed on a horizontally arranged holding frame 4 and the welding head is downwardly inclined at one end, and a roller rolling device is further installed on the holding frame, the roller rolling device comprises a pressing device 13, the telescopic arm 14 of the pressing device 13 is vertically downwardly arranged and a steel ultrasonic vibration rolling roller 15 is installed at the lower end of the telescopic arm, the side surface of the ultrasonic vibration rolling roller 15 is arranged towards the direction of the electric arc additive manufacturing welding torch and is an inner concave arc shape suitable for the cross-sectional shape of the electric arc additive manufacturing layer, and the roller rolling device further comprises an ultrasonic vibrator 16 for roller, the ultrasonic vibrator 16 for roller is fixedly connected with the pressing device and provides ultrasonic vibration for the pressing device.

[0062] In this way, the roller rolling device can rely on the pressing device to keep the roller applying pressure to the electric arc additive manufacturing layer, and can rely on the ultrasonic vibrator for roller to apply ultrasonic vibration, so as to realize the ultrasonic rolling effect. The roller rolling device and the electric arc additive manufacturing welding torch are installed on the same holding frame, so that synchronous following can be better ensured. In the implementation, the pressing device can be realized by an electric push rod, so that the pressure can be conveniently and accurately controlled.

[0063] The electric arc additive manufacturing welding torch 1 is installed on a welding torch mounting sleeve 5, and the welding torch mounting sleeve 5 is vertically rotatably installed on the holding frame 4 through a welding torch mounting sleeve rotation adjusting handle 6.

[0064] In this way, loosening the welding torch mounting sleeve rotation adjusting handle can rotate and adjust the inclination angle of the welding torch mounting sleeve in the vertical direction, so that the angle of the welding torch can be adjusted as required, and the welding torch mounting sleeve rotation adjusting handle can be tightened to be fixed after adjustment. The structure related to the adjusting handle for realizing adjustment and fastening belongs to mature prior art, and a bolt can be arranged on the adjusting handle, passes through the welding torch mounting sleeve and is matched with the corresponding screw hole on the holding frame, so that the adjustment and fastening can be realized, and the specific structure is not described here.

[0065] The electric arc additive manufacturing welding torch 1 is axially slidably installed on the welding torch mounting sleeve 5, and a welding torch fastening bolt 10 is further rotatably arranged on the welding torch mounting sleeve to realize the fixation of the electric arc additive manufacturing welding torch.

[0066] In this way, the height position of the welding torch can be conveniently adjusted after the inclination adjustment, so that the welding torch can maintain sufficient molten pool depth and the relative position matched with the stirring needle can be adjusted.

[0067] The holder 4 is in the shape of a long strip with consistent width from top to bottom, the roller pressing device comprises a sliding sleeve 17 horizontally slidably sleeved on the holder, a sliding sleeve fastening bolt 18 is also throughly screwed on the sliding sleeve 17 to fix the sliding sleeve, the pressing device is fixedly installed on the lower end of the sliding sleeve 17, and the ultrasonic vibrator for the roller is fixedly installed on the upper end of the sliding sleeve.

[0068] In this way, the relative distance between the roller and the welding gun can be better adjusted according to needs.

[0069] The holder 4 is fixedly installed on the mechanical arm of the electric arc additive manufacturing special robot (the electric arc additive manufacturing special robot is a mature existing product, can be computer programmed to control the walking path of the welding gun, realizes additive welding manufacturing, and therefore is not shown in the figure).

[0070] Specific embodiment two: in the specific embodiment, a step of using the stirring needle 2 to ultrasonically vibrate and stir the molten pool is added on the basis of the above-mentioned embodiment one, that is, during the electric arc additive manufacturing of the embodiment one, the stirring needle with the reciprocating ultrasonic vibration feature is inserted into the additive manufacturing molten pool and moves synchronously with the molten pool, directly implements ultrasonic vibration and stirring on the solidification process of the molten pool metal, and improves the solidification structure and mechanical properties thereof.

[0071] In this way, the stirring needle inserted into the vibrating molten pool introduces ultrasonic vibration into the molten pool through the stirring needle, can better utilize the cavitation effect and vibration effect of ultrasonic vibration, reduces welding pores, refines grains, improves the bonding strength of the molten pool edge of the welding area and the non-welding area during the crystallization process, and improves the solidification structure and mechanical properties of the molten pool metal. Compared with other ultrasonic vibration modes, such as loading on the base parent material or through the electric arc, the ultrasonic vibration loading mode of the present application is more direct for the molten pool, and has good mechanical stirring effect, and the improvement effect on the solidification structure and mechanical properties of the molten pool metal is better.

[0072] The stirring needle is made of tungsten or tungsten alloy.

[0073] In this way, the stirring needle can be better prevented from reacting with the molten pool metal.

[0074] The vibration direction of the stirring needle is along the axial direction of the stirring needle.

[0075] In this way, the stirring needle only drives the liquid metal in the molten pool to do high-frequency reciprocating vibration in a certain range, and the stirring needle relies on vibration to produce a stirring effect on the molten pool (which is not actually conventional stirring), so as to reduce welding pores, improve the molecular-level bonding density of the welding material, and then improve the mechanical properties of the welding area and the welding effect.

[0076] The stirring needle vibration frequency is 20-100 KHZ, and the amplitude is 0.2-1 mm. The vibration in this range can better ensure that the vibration has a good effect on metal crystallization, avoid excessive vibration that affects crystallization and reduce the welding quality.

[0077] As an option, the arc additive manufacturing welding gun is arranged in a direction perpendicular to the product plane during welding, and the stirring needle is inserted obliquely downward from the front or rear of the arc additive manufacturing welding gun to the lower part of the middle of the molten pool to achieve ultrasonic vibration.

[0078] This is because the welding gun is arranged in a direction perpendicular to the product plane during conventional arc additive manufacturing, so this method directly adds a stirring needle to introduce ultrasonic vibration on the basis of the conventional arc additive manufacturing process control process, without the need to adjust the control program of the arc additive manufacturing welding gun, facilitating implementation and application.

[0079] As another option, the arc additive manufacturing welding gun is arranged with the upper end inclined forward in the direction of travel of the arc additive manufacturing welding gun, and the stirring needle is arranged behind the arc additive manufacturing welding gun and inserted vertically downward into the middle of the additive manufacturing molten pool to achieve ultrasonic vibration.

[0080] In this way, the upper end of the arc additive manufacturing welding gun is inclined in the direction of travel, which can better preheat the to-be-processed area in front of the molten pool, and at the same time, space is left for the stirring needle to be arranged vertically in the middle of the molten pool. After the stirring needle is arranged vertically in the middle of the molten pool, the ultrasonic vibration of the stirring needle can be transmitted very uniformly to the entire molten pool, avoiding uneven transmission of ultrasonic vibration in the molten pool, which affects the effect of metal crystallization and fusion, and greatly improves the product forming quality.

[0081] After the step of directly stirring the molten pool with the stirring needle in the second embodiment, the device shown in Figures 3-4 The device is implemented, that is, on the basis of the above-mentioned arc additive and ultrasonic rolling combined manufacturing equipment, a vibration stirring device is additionally installed on the holder, the vibration stirring device includes a stirring needle ultrasonic vibrator 3, the lower end of the stirring needle ultrasonic vibrator 3 is provided with a stirring needle 2, and the stirring needle ultrasonic vibrator 3 can provide axial vibration for the stirring needle 2.

[0082] In this way, the welding gun and the vibration stirring device are installed on the same holder, which can better ensure that the stirring needle vibrates synchronously with the welding gun.

[0083] The stirring needle ultrasonic vibrator 3 is vertically installed on a vibrator mounting sleeve 7, the vibrator mounting sleeve 7 is vertically rotatably installed on a sliding sleeve 8 through a vibrator mounting sleeve vibration adjusting handle 9, and the sliding sleeve is horizontally slidably installed on the holder.

[0084] In this way, the angle of the stirring needle can be conveniently adjusted according to the need, so that the stirring needle is arranged vertically or obliquely to the molten pool, and the distance between the stirring needle and the welding torch can be conveniently adjusted, so that the lower end of the stirring needle is located at the middle position of the molten pool. The adjustment structure of the vibrator mounting sleeve vibration adjustment handle can be consistent with the welding torch mounting sleeve rotation adjustment handle, and will not be described here.

[0085] The sliding sleeve 8 is horizontally slidably sleeved and mounted on the holder 4, and a sliding sleeve fastening bolt 11 is further rotatably arranged on the sliding sleeve to fix the sliding sleeve 8.

[0086] In this way, the front and rear positions of the stirring needle can be conveniently adjusted and fixed.

[0087] The stirring needle ultrasonic vibrator 3 is mounted on the vibrator mounting sleeve through the vibration absorbing spring.

[0088] In this way, the vibration absorbing spring acts between the stirring needle ultrasonic vibrator and the vibrator mounting sleeve, so that the ultrasonic vibration is prevented from being transmitted to the holder through the vibrator mounting sleeve, thereby preventing the vibration of the welding torch. The working stability of the welding torch can be better maintained.

[0089] The stirring needle ultrasonic vibrator 3 is a pneumatic stirring needle ultrasonic vibrator.

[0090] In this way, the effect is stable, the control is convenient, the implementation is convenient, and the effect of the reaction of the ultrasonic vibration on the holder is small. Moreover, the pneumatic ultrasonic vibration source has a much higher tolerance to heat and high temperature, and is more suitable for high-temperature working conditions such as electric arc additive manufacturing.

[0091] The holder 4 is fixedly mounted on the mechanical arm of the electric arc additive manufacturing special robot (the electric arc additive manufacturing special robot is a mature existing product, and the walking path of the welding torch can be controlled by computer programming to realize additive welding manufacturing, so it is not shown in the figure).

[0092] In this way, automatic electric arc additive manufacturing of the product can be realized through computer control of the robot.

[0093] The lower end of the stirring needle 2 has a horizontal outer protrusion 12.

[0094] In this way, when the stirring needle vibrates up and down along the axial direction, the protrusion can greatly amplify the vibration of the molten pool, thereby improving the ultrasonic vibration effect. In specific implementation, the protrusion protrudes too much, which can be controlled within three times the diameter of the stirring needle, and the specific size can be obtained according to test verification.

[0095] The protrusions are uniformly arranged in the circumferential direction, and the upper surface and the lower surface of each protrusion are respectively provided as reverse-symmetrical inclined surfaces or spiral blade surfaces.

[0096] In this way, as the stirring needle reciprocates along the axial direction, the upper and lower surfaces of the protrusions will form an effect of reciprocating outward pushing of the molten metal in the circumferential direction during reciprocation, thereby generating an axial vibration and a circumferential vibration of the molten metal at the same time, wherein the axial vibration can better act on the bottom of the molten pool, and the circumferential vibration can better act on the circumferential wall of the molten pool, the double vibrations form a composite high-frequency vibration effect on the molten metal pool, greatly improve the combination of the molten pool on the circumferential metal, better refine the metal crystal organization, improve the influence of the vibration on the metal crystal fusion effect, and improve the forming quality of the product.

[0097] In order to further verify the effect, the applicant further carried out a plurality of comparative experiment verifications, and the parameters in each experimental example were consistent: the substrate geometric size was 100*50*10mm, a MIG (melted electrode argon arc welding) welding machine was used, the process parameters of the arc additive manufacturing were: welding current 80A, voltage 19.8V, welding wire diameter 1.6mm, wire feeding speed 120cm / min, welding speed (welding gun moving speed) 200mm / min, protective gas 99.99% argon, gas flow 15L / min. The arc additive manufacturing accumulation layer passes was 4, and each pass interval was two minutes, 3 samples were welded for each example, and three positions were taken for testing in front, middle and back of each sample, and the average value was taken after testing the performance.

[0098] Comparative example 1: the welding wire was AZ31 magnesium alloy, and no ultrasonic vibration and rolling was added during the arc additive manufacturing. The experimental result was that the average tensile strength was 222.34MPa.

[0099] Comparative example 2: the welding wire was ER5356 aluminum alloy, and no ultrasonic vibration and rolling was added during the arc additive manufacturing. The experimental result was that the average tensile strength was 251.4MPa.

[0100] Experimental example 1: the device and steps of the first specific embodiment were used for testing, and the welding wire was AZ31 magnesium alloy. The distance between the roller and the welding gun was 5mm. During the arc additive manufacturing, the dynamic ultrasonic vibration and rolling were applied to each hot additive accumulation layer, the ultrasonic vibration power was 100W, and the roller rolling pressure was 2.4KN.

[0101] The experimental result was that the average tensile strength of the arc additive manufacturing accumulation layer was 228.14MPa, and compared with the comparative example 1, the additive manufacturing accumulation layer organization was more dense, and the grain was more fine.

[0102] Experimental Example 2: The experiment was carried out using the equipment and steps of Embodiment 1, and the welding wire was AZ31 magnesium alloy. The distance between the roller and the welding torch was 10 mm. During the arc additive manufacturing, the hot-state additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 175 W, and the roller rolling pressure was 1.6 KN.

[0103] Experimental results: The average tensile strength of the arc additive manufacturing accumulation layer was 235.41 MPa, and compared with Comparative Example 1, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0104] Experimental Example 3: The experiment was carried out using the equipment and steps of Embodiment 1, and the welding wire was AZ31 magnesium alloy. The distance between the roller and the welding torch was 15 mm. During the arc additive manufacturing, the hot-state additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 250 W, and the roller rolling pressure was 0.8 KN.

[0105] Experimental results: The average tensile strength of the arc additive manufacturing accumulation layer was 230.14 MPa, and compared with Comparative Example 1, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0106] Experimental Example 4: The experiment was carried out using the equipment and steps of Embodiment 2, and the welding wire was AZ31 magnesium alloy. The distance between the roller and the welding torch was 15 mm. During the arc additive manufacturing, the hot-state additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 250 W, and the roller rolling pressure was 0.8 KN.

[0107] Experimental results: The average tensile strength of the arc additive manufacturing accumulation layer was 237.55 MPa, and compared with Comparative Example 1, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0108] Experimental Example 5: The experiment was carried out using the equipment and steps of Embodiment 1, and the welding wire was ER5356 aluminum alloy welding wire. The distance between the roller and the welding torch was 5 mm. During the arc additive manufacturing, the hot-state additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 50 W, and the roller rolling pressure was 2.4 KN.

[0109] Experimental results: The average tensile strength of the arc additive manufacturing accumulation layer was 269.05 MPa, and compared with Comparative Example 2, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0110] Experimental Example 6: The experiment was carried out by using the equipment and steps of embodiment one, and the welding wire was ER5356 alloy welding wire. The distance between the roller and the welding torch was 10 mm. During the arc additive manufacturing, the hot additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 125 W, and the roller rolling pressure was 1.6 KN.

[0111] Experimental results: The average tensile strength of the additive manufacturing accumulation layer was 266.30 MPa, and compared with comparative example 2, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0112] Experimental Example 7: The experiment was carried out by using the equipment and steps of embodiment one, and the welding wire was ER5356 aluminum alloy welding wire. The distance between the roller and the welding torch was 15 mm. During the arc additive manufacturing, the hot additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 200 W, and the roller rolling pressure was 0.8 KN.

[0113] Experimental results: The average tensile strength of the additive manufacturing accumulation layer was 264.37 MPa, and compared with comparative example 2, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0114] Experimental Example 8: The experiment was carried out by using the equipment and steps of embodiment two, and the welding wire was ER5356 aluminum alloy welding wire. The distance between the roller and the welding torch was 15 mm. During the arc additive manufacturing, the hot additive accumulation layer of each layer was subjected to follow-up ultrasonic vibration and rolling, the ultrasonic vibration power was 200 W, and the roller rolling pressure was 0.8 KN.

[0115] Experimental results: The average tensile strength of the additive manufacturing accumulation layer was 273.42 MPa, and compared with comparative example 2, the additive manufacturing accumulation layer was more dense and the grain was finer.

[0116] Therefore, according to the above experimental examples, under the same parameter conditions, the strength performance of the product obtained by embodiment two is greater than that of the product obtained by embodiment one, which is greater than that of the conventional arc additive manufacturing product. Therefore, it is shown that the method can effectively improve the tensile strength of the product obtained by arc additive manufacturing.

Claims

1. An electric arc additive and ultrasonic roller combined manufacturing device, comprising an electric arc additive manufacturing welding torch, the electric arc additive manufacturing welding torch is installed on a whole horizontally arranged holder and the welding head is downward at one end, characterized in that, The cage is also equipped with a roller rolling device, which includes a pressure device. The telescopic arm of the pressure device is set vertically downward and a steel ultrasonic vibration rolling roller is installed at the lower end of the telescopic arm. The side surface of the ultrasonic vibration rolling roller is set towards the direction of the arc additive manufacturing welding torch and is concave arc-shaped to adapt to the cross-sectional shape of the arc additive manufacturing layer. The roller rolling device also includes an ultrasonic vibrator for the roller. The ultrasonic vibrator for the roller is fixedly connected to the pressure device and provides ultrasonic vibration to it. A vibration stirring device is also installed on the cage. The vibration stirring device includes an ultrasonic vibrator for stirring needle. A stirring needle is set downward at the lower end of the ultrasonic vibrator for stirring needle. The ultrasonic vibrator for stirring needle can provide axial vibration to the stirring needle. The lower end of the stirring needle has a ring of horizontally convex protrusions; The protrusions are a plurality of circumferentially evenly arranged protrusions, and the upper and lower surfaces of each protrusion are respectively set as anti-symmetrical inclined surfaces or helical blade surfaces. As the stirring needle reciprocates along the axial direction, the upper and lower surfaces of the protrusions will form a reciprocating outward pushing effect on the molten metal in the circumferential direction during the reciprocating motion. This will generate a reciprocating vibration along the circumferential direction on the molten metal, thus creating a composite high-frequency vibration effect on the molten metal pool.

2. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 1, wherein, The arc additive manufacturing welding torch is mounted on a welding torch mounting sleeve, which is vertically rotatable on a cage via a welding torch mounting sleeve adjustment handle.

3. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 2, wherein, The arc additive manufacturing welding torch can be slidably mounted on the welding torch mounting sleeve along the axial direction. The welding torch mounting sleeve is also screwed through and fixed with welding torch fastening bolts to fix the arc additive manufacturing welding torch.

4. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 1, wherein, The retainer is a long strip with a uniform width from top to bottom. The roller pressing device includes a sliding sleeve that can be slidably mounted on the retainer. The sliding sleeve is also fixed by a bolt for fastening the sliding sleeve. The pressing device is fixedly installed at the lower end of the sliding sleeve, and the roller is fixedly installed at the upper end of the cylinder by an ultrasonic vibrator.

5. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 1, wherein, The stirring needle is made of tungsten or a tungsten alloy.

6. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 1, wherein, The stirring needle vibrates along its own axis; The vibration frequency of the stirring needle is 20-100KHZ, and the amplitude is 0.2-1mm.

7. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 1, wherein, The stirring needle is vertically mounted on a vibrator mounting sleeve using an ultrasonic vibrator. The vibrator mounting sleeve is vertically rotatable on a sliding sleeve via a vibration adjustment handle. The sliding sleeve is horizontally slidable on a retainer.

8. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 7, wherein, The cage is a long strip with the same width at the top and bottom. The sliding sleeve can be horizontally slidably fitted onto the cage. The sliding sleeve is also screwed through with a bolt for fastening the sliding sleeve to fix it.

9. The electric arc additive and ultrasonic roller compaction hybrid manufacturing apparatus of claim 8, wherein, The stirring needle is mounted on the vibrator mounting sleeve via a damping spring. The ultrasonic vibrator for the stirring needle is a pneumatic ultrasonic vibrator for the stirring needle. The cage is fixedly mounted on the robotic arm of the arc additive manufacturing robot.

Images