CN116237628A - Electron beam welding method and clamp for 2A70 aluminum alloy - Google Patents

Abstract

The application provides an electron beam welding method and a clamp for 2A70 aluminum alloy, which belong to the technical field of welding processes, and comprise the steps of cleaning a part, and compacting and assembling two ends of the part through a first clamp; placing the assembled part into an electron beam welding machine, wherein the position to be welded of the part and the position right below an electron gun of the electron beam welding machine have a certain offset distance, and performing localized welding on the position to be welded by adopting a first electron beam; taking out the part, disassembling the clamp, and fixing one end of the part through a second clamp; and (3) placing the fixed part into an electron beam welding machine, and welding a position to be welded by adopting a second electron beam, wherein electron beam spots of the second electron beam are multiple, and the energy of the second electron beam is larger than that of the first electron beam. Through the processing scheme of the method, defects such as cracks, perforation, air holes and the like generated by welding seams are avoided, and qualified welding of parts is realized.

Description

Electron beam welding method and clamp for 2A70 aluminum alloy

Technical Field

The application relates to the technical field of welding processes, in particular to an electron beam welding method and a clamp for 2A70 aluminum alloy.

Background

The 2A70 aluminum alloy (old brand LD7 aluminum alloy) is a heat-treatable reinforced alloy, has high heat resistance, is used at the temperature of 200-250 ℃, can be used for manufacturing aeroengine pistons, impellers, wheel discs and other parts used at higher temperature, and has good cold and hot processing performance and poor fusion welding performance.

A ventilation impeller part of a certain engine is made of 2A70 materials, and meanwhile, the ventilation impeller part is required to be welded and connected with a shell, and is limited by a structure, and the part cannot be welded by adopting a solid-phase welding method such as friction welding and can only be welded by adopting an electron beam welding method, but is limited by the comprehensive influences such as poor self fusion welding performance of 2A70 aluminum alloy, constraint conditions during part welding, metal vapor interference during welding and the like, so that defects such as cracks, air holes, discharge perforation and the like are easy to generate during part electron beam welding to influence the welding quality.

Disclosure of Invention

In view of this, the embodiment of the application provides an electron beam welding method and a fixture for 2a70 aluminum alloy, which at least partially solve the problem that defects such as cracks, air holes, discharge holes and the like are easy to generate during electron beam welding of parts of 2a70 aluminum alloy in the prior art to influence welding quality.

In a first aspect, embodiments of the present application provide an electron beam welding method of a 2a70 aluminum alloy for welding a part made of the 2a70 aluminum alloy, the method comprising:

cleaning a part, and compacting and assembling two ends of the part through a first clamp;

placing the assembled part into an electron beam welding machine, wherein the position to be welded of the part has a certain offset distance from the position right below an electron gun of the electron beam welding machine, and performing localized welding on the position to be welded by adopting a first electron beam;

taking out the part, disassembling the first clamp, fixing one end of the part through the second clamp, and removing external fixing constraint of the part in the welding process;

and placing the fixed part into an electron beam welding machine, and welding the position to be welded by adopting a second electron beam, wherein electron beam spots of the second electron beam are multiple, and the energy of the second electron beam is larger than that of the first electron beam.

According to a specific implementation manner of the embodiment of the present application, the welding parameters of the first electron beam are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1933+/-15 mA, the electron beam current is 3+/-0.5 mA, and the welding speed is 1200+/-10 mm/min.

According to a specific implementation manner of the embodiment of the application, the second electron beam current realizes an electron beam current deflection scanning function through high-frequency coil control, the electron beam spots are set to be 3 beams, the first beam current, the second beam current and the third beam current are respectively arranged in sequence, the first beam current is used for preheating, the second beam current is used for welding, and the third beam current is used for post-heating.

According to a specific implementation manner of the embodiment of the present application, the welding parameters of the second beam splitter are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1923+/-15 mA, the electron beam current is 10+/-0.5 mA, and the welding speed is 1200+/-10 mm/min; the energy of the first beam splitter and the energy of the third beam splitter are smaller than the energy of the second beam splitter.

According to a specific implementation manner of the embodiment of the application, the parameter of the first beam splitter is SET to be ac_set (5,1.0,0,500,0,0,0,30,1,8), the parameter of the second beam splitter is SET to be ac_set (5,1.0,0,2000,0,1,0,0,1,6), the parameter of the third beam splitter is SET to be ac_set (5,1.0,0,500,0,1,0, -30,1,2), and the parameters in the ac_set are, from left to right, a scan waveform, an X-direction scan amplitude, a Y-direction scan amplitude, a scan frequency, a scan waveform rotation angle, a scan number, an X-direction offset, a Y-direction offset, an offset manner, and a group in sequence; the welding time of the first split stream was set to 200 mus, the welding time of the second split stream was set to 600 mus, and the welding time of the third split stream was set to 200 mus.

According to a specific implementation manner of the embodiment of the application, when the positioning welding is performed, the position to be welded is uniformly divided into a plurality of sections, two sections which are oppositely arranged are a group, and the positioning welding is performed on each group in sequence.

According to a specific implementation manner of the embodiment of the application, when the two ends of the part are pressed and assembled through the first clamp, a welding seam gap of the position to be welded is smaller than 0.1mm.

In a second aspect, an embodiment of the present application further provides an electron beam welding fixture, where the fixture includes a first fixture used during tack welding, the first fixture includes a first bottom plate, a cover plate, a compression nut and a screw, the screw is vertically connected with the first bottom plate, the part and the cover plate are sleeved on the screw, the part is located between the first bottom plate and the cover plate, the compression nut is located on one side of the cover plate away from the part, and the compression nut is in threaded connection with the screw.

According to a specific implementation manner of the embodiment of the application, the fixture further comprises a second fixture used during welding, the second fixture comprises a second bottom plate, the second bottom plate is located at one end of the part, uniformly distributed screws are arranged on the second bottom plate, and the outer peripheral surface of the part is clamped and fixed through the screws.

According to a specific implementation manner of the embodiment of the application, one end, contacted with the part, of the screw is provided with a soft material layer.

Advantageous effects

According to the electron beam welding method and the clamp for the 2A70 aluminum alloy, the positioning welding and the formal welding are clamped separately, so that the clamping precision of parts is met, rigid constraint in the formal welding process is avoided, the stress is reduced, and the tendency of solidification cracks of welding seams is reduced; the adopted part misplacement method reduces the interference of metal vapor on electron beams and reduces the probability of weld defects caused by electron beam discharge; the high-frequency multi-beam flow welding method is adopted, so that the treatment of preheating, welding and post-heating of the welding seam is realized, the temperature gradient in the welding seam solidification process is reduced, and the welding stress and the tendency of welding seam solidification crack generation are reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a tack weld press assembly in accordance with one embodiment of the present invention;

FIG. 2 is a schematic illustration of a part placement position according to an embodiment of the present invention;

FIG. 3 is a schematic illustration of clamping during welding according to an embodiment of the present invention;

FIG. 4 is a beam splitting diagram of a second electron beam according to an embodiment of the present invention;

fig. 5 is a schematic diagram illustrating parameters of an electron beam according to an embodiment of the invention.

In the figure: 1. a first base plate; 2. a cover plate; 3. a compression nut; 4. a screw; 5. a part; 6. a position to be welded; 7. an electron gun; 8. electron beam current; 9. a second base plate; 10. a screw; 11. a first beam splitting stream; 12. a second beam splitting; 13. and a third beam splitting flow.

Detailed Description

Embodiments of the present application are described in detail below with reference to the accompanying drawings.

Other advantages and effects of the present application will become apparent to those skilled in the art from the present disclosure, when the following description of the embodiments is taken in conjunction with the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. The present application may be embodied or carried out in other specific embodiments, and the details of the present application may be modified or changed from various points of view and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application.

It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present application, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the illustrations provided in the following embodiments merely illustrate the basic concepts of the application by way of illustration, and only the components related to the application are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided in order to provide a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

In a first aspect, an embodiment of the present application provides an electron beam welding method for welding a part made of a 2a70 aluminum alloy, in which a ventilation impeller part of a certain type of engine is used as a welding object, and described in detail below with reference to fig. 1 to 5.

Specifically, the electron beam welding method of the 2A70 aluminum alloy comprises the following steps:

step one, cleaning the part 5, and compacting and assembling the two ends of the part 5 through a first clamp. During cleaning, an alloy brush is used for cleaning a to-be-welded area of the part 5, metallic luster is exposed, acetone is used for wiping, and impurities affecting welding are removed, so that welding quality is guaranteed. Then, the rear cover shell is assembled with the impeller, and is tightly pressed by a first clamp, so that a weld joint clearance is ensured to be smaller than 0.10mm, and the specific assembly structure at the moment is shown in fig. 1.

Step two, the assembled part 5 and a clamp are placed into an electron beam welding machine, a position 6 to be welded of the part 5 and a position right below an electron gun 7 of the electron beam welding machine have a certain offset distance, the position 6 to be welded is subjected to localized welding by adopting a first electron beam, the positional relationship between the part 5 and the electron gun 7 is shown by referring to fig. 2, and an electron beam 8 emitted by the electron gun 7 deflects through a deflection coil in the electron gun 7 so as to adapt to the situation of the position offset of the part 5. In this step, the position 6 to be welded of the part 5 is offset from the position immediately below the electron gun 7 of the electron beam welding machine by a distance in the range of 0 to 60mm. Preferably, the offset distance is set to 60mm.

And step three, taking out the part 5 subjected to positioning welding, dismantling the first clamp, fixing one end of the part 5 through the second clamp, and removing external fixing constraint of the part 5 in the welding process. In this step, the part 5 is fixed only by clamping the outer circle at the lower end of the part 5, and referring to the structural schematic diagram shown in fig. 3, at this time, no external restraining force is applied to the two ends at the axial position of the part 5, so that rigid restraint in the process of final welding is avoided during welding, stress is reduced, and the tendency of solidification cracks of the weld is reduced.

And fourthly, placing the fixed part 5 into an electron beam welding machine, and welding the position 6 to be welded by adopting a second electron beam, wherein electron beam spots of the second electron beam are multiple, and the energy of the second electron beam is larger than that of the first electron beam. It should be noted that this step is to place the part 5 at a position consistent with that at the time of tack welding, see fig. 2.

And fifthly, opening a vacuum chamber of the electron beam welding machine, and taking out the welded part 5.

In the embodiment, during welding, the position of the part 5 is not right below the electron gun 7, but is staggered from the electron gun 7 by a certain position, and the welding is realized through an electron beam deflection function, so that the interference of metal vapor on the electron gun 7 is reduced, and the perforation defect generated on the welding seam by discharge can be avoided. On the other hand, the positioning welding and the main welding are separated and clamped, so that the clamping precision of the part 5 is met, rigid constraint in the main welding process is avoided, the stress is reduced, and the tendency of solidification cracks of the welding seam is reduced.

In a specific embodiment, the second electron beam is controlled by a high-frequency coil to realize the deflection scanning function of the electron beam 8, the electron beam spot is divided into 3 beams, namely a first beam splitter 11, a second beam splitter 12 and a third beam splitter 13 in sequence, the first beam splitter 11 is used for preheating, the second beam splitter 12 is used for welding, and the third beam splitter 13 is used for post-heating. In the embodiment, a high-frequency multi-beam welding method is adopted, so that the treatment of preheating, welding and post-heating of the welding seam is realized, the temperature gradient in the welding seam solidification process is reduced, and the welding stress and the tendency of welding seam solidification crack generation are reduced.

In one embodiment, the welding parameters of the first electron beam current are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1933+/-15 mA, the electron beam current is 3+/-0.5 mA, and the welding speed is 1200+/-10 mm/min.

In another embodiment, the welding parameters of the second beam splitter 12 are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1923+/-15 mA, the electron beam current is 10+/-0.5 mA, and the welding speed is 1200+/-10 mm/min; the energy of the first and third partial flows 11, 13 is smaller than the energy of the second partial flow 12.

The electron beam current value in the above parameters is aimed at the condition that the thickness of the welding line is 2.0mm (the back surface is provided with a lock bottom with the thickness of 2.0 mm), and the electron beam current value can be adjusted according to a certain proportion when the thickness of the rest welding line is welded.

For setting each beam of the second electron beam, the parameter setting is described with reference to fig. 5, the parameter of the first beam 11 is SET to ac_set (5,1.0,0,500,0,0,0,30,1,8), the parameter of the second beam 12 is SET to ac_set (5,1.0,0,2000,0,1,0,0,1,6), the parameter of the third beam 13 is SET to ac_set (5,1.0,0,500,0,1,0, -30,1,2), and the parameters in the ac_set are, from left to right, a scan waveform, an X-direction scan amplitude, a Y-direction scan amplitude, a scan frequency, a scan waveform rotation angle, a scan number, an X-direction offset, a Y-direction offset, an offset manner, and a group in sequence; the welding time of the first split stream 11 is set to 200 mus, the welding time of the second split stream 12 is set to 600 mus, and the welding time of the third split stream 13 is set to 200 mus; by setting the welding time of each beam splitting, high-frequency beam splitting is realized, 3 beams of electron beams 8 work simultaneously in actual welding, and the treatment of preheating, welding and post-heat is realized in the welding process, as shown in fig. 4.

In one embodiment, when the positioning welding is performed, the to-be-welded position 6 is uniformly divided into a plurality of sections, two sections which are oppositely arranged are a group, and the positioning welding is performed on each group in sequence. For example, the position 6 to be welded is uniformly divided into 8 sections, two sections which are oppositely arranged are divided into one group, namely 4 groups are combined, and the 4 groups of welding seams are welded in sequence. It can be understood that the welding seams at symmetrical positions are welded sequentially during welding, so that the uniformity of welding is ensured, the problems of cracking or deformation of the welding seams can be avoided, and the welding quality is improved.

In a second aspect, an embodiment of the present application further provides an electron beam welding fixture, where the electron beam welding fixture is applied to any embodiment of the first aspect, where the fixture includes a first base plate 1, a cover plate 2, a compression nut 3, and a screw 4, where the screw 4 is connected to the first base plate 1 vertically, the part 5 and the cover plate 2 are sleeved on the screw 4, and the part 5 is located between the first base plate 1 and the cover plate 2, the compression nut 3 is located on a side of the cover plate 2 away from the part 5, where the compression nut 3 is in threaded connection with the screw 4, and the specific structure refers to fig. 1.

In one embodiment, the fixture further comprises a second fixture used during welding, the second fixture comprises a second bottom plate 9, the second bottom plate 9 is located at one end of the part 5, uniformly distributed screws 10 are arranged on the second bottom plate 9, the outer peripheral surface of the part 5 is clamped and fixed through the screws 10, a circle of outer extension edges are arranged in the circumferential direction of the second bottom plate 9, the screws 10 are arranged on the outer extension edges, the bottom of the part 5 is clamped and fixed through the screws 10, namely, the screws 10 apply force to the part 5 in the radial direction, and the clamping and fixing effects are achieved.

Specifically, the soft material layer is arranged at one end of the screw 10, which is in contact with the part 5, so that the problems that the screw 10 scratches the surface of the part 5 or the surface of the part 5 is deformed by external force in the clamping process can be avoided.

According to the embodiment provided by the invention, the positioning welding and the formal welding are clamped separately, so that the clamping precision of the part is met, the rigid constraint in the formal welding process is avoided, the stress is reduced, and the generation tendency of solidification cracks of the welding seam is reduced; the part misplacement method adopted in the invention reduces the interference of metal vapor to electron beams and reduces the probability of weld defects caused by electron beam discharge; the invention adopts a high-frequency multi-beam flow welding method, realizes the treatment of preheating, welding and post-heating of the welding seam, reduces the temperature gradient in the welding seam solidification process, and reduces the welding stress and the tendency of welding seam solidification crack generation.

By comprehensively adopting the welding measures and parameters in the method, the defects of cracks, perforation, air holes and the like generated by welding seams can be avoided, and qualified welding of parts is realized.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions easily conceivable by those skilled in the art within the technical scope of the present application should be covered in the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (10)

1. An electron beam welding method of a 2a70 aluminum alloy for welding a part (5) made of the 2a70 aluminum alloy, characterized by comprising:

cleaning the part (5), and compacting and assembling the two ends of the part (5) through a first clamp;

placing the assembled part (5) into an electron beam welding machine, wherein a position (6) to be welded of the part (5) has a certain offset distance from a position right below an electron gun (7) of the electron beam welding machine, and performing localized welding on the position (6) to be welded by adopting a first electron beam;

taking out the part (5), disassembling the first clamp, fixing one end of the part (5) through the second clamp, and removing external fixing constraint of the part (5) in the welding process;

and (3) placing the fixed part (5) into the electron beam welding machine, and welding the position (6) to be welded by adopting a second electron beam, wherein electron beam spots of the second electron beam are multiple, and the energy of the second electron beam is larger than that of the first electron beam.

2. The electron beam welding method of 2a70 aluminum alloy according to claim 1, wherein the welding parameters of the first electron beam current are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1933+/-15 mA, the electron beam current is 3+/-0.5 mA, and the welding speed is 1200+/-10 mm/min.

3. The electron beam welding method of the 2a70 aluminum alloy according to claim 1, wherein the second electron beam current realizes an electron beam deflection scanning function through high-frequency coil control, the electron beam spots are set to 3 beams, namely a first beam splitter (11), a second beam splitter (12) and a third beam splitter (13) in sequence, the first beam splitter (11) is used for preheating, the second beam splitter (12) is used for welding, and the third beam splitter (13) is used for post-heating.

4. An electron beam welding method of 2a70 aluminum alloy according to claim 3, wherein the welding parameters of the second split stream (12) are set as follows: the working voltage is 150KV, the working distance is 1020+/-10 mm, the surface collecting current is 1903+/-15 mA, the deflection reference value is 782, the collecting current during welding is 1923+/-15 mA, the electron beam current is 10+/-0.5 mA, and the welding speed is 1200+/-10 mm/min; the energy of the first beam splitter (11) and the energy of the third beam splitter (13) are smaller than the energy of the second beam splitter (12).

5. An electron beam welding method for 2a70 aluminum alloy according to claim 3, wherein the parameters of the first beam splitter (11) are SET to ac_set (5,1.0,0,500,0,0,0,30,1,8), the parameters of the second beam splitter (12) are SET to ac_set (5,1.0,0,2000,0,1,0,0,1,6), the parameters of the third beam splitter (13) are SET to ac_set (5,1.0,0,500,0,1,0, -30,1,2), and the parameters in the ac_set are, in order from left to right, a scan waveform, an X-direction scan amplitude, a Y-direction scan amplitude, a scan frequency, a scan waveform rotation angle, a scan number, an X-direction offset, a Y-direction offset, an offset manner, and a group; the welding time of the first split stream (11) is set to 200 mu s, the welding time of the second split stream (12) is set to 600 mu s, and the welding time of the third split stream (13) is set to 200 mu s.

6. The electron beam welding method of 2a70 aluminum alloy according to claim 1, wherein the position (6) to be welded is uniformly divided into a plurality of sections, two sections which are oppositely arranged are a group, and each group is subjected to the tack welding in sequence.

7. An electron beam welding method of 2a70 aluminum alloy according to claim 1, wherein when the two ends of the part (5) are press-fitted by the first clamp, the weld gap of the position to be welded (6) is less than 0.1mm.

8. An electron beam welding jig for use in an electron beam welding method of a 2a70 aluminum alloy according to any one of claims 1 to 7, wherein the jig comprises the first jig used in tack welding, the first jig comprises a first base plate (1), a cover plate (2), a press nut (3) and a screw (4), the screw (4) is vertically connected to the first base plate (1), the part (5) and the cover plate (2) are sleeved on the screw (4), the part (5) is located between the first base plate (1) and the cover plate (2), the press nut (3) is located on a side of the cover plate (2) away from the part (5), and the press nut (3) is in threaded connection with the screw (4).

9. An electron beam welding jig according to claim 8, wherein the jig further comprises the second jig used in welding, the second jig comprises a second bottom plate (9), the second bottom plate (9) is located at one end of the part (5), uniformly distributed screws (10) are arranged on the second bottom plate (9), and the outer peripheral surface of the part (5) is clamped and fixed through the screws (10).

10. An electron beam welding jig according to claim 9, wherein the end of the screw (10) in contact with the part (5) is provided with a layer of soft material.

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