A method for controlling back forming of a high-power laser composite welding of a medium plate aluminum alloy

Abstract

The present application relates to the technical fields of laser welding, and discloses a middle-thickness plate aluminum alloy high-power laser composite welding back forming control method, which comprises the following steps: S1, slotting the butt joint of the welding surfaces of two 8mm-thick 5083 aluminum alloys, the slot depth h=1mm, and the slot width d=1mm.The middle-thickness plate aluminum alloy high-power laser composite welding back forming control method butts the concave groove of the welding surfaces of the two 8mm-thick 5083 aluminum alloys, and the concave groove is downward, high-power laser composite welding is carried out, single-sided welding double-sided forming is carried out, a welding process is formed, the process parameters are as follows: laser power 10kw, welding speed 4.2m / min, defocusing amount-2mm, swing amplitude 0.1mm, swing frequency 200Hz, wire feeding speed 6m / min, welding current 135A, welding gun inclination angle 30°, wire dry elongation 14mm, the wire and the light spot are in tangential state, ER5356 aluminum magnesium wires with a diameter of φ=1.2mm are used, and 99.999% argon is used as the protective gas, and the protective gas flow is 25L / min.When the high-power laser penetrates the base material thickness, penetration welding is formed, a weld is formed on the back, and the weld back excess height just fills the concave groove.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser welding, in particular to a back forming control method for high-power laser composite welding of medium-thick plate aluminum alloy. BACKGROUND

[0002] Aluminum alloy has low density, relatively high strength, good plasticity, and can be processed into various profiles, and has excellent electrical conductivity, thermal conductivity and corrosion resistance, and has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industry. The wide application of aluminum alloy promotes the development of aluminum alloy welding technology, and the development of welding technology also expands the application field of aluminum alloy, so the welding technology of aluminum alloy is becoming one of the research hotspots. However, the characteristics of medium-thick plate aluminum alloy itself make the related welding technology face some problems to be solved:(1) high reflectivity and high thermal conductivity of aluminum alloy surface(2) difficult to dissolve the oxide film on the surface(3) joint softening(4) easy to produce pores(5) easy to heat deformation and too large thermal conductivity. SUMMARY

[0003] (I) Technical problems solved

[0004] In view of the deficiencies of the prior art, the present application provides a back forming control method for high-power laser composite welding of medium-thick plate aluminum alloy, which solves the problems raised in the background art.

[0005] (II) Technical scheme

[0006] The present application provides the following technical scheme: a back forming control method for high-power laser composite welding of medium-thick plate aluminum alloy, comprising the following steps:

[0007] S1, groove the butt joint of two 8mm thick 5083 aluminum alloy welding surfaces, groove depth h=1mm, groove width d=1mm;

[0008] S2, after grooving, the two medium-thick plate aluminum alloys are pretreated before welding: the surface and butt joint of the aluminum alloy plate are cleaned by using an oil-free dry steel wire brush; the surface and butt joint are cleaned by using acetone, then wiped with alcohol, and blown dry with compressed air;

[0009] S3, butt joint the two pretreated 5083 aluminum alloys, the plate thickness at the butt joint groove is 7mm, the grooves of the two plates are opposite and downward;

[0010] S4, the starting end and the end of the medium-thick plate aluminum alloy are fixed by spot welding, four points on the front and back surfaces;

[0011] S5, select ER5356 aluminum magnesium welding wire with a diameter of φ=1.2mm;

[0012] S6, set laser welding parameters, laser power 10kw, welding speed 4.2m / min, defocusing amount-2mm, swing 0.1mm, swing frequency 200Hz, wire feeding speed 6m / min, welding wire dry elongation 14mm, welding gun inclination angle 30°, laser head inclination angle 6°, make the welding wire and the spot in the tangential state.

[0013] Preferably, the medium plate aluminum alloy in step S4 is fixed by a locking type clamp.

[0014] Preferably, the 5083 aluminum alloy is single-sidedly butted with a groove, the groove depth h=1mm, the groove width d=1mm, and the plate thickness at the butted groove is 7mm.

[0015] Preferably, the grooves are opposite and downward when the two plates are butted.

[0016] Preferably, the composite welding process adopts CMT welding.

[0017] Compared with the prior art, the present application provides a medium plate aluminum alloy high-power laser composite welding back forming control method, which has the following beneficial effects:

[0018] The medium plate aluminum alloy high-power laser composite welding back forming control method butts the two 8mm-thick 5083 aluminum alloy welding surfaces at the groove, and the groove is downward, high-power laser composite welding is performed, single-sided welding is formed on both sides, a welding process is formed, the process parameters are laser power 10kw, welding speed 4.2m / min, defocusing amount-2mm, swing 0.1mm, swing frequency 200Hz, wire feeding speed 6m / min, welding current 135A, welding gun inclination angle 30°, welding wire dry elongation 14mm, the welding wire and the spot are in the tangential state, all ER5356 aluminum magnesium welding wires with a diameter of φ=1.2mm are used, and 99.999% argon is used as the protective gas, and the protective gas flow is 25L / min. When the high-power laser penetrates the base material thickness, penetration welding is formed, the back forms a weld, the weld back excess height fills the groove, the weld surface forming is better, the weld is slightly convex, the weld lines are uniform, and there are no welding defects such as undercut, cracks, and pores, and at the same time, the groove also reduces the thickness of the plate in the weld area, and solves the problem of insufficient laser power in continuous welding. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a welding work schematic diagram of the present application;

[0020] Figure 2 It is an 8mm groove weld cross section of the present application;

[0021] Figure 3 It is an 8mm groove weld cross section of the present application;

[0022] Figure 4 is a front view of a weld of the present application;

[0023] Figure 5 is a back view of a weld of the present application. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0025] Please refer to Figures 1-5 A back forming control method for high-power laser composite welding of medium-thickness plate aluminum alloy is provided. Two 8mm-thick 5083 aluminum alloy welding surfaces are butt-jointed at a groove, and the groove is downward. High-power laser composite welding is performed on the butt-jointed surfaces to form a welding process. The welding process parameters are as follows: laser power is 10kw, welding speed is 4.2m / min, defocusing amount is -2mm, amplitude is 0.1mm, swing frequency is 200Hz, wire feeding speed is 6m / min, welding current is 135A, welding gun inclination angle is 30°, and wire dry extension is 14mm. The wire and the light spot are tangent to each other. ER5356 aluminum magnesium wires with a diameter of φ=1.2mm are used. The protective gas is 99.999% argon, and the protective gas flow is 25L / min. When the high-power laser penetrates the base material thickness, a penetration weld is formed, and a weld is formed on the back. The weld back reinforcement exactly fills the groove, so that the weld surface is shaped more favorably, the weld is slightly convex, the weld lines are uniform, and there are no weld defects such as undercut, cracks, pores, etc. At the same time, the groove also reduces the thickness of the plate in the weld area, solving the problem of insufficient laser power in continuous welding.

[0026] Although the embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for controlling the back-side forming of high-power laser composite welding in medium-thick aluminum alloy plates, comprising the following steps: S1. Groove the joint of two 8mm thick 5083 aluminum alloy welded surfaces. Groove depth h = 1mm, groove width d = 1mm. S2. After the grooves are cut, perform pre-welding treatment on the two medium-thick aluminum alloy plates: use an oil-free, dry and clean wire brush to remove the oxide film on the surface of the aluminum alloy plates and the joint; use acetone to remove dirt on the surface and the joint, then wipe with alcohol and blow dry with compressed air. S3. Butt the two pre-treated 5083 aluminum alloy pieces together. The thickness of the plate at the butt groove is 7mm. Ensure that the grooves of the two plates are opposite each other and the grooves face downwards. S4. Fix the starting and ending ends of the medium-thick aluminum alloy plate by spot welding, with a total of four points on the front and back. S5. Select ER5356 aluminum-magnesium welding wire with a diameter of φ = 1.2 mm. S6. Set the laser welding parameters: laser power 10kw, welding speed 4.2m / min, defocusing amount -2mm, swing amplitude 0.1mm, oscillation frequency 200Hz, wire feed speed 6m / min, welding wire extension 14mm, welding gun tilt angle 30°, laser head tilt angle 6°, so that the welding wire and the laser spot are in a tangent state.

2. The back-side forming control method for high-power laser composite welding of medium-thick aluminum alloy plates according to claim 1, characterized in that: The medium-thick aluminum alloy plate mentioned in step S4 is fixed with a locking clamp.

3. The back-side forming control method for high-power laser composite welding of medium-thick aluminum alloy plates according to claim 1, characterized in that: The composite welding process uses CMT welding.

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