阅读说明：本技术 一种铝基复合材料低功率激光诱导双脉冲tig焊方法 (Low-power laser-induced double-pulse TIG welding method for aluminum-based composite material ) 是由 巴现礼 牛济泰 高增 邱得超 张璐璐 于 2020-05-21 设计创作，主要内容包括：一种铝基复合材料低功率激光诱导双脉冲TIG焊方法。本文涉及铝基复合材料的焊接领域,具体涉及一种铝基复合材料低功率激光诱导双脉冲TIG焊方法。是为了解决现有铝基复合材料焊接过程中存在的接头强度低、气孔等缺陷明显、高能耗以及焊接局限性的问题。本发明采用低功率脉冲激光和双脉冲TIG电弧作为复合热源,设置焊接路径,将复合热源作用在焊接夹具固定的铝基复合材料板材上。本发明用于焊接铝基复合材料,可以通过脉冲激光和双脉冲TIG电弧增强对焊接熔池的“震荡”和搅拌作用,促进熔池中气体的排除,能够大幅减少甚至避免接头焊缝中的气孔等缺陷的出现,同时还可以起到细化晶粒的作用。(A low-power laser-induced double-pulse TIG welding method for aluminum-based composite materials. The invention relates to the field of welding of aluminum-based composite materials, in particular to a low-power laser-induced double-pulse TIG (tungsten inert gas) welding method for an aluminum-based composite material. The method aims to solve the problems of low joint strength, obvious defects of air holes and the like, high energy consumption and welding limitation in the existing aluminum matrix composite welding process. The invention adopts low-power pulse laser and double-pulse TIG electric arc as composite heat sources, sets a welding path, and applies the composite heat sources on the aluminum-based composite material plate fixed by the welding fixture. The invention is used for welding aluminum matrix composite materials, can enhance the 'oscillation' and stirring effects on a welding molten pool through pulse laser and double-pulse TIG electric arc, promotes the elimination of gas in the molten pool, can greatly reduce or even avoid the defects of pores and the like in a joint welding line, and can play a role in refining grains.)

1. A low-power laser-induced double-pulse TIG welding method for an aluminum-based composite material is characterized in that a low-power pulse laser and a double-pulse TIG electric arc are used as a composite heat source in the low-power laser-induced double-pulse TIG welding method for the aluminum-based composite material, a welding path is set, and the composite heat source acts on an aluminum-based composite material plate fixed by a welding fixture, so that good welding of the material is realized.

2. A low-power laser-induced double-pulse TIG welding method for an aluminum-based composite material according to claim 1, characterized in that the low-power laser-induced double-pulse TIG welding method for the aluminum-based composite material is carried out according to the following steps:

firstly, cutting and polishing an aluminum matrix composite material: cutting the aluminum matrix composite material according to the actual requirement, and then polishing each surface of the aluminum matrix composite material by using an angle grinder until the surface appears bright color to obtain an aluminum matrix composite material part to be welded;

secondly, removing the film of the aluminum matrix composite material: polishing the butt joint surface of the aluminum-based composite material piece to be welded by using sand paper, firstly ultrasonically cleaning the polished aluminum-based composite material piece to be welded for 15-20 min, and then adoptingCleaning with alcohol for 10-15 min, and drying the residual alcohol on the surface with a blower to obtain a clean aluminum-based composite material part to be welded; then soaking the butt joint surface of the clean aluminum-based composite material piece to be welded in 8% NaOH solution for 5-8 min, and then soaking the butt joint surface in 30% HNO₃Soaking the solution for 2-5 min to obtain a to-be-welded aluminum-based composite material piece after the film is removed;

placing the two pieces of the stripped aluminum-based composite material to be welded on a welding fixture in a butt joint mode for fixing to obtain a butt joint plate; the low-power pulse laser and the double-pulse TIG electric arc form a composite heat source in a mode that the low-power pulse laser is in front and the double-pulse TIG electric arc is behind; the laser gun is vertical to the substrate, the included angle between the laser gun and the TIG welding gun is alpha, the distance between the tungsten electrode and the substrate is D, and the laser gun and the TIG welding gun are both positioned above the substrate;

fourthly, respectively setting process parameters of low-power pulse laser and double-pulse TIG electric arc, setting a welding path and controlling a welding process; adjusting the welding speed under the state that the laser gun and the TIG welding gun are both closed, then opening the laser gun and the TIG welding gun, enabling the laser gun and the TIG welding gun to firstly run once along the welding path, and adjusting the running path to have no deviation with the butt seam of the butt plate;

fifthly, searching an arc starting point on the butt-jointed plates, pre-introducing protective gas, sequentially opening a laser gun and a TIG welding gun, and welding according to a set welding path;

and sixthly, closing the laser gun, the TIG welding gun and the shielding gas in sequence after welding, then increasing the laser gun and the TIG welding gun by 100mm, and moving the laser gun and the TIG welding gun to a preset position to obtain the butt-welded aluminum-based composite material plate.

3. A low-power laser-induced double-pulse TIG welding method for an aluminum-based composite material as recited in claim 2, characterized in that in the third step, when two pieces of the aluminum-based composite material to be welded after film removal are fixed on the welding fixture in a butt joint manner, Ti sheets or Ti alloy sheets with the thickness of 0.1-1 mm are placed in the middle of the butt joint.

4. A low-power laser-induced double-pulse TIG welding method for aluminum-based composite materials according to claim 2, characterized in that in the third step, the included angle alpha between the laser gun and the TIG welding gun is 30-50 degrees.

5. A low-power laser-induced double-pulse TIG welding method for an aluminum matrix composite according to claim 2, characterized in that in step three, the distance D between the tungsten electrode and the substrate is 1-10 mm.

6. A low power laser induced double pulse TIG welding method for aluminium matrix composites according to claim 2, characterised by the process parameters of the low power pulsed laser of step four: the laser power is 100-1000W, the frequency is 20-40 Hz, and the pulse width is 2-8 ms.

7. A low power laser induced double pulse TIG welding method for aluminium matrix composites according to claim 2, characterized by the four steps of the process parameters of double pulse TIG arc: the welding current is 80-220A, and the welding speed is 400-1500 mm/min.

8. A low-power laser-induced double-pulse TIG welding method for an aluminum-based composite material as claimed in claim 2, wherein the shielding gas in the step five is argon gas, helium gas or a mixed gas of argon gas and helium gas, and the flow rate of the shielding gas is 10-30L/min.

9. A low-power laser-induced double-pulse TIG welding method for aluminum-based composite materials as claimed in claim 2, characterized in that in the sixth step, when the thickness of the aluminum-based composite material plate is 4-10 mm, double-sided welding is required, the composite material plate after the first butt welding is taken off from the fixture, and is fixed again after being turned over, and the operations of the third step to the sixth step are repeated.

Technical Field

The invention relates to the field of welding of aluminum-based composite materials, in particular to a low-power laser-induced double-pulse TIG (tungsten inert gas) welding method for an aluminum-based composite material.

Background

As a novel material with excellent performance, the aluminum-based composite material has more excellent performance than common metal materials, such as higher specific strength, specific rigidity, good stability, heat resistance, wear resistance, creep strength and the like, and can meet the rigorous requirements of modern scientific and technological production and development on material performance. The aluminum-based composite material has a very wide application prospect in the fields of aerospace, advanced weapons, electronic packaging, automobile manufacturing and the like. In addition, the aluminum resource in China is rich, the source of the reinforced phase particles is wide, the preparation cost is relatively low, the aluminum-based composite material becomes one of the most development potential materials in the research field of numerous metal materials, and the aluminum-based composite material attracts the close attention and deep research of numerous experts and scholars at home and abroad. However, because the physical and chemical properties of the matrix aluminum alloy and the reinforcing phase are greatly different, good connection between the matrix aluminum alloy and the reinforcing phase is difficult when an engineering component is formed, and the practical application and industrialization of the engineering material are limited, welding is a key problem affecting the popularization and application of the engineering material.

There are many common welding methods for aluminum matrix composites, such as fusion welding, friction stir welding, resistance spot welding, brazing, diffusion welding, etc. The stirring head for welding the aluminum-based composite material by friction stir welding has the advantages of high abrasion speed and high cost and is limited by the shape of the material. Resistance spot welding, brazing, and diffusion welding have great limitations due to the influence of a specific welding environment, and the welding strength is not high. TIG in fusion welding has the advantages of simple operation, capability of welding engineering components with irregular shapes and complex structures, and the like, but has the problems of low joint strength, easy formation of air holes in joints, and the like, large power consumption during welding, incapability of achieving high-quality welding effect, and the like.

Disclosure of Invention

The invention provides a low-power laser-induced double-pulse TIG welding method for an aluminum matrix composite, which aims to solve the problems of low joint strength, obvious defects of air holes and the like, high energy consumption and welding limitation in the welding process of the existing aluminum matrix composite.

The low-power laser-induced double-pulse TIG welding method for the aluminum-based composite material adopts low-power pulse laser and double-pulse TIG electric arc as composite heat sources, sets a welding path, and enables the composite heat sources to act on the aluminum-based composite material plate fixed by a welding clamp so as to realize good welding of the material.

The invention has the advantages that:

compared with other methods such as a welding method of an aluminum matrix composite (application number: CN201910062203.6) and a laser powder filling welding method of a particle reinforced metal matrix composite (application number: CN201511027957.6), the low-power laser induced double-pulse TIG welding method of the aluminum matrix composite does not need to be beveled, can directly carry out butt welding, simplifies pre-welding processing, simpler welding operation process and the like, simultaneously saves more energy, and has the welding characteristics of simplicity, high efficiency, energy conservation and environmental protection. Compared with a welding seam in-situ reinforcing method for argon tungsten-arc welding of a discontinuous reinforced aluminum-based composite material (application number: CN200510010266.5), a resistance spot welding method for an aluminum-based composite material (application number: CN201410199882.9) and the like, the pulse laser and the double-pulse TIG electric arc introduced by the method improve the oscillation effect of the pulse on a welding pool through the composite action, reduce the generation of defects such as air holes in the welding seam and the like, and have the function of refining grains to a certain extent and promote the great improvement of the strength of the joint.

The low-power laser-induced double-pulse TIG welding method for the aluminum-based composite material, disclosed by the invention, has the advantages that the low-power laser and the double-pulse TIG electric arc are used as a composite heat source and directly act on the composite material plate, the butt welding of two composite materials is realized, and the welding seam is formed excellently. The method has the characteristics of two processes of laser welding and TIG welding, can achieve the welding effect of 1+1>2, and the high peak power pulse laser circulation after the compounding acts in a welding pool to achieve the effects of shaking and stirring the welding pool, so that the gas in the welding pool is promoted to be discharged, the defects of air holes and the like in a joint welding line can be greatly reduced or even avoided, and the joint strength is very high. Meanwhile, the welding device has the advantages of energy conservation, environmental protection and the like, and can realize the welding effect with low energy consumption and high quality; after welding, mechanical property tests are carried out on the joint, and the tensile strength of the joint can reach 209MPa at most.

Drawings

FIG. 1 is a schematic view of the relative positions of a laser gun and a double pulse TIG welding gun according to the present invention; wherein 1 is a laser gun, 2 is a TIG welding gun, and 3 is a substrate;

FIG. 2 is a macro topography of the front surface of the butt-welded aluminum-based composite material plate obtained in the first embodiment;

FIG. 3 is a back macro topography of the butt-welded aluminum-based composite plate obtained in the first embodiment;

FIG. 4 is a metallographic microstructure of a welded joint of the butt-welded aluminum-based composite plate obtained in the first example.

Detailed Description