阅读说明：本技术 一种基于超声振动熔池辅助熔钎焊的方法 (Ultrasonic vibration-based molten pool auxiliary fusion brazing method ) 是由 刘积厚 牛红伟 王江涛 卢雅琳 于 2019-09-27 设计创作，主要内容包括：本发明属于焊接技术领域,具体涉及一种基于超声振动熔池辅助熔钎焊的方法,具体包括：(1)对待焊母材的待焊区域进行表面清理,然后以搭接或对接形式固定在工作台上,调整搭接区域或调整对接间隙；(2)调节焊枪的焊丝位于待焊母材的搭接区域的正上方或对接间隙的中心位置,再调节超声头的金属探针位于焊丝的后方,并保证所述金属探针位于焊接的熔池中；(3)先启动超声装置,随后启动焊枪,进行焊接。本发明方法通过将超声振动作用于熔池中的方式,促进熔钎焊过程中钎料的润湿性,改善接头组织,和界面金属间化合物形貌及分布,最终实现异种金属间的高质量连接。(The invention belongs to the technical field of welding, and particularly relates to an ultrasonic vibration molten pool-based auxiliary fusion brazing method, which specifically comprises the following steps: (1) cleaning the surface of a to-be-welded area of a to-be-welded base metal, fixing the to-be-welded area on a workbench in an overlapping or butt joint mode, and adjusting the overlapping area or the butt joint gap; (2) adjusting a welding wire of a welding gun to be positioned right above a lap joint area of a base metal to be welded or at the center of a butt joint gap, adjusting a metal probe of an ultrasonic head to be positioned behind the welding wire, and ensuring that the metal probe is positioned in a welding pool; (3) the ultrasonic device is started first, and then the welding gun is started to weld. The method of the invention promotes the wettability of the brazing filler metal in the process of melt brazing, improves the joint structure and the appearance and distribution of interface intermetallic compounds by acting ultrasonic vibration on a molten pool, and finally realizes high-quality connection between dissimilar metals.)

1. The method for assisting the melt brazing based on the ultrasonic vibration molten pool is characterized in that ultrasonic vibration is applied to the molten pool or the molten pool/base metal to be welded in the melt brazing process, and the method specifically comprises the following steps:

(1) cleaning the surface of a to-be-welded area of a to-be-welded base metal, fixing the to-be-welded area on a workbench in an overlapping or butt joint mode, and adjusting the overlapping area or the butt joint gap;

(2) adjusting a welding wire of a welding gun to be positioned right above a lap joint area of a base metal to be welded or at the center of a butt joint gap, adjusting a metal probe of an ultrasonic head to be positioned behind the welding wire, and ensuring that the metal probe is positioned in a welding pool;

(3) the ultrasonic device is started first, and then the welding gun is started to weld.

2. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to claim 1, wherein the base materials to be welded are homogeneous metal plates or dissimilar metal plates.

3. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to the claim 1 or 2, characterized in that when the base materials to be welded are the same metal plate, the base materials are low-melting metal plates; when the base metal to be welded is a dissimilar metal plate, the base metal to be welded is a low-melting-point metal plate and a high-melting-point metal plate respectively.

4. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to claim 3, wherein the low-melting-point metal is an aluminum alloy or a magnesium alloy, and the high-melting-point metal is stainless steel, a copper alloy or a titanium alloy.

5. The method for assisting molten pool welding and brazing based on ultrasonic vibration according to claim 1, wherein the metal probe is tungsten alloy or molybdenum alloy.

6. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to claim 1, wherein the direction of the ultrasonic vibration is longitudinal vibration and is perpendicular to the surface of the parent metal to be welded.

7. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to claim 1, wherein the base materials to be welded are fixed in a lap joint mode, and the metal probe of the ultrasonic head is positioned in the molten pool above the base materials to be welded.

8. The method for assisting the melt brazing based on the ultrasonic vibration molten pool according to claim 1, wherein the base metal to be welded is fixed in a butt joint mode, and the metal probe of the ultrasonic head is positioned in a lower molten pool or an upper molten pool of the base metal to be welded.

9. The method for assisting molten pool melting and brazing based on ultrasonic vibration is characterized in that when the metal probe of the ultrasonic head is positioned in the lower molten pool of the base metal to be welded, the ultrasonic vibration is simultaneously applied to the molten pool and the base metal to be welded.

Technical Field

The invention belongs to the technical field of welding, and particularly relates to an auxiliary melting and brazing method based on an ultrasonic vibration molten pool.

Background

A major problem affecting the performance of a welded joint in a welding process is that the large heat input during welding results in a large number of coarse grains in the weld, and a coarse grain structure is also created near the fusion zone. The coarsening of the crystal grains often reduces the strength, the plastic toughness and the like of the joint, and finally can not meet the use requirement, thereby reducing the service time of the joint. Therefore, the problem of refining the weld joint structure is always solved in the welding field.

In addition, in order to reduce weight, save energy, reduce cost, and satisfy different working conditions, lightweight structural members made of different materials are increasingly receiving attention. The metal with low melting point and small density, such as aluminum alloy and magnesium alloy, is used for replacing the original stainless steel, copper alloy, titanium alloy and the like with high melting point, so that the weight of the structural member can be greatly reduced, and the method has good application prospect in the aspect of light weight of heavy equipment. When two metals with large difference of melting points are welded, if the two metals are in a melting state, a large amount of brittle intermetallic compounds are generated in a welding line, so that the performance of a joint cannot meet the requirement. Research shows that by strictly controlling welding heat input, the low-melting-point metal is ensured to be molten and the high-melting-point metal is not molten in the welding process, so that the molten low-melting-point metal and the solid-phase high-melting-point metal are connected together through wetting spreading and interface metallurgical reaction, and the combination form has the characteristics of fusion welding and brazing and is called fusion-brazing. The joint form is generally a lap joint or butt joint form. Although the weld brazing process has significantly improved joint performance, the problem of wettability of the molten metal on the surface of the refractory metal, pore defects in the braze seams, coarsening of the alloy structure, and the generation of brittle intermetallics between the interfaces still limit further improvements in joint performance to some extent.

In view of this, the invention is particularly proposed.

Disclosure of Invention

In order to solve the problem of poor weld performance of the melt brazing in the prior art, the invention provides a method for assisting the melt brazing based on an ultrasonic vibration molten pool.

The technical scheme of the invention is as follows:

a method for assisting melting and brazing based on ultrasonic vibration molten pool is characterized in that ultrasonic vibration is applied to the molten pool or the molten pool/base metal to be welded in the melting and brazing process, and the method specifically comprises the following steps:

(1) cleaning the surface of a to-be-welded area of a to-be-welded base metal, fixing the to-be-welded area on a workbench in an overlapping or butt joint mode, and adjusting the overlapping area or the butt joint gap;

(2) adjusting a welding wire of a welding gun to be positioned right above a lap joint area of a base metal to be welded or at the center of a butt joint gap, adjusting a metal probe of an ultrasonic head to be positioned behind the welding wire, and ensuring that the metal probe is positioned in a welding pool;

(3) the ultrasonic device is started first, and then the welding gun is started to weld.

Preferably, the base metal to be welded is a same kind of metal plate or a different kind of metal plate.

Preferably, when the base materials to be welded are the same metal plates, the base materials are all low-melting-point metal plates; when the base metal to be welded is a dissimilar metal plate, the base metal to be welded is a low-melting-point metal plate and a high-melting-point metal plate respectively.

Preferably, the low-melting-point metal is an aluminum alloy or a magnesium alloy, and the high-melting-point metal is stainless steel, a copper alloy or a titanium alloy.

Preferably, the metal probe is a tungsten alloy or a molybdenum alloy.

Preferably, the direction of the ultrasonic vibration is longitudinal vibration and is perpendicular to the surface of the parent metal to be welded.

Preferably, the base metal to be welded is fixed in a lap joint mode, and the metal probe of the ultrasonic head is positioned in a molten pool above the base metal to be welded.

Preferably, the base metal to be welded is fixed in a butt joint mode, and the metal probe of the ultrasonic head is positioned in a lower molten pool or an upper molten pool of the base metal to be welded.

Preferably, when the metal probe of the ultrasonic head is positioned in a molten pool below the base metal to be welded, ultrasonic vibration is simultaneously acted on the molten pool and the base metal to be welded.

The invention has the beneficial effects that:

aiming at the problems of the existing melt brazing technology, such as the wettability problem of molten metal on the surface of high-melting metal and the brittle intermetallic compound generated between interfaces, the invention provides an ultrasonic vibration molten pool assisted melt brazing method, which utilizes the ultrasonic effect in the molten pool and the ultrasonic mechanical vibration on the surface of base metal to weaken the residual stress of a weld joint, promote the wetting behavior of the molten metal on the surface of solid-phase base metal in the melt brazing process, improve the appearance and distribution of the intermetallic compound of the interfaces, simultaneously refine the solidification structure of the weld joint, remove the residual pores in the weld joint and finally obviously improve the performance of the joint.

Drawings

FIG. 1 is a schematic diagram of an ultrasonic vibration assisted molten bath MIG lap brazing in example 1 of the present invention;

FIG. 2 is a schematic view of the ultrasonic vibration assisted molten bath MIG butt-welding brazing in example 2 of the present invention;

FIG. 3 is a schematic view of the ultrasonic vibration assisted melting bath and the aluminum alloy plate of the base material to be welded in butt welding brazing in embodiment 3 of the invention;

fig. 4 is a schematic structural view of an ultrasonic head in embodiment 3 of the present invention.

In the figure, 1-stainless steel plate; 2-aluminum alloy plate; 3-an ultrasonic head; 31-a metal probe; 4-a welding gun; 41-welding wire.

Detailed Description

The present invention will be described in further detail with reference to the following examples and drawings, but is not limited thereto.