阅读说明：本技术 一种黄铜与紫铜的激光焊接方法 (Laser welding method for brass and red copper ) 是由 刘雁清 蒋京刚 何培 曾丽娜 吴葛铭 于 2021-09-29 设计创作，主要内容包括：本发明涉及一种黄铜与紫铜的激光焊接方法,包括如下步骤：(1)将待焊接的紫铜放置在黄铜的上方,紫铜和黄铜中间设有一层锡片或锡膏,将焊接位置压紧；(2)激光束焦点照射在的紫铜上表面,通过热传导方式进行焊接。本发明的技术方案激光只能直接加热紫铜,通过热传导,将热量传递到黄铜上,黄铜紫铜中间加入锡片或锡膏作为热传导材料,导热效果更好,黄铜和锡融化后,形成铜锡合金,黄铜中的锌大量溶解于铜锡合金中融合生成锡青铜,可有效防止锌蒸汽溢出,同时锌能改善合金的流动性,缩小结晶温度范围,减轻逆偏析,可将其牢固的焊接在一起,强度能够达到100kgf以上。(The invention relates to a laser welding method of brass and red copper, which comprises the following steps: (1) placing the red copper to be welded above the brass, arranging a layer of tin sheet or tin paste between the red copper and the brass, and pressing the welding position; (2) the laser beam focus is irradiated on the upper surface of the red copper, and welding is carried out in a heat conduction mode. According to the technical scheme, the laser can only directly heat red copper, heat is transferred to the brass through heat conduction, a tin sheet or tin paste is added in the middle of the red copper of the brass to serve as a heat conduction material, the heat conduction effect is better, the brass and tin are melted to form a copper-tin alloy, a large amount of zinc in the brass is dissolved in the copper-tin alloy to be fused to generate tin bronze, zinc steam can be effectively prevented from overflowing, meanwhile, the fluidity of the alloy can be improved by the zinc, the crystallization temperature range is narrowed, inverse segregation is reduced, the alloy can be firmly welded together, and the strength can reach over 100 kgf.)

1. A laser welding method of brass and red copper is characterized by comprising the following steps:

(1) placing the red copper to be welded above the brass, arranging a layer of tin sheet or tin paste between the red copper and the brass, and pressing the welding position;

(2) the laser beam focus is irradiated on the upper surface of the red copper, and welding is carried out in a heat conduction mode.

2. The laser welding method of brass and red copper as claimed in claim 1, wherein the light spot at the exit of the optical fiber of the laser welding device used in step (2) is a flat-top beam.

3. A laser welding method of brass and red copper according to claim 2, wherein the red copper to be welded is clamped by a jig in the step (1).

4. The laser welding method of brass and red copper as claimed in claim 2 or 3, wherein the flat-top beam emitted from the welding head of the laser welding apparatus during welding in step (2) is 70-80 ° to the heating surface of the red copper to be welded.

5. The laser welding method of brass and red copper as claimed in claim 4, wherein said laser welding apparatus is a semiconductor laser or a fiber laser.

6. The laser welding method of brass and red copper as claimed in claim 5, wherein the laser welding apparatus in the step (2) stops heating the red copper for a predetermined time at an initial position after emitting the beam, then moves at a predetermined speed in the welding direction, and stops emitting the beam after the welding is completed.

7. The laser welding method of brass and red copper according to claim 6, wherein the thickness of the solder sheet or solder paste is 0.08 to 0.15 mm.

8. The laser welding method of brass and red copper according to claim 7, wherein the brass and the red copper are welded in an edge butt joint, lap joint or angle joint manner.

Technical Field

The invention belongs to the technical field of laser welding, and particularly relates to a laser welding method of brass and red copper.

Background

The red copper and the brass are two different materials, the brass contains a large amount of zinc, the melting point of copper is 1083.4 ℃, the melting point of zinc is 419.5 ℃, the boiling point of zinc is 907 ℃, the melting point of tin is 231.89 ℃, and the boiling point of tin is 2260 ℃. When the conventional Gaussian beam optical fiber laser is used for welding, copper is easily melted during welding and overflows by boiling zinc vapor, so that the welding surface splashes and overflows.

At present, the laser industry has not provided a proper brass (under) red copper (above) stitch welding solution, seam welding, T-shaped welding and fillet welding, and the welding effect of the brass (under) red copper (above) stitch welding, the surface effect is rough, the appearance is poor and the strength is low due to zinc vapor in the brass. The existing laser welding can realize laser welding of brass on the upper part and red copper on the lower part, but the strength and the appearance effect are not very good.

In the prior art, the effect of stitch welding red copper (on top) and brass (on bottom) can be realized by resistance welding, but the effects of seam welding, T-shaped welding and fillet welding cannot be realized.

In summary, there is a need for a method for laser welding of brass and red copper, which can realize the welding of red copper on the top of brass, has good welding appearance effect, and effectively improves welding strength.

Disclosure of Invention

The invention aims to provide a laser welding method of brass and red copper, which can realize the welding of red copper above brass, has good welding appearance effect and effectively improves the welding strength.

The above purpose is realized by the following technical scheme: a laser welding method of brass and red copper comprises the following steps:

(1) placing the red copper to be welded above the brass, arranging a layer of tin sheet or tin paste between the red copper and the brass, and pressing the welding position;

(2) the laser beam focus is irradiated on the upper surface of the red copper, and welding is carried out in a heat conduction mode.

According to the technical scheme, the laser can only directly heat red copper, heat is transferred to the brass through heat conduction, a tin sheet or tin paste is added in the middle of the red copper of the brass to serve as a heat conduction material, the heat conduction effect is better, the brass and tin are melted to form a copper-tin alloy, a large amount of zinc in the brass is dissolved in the copper-tin alloy to be fused to generate tin bronze, zinc steam can be effectively prevented from overflowing, meanwhile, the fluidity of the alloy can be improved by the zinc, the crystallization temperature range is narrowed, inverse segregation is reduced, the alloy can be firmly welded together, and the strength can reach over 100 kgf.

The further technical scheme is that the light spot at the optical fiber outlet of the laser welding equipment adopted in the step (2) is a flat-top light beam. Therefore, by adopting the flat-top light spot technology which is generally applied to the square or round large light spots of laser quenching at present in a large range, the power of the light spots emitted by the optical fiber is uniformly distributed, unlike Gaussian beams, the center power is high, the edge power is low, and the welding effect is ensured.

The further technical scheme is that in the step (1), a clamp is adopted to clamp the red copper to be welded.

The further technical scheme is that the flat-top light beam emitted by the welding head of the laser welding equipment during welding in the step (2) forms an angle of 70-80 degrees with the heating surface of the red copper to be welded. Thus, it can prevent the laser from reflecting back to the optical fiber due to the high adverse effect of copper, which leads to burning out the optical fiber.

The further technical scheme is that the laser welding equipment is a semiconductor laser or a fiber laser.

The further technical scheme is that in the step (2), after the laser beam is emitted by the laser welding equipment, the laser beam is stopped at an initial position for a preset time to heat the red copper, then the red copper moves along the welding direction at a preset speed, and the light beam is stopped to be emitted after the welding is finished.

The further technical scheme is that the thickness of the tin sheet or the tin paste is 0.08-0.15 mm.

The further technical scheme is that the brass and the red copper are welded in a mode of edge butt joint, lap joint or angle joint.

Compared with the prior art, the laser welding adopted by the invention is non-contact welding, single-side continuous welding, automatic movement and superior to resistance welding, and the laser equipment is not in contact with a product, so that the red copper brass welding in a large range can be realized, and the high-strength welding of two materials of brass and red copper with large difference, including seam welding, T-shaped welding and fillet welding, is realized; the invention effectively solves the technical problems of rough surface effect, poor appearance and low strength caused by that zinc vapor in brass overflows from the welding surface and splashes in the prior art, and the welding not only has good welding appearance effect, but also effectively improves the welding strength.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention.

Fig. 1 is a diagram showing a gold phase of a product welded by a laser welding method of heat-generating brass and red copper according to an embodiment of the present invention.

Detailed Description

The present invention will now be described in detail with reference to the drawings, which are given by way of illustration and explanation only and should not be construed to limit the scope of the present invention in any way. Furthermore, features from embodiments in this document and from different embodiments may be combined accordingly by a person skilled in the art from the description in this document.

The embodiment of the invention is as follows, referring to fig. 1, a laser welding method of brass and red copper comprises the following steps:

(1) placing the red copper to be welded above the brass, arranging a layer of tin sheet or tin paste between the red copper and the brass, and pressing the welding position;

(2) the laser beam focus is irradiated on the upper surface of the red copper, and welding is carried out in a heat conduction mode.

According to the technical scheme, the laser can only directly heat red copper, heat is transferred to the brass through heat conduction, a tin sheet or tin paste is added in the middle of the red copper of the brass to serve as a heat conduction material, the heat conduction effect is better, the brass and tin are melted to form a copper-tin alloy, a large amount of zinc in the brass is dissolved in the copper-tin alloy to be fused to generate tin bronze, zinc steam can be effectively prevented from overflowing, meanwhile, the fluidity of the alloy can be improved by the zinc, the crystallization temperature range is narrowed, inverse segregation is reduced, the alloy can be firmly welded together, and the strength can reach over 100 kgf.

On the basis of the above embodiment, in another embodiment of the present invention, the light spot at the outlet of the optical fiber of the laser welding apparatus used in step (2) is a flat-top light beam. Therefore, by adopting the flat-top light spot technology which is generally applied to the square or round large light spots of laser quenching at present in a large range, the power of the light spots emitted by the optical fiber is uniformly distributed, unlike Gaussian beams, the center power is high, the edge power is low, and the welding effect is ensured.

On the basis of the above embodiment, in another embodiment of the present invention, in the step (1), the fixture is used to clamp the red copper to be welded.

On the basis of the above embodiment, in another embodiment of the present invention, when welding in the step (2), the flat-top light beam emitted by the welding head of the laser welding device and the heating surface of the red copper to be welded form 70 to 80 °. Thus, it can prevent the laser from reflecting back to the optical fiber due to the high adverse effect of copper, which leads to burning out the optical fiber.

On the basis of the above embodiment, in another embodiment of the present invention, the laser welding apparatus is a semiconductor laser or a fiber laser.

On the basis of the above embodiment, in another embodiment of the present invention, in the step (2), the laser welding device stops heating the red copper at an initial position for a predetermined time after emitting the light beam, then moves along the welding direction at a predetermined speed, and stops emitting the light beam after the welding is completed.

In another embodiment of the present invention, the thickness of the solder sheet or the solder paste is 0.08 to 0.15 mm.

On the basis of the above embodiment, in another embodiment of the present invention, the brass and the red copper are welded in an edge butt joint, lap joint or angle joint manner.

In order to better illustrate the technical solution of the present invention, the present invention provides a specific embodiment herein:

taking stitch welding of red copper after 1.5mm and brass after 4mm as an example, the red copper is on the top, the brass is under, the laser welding equipment is more than 2kw, the light spot at the outlet of the optical fiber is a flat-top light beam, namely the power of the whole light spot must be distributed evenly.

1. Red copper and brass are arranged on a clamp, a tin sheet with the thickness of 0.1mm is padded in the middle, and the welding position is pressed tightly;

2. the welding head of the laser welding equipment is inclined by about 10 degrees (compared with the vertical direction), so that the optical fiber can be prevented from being burnt out due to the fact that laser is reflected back to the optical fiber due to the high reflection effect of copper, and laser power parameters are set;

3. adopting a laser spot with a square spot or a large circular spot, wherein the focal point of the laser is positioned on the upper surface of the red copper, stopping at the welding initial position after the laser emits light, heating the red copper, heating to the light emitting position, enabling the red copper to be red, and enabling the laser head to move along the direction of a welding seam immediately like burning a red iron block; and after welding, stopping the laser to emit light.

4. After welding, the welding product is subjected to bending test, the red copper is broken, and the welding part is not cracked. The metallurgical effect is shown in fig. 1, and it is understood from fig. 1 that the upper layer is red copper, the lower layer is brass, the red copper and the brass are closely adhered to each other, zinc pores are generated (large black circles in the drawing), and the black line in the drawing is a boundary line of the bonding surface of the brass red copper.

5. And (3) testing the tearing effect of seam welding, wherein brass particles are adhered to the red copper at the tearing position, so that the welding effect is good, and the surface of the product is free from splashing.

6. The product strength test, the welding area is in the range of 48 square millimeters, and the test strength is already more than 100 kgf.

Of course, for different thicknesses of material, the parameters may vary. The experiment proves that the invention effectively solves the technical problems of rough surface effect, poor appearance and low strength caused by the fact that zinc vapor in brass overflows from the welding surface and splashes in the prior art, and the welding not only has good welding appearance effect, but also effectively improves the welding strength.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.