阅读说明：本技术 一种多层铝及铝合金带焊接方法 (Method for welding multi-layer aluminum and aluminum alloy strips ) 是由 李学浩 孙爱俊 朱仁萍 迟永强 王炜 卞金强 于 2019-09-26 设计创作，主要内容包括：一种多层铝及铝合金带焊接方法：多层铝带焊接部分的每层之间涂覆活化剂,涂覆的焊接部分长度包括靠近端部的预焊区域和实际需要焊接区域；叠加后的铝带预焊区域放置在扩散焊机接触电极之间,加压通电加热,使预焊区域的每层都连接起来,停止加热；移动多层铝带,实际需要焊接区域置于扩散焊机的接触电极之间,加压通电加热至铝带至580～650℃,温度均匀后,停止加热,温度降至580℃以下,取出工件。本发明每层之间涂覆活化剂,去除氧化层,既省去机械抛光和表面化学处理,又能保证多层铝带焊接的层间结合力,增加预焊区域,使初始阶段出现的焊接飞溅发生在预焊区域,而不产生在实际的焊接区域,避免了工件因焊接飞溅造成的报废。(A method for welding multi-layer aluminum and aluminum alloy strips comprises the following steps: coating an activating agent between each layer of the multi-layer aluminum strip welding part, wherein the length of the coated welding part comprises a prewelding area close to the end and an actually required welding area; placing the superposed aluminum strip pre-welding area between contact electrodes of a diffusion welding machine, pressurizing, electrifying and heating to connect each layer of the pre-welding area, and stopping heating; and moving the multilayer aluminum strip, placing the actually required welding area between contact electrodes of a diffusion welding machine, pressurizing, electrifying and heating the aluminum strip to 580-650 ℃, stopping heating after the temperature is uniform, reducing the temperature to below 580 ℃, and taking out the workpiece. According to the invention, the activating agent is coated between each layer to remove the oxide layer, so that mechanical polishing and surface chemical treatment are omitted, the interlayer bonding force of multi-layer aluminum strip welding can be ensured, the pre-welding area is increased, welding spatter generated in the initial stage is generated in the pre-welding area, the actual welding area is not generated, and the rejection of workpieces caused by welding spatter is avoided.)

1. A method for welding multi-layer aluminum and aluminum alloy strips is characterized in that: the welding method is realized by the following steps:

A. coating an activating agent (2) for removing an oxide layer between each layer of a welding part of a multilayer aluminum strip (1), wherein the length of the coated welding part comprises two parts, one part is a prewelding area (1 a) close to the end part, the other part is an actually required welding area (1 b), two surfaces of the outermost layer which are not welded are not coated, and the multilayer aluminum strips are superposed;

B. Placing the pre-welding area (1 a) of the stacked multilayer aluminum strip (1) between contact electrodes (3) of a polymer diffusion welding machine, pressurizing, electrifying and heating until the temperature of the aluminum strip reaches 580-650 ℃, connecting each layer of the pre-welding area (1 a), cutting off the power, stopping heating, and removing pressure;

C. And moving the multilayer aluminum strip (1) to enable the actually needed welding area (1 b) to be placed between contact electrodes (3) of a polymer diffusion welding machine, pressurizing, electrifying and heating until the temperature of the aluminum strip reaches 580-650 ℃, cutting off the power and stopping heating after the temperature of the actually needed welding area (1 b) is uniform, reducing the temperature to below 580 ℃, removing the pressure, and taking out the workpiece.

2. the method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: the contact electrode (3) of the high-molecular diffusion welding machine is made of graphite, the contact electrode (3) is connected with a cast iron plate (4) of the welding machine, and the cast iron plate is connected with a cooling copper plate (5).

3. The method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: the material of each layer of the multilayer aluminum strip (1) can be the same grade material or different grade material, and is any one of pure aluminum and aluminum alloy.

4. A method of welding multi-layer aluminium and aluminium alloy strips according to claim 1 or 3, characterised in that: the thickness of each layer of the multi-layer aluminum strip (1) is 0.1-5 mm, and the thickness of each layer can be different.

5. The method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: the components of the activating agent (2) for removing the oxidation layer comprise fluoride soldering flux, paste forming agent and regulator.

6. The method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: the length of the prewelding area (1 a) is 1-50 mm.

7. the method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: and the pressure applied between the two electrodes during welding is 0.5-10 MPa.

8. The method of claim 1, wherein the welding of the multi-layer aluminum and aluminum alloy strip comprises: after the welding is completed, the pre-welding area (1 a) is machined and removed.

Technical Field

The invention relates to a multi-layer strip welding method, in particular to a multi-layer diffusion welding method of aluminum and aluminum alloy strips.

Background

At present, the multi-layer connection of aluminum and aluminum alloy belts mostly adopts the mode of argon arc welding at the periphery of the belt materials or pre-arranging brazing filler metal between each layer of belt materials and connecting the multi-layer belt materials by a flame heating or intermediate frequency heating mode, and the aluminum alloy flexible connection also adopts the mode of argon arc welding of the end parts of the multi-layer aluminum and aluminum alloy belt materials and an aluminum plate. Because of polymer diffusion welding or resistance welding circular current is great, aluminium and aluminum alloy surface are easy to oxidize, and contact resistance between multilayer aluminium strip layer is big when leading to the welding, even some technologies adopt multilayer aluminium and aluminum alloy polymer diffusion welding or resistance welding, the surface needs mechanical polishing and surface chemical treatment in order to remove oxide film before the welding, may produce secondary oxidation before the welding with the welding start process, easily produces during the welding and splashes or the welding interlayer is connected insecurely, causes scrapping of work piece. Mechanical polishing and surface chemical treatment before welding are labor-consuming, time-consuming and environmentally-friendly.

Disclosure of Invention

the invention aims to provide a high-molecular diffusion welding method for multi-layer aluminum and aluminum alloy strips, which is characterized in that an activating agent is coated between every two layers of aluminum or aluminum alloy strips, and an oxide layer is removed in the welding process, so that the mechanical polishing and surface chemical treatment before welding are omitted, the welding firmness of a welding seam can be ensured, a pre-welding area is increased, welding spatters possibly generated in the initial stage can be generated in the pre-welding area, the welding area actually required by a workpiece is not generated, and the rejection of the workpiece caused by spatters generated by welding is avoided.

The technical scheme adopted by the invention is as follows:

A method for welding multi-layer aluminum and aluminum alloy strips is realized by the following steps:

A. Coating an activating agent for removing an oxide layer between each layer of a multilayer aluminum strip welding part, wherein the length of the coated welding part comprises two parts, one part is a prewelding area close to the end, the other part is an actually required welding area, two surfaces of the outermost layer which are not welded are not coated, and the multilayer aluminum strips are stacked;

B. Placing the pre-welding area of the stacked multilayer aluminum strips between contact electrodes of a polymer diffusion welding machine, pressurizing, electrifying and heating until the temperature of the aluminum strips reaches 580-650 ℃, connecting each layer of the pre-welding area, cutting off the power, stopping heating, and removing pressure;

C. And moving the multilayer aluminum strips to enable the actually needed welding area to be arranged between contact electrodes of a polymer diffusion welding machine, pressurizing, electrifying and heating until the temperature of the actually needed welding area reaches 580-650 ℃, cutting off the power and stopping heating after the temperature of the actually needed welding area is uniform, reducing the temperature to below 580 ℃, removing the pressure, and taking out the workpiece.

The contact electrode material of the high-molecular diffusion welding machine is graphite, the contact electrode is connected with a welding machine cast iron plate, and the cast iron plate is connected with a cooling copper plate.

the material of each layer of the multilayer aluminum strip can be a same-grade material or a different-grade material, and is any one of pure aluminum and aluminum alloy.

the thickness of each layer of the multi-layer aluminum strip is 0.1-5 mm, and the thickness of each layer can be different.

The components of the activator for removing the oxide layer comprise fluoride soldering flux, paste forming agent and regulator.

the length of the prewelding area is 1-50 mm.

And the pressure applied between the two electrodes during welding is 0.5-10 MPa.

And after the multilayer aluminum strip is welded, machining to remove the prewelding area.

Description of the drawings:

FIG. 1 is a schematic view of a pre-weld zone weld embodying the present invention.

Fig. 2 is a schematic diagram of the welding area actually required to implement the present invention.

The specific implementation mode is as follows: