Spot Welding Process Of Copper Nickel Composite Sheet

The spot welding process of copper nickel composite sheets is mainly achieved through resistance spot welding, and its core is to use the resistance heat generated when current passes through the workpiece to locally melt the material and form solder joints. The specific process includes the following steps:

1. Welding principle:

During spot welding, current passes through the workpiece and electrode, generating resistance heat, causing the material to melt locally and form a weld point. Due to the different melting points of copper and nickel, it is necessary to control the current and time during welding to ensure the quality of the solder joint.
2. Welding methods:

Common spot welding methods include arc welding, argon arc welding, laser welding, etc. Among them, arc welding is one of the most commonly used methods, which adapts to the welding needs of different workpieces by adjusting welding parameters and selecting appropriate welding rods. In addition, green laser is also used for spot welding of copper nickel composite sheets, which can achieve uniform welding points and high connection strength.
3. Welding difficulties:

• Hot cracks and porosity: Due to the different melting points of copper and nickel, defects such as hot cracks and porosity are prone to occur during the welding process.
• Oxidation phenomenon: Copper has strong oxidizing properties and is prone to oxidation during the welding process, which affects the welding quality.
• Welding parameter control: During welding, it is necessary to strictly control parameters such as current and time to avoid excessive heating or insufficient welding.
• Material selection: When welding copper nickel composite sheets, pure nickel is usually used as the filler metal to prevent penetration cracks and improve welding quality.

4. Precautions:

Before welding, ensure that the material is clean, removing all dirt and grease, especially elements that may cause weld cracking. When welding, consistent gaps and alignment should be maintained between the welded parts, using nail welds with a spacing of about half of the usual spacing for carbon steel.
5. Welding equipment:

In order to achieve high-quality spot welding, high-power spot welding machines such as 25 square millimeter spot welding machines can be used, which can achieve a pen tip current of 3200A and are suitable for welding copper, aluminum, and nickel composite strips.

The spot welding process of copper nickel composite sheets requires comprehensive consideration of welding methods, parameter control, material selection, and equipment performance to ensure welding quality.