Process name

Process characteristics

Grad

Continuous casting rolling composite

①The overall cost is low, basically the same as the brazing process. It has the fewest processing steps and the highest comprehensive product yield, which can save a lot of processes, equipment, manpower, energy consumption, etc.;

②High bonding strength. Using continuous casting and rolling composite patented technology, continuous production under high temperature, high pressure and oxygen-free conditions, the interface bonding layer has no oxidation and eutectic;

③Good mechanical properties. The higher bonding strength makes the product more suitable for deep processing such as bending, punching (drilling), and shearing;

④High conductivity, the copper material is made of national standard T2 material, and the aluminum material reaches the national standard 1060 or above, and there is no other medium between copper and aluminum, achieving true oxygen-free metallurgical bonding, coupled with a high bonding rate, so the conductive performance is very good;

⑤ Use less copper to achieve better performance, the overall weight is smaller, more energy-saving and environmentally friendly, and in line with the national development direction of new materials ;

Brazing

① Low bonding rate: The contact area is small, which directly affects the conductive performance of the product. During long-term power-on use, high temperatures are easily generated, causing the copper sheets to fall off and cause power outage accidents;

② Low bonding strength: directly affects the mechanical properties of the product, and delamination is prone to occur during deep processing such as bending, punching, and drilling.

Flash welding / friction welding

①Poor welding performance: The welding performance of copper and aluminum (especially aluminum) is poor. Due to the different physical and chemical properties of the two metals, and the melting point of aluminum is much lower than that of copper, the eutectic phase structure cannot be reached during welding. They are completely integrated with each other, and some cracks or cracks can even be identified with the naked eye. Therefore, the welding strength of the welding surface is actually greatly reduced, and cracks or even fractures may occur during shear or bending tests;

② Stress conditions during installation and use: The wire clamp must withstand both wire tension and shear force during installation and operation. The welding area of ​​flash welding and friction welding is small, and the working torque acting on the welding surface can easily cause stress concentration, thereby causing fatigue damage of the wire clip. Since the mechanical strength of aluminum is lower than that of copper, it generally manifests as physical fracture of aluminum first;

    ③Effects of long-term energization (heating): Due to the different expansion coefficients of copper and aluminum, under the action of high temperature, the internal stress is uneven, causing the product to break. During actual use, the wire clip of the friction welding process is prone to breakage when the temperature reaches above 240 °C.

Explosive welding

Explosive welding is very inefficient when processed into copper-aluminum composite panels and cannot be industrialized. Although the process of processing equipment wire clips requires fewer man-hours than brazing, flash welding, and friction welding, the overall cost is very high.