Copper electrode sheet

Copper Electrode Sheet

Mask machine ultrasonic transducer electrode sheet Ultrasonic copper sheet Ultrasonic transducer accessories

Electrode sheet of ultrasonic transducer Electrode sheet of vibrator generator Phosphor bronze Brass Cupronickel 0.2 0.3mm

As the power source of new energy vehicles, the development of key materials and manufacturing processes of laminated lithium batteries is a current hot issue. Lithium battery manufacturing mainly includes pulping, coating, welding, assembling, forming and other processes. As a key part of the lithium battery manufacturing process, the welding process is used in lithium battery aluminum/copper positive and negative current collectors, pole pieces and batteries For the connection of multiple locations such as packaging, any welding joint defects will significantly affect the consistency of lithium battery performance. Therefore, how to ensure the quality of the welded joints of the metal pole pieces of lithium batteries is one of the key issues that need to be solved urgently in the manufacture of lithium batteries. 

Ultrasonic metal welding, as a high-quality, high-efficiency, low-consumption, and clean solid-phase connection technology, is suitable for the connection of aluminum/copper and other highly conductive and thermally conductive materials. It has attracted the attention of domestic and foreign automobile manufacturers and lithium battery manufacturers. However, due to the influence of material properties (aluminum/copper/nickel, etc.) and material thickness (10μm-1mm), the influence mechanism of frictional heat generation and plastic deformation during welding is still unclear, resulting in poor quality uniformity of ultrasonic welded joints. Problems such as small selection range of process parameters. Aiming at the above problems, this article first established an aluminum/copper metal pole piece ultrasonic welding experiment system to study the influence of welding head area, welding head tooth depth, pressure, amplitude, time and other process parameters on the joint strength. 

Secondly, the infrared thermal imaging method is used to study the change law of the temperature of the welding head-workpiece contact area during the welding process, revealing the frictional heat generation behavior of the welding process and its influence on the formation of the joint. Thirdly, the law of plastic deformation between the workpiece and the contact interface of the workpiece in the welding process is studied, and the mechanism of plastic deformation on the formation of the joint is revealed. Finally, an optimization model of welding process parameters based on response surface methodology was established to obtain the optimal welding process parameters to improve the quality of joints. The main research contents and conclusions of this paper are as follows: 

(1) Experimental study on the temperature of the welding head-workpiece contact area Aiming at the frictional heat generation during the ultrasonic welding of pole pieces, the influence of process parameters on the temperature of the welding head-workpiece contact area is studied. The temperature change of the welding head-workpiece contact area monitors the change of the strength of the ultrasonic welded joint to realize the on-line inspection of the joint quality. The results show that the material to be welded does not reach the melting point during the welding process, and the pole piece ultrasonic welding is a solid phase connection instead of a fusion connection. When the temperature in the contact zone is equal to the critical value, the joint strength is the highest; the temperature in the contact zone lower and higher than the critical value will reduce the joint strength. The critical temperatures during the ultrasonic welding of 0.2mm copper/copper, aluminum/aluminum, and aluminum/copper are 179.5°C, 77.4°C, and 79.1°C, respectively. 

(2) Experimental study on the plastic deformation of the joint between the workpiece and the workpiece Using metallographic inspection, SEM, EDS and other methods, the influence of the process parameters on the plastic deformation of the joint between the workpiece and the workpiece in the pole piece ultrasonic welding joint was experimentally studied. The results show that when copper/copper and aluminum/aluminum are welded with the same metal, the joint area between the workpiece and the workpiece is subjected to plastic deformation, forming a mechanical interlocking connection. When aluminum/copper dissimilar metals are welded, stable intermetallic compounds are not formed in the joint area, but there is a phenomenon of element diffusion. The effective thickness and effective connection length are used to characterize the plastic deformation of the bonding zone. Increasing the welding pressure, welding amplitude, and welding time can increase the effective connection length of the joint. Finally, a quantitative relationship model between plastic deformation and joint strength is established to determine the critical effective connection size. 

(3) Ultrasonic welding process parameter optimization method based on response surface method Take the aluminum/copper material ultrasonic welding as an example, adopt response surface and uniform test design method to establish welding head area, welding head tooth depth, welding pressure, welding amplitude, welding The response surface model of time and other parameters and the temperature of the contact area shows that the tooth depth of the welding head and the welding time are the main factors affecting the temperature of the workpiece. Considering the critical temperature of the workpiece, the optimal parameters of the aluminum/copper connection are obtained. The welding head has an area of 33.65mm~2 and a tooth depth of 0.31mm. High-quality connection joints can be obtained by using medium welding pressure, large welding amplitude, and short welding time. , The optimal parameter is 1.52kN, 24.4μm, 0.067s.