|
The essence of resistance spot welding of Cu and Ag terminals is a process that taking copper strip as substrate, silver as solder, under the action of electrode pressure and current, the metal atoms on the welding surface move violently to form a bonding structure. Although the surface quality of solder joints can be characterized by microscopic morphology, the growth of microstructure can also indicate the formation process of welding structure, studying from the view of molecular of welded components can better uncover the essence of welding. In order to accurately evaluate the welding quality of terminals, the movement of molecules of the surface of welding is simulated by calculating the different coordinates of molecules at different times based on molecular dynamics, and the molecular bonding in the system is visually displayed. The molecular dynamics simulation of Cu -Ag is to first determine the initial positions of all atoms in the system, under the constraints of Classical mechanics and ignoring the influence factors other than the atomic nucleus, the real-time positions of each atom are calculated after the next time step, and then iterate in turn until the end of the simulation, to obtain the atomic motion trajectory. Through MD simulation method, the movement process and combination morphology of Cu and Ag atoms in the spot-welding process are visually observed. Different Initial conditions are set to obtain the desired structures and analyze and get the most ideal process parameters. Through molecular dynamics theory analysis, the movement mechanism of atoms in the copper silver welding process is understood. Conduct molecular dynamics simulations of the copper silver atomic system under different conditions and explore the process steps for obtaining the most ideal structure of the copper silver atomic system as in three stages.
|
