In general, when the workpiece and electrode are fixed, the specific resistance of the workpiece depends on its resistivity. Therefore, the resistivity is an important property of the material being welded. The metal with high resistivity has poor conductivity (such as stainless steel) while the metal with low resistivity has good conductivity (such as aluminum alloy).As a result, spot welder spot welding of stainless steel is easy to produce heat and difficult to dissipate heat, so spot welding of aluminum alloy is difficult to produce heat and easy to dissipate heat.
In this way, the resistivity depends not only on the type of metal, but also on the heat treatment state, processing mode and temperature of the metal.Such electrode pressure has an effect on the total resistance R between the two electrodes. As the electrode pressure increases, R decreases, but the welding current increases by a small amount, so the heat production reduction caused by R decreases cannot be affected.Therefore, the strength of welding spot always decreases with the increase of welding pressure.The solution is to increase welding pressure and welding current.
Lithium battery spot welding machine to ensure the size and welding spot strength, if the welding time and welding current in a certain range can complement each other.Is in order to obtain a certain strength of the solder joint, but also can use large current and short time (strong conditions, also known as hard specifications), of course can also use small current and long time (weak conditions, also known as soft specifications).Is to choose the hard specification or the soft specification, so it depends on the performance and thickness of the metal and the power of the welding machine used.