If a design change at this stage is not possible, the remedy could be a slight modification of the welding fixture and the anvil. As an alternative, the parts can be specially clamped in certain areas and the energy concentrated in local areas. When several spots-weldings are carried out on one part, nodal points may form in places where they are undesirable. In order to obtain a constant weld quality it is important to have a uniform surface. Slight contamination is usually acceptable, but heavily oiled, greased or oxidized parts impair the welding process to such an extent that the previously defined amount of energy cannot be introduced into the process, even if the welding time is increased.
Coated surfaces are likewise to be evaluated to determine their suitability for welding.
A major area of application for ultrasonic metal welding is the bonding of enamel copper wires such as those used for coils, transformers, etc. Based on today's technology, good quality, pipeless and homogeneous welds without having to first strip the enamel are rare. The decisive factor here is the quality of the enamel as well as its proportion to the total weld. Considerable experience Tests in the welding applications laboratory Ultrasonic metal welding is already widely used in industry. This means that there is significant application experience in this field.