Study on Ultrasonic Welding (4th Report)

On Effect of Sizes of Materials to be Joined on Joining Properties

Abstract

To obtain sound joints, it is considered that the vibration energy induced by transducer should be effectively transmitted to the contact face of materials to be joined so as to give enough relative motion (speed) to the contact face of materials.
In this study, we have investigated about a relation between the joinability and the sheet length of materials to be joined, and obtained the following results.
1. In lap joining of aluminum with solenoid tip vibrating in the longitudinal direction of sheet length, good joints were obtained when longitudinal length of aluminum on tip side is an even times of 1/4 λ(λ : wave length in aluminum), if not so, successful joints are not obtained. However, we observed there is very little affect of sheet length of aluminum on anvil side on joining properties.
2. In lap joining of titanium with solenoid tip vibrating in the longitudinal direction of sheet length, we observed "hot spot and crack" near joined parts when titanium was a certain length.