Ultrasonic Welding of Heat Treatable Aluminum Alloy A6061 Sheet
Takehiko WATANABE, Hajime ITOH, Atsushi YANAGISAWA, Makoto HIRAISHI
In this study, the authors applied the ultrasonic welding method to weld A6061 heat treatable aluminum alloy and investigated the effects of clamping load and welding time on the properties of the weld. In addition, in order to improve the strength of the joint the effectiveness of the ethanol droplet on the faying surface was examined. The following results were obtained.
The joint strength increased with clamping load and welding time. The fracture of the joint produced under the welding conditions of 1176N clamping load and 1.5s welding time occurred in the base metal. The ethanol droplet on the faying surface successfully produced the joint with the strength equivalent to that of the base metal under the welding conditions of smaller clamping load and shorter welding time than the case without ethanol droplet. The softening around the welded area that was performed with the ethanol droplet was smaller than that in the welded area produced by other methods such as TIG and FSW. The fracture surface of the joint welded with the ethanol droplet was remarkably irregular and rough. Dimple pattern was observed over the wide area, indicating that the welded area was significantly expanded. The ethanol droplet made the temperature of the weld area higher than that without ethanol, resulted in improving the joint strength with the increase of the plastic deformation at the interface.