Ultrasonic soldering is a little-known technology that allows soldering together a variety of metals and ceramics that would not normally be possible. It requires a special ultrasonic soldering iron and solder that is not cheap or easy to get hold of, so [Ben Krasnow] of [Applied Science] made his own.
Ultrasonic soldering irons heat up like standard irons, but also require an ultrasonic transducer to create bonds to certain surfaces. [Ben] built one by silver soldering a piece of stainless steel rod (as a heat break) between the element of a standard iron and a transducer from an ultrasonic cleaner. He made his special active solder by melting all the ingredients in his vacuum induction furnace. It is similar to lead-free solder, but also contains titanium and small amounts of cerium and gallium. In the video below [Ben] goes into the working details of the technology and does some practical experimentation with various materials.
Ultrasonic soldering is used mainly for electrically bonding metals where clamping is not possible or convenient. The results are also not as neat and clean as with standard solder. We covered another DIY ultrasonic soldering iron before, but it doesn’t look like that one ever did any soldering.
Ultrasonic energy has several interesting mechanical applications that we’ve covered in the past, including ultrasonic cutting and ultrasonic welding.