Ultrasonic soldering bonds glass, titanium, stainless steel, ceramics, tungsten, nichrome...

Technical details and how to build an ultrasonic soldering iron. This technique can bond difficult-to-solder metals such as titanium as well as glass and ceramics.

Cerasolzer technical info:

S-bond technical info:

Overview of active soldering process:

Another good overview:

Discussion of Sn - La solders:

Sn - Ti phase diagram:

This patent has the key list of ingredients (not just broad ranges) listed at paragraph 45:

nichrome...