Lead-free solder alloys have been around for as long ... These higher silver alloys are true eutectic alloys — completely changing form a solid to a liquid at the melting point of 217°C.

The video does have a bit of theory on soldering chemistry and the difference between eutectic alloys and other tin-lead mixes, as well as a little about the proper use of silver-bearing solders.

Image Credit: Anucha Cheechang/Shutterstock.com Low-melting metal alloys, such as (near-) eutectic alloys ... of APT specimens for low-melting SAC305 solder materials. The SAC305 solder alloy ...