Sometimes with sterling. And a very good temperature controller is
needed. My experiments years ago with an old analog controller were
less than exciting, my present digital one has much better control.
Might be worth an afternoon of play.
From a google on precipitation hardening sterling
Sterling Silver. It is recommended to solution treat sterling
silver at 750 C to 760 C/1,382 F to 1,400 F for 30 minutes,
quench immediately, and age for one hour at 300 C/572 F. The
hardness of the sterling alloy can be effectively doubled with
this process, from HV 60 in the fully annealed state to HV 120.
The only problem posed by this process is that the solution
treatment temperature is above normal soldering temperatures for
sterling, so only articles with no solder can be treated.
Soldering after hardening sterling will over-age the material
dramatically to the point of nullifying the hardening effort.
Analog/Digital Modelling & Goldsmithing