I have taken interest in an alloy of 97% silver and 3% copper as its properties are very close to fine silver, the difference is that it’s hardness is only that of Annealed copper, or only 3/4 the hardness of sterling, around 50 Bhn. HoweverTheory and Practice of Goldsmithing mentions the alloy may be Hardened to over 100 Bhn Which is the Annealed hardness of some 18K yellow golds. Much, much harder.
How do I age harden this alloy? What temperature must I heat it to and for how long? Do I need a kiln to do so and if so, which one? How much can i expect to pay for this kiln?